Four Resistor Makers, Four Different Strategies: KOA, Hokuriku Electric, Susumu, and ROHM at TECHNO-FRONTIER 2026
イチケン / ICHIKEN
At TECHNO-FRONTIER 2026, held July 15–17, 2026, the electronics YouTuber Ichiken hosted a session at the "Ichiken Lounge" called "Roundtable Discussion on the Future of Electronic Components: Resistors." Four resistor manufacturers took part: KOA, Hokuriku Electric Industry, Susumu, and ROHM. Each sat down with Ichiken for a one-on-one interview.
Ichiken framed the session around a common assumption. Resistors are plain-looking parts, used for current limiting, voltage division, and current detection, so people may think all resistors are basically the same. Ichiken noted that their importance has been rising in areas such as EV current-detection shunts, server power supplies, renewable energy, and power electronics. The aim of the session was to show how differently each company approaches the same component. At the end of every interview, Ichiken asked the same question: what is the biggest selling point of your company's products?
KOA: A Broad Lineup and a Focus on Thermal Design
KOA's representative opened with a small gift. The company combines agriculture with manufacturing and also does woodworking, including custom furniture, which Ichiken said they had not known.
The representative then described the company. KOA is based in Nagano Prefecture and was founded 86 years ago. It has annual sales of about 70 billion yen and about 4,000 employees. Roughly 70% of its production is domestic, and it also manufactures and sells overseas. Resistors make up the vast majority of its revenue. Many customers are automakers, and industrial equipment makers are another important group. The core product is the thick-film chip resistor, but KOA also makes thin-film resistors, metal and milliohm-range resistors, leaded resistors, cement resistors, and modules. The representative's message was that if you need a resistor of almost any reasonable size, KOA probably has one.
Asked which products KOA most wants to promote, the representative named the thick-film chips, including the high-power models covered later in the interview, and a wide variety of low-resistance metal-plate resistors.
Why Terminal Temperature Now Matters
Most of KOA's presentation was about thermal design. The representative explained that traditional thermal design dealt with cooling components by blowing air over them. Lately, dissipating heat through the circuit board has become much more important. That makes layout a thermal concern and raises the problem of how to measure the temperature of many small parts. For a component maker, the implication is that part specifications must now assume heat will flow into the board.
Ichiken related this to their own work. They are running a "Domestic USB Charger Project" with the Japanese charger maker CIO, and the case temperature reaches 70–80°C. Ichiken said they fully agree that thermal design is extremely important.
The representative then explained the derating curve, which plots temperature on the horizontal axis and power on the vertical axis and shows how far power must be reduced as temperature rises. Traditionally that temperature was the ambient air temperature, which the representative called somewhat vague. KOA instead bases the curve on the temperature at the terminal, where the component joins the board. Under this "terminal temperature specification," the resistor's operating limits are defined by the temperature of the part itself. The representative said this approach has been reflected in international standards and JIS standards. KOA provides terminal-temperature derating curves for almost all of its resistors, and the representative said this matters in every application, including automotive, renewable energy, and server power supplies.
Raising Power Ratings on Evidence Rather Than Guesswork
Over the past two years, KOA has been raising the power ratings of existing products. One example is a pulse-resistant resistor designed to handle more power than general-purpose parts. In the 2012 size, where a standard part is rated at 0.25 W, this one is rated for up to 0.75 W. The representative also mentioned the wide-terminal (long-side) type that has become popular recently. On a terminal-temperature derating graph, these parts can handle high power even at high temperatures. The representative acknowledged that other companies sell similar products, but said heat dissipation is critical here.
Ichiken asked the obvious question: if the rating goes up, what happens to service life and long-term drift? The representative's answer was that terminal-temperature specifications let customers see the temperature at which the part is actually operating, which makes reliability easier to judge.
The representative also explained how the higher ratings were set. In the past, ratings were often raised a little at a time in response to individual customer requests. KOA's thermal design work has improved its ability to control the temperature of parts mounted on a board, so it can now build test environments for resistor ratings. Using in-house technology, KOA identified the limits imposed by materials and structure and ran tests with finely adjusted temperatures. The representative said the rating was pushed close to the limit, but that the basis for it is clearly stated. Ichiken summarized the point: once the PCB is the main heat sink, this kind of evidence is what matters.
The Heat-Dissipating Metal Chip
KOA also presented a new product, the "heat-dissipating metal chip," which was on display at its booth. It is a copper chip mounted on top of a copper trace on the board. In the demonstration, about 60 A flows through a pattern and heats it considerably. Adding the chip lowers the resistance of that section of the pattern, which reduces Joule heating and slows the temperature rise. The representative explained that it works by reducing the heat generated in the first place, not by dissipating heat, and admitted it is not really a resistor.
On applications, the representative said automotive customers building integrated ECUs sometimes need to carry significant current in specific places. Designers have been using larger chunks of metal or jagged parts for this, and KOA hopes to offer its small chips as an alternative. Ichiken restated the idea as using extra copper only where it is needed, instead of thickening the copper foil across the whole board, and the representative agreed.
A Ceramic Chip Resistor for Pulses, Still in Development
The last KOA product was a pulse- and surge-resistant ceramic chip resistor. On a graph with pulse width on the horizontal axis and pulse limit power on a log vertical axis, its limit at a 1 ms pulse was about two orders of magnitude above standard parts. The construction differs from an ordinary chip resistor. A typical chip has a resistive film on an insulating substrate. In this part, the whole body is conductive ceramic, similar in concept to the old solid resistors. KOA already sells leaded versions but had struggled to make a chip version. The representative described it as a component with almost unmatched pulse resistance and said it is still a work in progress and will take a while longer.
Ichiken said they had not seen this type from other makers, even in leaded form. When asked about downsides, the representative said the TCR can be strongly negative, so users need to be creative in how they apply it. Tolerance is also poor, because the finished body is cut and then fitted with electrodes, so precise resistance values are hard to achieve. The part has to be used selectively, but it could work well in places with impulsive loads, such as snubber circuits.
KOA closed by pointing to its web pages and videos on thermal design. For its biggest selling point, the representative named the breadth of the lineup: thick-film, thin-film, metal, leaded, wirewound, and cement resistors, including some very tall parts. They also mentioned using the leaded ceramic technology in a chip format. The message was that anyone unsure which resistor to use should contact KOA.
