How COBstr Turns Windows And Glass Walls Into LED Displays

April 19, 2023 by Dave Haynes

Technology tends to improve as it matures. That’s certainly the case with LED displays marketed as being transparent. The first generations looked okay from the front, but the back sides were big metal grid arrays that often looked like hell.

That’s improved a lot with newer generations, but the technology now has competition in the form of displays that are embedded in foil or film.

I was intrigued by some online posts recently from a Dutch company called COBstr, which is the sales and marketing front end of a Chinese manufacturer focused on displays that use Chip On Board technology. That’s the COB part of the name.

COBstr markets super-skinny displays that use the transparent material as the surface, either adhering to window glass, or laminated the material inside the glass.  The product has a foil layer the peels off and allows the display to be stuck to glass and then if needed, pulled off, rolled up and reused.

I had a good chat with Marius van Bergen, the company’s founder about the roots of the product, his Chinese manufacturing partner and the distinctions and benefits of COB versus other LED technologies.

Subscribe to this podcast: iTunes * Google Play * RSS


Marius, thank you for joining me. Can you tell me what COBstr is all about?

Marius van Bergen: Hello, Dave. Thank you for having me. COBstr, COB stands for chip-on-board. Now, chip-on-board technology has been around for a long time in the lighting industry. But my business partner is in China and was the first one who has been doing this for LED displays. So she’s the one who’s filed patents, and she made some mistakes, but she’s a woman that I have a lot of respect for because it’s tough in China to make it as a company without help from the state and when you have to fight the big dogs. But she’s very impressive regarding technology, which is not my core business.

I’m just a person who studied Chinese and who knows China a little bit. But we hooked up about 10 years ago, and we’ve been going to the ISE and trying to get a little bit more renowned, and the thing with COBstr is not very easy to do. The big dogs are Absen, Leyard, and LEDman, they’re all trying, and we do a lot of R&D for some of the big boys because they don’t really master the technology. But it is the only way, that’s the way I interpret it anyway, it’s the only way forward for the LED industry.

It doesn’t matter if you look at it from a sustainability point of view or if you look at it from an economic point of view, there’s just no way around it because you skip an entire step in the production process because you don’t have packages, which makes it a cheaper technology theoretically, I have to add theoretically, because if you are a big company and you can buy LED packages in bulk, then, of course, you have some price advantages. 

So what’s basically happening is with a chip on board, you’re able to apply a lot more LED light emitters to a surface without having to do the packaging, and you’re skipping an entire step and also speeding up the process. Is that an accurate way of describing it?

Marius van Bergen: Yes, it is, and the package manufacturers, which are also usually very big operations, don’t like us very much because if we don’t need a package, we don’t need their product. The big advantage and that’s basically what our R&D has all been about, is that you reduce the number of components and the vulnerabilities within a display.

So is your company kind of the sales front end for a Chinese LED manufacturer, or is it a partnership where you’re co-developing something, and it’s coming out of the Netherlands? 

Marius van Bergen: Manufacturing is in China, so it’s a business partnership where they concentrate on the Chinese markets where I’m a little bit involved as well because that’s a different story, maybe I shouldn’t get into that, but I basically start with marketing and business development in Europe. That’s my main responsibility. 

I got interested in this because I saw something on LinkedIn talking about LED and COB-LED on foil, and I thought, okay, this is interesting. There’s a company in Germany, probably a couple of hours from you that has a foil-based product that is lower resolution, super lightweight, and so I saw this and thought, oh, are you reselling that or is this something different? 

Marius van Bergen: We’re not reselling that. This is our own product. It’s a new product.

We had our first sample back in 2019. I guess that’s when COVID broke out, at ISE, we showed it. It was a prototype that we lit, but we didn’t display any images on it. But we took advantage of COVID to really bear down on the R&D, and we have now a finished product that’s finished and ready for mass production, and so it’s hot off the press really because we introduced it at the Signs and LED Display exhibition in Shenzhen last week and we saw a couple of other players who were also getting into this area. I guess there were about five companies also doing LED foil, but from our point of view, a very different level. Because their foil was SMD based, and also no flip chip because they don’t have the equipment, and without going into the technical details they have about 2000 nits brightness, and we had 7000 at the exhibition, and we could do much more. But at the exhibition, actually, we are very proud of the product, there were people with a luminescence meter who were measuring the brightness, and they said, oh, 7000 knits. That’s pretty nice. 

When you say foil, I’ve looked on the website, and when I think of foil, I think of shiny metallic material, but is it that or is it more of a film?

