 This week's Ion MPI is Milmax. Yes. First off, this logo's great. It is really cool. What does Milmax do? Okay, I think this is our first Milmax product. So Milmax, they're known for their connectors. And so when this popped up, I was like, I know exactly what this is and what this is good for. This is the 3305 sockets for mechanical keyboards. That's what they're selling them as. And they look like this. And you're like, okay, it's like a little round yellow thing. How do you use that? Well, this is a kind of cool thing. So what you do is, it's a really nice rendered image. You can see on the left, there's a mechanical key that's about to plug into a PCB. And normally these mechanical keys are soldered into the circuit boards and that's how they are held in place with the two contacts. Well, this farewell, as you see, the three things on the bottom, what they do is they get slipped into what would normally be the through hole, the plated through hole in the circuit board that you would plug the mechanical key switch into. Instead, when these get soldered in, the switch becomes removable because there's little grippies. You see kind of in the middle there on the second switch, there's little grippies inside that will grab onto the rectangular tabs of the switch and hold them mechanically in place but still allow you to remove them. These are designed to be used with Cherry MX and compatible switches which you can also get at Digi-Key. What's really nice about Cherry MX compatible switches is they all have this kind of thing going on the bottom. You see there's like a big circular mechanical placement knob and then there's two rectangular pins and those pins are what are the switch. They're normally opened when the switch is pressed. They're closed. They're closed together in contact. This is the circuit board layout for Cherry MX switches and you can see there's LEDs and stuff but basically you've got the two pins, you've got the hole and if you have those, you can use these MX switches. These have been used for decades. These are very old switches. They've been used for a very, very long time and so traditionally when you get a keyboard or a macro pad or something that uses these Cherry MX switches, a control surface, they're soldered in. This is what it looks like on the bottom. This is like a Neo-Key trinket. This is one of the few boards we have where you would solder the key in directly and you see that center hole, again, where the switch goes through and the two pads where the mechanical switch is soldered into. This doesn't work great. People have been soldering in these switches into mechanical key slots for a very long time. I've got keyboards with Cherry MXes that, again, historically decades of use. However, there's now dozens and dozens of different types of Cherry MX compatible switches available and it could be that you have a circuit board that's designed for Cherry MX but you want to use Gaterons or Kales or Milks or Jades or whatever you want and it could be also that you want to be able to change out what switches you use because, for example, on my keyboard I have linear red keys but some people really want tactile browns or they want clicky blues. Well, what would you do? Well, if you were using a chip, you would use a socket like this, right? This is a dip socket. We've talked about these before. You solder these in and they mechanically go into the same holes that a dip switch or dip chip go into but what's nice is that then you can fairly easily remove the dip chip and you can easily replace it if it gets damaged or burnt out trying different chip or whatnot. So what do you do for Cherry MXes? Well, in the last few years there's been this invention of the Cherry MX socket and this is a Kale socket. Gateron also makes sockets that are compatible and these get soldered onto the bottom of a PCB and you can't use the same layout where it's a different layout for these because you have these big SMT pads as you can see the four sockets in the middle there but if you have a modified layout for these sockets then you can see the two holes you can plug in the Cherry MX into the holes and they're mechanically held in place. So again, you need to have a new layout. So this is like a layout showing there's no through holes, played through holes instead there's two SMT pads where the socket picking places on and then creates the two holes that the switch goes into. So if you're making a new design and you have the space using these pick and placeable Kale sockets is great for mechanical keyboards but like I said there are some cases where you have a board that already has it's already been designed you can't change the layout or you're reworking an existing board you want to change the switches out in that case that's where you would use these Milmax sockets because they're actually so thin that they can be put into the PCB that has already been designed with the standard Cherry MX through hole played through holes pads and this gets soldered in it's so skinny that it can go in and you still have enough clearance to let you plug in the socket sorry, the switch into the socket there's a lot of S's here so they come in different lengths they're open bottom so you know the switch even if you have switches with different lengths the pins are not like closed bottom where it can bottom out and you can see inside there's two little grippies there are a couple different grippies that will grip onto the rectangular tab of the switch so there's been previous versions of this I think 0305s and 7305s but these ones are a little bit better quality they're getting better at the top of the fairing is thinner they're plated they're really copper they're very good quality sockets they're quite nice they'll last a very long time they're good for any high end or just hobbyist desires for replaceable switch sockets another thing that I thought was kind of nice is although the ones I got came loose you can get these pick in placeable so you can pick and place them into your design and then with a little bit solder paste on the pads to have it be soldered in place automatically by your pick and place line or you can do it by hand either way so I thought I would you want to show the part number and then we'll show you over so it's on Digikey because IonMPI is brought to you by Digikey and you can go there there's a giant product ID you want to use a short URL or just search for Milmax330 easy to find and then you also have a video yes I have a great little demo that I can show so this is the NeoKey Trinky so again this is one of our only designs that you would solder in the switch and the reason you had to solder in the switch is because it's just so packed there literally wasn't enough space to put in a socket because the sockets are quite large this is what the sockets look like so you see they're quite big they wouldn't fit on the bottom of this PCB with all the other circuitry so for this you would solder it in now normally you would solder it and it would be permanently connected but with this one I have soldered in the Milmax3305 so you can barely see it but there's this very slight bump that's the top of the ferrule and then it goes through to the bottom and you can see here how it sticks out I just did it put a little bit of solder in and then it works very well then it's mechanically secure but then when you give it a yank it can come out and you can switch out your CherryMX switch now you're probably like, look Lady Eda I'm not obsessed with keyboards the way you are right now so what is this good for if I'm not into that this is good for anything right so even though I'm using this for CherryMX switches you can make custom sockets for Nixie tubes or specialized sensors that are not on a 0.1 inch grid or really anything that has you know through a whole parts but you don't want to solder in because it's expensive or because it gets damaged or because you want to try different versions what's nice about this is it doesn't stick up there's a very very very slight bump but you pretty much get to have it sit flat and again as long as the hole is I think 0.06 or 60mm it it goes in the hole but you can also solder into it so you can have like a mix and match design or you could have it be socketed or you can solder it directly but without that height change of the dip socket so I thought this is a very interesting and useful part not just for keyboards but for other mechanical uses where you want to swap out expensive sensors or components and Milmax made a video we're going to play it as a product design engineer you know that connectors play a critical role in the electrical system of any product you design it is not the place to take shortcuts a good connector can help avoid costly repairs and recalls down the road when you design your next product consider the Milmax receptacle first the quality and reliability of our two-piece construction delivers maximum performance and durability in every application including challenging or rugged environments our receptacles are precision machine for ultimate reliability of critical components across a wide variety of industries including aerospace, military, medical just about anywhere product failure is not an option the Milmax two-piece receptacle design allows for the widest mating pin acceptance range the largest variety of shapes, sizes and materials and multiple contact points to ensure a dependable connection every time pin receptacles are typically the backbone of any interconnect system so why settle for anything less than the maximum in performance, reliability and flexibility the predictable quality of a Milmax interconnect can play a fundamental role in determining our product's performance with almost 45 years of experience working with suppliers all over the world consider specifying Milmax receptacles into your design sooner rather than later and ensure the optimal solution for the unique requirements of your application this week's IonMPI thank you Milmax