Hokuriku Electric Industry: From Carbon Film to Derivative Chip Products
Hokuriku Electric Industry is based in Toyama Prefecture. Its representative traced the company's history from carbon-film resistors, which were discrete parts originally for military use, to printed resistors, hybrid ICs, and high-voltage resistors. That technology led to thick-film chip resistors as the industry moved from discrete to surface-mount parts. Today the company also focuses on sensors and modules. It has three business divisions, and chip resistors belong to the Components Business Division. The representative said the company does not specialize only in resistors.
The development roadmap started from an observation about price. A chip resistor can cost around 1 yen, or even a few sen, yet it is indispensable in circuits. Customers ask for more than low cost, so Hokuriku is working toward higher power, lower resistance, resistance to harsh environments, and environmental compliance. The representative said the company's low-cost manufacturing technology has also led to derivative products such as chip fuses and ESD-resistant chips. Ichiken summarized the direction as ruggedness, high power, low resistance, and high precision, and asked whether the goal is to differentiate through high-performance products. The representative said yes, and added that the company will also keep supporting standard parts that customers need, however cheap they are.
A representative product is a compact high-power resistor: the 3216 size rated at 1.5 W, which the representative noted KOA had also mentioned. The main difference from standard parts is a resistive material that can withstand high power.
Sulfurization, Space, and Ultra-Precision Thick Film
Asked where the company is putting extra effort, the representative pointed to automotive customers, with whom the relationship is getting stronger. Sulfur exposure is becoming more common in applications, and sulfurization-induced open circuits are a known failure mode of chip resistors. Hokuriku offers two anti-sulfurization products. One is a highly sulfur-resistant chip intended to eliminate this failure. The other, the CRS series, is for customers who prioritize cost because the problem occurs rarely. The representative explained the mechanism: sulfur compounds dissolved in water enter at the interface between the plating and the overcoat and sulfurize the silver in the inner electrode, which causes the break. The CRS series adds an extra layer to block this, balancing sulfur resistance with cost.
Hokuriku also makes JAXA-brand chip resistors for satellites. The representative explained that space is a vacuum and a very different environment from Earth, so the structure uses materials certified for space. Ichiken asked about lead-free plating. The representative said lead-free plating is now standard under RoHS, but tin plating grows whiskers in space, so these parts use external electrodes designed to deal with that.
Another product is an ultra-high-precision thick-film resistor. The representative said thick film was previously limited to 0.5% tolerance and 50 ppm, while customers are asking for 0.1% and 25 ppm. Hokuriku uses its own resistive materials to reach 0.1% and 25 ppm while also raising rated power. When Ichiken asked how this is possible with thick film, the representative said the company was originally a materials manufacturer. TCR varies with process patterns and conditions, and having in-house materials allows adjustment within the production process. Ichiken summarized it as controlling the ingredients, and the representative agreed.
For its biggest selling point, Hokuriku named its proprietary production facilities and its ability to make resistors from its own materials. Ichiken described this as the ability to tailor products to customer needs.
Susumu: Sixty-Two Years of Thin Film Only
Susumu's representative said the company was founded in 1964 to develop the world's first thin-film resistors, established mass-production technology in the 1980s, and has focused only on thin-film resistors since then. Ichiken noted that a photo of the production floor looked like a semiconductor cleanroom. The representative confirmed that the process is complex and done in a controlled cleanroom. Last year the company set up a new cleanroom production line near Obama City in Fukui Prefecture. As in semiconductor manufacturing, the process uses photoresist, and work is done under UV-blocking light.
On thickness, the representative said the resistive film is on the order of nanometers. A human hair is about 100 μm, while Susumu's films are 100 nm or less, about one-thousandth of that. The company relies on the very high quality of this film for performance.
Susumu's products go into automotive and mobility, industrial equipment, high-precision measuring instruments, consumer and telecom products, medical devices, and aerospace. The representative said measuring instruments are sensitive to noise, and in space and communications small amounts of noise or drift affect speed and accuracy. The company's role is to help systems deliver their full performance. One medical device was mentioned as a newer adoption. The point there was that small errors are unacceptable when a doctor operates a machine. Medical is still a small share of sales but is an area the company wants to grow.
What Thin Film Can and Cannot Do
The representative listed Susumu's capabilities: ultra-low-resistance thin-film chips in the milliohm range, high-frequency chips, tolerance down to 0.01%, and TCR of 1 ppm/°C, which they called the greatest strength of thin film. The parts are also low-noise and contain no silver, so there is no sulfurization risk. The representative credited over 60 years of process and design work by earlier engineers for making mass production possible.
Ichiken asked whether such thin films can handle high power. The representative acknowledged that beyond a certain threshold, thin film cannot compete with thick film. Within its operating range of temperature and voltage, however, they said it delivers overwhelming performance. Susumu has separate high-voltage chips, and the representative said the priority is supplying consistent performance even at hundreds of volts.
On price, which the representative called a sore spot, they said thin-film parts cost more than typical thick-film resistors because the process has many complex steps. Their position was that the company wants customers to value precision and reliability, and to let performance justify the cost. They stressed long-term stability: once something goes into space it cannot be repaired, and automotive and medical applications have similar demands.
NASA, the Roman Space Telescope, and Low Noise
The representative said Susumu's chips are registered on NASA's COTS list and described the company as the first parts manufacturer in the world to be registered. Last year the RG and KRL series were also added to a NASA listing. Ichiken asked whether space technology feeds back into commercial products, as F1 technology does for passenger cars. The representative said it works the other way for Susumu. Parts made to automotive quality standards, using the same process and structure as standard products, are adopted by NASA and used as-is. They added that space-specific components exist, especially in semiconductors, but they were pleased that their existing process, structure, and materials were approved.
The representative also said Susumu's chips are on NASA's Roman Space Telescope, which they said would launch on August 30 of this year, and on the Falcon 9 carrying it. They said they hope the telescope will produce images no one has seen before and that contributing to it is a source of motivation.
On noise, the representative described thin film as a dense, stable structure through which electrons flow smoothly, which supports 1 ppm stability. Ichiken asked whether the graph showed thermal noise. The representative said the graph shows electrical current noise, reduced by a good electrode–resistor interface, and that the pattern holds even as temperature rises. Ichiken suggested this might appeal to audio users. The representative agreed and shared a customer comment: after hearing wind in the grass, a murmuring stream, and birdsong reproduced in fine detail, the customer was told the equipment used Susumu chips, which the representative said made them very happy.