Marius van Bergen: Film would be maybe a more accurate word because it’s transparent. We can make it non-transparent also. But yeah, it is transparent, and that’s one of the markets that we are looking at, obviously, because you can use it as a window display for the retail industry.

How would you apply it to a window, would it be adhered or is it just hanging? 

Marius van Bergen: We are looking at hanging also, but the original idea was adherence. It has a protective foil, and when you take off the foil, it adheres so it sticks to the glass, and we have great viewing angles. It looks pretty damn nice, if I may say so. 

But the problem that we’ve encountered it now because we sold some to a store in New York, but as it turns out, there are regulations that you’re not allowed to stick a foil like that to the window. So I think they have a regulation that it needs to be eight inches from the window. They don’t have this regulation in China, and I’m sure it’s not like that everywhere, those are some of the challenges you run against when you’re working the market. 

Why do they have that regulation? 

Marius van Bergen:  I have no idea, but I’m sure we’ll find out. 

So if it is adhered to window glass or partition glass or something like that. I understand is that the transparency is gonna depend on the pixel pitch and the amount of LED in there, but what kind of transparency can you realise?

Marius van Bergen: I have to admit, I don’t know how they measure it, but we actually have two products. We have one with LED strips that are still visible and there’s the more transparent product and the product without the strips, we claim, again, I don’t know how we measure it, but 89% transparency, which is not bad.

Can this work out outdoors, or is it a pure indoor product? 

Marius van Bergen: We sell it as a semi-outdoor or indoor product, but we can make it outdoors as well. It just takes more protective measures. So it’s a little bit more expensive if we make it for outdoor applications.

So by semi, you mean it would be in like a sidewalk window or something like that, it’s  protected, but it’s intended for outdoor viewing. 

Marius van Bergen: Yes, exactly, or public spaces. 

What are the other benefits to it? Are there weight benefits or when you’re pitching this, what are you saying are the key reasons you wanna take a look at this?

Marius van Bergen: As you said yourself, it’s very light so instead of carrying these LED cabinets, which weigh a lot, you can just walk around and just hang them in front of a window or have them on a roll and let them hang down. They’re very thin. We’re between one and one and a half millimeters, so it’s extremely thin. It has no frame, which is another big advantage. 

When you have a LED mesh, you have this frame that you have to install in front of a window. So all of that we do not have to do, and another advantage, again, that’s what I mentioned before, is the sustainability component because sooner or later, everybody will have to switch to COB at least, that’s the way I look at it because it’s just too polluting to have this packaging industry go on, and it’s a race to the bottom really because it’s all about mini LED and micro LED and getting as small as you can, but it’s still based on packages, and the package is just not necessary. It’s less complicated, but it’s not necessary. 

So would you see a day when you would use micro LED as the light emitters, or COB is the way forward? 

Marius van Bergen: We believe very strongly that COB is the way forward, but you can theoretically again because we don’t have the purchasing power, but theoretically, you can do micro with a COB technology without a package. It’s something called perpendicular stacking, which maybe doesn’t mean a lot to people who are not into the technology, but it boils down to you the fact that you are able to go to a very fine pitch with COB, so without a package. So it’s definitely possible to get into that area. 

But I don’t see micro LED getting very mature within, I don’t know, five years or anything. It’s just too expensive right now. 

What would you be paying roughly at, whether it’s in EU or USD, for a square foot of this material to put in something like a window?

Marius van Bergen: I don’t feel comfortable talking about pricing right now. We’re talking to prospects, and we’re having the discussions, but we will be selling it by a square meter, and it’s not a cheap technology, let me put it that way. And the reason is that each LED chip also has its own IC driver so there is a cost attached to reaching that kind of brightness that we have. 

But by having each IC driver like that, each light is addressable so you can control it, fine-tune it, and do whatever you need.

Marius van Bergen: Yes, exactly.

Are there physical limitations or dimensions to how you do this? Are they rolls? Are they are two meters wide or something like that? So if you want something that’s fitting a six-meter area, you’d need three rolls side by side?

Marius van Bergen: Yes. We could make them in length that is pretty undefined.

We can make rolls for 20 meters, and we can connect them and go even longer, but the width for now, and that has to do with the equipment we have, is 32 centimeters, if I’m not mistaken. So you put the roll next to each other, and then you can build up a bigger one, and you can just cut it like, like you have LED strips at the at your local DIY store. You can cut the foil actually and make it fit for purpose, which is another really nice property of this LED foil or film if you want because you can make all kinds of shapes with it, and that makes it a very suitable product for creative projects. 

