 MPI, brought to you by DigiKey and Interferent, thank you. DigiKey, this week it is 3M, Alidieta, what is IonMPI? This week! Okay, I love 3M stuff, because of course American company, Minnesota Mining Corporation, but now officially 3M, and they make really good quality tools and products, even if we don't necessarily buy electronic components from them, you're going to use their stuff. So this week, I was really psyched to see that DigiKey is highlighting VHB Tape from 3M, which might be familiar to you, that red overlay plastic. If you've done electronics or assembly or manufacturing, that looks really familiar. VHB Tape, very high bond tape, apparently it's been around since the 1980s, it was invented at 3M, and they have a wide variety of different types and shapes sizes, so just because it's called VHB Tape doesn't mean they're all the same, there are a couple variations to it, and DigiKey stocks all the different types, and so I thought it was a good time to cover this product, and then you can go over DigiKey and buy a reel or a sheet. So VHB Tape, I think it was originally designed to replace rivets in architectural or automotive applications where you have a panel and you want to attach a panel onto a frame substrate, like up there, up our right, for an automotive trailer, you have these panels that you may want to remove and adjust eventually, but riveting is actually going to be, is going to give you a like a rackety like TikTok sound, because the rivets eventually get loose, and the whole thing rattles, whereas if you bond it with VHB Tape, it's going to be a nice strong bond, and then it was used for architectural uses, so you see on the left there, I think that's the MIT computer science building, any kind of funky style building with these panels over it, architectural panels, this can also be VHB bonded on, and then for white goods, you see a washing machine, and also for the signage that's also really common, but now it's also really used often for electronics. If you are attaching screens or panels, or you want to have a battery on one side bonded onto an enclosure, I remember I got a cable holder and it had VHB Tape, and that's how you would attach it onto your desk, and it's been 10 years, and it's still there, even though I bump into it almost every day, and I yank on it with cords in it, so this tape is used in a lot of different functions, and electronics is kind of, even though a lot of people might be used to using something like hot glue, which is very fast and easy, but of course, 3M makes hot glue guns and hot glue sticks, good for quick bonding, but not very strong, peels very easily. Epoxy is okay, but it's very messy, I've used Epoxy a lot to bond different components together and build, you have the enclosure, and then you have to have the PCB and the display and buttons and sensors. I've used Epoxy before, Epoxy is really good, but it's very messy to use, and it's very easy to mess it up if you don't mix well enough, and you don't know, and it's like two days later you check and it didn't harden, it's very annoying. Also, if you don't pick exactly where Epoxy could crack off, you do have to prime the surfaces really well, which is one of the nice things about the VHB Tape is that you can do prep, but you can get away with not a lot of prep. Another option is foam tape, we've used foam tape, this sort of stuff is often engineered, see this on the back of breadboards, is that white foam, kind of thick foam tapes, couple millimeters thick, and it's good for attachment, but it does eventually dry out, and it's not meant for high temperature or cold temperature uses whereas VHB Tape, this is much cheaper, but VHT Tape, you saw it's used for automotive, for architectural, it can be weatherproof and temperature, hot and cold, resistant, it doesn't dry out and crack off. So I checked out the VHB design guide, and they talk about all the different variations in some use cases, and one thing that I didn't realize is that, first up, there are some preparation steps you want to take to get the best bonding, and there are different varieties of VHB Tape. So first up, you can actually get stronger than raided bonding if you do surface cleaning. So for glass, for example, you want to use silane, and then for other materials, there's different solvents, they actually have in the design guide a list of all, like you're using wood or using metal or using aluminum or using glass, here's what you do to surface prep. Next, you can abrade, and abrading, especially for smooth surfaces will let the glue seep in a little bit better, it's not essential, but if you do it, you're going to get much better bonding grip at the end of the three-day curing cycle. Priming is another thing I didn't realize, you can prime it. Again, I think it's going to be for outdoor uses where you really want to have the best bond possible, but you can actually skip these if your things are clean, and you don't need it to stand up to automotive or industrial use cases. And then finally, you can apply it. And they do actually talk a little bit about automatic application, like using robotics or laminators, and they have like fixed laminators, or you can do manually, right? You can actually just like by hand, cut a piece of tape, put it on, and then you do want to use a roller to attach it. And I think we covered like 3M rollers before, that you want to roll it on with the one side of the adhesive, and