For its biggest selling point, Susumu named 62 years of focus on thin film only, prioritizing precision, reliability, and long-term stability over mass production. The company is applying this to automotive and medical, and expects adoption in AI, space, and next-generation communications. Ichiken said the specs were cutting-edge and very interesting.
ROHM: A Resistor Company That Became a Semiconductor Company
ROHM's representative explained that the Kyoto-based company started as a resistor maker. The original logo combined the "R" of resistor or reliability with the ohm symbol, which gave the name. Ichiken noted that ROHM is now better known for power and analog semiconductors. The representative said the resistor business focuses on current detection in power applications, with computer storage, industrial equipment, and automotive as the main markets. Automotive has long been the priority, and the QCDS capabilities built there are now being applied to industrial and storage products, with new products released continuously.
ROHM's main differentiator is that it can propose complete solutions. Most component makers suggest a part for one socket. ROHM also makes LSIs and discrete semiconductor modules. A current-sensing resistor needs a current-sense amplifier and a microcontroller, and ROHM sells both, so it can propose the whole set. Its technical support also covers thermal and mounting design. The representative gave Ichiken a reference-design evaluation board for current sensing and suggested using it for current-detection experiments on the channel.
Three Current-Sensing Resistors: High, Medium, and Low Current
ROHM introduced three current-sensing resistor lines for high, medium, and low current, which the representative jokingly called three brothers.
The "eldest," the PSR series, covers currents of 100 A and above. It uses a resistive alloy welded to copper electrodes, which the representative described as a simple, strong design. ROHM claims the industry's smallest size and lowest height together with industry-leading rated power. Ichiken pointed out that at values as low as 0.1 mΩ, the resistance of board traces and solder joints can no longer be ignored. The representative agreed that this is a real challenge and that the effective value can shift depending on the customer's pattern design. ROHM publishes design-support tools and technical documents on its website, and offers high-precision models so customers can estimate in advance how hot the surrounding wiring will get.
The "second son," the GMR series, covers 5 to 220 mΩ with high power and high pulse resistance. It is used in motor drive and snubber circuits. The representative said it offers high guaranteed power in a package one size smaller than competitors'. Thermal images showed heat spread evenly instead of concentrating in one spot. The representative explained that in a typical resistor, heat is generated in the center and flows out through the left and right electrodes into the board. In the GMR design, heat also flows straight down, which greatly reduces the temperature. Ichiken noted the wide metal electrodes and said the part seems suited to snubbers, where repeated intense pulses build up heat.
The "third son" is a metal-sintered resistor that combines high power, high reliability, and high precision for currents of a few amperes. It is available in the 2012 size with ratings such as 1 W or 1.25 W, and the representative said inquiries have been strong. Ichiken said they had not heard of metal sintering. The representative explained that conventional parts are hardened by firing, while this one uses different materials and a different baking technique, hence "sintering." Target uses are current detection in robots, FA equipment, and tablets. Unlike the other two, it is a thick-film shunt that includes ceramic, and it is designed to release heat efficiently to lower its temperature. The representative said temperature-related drift is less than half that of conventional parts. Because thick-film resistors can fail from solder cracks, the structure was also redesigned, and ROHM says service life is 5 to 10 times longer than before.
Support From Selection to Purchase
ROHM stressed that the best part depends on the application, and that its three series cover the high, medium, and low current ranges. Beyond selling parts, ROHM supports customers through choosing and using them, organized online as Search, Try It Out, Consult, and Buy. The Consult stage includes the Engineer Social Hub (ESH), a community site with technical articles and tips where engineers can discuss problems. The representative said resistor engineers, including themself, post replies on its message board, and experts on each component are available to answer questions quickly.
For its biggest selling point, ROHM named the combination of high power ratings and technical support to help customers use that power well. Ichiken summarized this as support that covers how to use the parts, not just the parts themselves, and the representative agreed.
Closing: The Same Component, Different Directions
Ichiken closed by returning to the opening question. Resistors are common parts, but each manufacturer has distinct strengths, such as Susumu's thin film or others' focus on power. Under the single label of "resistor," the companies are doing quite different things. Ichiken said they hoped the session would help viewers understand these differences.
Hello. In this video, here’s a look at the discussion that took place at the Ichiken Lounge at Techno Frontier 2026, held between July 15 and 17, 2026. In this “Roundtable Discussion on the Future of Electronic Components,” I, Ichiken, met face-to-face with representatives from manufacturers at the forefront of the industry. We’ll take an in-depth look at each company’s strengths and the features of their products.
The theme for this session is resistors. Resistors may be rather unassuming components, but they have become indispensable to the operation of electronic circuits. Each company’s latest product lineups and technical features bring out the full potential of your key applications. Here you go.
Before we begin, I'd like to explain the outline of this meeting. Starting today at 1:00 p.m., titled “Roundtable Discussion on the Future of Electronic Components: Resistors,” we have representatives from four companies here: KOA, Hokuriku Electric Industry, Susumu, and ROHM. It takes the form of one-on-one interviews between representatives from these four resistor manufacturers and me.
The theme is resistors. Although they are one of the major components in electronic devices, I think they're pretty plain-looking parts. With current limiting, voltage division, current detection, and so on, there is no doubt that resistors are the foundation of circuit design. Recently, for example, with shunts for current detection in EVs, server power supplies, and fields such as renewable energy and power electronics, I think the importance of resistors has been rising quite a bit.
People might think, “Honestly, all resistors are pretty much the same.” But I think you'll see the differences between each company in today's discussion. It's 1:00 p.m. now, so I'd like to get started.
First up is the first company. I'd like to start with KOA. I look forward to working with you today. Thank you in advance.
First, just a moment—I brought a little something back as a souvenir. Thank you very much. Our company integrates agriculture and manufacturing, and I also do woodworking. Can I have that merchandise for a second? Thank you very much. When things like this are happening, we also make custom furniture and similar items. Is that so? I didn't know that. Thank you very much.
Let's get started. Please. We are KOA Co., Ltd. Thank you for taking the time to meet with me today. I'll introduce our company, product features, and initiatives. We're also working on thermal design, so let's talk about that. Next, I’d like to talk about our new products.