Are you restricted to rectangles as the shapes or squares, or could you do something round?

Marius van Bergen: You can do anything. You think of it, and you can basically do it because it’s so flexible. 

So you could conceivably cut a big round disc and put it on window glass, except in New York, and connect it through some sort of like super thin filament wiring or whatever?

Marius van Bergen: Yes. It’s not as if there are no limits, obviously, because you shouldn’t cut the circuits that are crucial to the system. But basically, yes, you can do a lot of things in all kinds of shapes and forms. 

What are the challenges you face in selling this?

I would imagine a key challenge is that people don’t understand that you can even do this, and also that perhaps what they’ve seen in terms of transparent film at trade shows, if they’re pro AV people, is what companies like LG have, which are LED on film, but pretty coarse, so to speak, pixel pitch that you’d look at and go that’s cool, but I’m not sure what I could actually do with that.

Marius van Bergen: Yeah, and LG is one of these companies that, as far as I can understand it, they haven’t managed to really market this thing maybe because of price, I don’t know. They have a brightness of only 2000 nits, I think, and it’s pretty coarse, as you said. We have a P10, a P8, and a P 6.67 now that we are selling in China. We’re selling the first samples, I should say. But we can go down to 2.5, and we could probably go down even further but then, where’s your transparency? Because that’s what we are looking at, and when you’re asking me about applications or potential clients, I’ll give you an example.

We’re talking to a very nice Dutch company, it’s called HoloConnect, and they make these holograms, and there are only three companies doing that. There’s one in the United States, and there’s one in Canada, if I’m not mistaken, and there’s one in the Netherlands, and it’s a very nice product, and they’re thinking, if we use that film maybe we can do more than just show the hologram. You can actually show an NFT with a metaverse world or something like this. It’s wherever your imagination takes you. But you can add this digital layer to the hologram to the box, which would be a very nice application.

I’ve been paying attention to “transparent displays” for years, and when I see the mesh-based LEDs, I’ve thought those are getting better, they look really good from the front now, but when I go in behind them, they’ve improved, but they still look like a mesh or a grill and when I’ve seen most of the transparent LED on film products, they look really nice from the front, and when I look at them from the rear, the non-business end, it’s reminiscent of the old printer ribbon cables, that sort of thing, where you see this plastic kind of long, horizontal or vertical stripes.

What does your product look like from the nonilluminated side? 

Marius van Bergen: The very honest answer, I have no idea. I’ll explain why, because we’ve been focusing on introducing this product last week at the fair, that’s the reason why I haven’t got a sample yet. So we’ve been producing for the fair and our first distributors. We’re building a distributor network is in China because, like I said, the factory’s in China, and that’s where our focus is for now. 

T=hey promised me that I’d get my first sample this week so they’ll send it my way this week and then I’ll tell you what it looks like from the back, or I’ll put it on the website so that you can see it. But I’ve seen videos, obviously, and it’s not intrusive. It’s not disturbing or painful for the eyes. It’s very soothing because it’s transparent, and the natural sunlight still comes into space. 

Does all the light that is generated go out, or does some of it lead back into the rear view? 

Marius van Bergen: From what I can tell from videos and pictures, it doesn’t lead back into the room or the space. 

What do you see as the market for this? 

Marius van Bergen: It’s pretty broad. We said retail industry, public spaces, the entertainment exhibition industry. The Christmas market is actually an interesting one because we have Christmas trees now with LED strips for the festivals, but you can do more than that if you have a transparent ribbon, that way you can show your Christmas bars or snowflakes or stuff like this, and the creative projects 

Is this sort of thing that can be used on a temporary basis or if you adhere this to window glass, it’s on that window glass and if you’re getting it off, you’re pulling it off and you’re done with the thing, you can’t apply it to another sheet of glass?

Marius van Bergen: You can apply again. It’s like a sticker but it’s not like you take off the sticker and you’re done with it. It’s reusable. But again, one of the big advantages is it’s light and it’s very thin, so you can transport it back and forth. You can actually also make fixed installations, of course, and use it like a curtain maybe, or something that you pull up when you don’t need it and you let down when you do need it. 

So could this be a rental unit? 

Marius van Bergen: Absolutely. 

When you say you could transport it, could it actually be rolled up or do you put it on some sort of flat pieces of cardboard or whatever on both sides to protect it?