then let the acrylic glue seep in, and then you can pull the wet plastic cover off, and then attach to the other side, and then apply pressure again. So it looks like you need about 15 psi, which is, again, a human can easily apply it. And then another thing I noticed is that they mentioned you can heat up the bond up to 38C. So it's just a little bit hotter than room temperature. Like maybe a light heat gun, and you'll also get much better bonding if you do that. I guess the heat activates the glue a lot better. And then within 20 minutes, I think you get 50% bond strength and 90% bond strength at 24 hours. And after three days, it's 100%. And they do have tutorials on how to remove it, but it's kind of not meant to be removable. Like once you glue it on, you're supposed to keep it on. Hot temperatures will make it bond better. Cold temperatures don't bond as well. But as long as you over-spect the hold strength you need for the cold temperatures, just make sure that you have enough tape to hold your thing on even if it gets down to like zero or negative 20 degrees C. Okay, so I mentioned that there's families. So there's more than one kind of VHB tape, which I did not realize. So some of them have different adhesives on one or the other side. Some of them have thicker or thinner foam. Your shear strength is not going to be as good if you have a thick foam because the thick foam itself is not going to have a lot. It's going to move back and forth. There are ones that are good for high temperature, low temperature, general purpose, different colors. They do have... I thought this graphic was really handy if it's in one of the design guides. They tell you based on the surface energy of one of your substrates, you know, basically like, will the glue be able to seep into the surface? That'll affect which kind of adhesive you want. But the 4950 is kind of the standard issue, kind of like everyone uses that. And then on the bottom, it has which materials. So if you're connecting, trying to attach something to silicone, right, which is very low surface energy, it's very hard to stick stuff to. Use the LSE family. You're probably going to have to pay more if you're using metal, especially metal or glass, that you can abrade lightly. The 4950 wand will do the good job. So... And then of course, Prima will help. It seems if you have these, especially silicone, I'm kind of surprised if you can stick anything to it. It's usually so inert. And they also have a more interactive selector at the 3M site. If you're just like Google 3M, VHV, it'll take you to the selector and you can tell it what you want and what sizes. And of course, you can get customized sizes and shapes if you need. So they come in reels normally and DigiKey stocks all the different reels. I'll say that sometimes there's an image of a reel, but the image is like it's a generic image. So look at the number. So for example, there's one, the top one is six inches by 18 yards. And the one below it is three quarters of an inch by 18 yards, but the image is the same. But obviously the six inch one is going to be like way thicker. So I weigh fatter at six inches wide. You're going to pay a little more for the wide ones too. You can also get sheets by the way that you can die cut. And they do mention that as one of the services that you can get. If you have an unusual shape and you want like curves and cutouts, you can buy it by the sheet, get it die cut. It's going to be more expensive than just strip, but you'll get perfect shaped outlines. VHV take available on DigiKey. We also have a video. Yes. DigiKey did this video and they say, do not try this at home. But every video I look because I was like, I want to find like a video about VHV tape. Every video is kind of the same. People just love sticking things you're not supposed to stick together and then doing a video. Like here's something that makes things stick. But by the way, never do this, but we have to demonstrate it anyways. So a lady just sent me this video and she's like, Oh, here, get these two clips. So from the beginning in the end and in the middle, they have how to use the VHV tape, but let's just get to the part. So I smooshed it together. I glued it together. The VHV tape. Hi and welcome to another geek moment. Today we'd like to feature 3M's VHV or very high bond dual sided adhesive products. We have a couple of demos set up to show you some of its attributes, but remember safety first. Now I'd like to show you just how easy it is to use VHV by assembling these two sheets of aluminum. First thing we need to do is clean both of them with a mixture of 50% isopropyl alcohol and 50% water, which can be found in most stores. Now that those are both prepped, we need to adhere our tape to both to this. We'll roll that pressure. Now our second chunk of VHV. We'll roll that out. Now I just take the backing off here. Now we'll put the top plate on. Roll pressure on both pieces of VHV under there. Now we're complete. After 20 minutes, this will be 50% adhered. After one day, it'll be 90%. After three days, 100% adhesive. As I mentioned, VHV is great at handling dynamic loads. We decided to test it under a static load condition as well. While filming this portion of the video, I've been suspended by the plates I assembled earlier. The VHV has been enough to suspend my 250 pounds of body weight. Next time you need adhesives in your product, think of 3M's VHV. Thanks for watching.