First, here is an overview of our company. We are a manufacturer based in Nagano Prefecture. It has been 86 years since the company was founded, and it's a company with annual sales of about 70 billion yen. We manufacture quite a lot of products domestically, with a domestic production ratio of around 70%. We also engage in manufacturing and sales overseas, and it's a company with about 4,000 employees. Resistors account for the vast majority of our revenue. Many of our clients are automakers. We also have customers in the industrial equipment sector. That is the name of the company.
As for products, we mainly handle thick-film chip resistors, the ones you all use frequently. We also work with thin-film materials, metals, and milliohm resistors. I'm also working on modules and other things. We still make leaded components and cement resistors, so I figured that if it's a decent-sized resistor, I probably have just about anything I need. I think it would be good if you could talk to me about it.
I see. Looking at this, I think there are all kinds, from thick films to thin films. What is KOA's strongest product, or what kinds of items would you like to promote as KOA?
The key point here is these thick-film chips, like the high-power models I'll be introducing later. There is also a very wide variety of these low-resistance metal plates. I'm hoping you'll find a variety of options to choose from. I see. Thank you.
First, since we’re discussing thermal design, let me explain why that is the case. Traditionally, thermal design methods have involved directing air at components to dissipate heat. Lately, it has become increasingly important to dissipate heat through the circuit board. In that context, thermal design also requires careful consideration of the layout by PCB designers. Since there are so many small parts, there are issues such as how to assess temperature. As a parts manufacturer, we must ensure that our component specifications are based on the assumption that heat will be dissipated to the circuit board. That is why this has become so important, and that's where we're focusing our efforts.
I see. It's called the “Domestic USB Charger Project.” In collaboration with CIO, a Japanese charger manufacturer, I'm currently working on the design of a USB charger. Heat dissipation is extremely difficult, and the case temperature rises to between 70 and 80°C. I completely agree that thermal design is extremely important.
In that context, as far as parts are concerned, what exactly is thermal design? As some of you who have used resistors may already know, there is something called a derating curve. The horizontal axis represents temperature, and the vertical axis represents power. If the temperature gets too high, you'll have to turn the wattage down a little. This diagram shows that the temperature has gotten too high and is dangerous.
Since using the ambient air temperature makes things a little vague, focus on the temperature at the terminals, the connection point between the circuit board and the components. This is what we refer to as “terminal temperature specifications.” This means that the operating limits of the resistor are determined based on the temperature of this component, allowing customers to use it in a reasonable manner. This has been reflected in international standards as well as JIS standards. Thermal design that focuses primarily on PCB heat dissipation is considered essential, so we’re doing our very best to focus on these areas.
Does this apply to all applications? For example, in any application—such as in-vehicle systems, renewable energy systems, or server power supplies—is it important to consider the temperature at this terminal?
For almost all resistors, we offer this derating curve with terminal temperature on the horizontal axis. I see. Thank you.
In light of that, how does this come into play for your parts? In the year before last and last year, we increased the power ratings of existing resistors. This product is a pulse-resistant resistor designed to handle higher power than general-purpose versions. For example, for the 2012 size, standard products are rated at 0.25 W, but this can handle up to 0.75 W. We are expanding our wattage range.
This is the long-side type that people have been using quite a bit lately. We've increased its wattage further. If you look at the derating graph with terminal temperature along the horizontal axis, it can handle high power even at high temperatures. Other companies offer similar products as well, but we're working hard to advance the terminal temperature specifications we discussed earlier. Heat dissipation is extremely important here. That's right.
Given that the rating has increased, what about the service life and changes or deterioration over time? The question of how reliable it is really makes you wonder, doesn't it? That's right. Once you can actually see those aspects clearly, you'll be able to see the temperature at which it's being used. This is part of the efforts being made in that area.
Regarding this rating increase, there's also a story going around that they worked hard to raise the rating. As for what I can do to help, until now, resistors have been manufactured on a case-by-case basis according to customer requests: “Just a little higher, just a little higher.” I’ve actually been doing that quite a bit. We’ve raised the rating quite significantly with the adjustment we made earlier. As for how I did that, we've been working hard on thermal design, including how to control the temperature of components mounted on the circuit board. This allows us to create an environment in which we can test the ratings of resistors. I've gotten pretty good at controlling it.
Also, based on our original technology, we identify the limitations imposed by material structure. We conducted tests while adjusting the temperature quite precisely. By pushing the boundaries of this limit, as long as we clearly state the basis for our decision, we should be able to push it to this limit. We're increasing the power in this way, pretty close to the limit. The point is that I’ve presented this based on solid evidence.
Since the PCB will be the primary heat sink, this is really important, isn’t it? You're absolutely right.
On a slightly different note, though it’s somewhat related, we’re also setting up a booth on the first floor today, and I’m promoting it. Here, we’re introducing a new product called the “heat-dissipating metal chip.” What exactly is this? You mount this copper chip on the copper foil patterns on the circuit board, in the area that's currently orange. This is an experiment in which we're passing a current of about 60 amps, which causes the temperature to rise quite a bit. If you attach this chip, the resistance of the pattern decreases. Some areas get hot, so reducing the heat generation naturally reduces the temperature rise as well. Rather than dissipating heat, it reduces Joule heating and the temperature rise on the circuit board. It's not really a resistor.
By the way, where exactly is this used?
It's not exactly the same thing, but lately, automotive customers use integrated ECUs and other circuit boards where they really need some current. They use quite a few parts that look like slightly larger chunks of metal, or things with jagged edges, that really enhance the design. That's where we're wondering if we can make suggestions using our small parts.
Rather than increasing the thickness of the copper foil across the entire circuit board, it's like, “I want to use this exactly where I need it,” right? That's right. Partly because of the heat generation, these are some of the items we’d like to introduce to you.
Another is a surface-mount ceramic resistor that is pulse- and surge-resistant. It looks like this kind of chip resistor. Here, the horizontal axis represents pulse width, and the vertical axis says “pulse limit power.” Basically, it's a resistor that can handle a lot of pulses. It's this dashed-line resistor. For a given pulse width—for example, 1 ms—there are values like X watts. It's usually about two orders of magnitude higher than standard items, since the vertical axis is logarithmic. It has that kind of strength. These are examples of chip resistors we offer.