Marius van Bergen: It has a protective foil that you remove when you use the film but it’s rolled up. You can’t fold it because when you go, you are 90 degrees, then you have a circuit problem. 

So the transport costs of this versus traditional LED cabinets would, in theory, be substantially lower.

Marius van Bergen: Substantially lower, and there’s almost no installation once you have your content, and you have your setup, but you don’t have all these cabinets to build up, which are heavy, clumsy, and not very practical. And now you just have a roll, you roll it up. 

So the entertainment industry is also something that we think has potential for this product, especially with the brightness that we can achieve. 

When you’re talking to potential customers and partners in Europe, what are they interested in? Is it the transparency, the lightness, or the ability to put in windows? 

Marius van Bergen: All of the above. The challenge, I think, is going to be to determine the right price for this product because, as I said, not the cheapest technology. It’s COB, it has its own IC driver per LED chip, but y I think, for something like this, which people like to use the word disruptive, but, if you look at it and you have a bit of a vision, you can see this thing going into the consumer market even.

I’m biased, obviously, and price-wise, it wouldn’t be something that you can consider at this point, but we have our mass transfer system, so we can go down with prices pretty quickly once it gets traction in the market. 

Are your plans to sell primarily in the EU or are you looking at North America and other markets as well? 

Marius van Bergen: Yes, global. We’re looking everywhere.

The main focus right now is China. But Europe, the United States, Canada, you name it. We have a lot of countries that we look at. So we’ll see where the market takes us. 

And are you selling direct, or are you developing country-by-country partnerships or reseller partners?

Marius van Bergen: We haven’t ruled anything out, and in China, we’ll be using distributors—just channel partners. 

You mentioned that there are some other companies that have products as well that don’t have the same level of brightness and so on. Do you consider those competitors, or are they going after a different part of the market?

Marius van Bergen: Personally, I don’t see them as competitors, but again, I’m biased because I have a very strong belief in the woman who’s the brains behind this technology, and that’s because I’ve been with her to ISE for a couple of years, and I know that all big players that everybody knows, they know this very small company, they know there’s so much knowledge there but they’re a bit afraid of letting us get on the radar. But I think it’s going to happen, it’s just a way forward. 

As I explained, there’s no way around COB. With everything going on in the world, whether you are a climate activist or climate denier sustainability, it’s just from an economic point of view. You don’t buy a package. You have a cheaper product and a better product at that. So I really believe that we have technology that has a bright future. 

When you talk about the “green signage” aspect of this, are the benefits around energy savings, or is it as much about the manufacturing footprint that you don’t have the same amount of material that you’re required to produce a display?

Marius van Bergen: It’s both as well. It’s not only the material, as I said, but we also have a strong R&D background, so it’s all about reducing the number of components to get better heat dissipation and use less power. 

The company, the Chinese side of this, are they in Beijing or Shanghai or Shenzhen or somewhere else?

Marius van Bergen: Dongwang, next to Shenzhen. But the woman who started this at beginning of. 2000, she’s from Sichuan. I don’t know if you know where that is. But she started with this very small company, almost a sweatshop doing traditional modular displays, the top matrixes, and from there, she evolved and got this idea. She was working for a PCB company in Taiwan, and then she got this idea, what’s this SMD all about? And then she started thinking about COB, and it’s very interesting how she developed, and then she moved to Beijing, then she moved back to Shenzhen, and now we have a factory in Dongwang. It’s not a very big factory. It’s very clean. It’s very nice, and yeah, we’re very confident. 

I assume part of her thinking, along with her interest in COB, is just simply that there are so many LED manufacturers in China, particularly addressing the domestic market, that if you’re going to be successful, you somehow or others have to come up with some kind of differentiation, right?

Marius van Bergen: Yes, very true, and again, I think maybe it’s not the wise thing to say on the podcast, but I think maybe it’s changing a little bit, but very much mission-driven. Like we want to educate the LED industry. Why are people making all these packages when it’s not necessary?

And so there is a drive on educating the industry and making it clear that COB is the way forward, and actually, COB is only a name but what we have now, we actually call it COB-IP because it’s a chip-on-board integrated package. So it’s actually a sealed assembly of a LED ship and an IC driver within one pixel.

All right. If people want to know more about this, where can they find you online? 

Marius van Bergen: Online, you can find us at, but you can ask me, and I’ll be glad to share all the information. 

All right. Marius, thank you very much for your time.

Marius van Bergen: Dave, thank you very much for having me, it was a pleasure.

Leave a comment