What exactly is this? Usually, with chip resistors, there's a resistive film on the square insulating substrate. These are made entirely of conductive ceramic. Like the solid resistors of old? That's pretty much the general idea. Ours are made of a rather unique type of ceramic.
We have this type of part with leads, but we just couldn't seem to get it into chip form. We thought we might somehow make it work. It's a component with virtually unparalleled pulse resistance. This is still a work in progress, so it's going to take a little while longer, but we do things like this.
Other companies don't make ceramic chip resistors like these very often, do they? That's right. I haven’t really seen this type of thing even with leads, so I don't think they've made it into chip form yet.
By the way, what about the downsides? The temperature characteristics are a bit... That's right. Sometimes there's a fairly negative TCR, so you need to be a little creative with how you use it. Also, the tolerance is poor. Since we cut the finished product and attach electrodes to it, as you might imagine, it doesn't provide very precise resistance values.
I see. You have to be selective about when to use it, but its pulse resistance is very good. I think it might work out pretty well in situations involving brief pulses or snubbers.
Since time is running out, this is the last slide, isn't it? Could you please give us a brief explanation?
As we mentioned earlier, we're working very hard on thermal design. We also provide information on webpages and other resources to share information about thermal design. We post videos and other content there, so please start there to get thermal design information. I would really appreciate your help. So there's a webpage.
There’s one question I always ask every company at the end: What is the biggest selling point of your company's products? In KOA’s case, what is the most distinctive feature of your products?
As I mentioned briefly at the beginning, we have a large product lineup among resistors: thick-film, thin-film, metal, and those with leads, too. We handle everything from wirewound to cement resistors. Among all these resistors, in some cases there might be some that are incredibly tall. Since there are products like that available, if you're looking for any kind of resistor, we’d really like you to consult with us.
Among those, there’s a ceramic resistor with leads that looks just like a chip-type ceramic resistor—that’s pretty clever, isn’t it? I want to move forward while making the most of what I have. If you ever find yourself unsure about which resistor to use in various situations, I would really appreciate it if you could reach out to KOA.
Thank you very much. The first company we visited was KOA Corporation. Thank you very much. Thank you very much.
This is the second company. This is an interview with Hokuriku Electric Industry Co., Ltd. I look forward to working with you today. Thank you in advance.
Our company is Hokuriku Electric Industry. First, I’d like to give a brief introduction to Hokuriku Electric Industry. The company's name is Hokuriku Electric Industry Co., Ltd. As the name suggests, it is located in Toyama Prefecture in the Hokuriku region. Originally, the carbon-film resistor on the far left...
This is made from discrete resistors originally used for military applications. The company that issued it went from there to printed resistors and hybrid ICs. We've now reached the stage of high-voltage resistors, and by applying that technology, a thick-film chip resistor has been developed. The era has shifted from discrete components to surface-mount components. These days, it's all about sensors and modules. We are a company that specializes in that kind of work.
These are the main products manufactured by our three business divisions. We, the chip resistor division, are part of the Components Business Division, which manufactures them.
Looking at the current product lineup, it's not that you specialize exclusively in resistors. Besides resistors, you're working on sensors and all sorts of modules, and as one of those efforts, you're also involved in resistors.
Here are some general-purpose chip resistors. What kind of development roadmap are you following? This represents that concept. Starting at 1 yen per item, it's a very inexpensive part—you can buy a dozen or so of them—but it has become an indispensable component in electrical circuits. In that context, it's not just about cost. We receive a variety of requests from our customers: trends toward higher power and lower resistance, chip resistors that are resistant to environmental conditions, and addressing environmental concerns. We have a need for those chip resistors.
As a manufacturer of chip resistors, we have outstanding technology that allows us to manufacture products at a very low cost. We also handle derivative products from these chip resistors, such as chip fuses and ESD-resistant chip components.
Looking at the big picture, it's ruggedness and high power. I also get the impression that you're really working hard to achieve low resistance and high precision. Rather than relying on off-the-shelf products, is the idea to differentiate yourselves with high-performance products?
That is our goal. We're talking about a world where a single resistor costs just a few sen, after all. We'll take care of everything our customers need, even if the parts are inexpensive, so we'll continue to do our best with our standard products as well.
I see. Thank you.
Among these, a representative example is a compact, high-power resistor. As KOA mentioned earlier, we're also developing products like the 3216 type, 1.5 W. The main difference from off-the-shelf products lies in this resistive material. The fact that it uses materials that can withstand high power is our most distinctive feature.
This is related to the previous slide. It depends on the circumstances, but I think the idea is to keep pushing forward with high-performance products. Are there any specific areas where you're really putting in extra effort?
Our relationship with them is becoming much stronger, and our automotive customers are the strongest. This is a chip resistor with high resistance to sulfidation. In your applications, contact with sulfur has become more frequent. Among these, the inevitable fate of chip resistors—the issue of sulfidation-induced wire breaks—is coming under increasing scrutiny.
We carry two types of anti-sulfidation products. One is a chip resistor that is resistant to sulfidation and will never fail again. Another point is that, regarding this sulfidation issue—which rarely occurs—there are so many customers for whom cost is the top priority. This is what's known as the CRS series.
As shown here, the mechanism of sulfidation is that sulfur compounds dissolved in water enter from the interface between this plating and the overcoat. By sulfiding the silver in the inner electrode, this leads to a wire break. To suppress that mechanism, we add another layer. We have a lineup of chip resistors that offer both sulfur resistance and cost-effectiveness.
I guess the red part is what makes it different from a regular resistor, right?
It's this red part here.
Since this is intended for use in space satellites, these are JAXA-brand chip resistors. The environment is completely different from that on Earth. Since this will be used in space, naturally, it's a vacuum. This is structurally operating at a loss. We specialize in these types of aerospace components, using a material that has been certified as suitable for use in outer space.
What is the difference between a standard resistor and one designed for space applications?
The structure shown here in red—this material is used in space. That's the main difference.
What's the deal with lead and lead-free products?
Given the current global environmental regulations, we are now in compliance with RoHS, so lead-free plating has become the norm. In outer space, if it's tin-plated, it develops whiskers.
That's right. We use external electrodes that incorporate measures against that.
I see. I understand. Thank you.
This is an ultra-high-precision resistor. For a thick-film chip resistor, previously the limit was 0.5%, or 50 ppm. As for further requirements, we also have requests for resistors like this one, with 0.1% at 25 ppm. This one largely comes down to the resistive material. By using our proprietary materials, the rated power can also be increased. This resistor is capable of handling an additional 25 ppm and high power.
It's a thick-film resistor with high accuracy, at 0.1% and 25 ppm. I wonder if this is an area that's particularly difficult when dealing with thick films. How exactly do you manage to do that? I suppose there are things that can and cannot be disclosed.
This company was originally a materials manufacturer, and TCR is adjusted. Our manufacturing process and our material suppliers have different patterns and conditions, so variations in TCR inevitably arise. Given that situation, we can make adjustments within our production process. The fact that we use this as our basis is the key difference.
I see. So basically, it comes down to changing the ingredients. Is that how it works?
Yes.
I understand. Thank you. I guess this is the last one. Thank you. You make all kinds of general-purpose products like this, and I understand that you're also working on even more high-performance products. This is the final question we ask each company: What is the biggest selling point of your company's products? Please tell us.
Our proprietary production facilities and the ability to make resistors using these materials are our competitive advantage.
Like making something tailored to a customer's needs? I guess that's one way to look at it?
Yes.
Thank you very much. The second company was Hokuriku Electric Industry Co., Ltd. Thank you very much.
This is our third interview today. The third company to visit was Susumu Co., Ltd. I look forward to working with you today.
Thank you in advance. Our company is Susumu Co., Ltd. Thank you in advance.
Thank you for taking the time to join us today.
Let's start with Susumu. I'll start by introducing this. We at Susumu were founded in 1964 as a company dedicated to developing the world's first thin-film resistors. Having established mass production technology in the 1980s, we've focused exclusively on thin-film resistors ever since, and still do to this day. We have been continuously developing our technology, driven by our belief in the characteristics and potential of thin films.
There's an image displayed in the middle. It feels a bit like a semiconductor cleanroom, doesn't it? Does this mean this is actually being done here?
That's right. We use a very complex process. We have a cleanroom with controlled environmental conditions. Last year, in the area around Obama City in Fukui Prefecture, we successfully established a production line equipped with a cleanroom. This involves precision machining, and just like with semiconductors, we perform processing using photoresist. Creating objects under light that blocks ultraviolet rays, such as the kind shown here, is what is currently being done.
I see. It's quite a unique company that's been specializing in thin films all along. I think that's what makes it so unique. When we say "thin-film," it means that the resistive layer itself is thin, right?
Yes, that's right.
Roughly speaking, how thin is it?
It's on the order of nanometers. A hair is 100 μm thick, isn't it? In the case of our products, the size is 100 nm or less, so the film thickness is just one-thousandth—an extremely thin film. By using a film of exceptionally high quality, we specialize in delivering top performance.
I see. Thank you.
This is a lineup of our upcoming products. Our company, Susumu, manufactures products for in-vehicle mobility, industrial equipment, extremely high-precision measuring instruments, consumer goods and telecommunications, medical devices, and aerospace-related industries. Our products are used in a variety of fields.
I do get the impression that thin films are quite precise. In this context, I'm thinking the areas where precision is required might be around the measuring equipment on the left. Does that mean they're also being used in situations besides those that require extremely high precision?
Yes. Measuring instruments have certain characteristics. They're very sensitive to noise. Then there are space-related and communications-related applications. When it comes to these, even small amounts of noise or slight discrepancies affect the speed and accuracy of communication. How can we minimize that while still delivering the performance our customers expect? Will it deliver the system's full performance? That's where our product comes in. I think that's where they're using it.
I see. Thank you.
This is a bit of an unusual one, but it's a medical device like this. Even in areas like this, subtle movements are increasingly in demand these days, and our products have been adopted. It comes down to how the doctor operates the machine: there must be no small errors. This is said to be extremely important. This field is likely to continue growing in the future, and we really hope our products will be used more and more.
Although it still accounts for a small percentage of sales, it might grow a little in the future?
This is definitely an area we want to expand as part of our growth strategy.
I see. Thank you.
Next, I talked about our performance, and I've posted a small selection here. These include ultra-low-resistance thin-film chip resistors in the mΩ range and high-frequency chips, among others. For ultra-high-precision thin-film chips, a resistance tolerance of 0.01% can be achieved. With regard to fluctuations in air temperature, the TCR is 1 ppm per 1°C. The fact that we can take it this far is the most notable feature, or the greatest strength, of this thin film.
Then there's low noise. It also handles noise well. We don't use silver, so there is absolutely no need to worry about sulfidation. For over 60 years, we've had processes designed with this kind of resistance to sulfidation in mind. I suppose you could call it the wisdom of our predecessors, who thought deeply about product design. I really think they're amazing. That's how we've managed to bring it to mass production and get to where we are today.
You have a variety of products like these. With thin-film resistors, the thickness of the resistor itself is extremely thin, so I wonder if it can't handle high power. It just popped into my head. What's the real story here?
That's one important point. Since we're dealing with a thin film, once we exceed a certain threshold, it's definitely no match for thick-film technology. However, within its operating range, it can deliver overwhelming performance. I think we should focus on this. It exhibits excellent performance within the specified temperature range.
Things like temperature and voltage, right?
We also have high-voltage chips available separately. More importantly, in a world of hundreds of volts, how consistently can we supply products with stable performance? That is what I hope to pursue.
I see. I also think this might be a bit of a difficult question to answer: the price. How do thin-film and thick-film technologies compare in that regard?
This is a sore spot, but compared to typical thick-film resistors, they are in a higher price range. Because of the process and the complexity of manufacturing, there are many steps. But what matters to us isn't the price. We hope you'll see the value in precision and reliability here. We want to bring products like that to the market. This isn't exactly a case of "each to their own," but we want to stay focused and let the product's performance speak for itself.
Even if the price is high, as long as it delivers solid performance, customers are satisfied and make a purchase, right?
There is the option to choose. The accuracy remains consistent even when the temperature changes. In cars, medical devices like the ones I mentioned earlier, and space-related fields, long-term stability matters. If you take it into space, it won't be possible to repair it anymore. The key question is whether it can maintain stability over the long term and deliver that level of performance. I think that's where our main battle will take place.
I see. Thank you.
This ties in with what we were just talking about. Just a little plug: Susumu's chips have been adopted by NASA. It's called COTS, and we're registered on this list. Susumu is the world's first parts manufacturer to be registered. Last year, the RG and KRL series were also included in NASA's software package. Chips like these are working in space now and will continue flying into space in the future.
I'm not really that knowledgeable about space. In the case of F1, for example, the technology developed in F1 is applied to passenger cars. I think this happens quite often. Are there actually things like that—space-quality technology providing feedback into your own products, for example?
In this case, it's the opposite. It's about deploying the quality and performance in mobility that we have cultivated through our automotive business into space as-is. The term "COTS" mentioned here refers to exactly that. This is the quality standard generally adopted for automotive applications. Standard products manufactured using the exact same process and structure have been adopted by NASA and are being used as-is.
I see. When it comes to automotive applications, I get the impression that they're pretty strict about quality. So, is it like taking the technology you developed there into space?
Yes, that's right.
I see. Thank you. Some of them are processes designed for space applications. Components for space applications—you see them a lot in things like semiconductor SoCs, right? I think there's a place for things like that.
The process, structure, and materials I'm currently working on—the fact that something like this was approved—I'm really happy that I was able to do it. Also, as it says here, things like this will start appearing in the future.
This happened on August 30 of this year. This will be the Roman Space Telescope, to be launched by NASA. We're trying to map out every last corner of the universe. Our chips are also installed in the Roman Telescope. This is the Falcon 9 that will carry out this launch, right? Our chips are used here as well.
Through things like this, I think we'll see some wonderful footage in the near future—footage I've never seen before. If we can make a contribution somewhere like that, where everyone can see it, that would be great. I wonder if it serves as a source of emotional support.
I see—it really is quite grand, isn't it?
Here, I've written a little about the difference between thick films and thin films. Since we're referring to a thin film, the structure will be as follows: this is a film composite with an extremely dense and stable structure. When an electron passes through here, it ensures a smooth flow. If we can maintain a level of 1 ppm...
I see. So is this graph itself just thermal noise?
Thermal noise refers to the resistance as a whole, but what is shown here as "Electron" takes the form of electrical noise. This is because the interface works well.
Up to this point, it's more like noise. Is that the general idea—that it reduces background noise?
These electrodes and resistors—these are also electrodes and resistors. It was just the other day, or something like that. The movement of electrons flowing through the resistor is very smooth, so even if the temperature rises or it gets hot, unless this trend changes, the advantage is that you can control it. I believe this is the primary source of the advantages of thin films.
I guess what they're saying is that there's less noise like this. When it comes to audio and other applications like that, I wonder if people will actually like it.
That's right. Sound quality and precision measuring instruments—how to convey signals correctly—I think this is extremely important. A customer told me that what really brings out all the subtle sounds in the background—the sound of the wind in the grass, the murmur of a stream, the sound of birds chirping—was Susumu's chip. I was really happy.
That sounds pretty good. It's getting a little late, so could you briefly explain this slide?
Our small resistors are this size—they sit on top of your finger. There are all kinds of worlds like this. In addition, in terms of various technologies, there is something I'm able to bring to the world.
Thank you very much. Since it's about time, I'd like to move on to the final question: What is the biggest selling point of your company's product? Please.
The defining feature of Susumu has been, for 62 years, that we have consistently focused solely on thin-film technology. We don't rely on mass production. High precision, high reliability, and long-term stability—I have continued to refine these things, seeing value in them.
We are currently applying this technology to the automotive and medical fields, AI, space, and next-generation communications. It will likely be adopted in fields that require high reliability, and we would like you to go there. We will continue to drive global progress through thin-film technology. I hope to make a contribution in that area. That's all.
Thank you very much. It features some pretty cutting-edge technology and specs, and I thought it was very interesting, too. Our third company interview was with Susumu Co., Ltd. Thank you very much.
This is a roundtable discussion exploring the future of resistors. Today, the fourth company is in the final session. The fourth company is ROHM Co., Ltd. I look forward to working with you today.
Thank you in advance. This is ROHM Co., Ltd. Thank you in advance.
This is an introduction to ROHM. ROHM is a company headquartered in Kyoto. This company began as a manufacturer of resistors, which were its first products. Please take a look at the bottom right here. This is ROHM's original corporate logo from when the company was founded. It is the origin of the name "ROHM": the "R" in "resistor" or "reliability," combined with ohms (Ω), the unit of resistance. The name "ROHM" is derived from "R.ohm."
Right here toward the bottom is the power zone. ROHM is a company that specializes in semiconductors—power semiconductors and analog semiconductors, for example. I think it's probably a very strong company. Focusing on current detection needs in the power domain, particularly computer storage, industrial equipment, and automotive applications, there are these applications. Where exactly are the areas you are focusing on most within this context?
That's right. We have long placed a strong emphasis on the automotive market. As part of those efforts, our QCDS capabilities have been significantly strengthened. With those strengths, we are now involved in industrial equipment and computer storage as well. We are constantly introducing new products.
I see. Thank you.
Next, I'd like to discuss ROHM's ability to make proposals. Generally speaking, since we're a parts company, suggesting a part for a specific location is quite common. As I mentioned briefly on the previous page, in addition to resistors, ROHM offers a wide range of products, such as LSIs and discrete semiconductor modules. We can provide a comprehensive proposal for all those parts. That is a major strength of ours.
Among other resistor companies, there are quite a few that specialize in resistors. I wonder if that's a high percentage. ROHM, as mentioned earlier, works on analog ICs and power semiconductors while also making resistors. Are there any advantages to using ROHM resistors?
As it says right here, we can provide comprehensive support. The key point is that we can propose a large number of parts all at once. For example, the part written here on the left: what I'm going to introduce today is a resistor used for current sensing. To use this resistor, you'll also need various other components, for example, a current-sense amplifier and a microcontroller. ROHM also offers products for these applications, so our strength lies in our ability to present proposals all at once.
Like what's written in the lower right corner here, if you ask the technical support department, I hear they're willing to teach you all sorts of things—thermal design, for example.
Support for implementation-related matters is comprehensive. Since it's such a special day today, there's something called a reference design evaluation board that we are currently selling.
I wonder if I'll get something.
This is the reference board for this current sensor. I have it here. If you'd like, I hope you'll use this on Ichiken's channel to experiment with current detection. I look forward to working with you.
Thank you very much. I'll take this, please.
Now, let's move on to the product introduction. Today, I'll be introducing three current-sensing resistors. Each covers the high, medium, and low current ranges. They're like three brothers.
That's the oldest brother on this page, isn't it?
This is the PSR series, designed for high-current applications. This series supports high-current ranges of 100 A or more. As for the structure, we connected the resistive alloy and copper electrodes using a welding technique. It features a simple yet powerful design.
This product has features such as a low profile and the smallest size in the industry. This product also guarantees industry-leading rated power.
If you look around here in the lower left corner, it seems to have the industry's smallest footprint and the industry's lowest height. I'm wondering if this is a product with some unique features. It's in the mΩ range, isn't it? When the value reaches a minimum of 0.1 mΩ, the resistance around the resistor itself—in the circuit boards and wiring we're using, and in solder joints and other areas—can no longer be ignored. I do think it might be getting pretty hard to use. Are there any points I should keep in mind regarding that?
It's certainly true, as you say, that this is quite a technical challenge. It also depends on the customer's layout pattern; the resistance value might be a little off. Given that, we offer design support tools on our website. We also publish technical texts.
There's also the issue of resistance, but heat can build up around the wiring as well. For places where you might wonder, "How hot does it get around there?", we also provide support in the form of high-precision models, tailored to your needs so you know in advance.
I see. It seems pretty useful. Thank you very much.
Next up is the one in the middle. This would be the second son, the GMR series. The features of this product are, first, the resistance range from 5 mΩ to 220 mΩ, accommodating a wide range of resistance values, and its high power. This product is used in motor drive circuits and snubber circuits. It features high pulse resistance. As you can see in the lower left corner, the guaranteed power rating is quite high, so this product also offers a size one step smaller than competing products.
Is this the image in the upper right corner? It doesn't feel like just one spot on the resistor is getting hot. Is that the general idea—that the heat seems to be spreading out evenly?
In terms of heat dissipation, we put a great deal of thought into the device design. It is designed to ensure very even distribution. As for the design that allows heat to escape, this is a standard resistor. In a typical resistor, heat is generated right in the center. It passes through the left and right electrodes and out toward the circuit board. With this product, the heat generated is also dissipated, and furthermore, it's designed so that it goes straight down. This product is designed to significantly reduce heat.
It's true—the metal electrode part is pretty wide, isn't it, if you look over on the left?
That's right. To cool it down.
So it's basically a matter of dissipating the heat onto the circuit board, right? I see. As was mentioned earlier, I'd like to try using it in something like a snubber circuit. With a snubber, you get really intense pulses even in rapid succession, so heat keeps building up. When it comes to effectively dissipating heat, it says it can be used in snubber circuits. I see. Thank you.
That's the third one, isn't it?
This is the third son. This product achieves high power, high reliability, and high precision all at once. The corresponding current values are in the range of several amperes. This product is also available in the 2012 size right now. With rated power of 1 W or 1.25 W, for example, this product guarantees a fairly high power rating. This is a product that we are still receiving quite a few inquiries about.
I don't think you hear much about metal-sintered resistors. What exactly is this?
Traditionally, the material is hardened using a process called firing. This one uses ingredients that are a little different from what we've used before. We're also using a slightly different firing technique than before. That's why we call it "sintering."
I see. By the way, what kind of applications is this resistor itself best suited for?
As I mentioned earlier, this detection is in the range of a few amperes, so robots, FA equipment, tablets, and other devices like that. That's basically what it can be used for—current detection.
Also, if you take a look at the image in the upper right corner, for example, I wonder if they really understand. I guess the whole thing is made of metal. It feels almost like metal, doesn't it? So it seems to conduct heat quite well, too. Is that a common way to use it, or is that just the general idea?
Unlike the eldest and second sons so far, this is a shunt resistor that uses thick-film technology. It's shown on the left. Compared to metal resistors, it's a resistor that also contains ceramic components. The heat generated there is all being dispersed. It's designed to let it escape smoothly, lowering the temperature far more than resistors to date.
Also, there's actually very little fluctuation due to temperature changes. If you take a look at this, we've also kept the temperature coefficient quite low. Compared to what has traditionally been done in this area, they've managed to keep the fluctuation well below half. It's quite accurate.
As you'll see if you check the lifespan, thick-film resistors can be damaged by solder cracks. There's this one place, though. We've also put some thought into the structure here. We have achieved a service life that is 5 to 10 times longer than before.
I see. Thank you.
This will be the last one. For components such as resistors and various other parts, the optimal component varies depending on the specific application. For current-sensing resistors like those in this case, in the high-current, medium-current, and low-current ranges, the three series I introduced today are where we'll be able to offer you the best possible solution.
It's not just about selling products. How customers plan to use them or how they plan to choose them—we provide support starting from that stage as well. As shown below: search, try it out, get advice, buy. We provide comprehensive online support for this entire process.
What's more, in the "Consult" section, the third item, there's Engineer Social Hub, commonly known as ESH. Here, you'll find technical articles, tips, and more. This is a community site where engineers can discuss topics with one another. When it comes to resistors, engineers like me are regulars here. It's a message board, after all, so I do post replies. Experts on each component are available to answer any questions you may have right away. It is designed to be a community site that can accommodate such needs.
I see. Thank you. Since we're running out of time, here's a question I've been asking various companies: What is the biggest selling point of your company's product?
The most notable feature of ROHM resistors is their power rating. We also provide technical support to help you make the most of that power. That set is what sets us apart.
I guess you could say it's support that goes beyond just the parts—it covers how to use them, too.
That's right.
I understand. Thank you. Today, the final session of the roundtable discussion exploring the future of resistors was with ROHM Co., Ltd. Thank you very much.
Thank you very much.
I'd like to say a few words as well. To wrap things up, resistors are actually pretty common components, but I do think that these parts have various unique features depending on the manufacturer. For example, Susumu with thin films. Then there's power, and so on. Each company has its own unique strengths in that regard, and...
Although they're the same when viewed under the umbrella of "resistance," it feels like what we're doing is actually quite different. That's true for each company and the industry as a whole, isn't it?
So, I'd like you to take a look at today's trends. I'd be happy if this helps you understand it even a little bit.
And with that, this session has come to a close. Thank you for watching until the end.
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