 Thank you for coming. This talk is about how to design your board so that it is manufacturable so that the companies that you will find in Shenzhen in the Futian district, according to the advice in Bunny Huang's Guide to Shenzhen, will actually be manufacturable. So I apologize if you can't hear, I was thinking, but I do need, I will need to go back to the laptop to show you what's on the screen. So we just have to bear with me on this, okay? All right? So your nightmare scenario is one which actually happened, this is a real world scenario that regularly happens with the factory that I know in Shenzhen. Mike tells me that he receives PCBs with a bill of materials from companies in the United States and the United and the rest of Europe, which have been exclusively designed using AVNet, RS Online, Farnel and Digikey, and they expect him automatically to be able to beat the pricing for the components by a factor of four to five to ten. Okay? All right? It turns out though that the parts that the people ordered were last manufactured in China ten years ago. For a project, which was some very large thing that there were a million made ten years ago, Digikey was the main buyer of those parts because they were very commonly available. They ordered 100,000 to keep stock to supply the repair centers, etc. You get the idea. Then that product went end of life and to make space in the factory in China, the company destroyed the tooling. You know what's going to happen in going to come next, okay? So basically that part is no longer manufactured and the only place in the world from which that part may be obtained is the warehouse in Digikey somewhere in Phoenix, Arizona. So in order to fulfill the order that Mike has done, he has to go back to that has been received. He has to go back to the factory, the owner, and say, I'm very sorry. The only place I can fulfill your order with is to order these parts, oh, which were from China shipped to the US, get them imported back into China with a six to eight week delay and customs duty of 30 to 40%. On top of the fact that the parts were made in China for one dollar, by the time they got to China there were two dollars for the shipping cost, plus import duty, plus warehouse storage fees, plus things so it's that one dollar was now ten dollars for a one dollar component. It's now going to come back into China with a 30% import jack. Now it's $13. Yeah, for a one dollar part. You do not want to do this. Okay. All right. So what I'm going to do I think is I'm going to give you some advice on how to source the components and check that they are available. Okay. All right. So your two friends, can you hear me over there? Brilliant. Your two friends are AliExpress.com and Taobao.com. All right. Do not buy from these people unless you are in China and you are a or you are a Chinese citizen. Okay. If you really, really want to buy from AliTaoBao.com, you should go to EngTaoBao.com. All right. This guy is a Chinese national. By law, if he is ripped off by a Chinese citizen, he is entitled to take them to court. You are not. Okay. So you pay 5% extra, but you can give that that you can give the guys some money to beat them over the head to get your money back. Okay. All right. They don't listen to foreigners, but I am assuming that you are all aware that there are fake suppliers on these sites who sell, even to Chinese national citizens, they will sell, the famous one was the people put concrete in milk powder cartons. Okay. So it happens, you know, you get 100 microfarad capacitors in 10 microfarad capacitors in 100 microfarad case and three and a half inch ID drives turn out to have a two inch ID and three and a half inch SATA drives turn out to be a two and a half inch ID drive with an ID to SATA converter in it. Okay. So I must I'm that he's out of scope for this talk. Okay. All right. Just bear that in mind. So EngTaoBao is your is your friend. If you are abroad and you actually want to buy the components. Okay. Bear in mind, it's the Chinese equivalent of eBay. You get what you buy. So you're not actually buying, but what you are doing is you are checking the availability of the part. Okay. Your most important thing is when you want to find whatever it is, you first go to dig a key or whatever. Okay. Now I searched here. Some people paying attention will have noticed I searched for the SN 75 LVDS 83B, which is a Texas Instruments part, which also was cloned under the name NT 71 in China. They're identical. All right. Surprise. And on here, you get the original masks. Yeah. And they were the original masks. So on dig a key, you get access to the data sheet on the Chinese equivalent of eBay. Don't even think about asking them for the data sheet. Okay. All right. But you don't even want to buy the part. You just checking the quantities of suppliers that have it available. If you've ever been to Fujian district, one of the places that the ground floor is football pitch sized and it is five stories high. Okay. There are 5000 suppliers of parts in the one building. Okay. So you want to check quantity rather than quality. And so having done your search on here for SN 75 LVDS and got the data sheet and designed everything. Before you commit to that, you go to the Taobao website and search for exactly the same part. And you check, if I can get this over, how many pages of stuff there are. Look, there's loads of suppliers. They're all different. They're not identical photographs. Okay. You can tell all the names of the people selling a different. You can get a rough idea of the price from the thing. Discard the low ones, discard the high ones, roughly in the middle of somewhere. But if you want absolute guarantees of pricing quotes, you use your Ha Chua Chang Road, your factory in Shenzhen. Okay. All right. And this is very important. This bit is that there are five pages and more of the same part. So you know that there are massive numbers of suppliers and you can, it's not totally guaranteed. You can pretty much guarantee that this part will be available when you go to the Shenzhen markets. Okay. This is the bit of information that is missing from Bunny's extremely otherwise very, very good book. Okay. Bunny has assumed that you know how to order these parts and which ones to get. Yeah. Okay. And he helps you to find the ones and distinguish between the parts that are prime quality and the ones that are secondhand recycled, et cetera, et cetera, and the dodgy guys. All right. So, but it's this information of what I'm giving you here is completely missing. So step one, look on Digikey. Find the data sheet. Check that it is for, it suits your needs. Step two, before you design the PCB and the schematic with the part, check the availability using either AliExpress or Taobao to check the quantity of suppliers and the diversity of suppliers. Okay. And if it's not available, don't use it. I'm really serious. Do not use that part. Find an equivalent circuit that uses an alternative part. Okay. The other more popular one, there is, it's very common, for example, for people to use a Texas Instruments or a USA designed current limiter chip for USB power. Okay. In certain circumstances, you can't use the power of the USB hub. You have to do the power check, the current limiting yourself. Now, in some cases, like the Sylergy Sy6280, you will not find the data sheet online. And the only way to find out about this chip is to find somebody else's schematic, which has this in. So there is, it's a bit of hidden miss. Some stuff you will find on Digikey or Finale, et cetera, really easily. Some of it, you will just have to find somebody who knows, who has specialists in this area knows their parts. Okay. All right. So copies of this data sheet are now being distributed over the thing. Thank you very much for marking this as time. There is one last thing, which is very, very important. LCDs. If you are sourcing LCDs, use this website, panellook.com. It overwhelmed all of the other websites that were court sourcing. You don't buy from there. You put the information about in the brand, blah, blah, resolution, et cetera. Make sure that you put the available, that it is available rather than discontinued. And just search for it. And you're looking for quantities, multiple suppliers, again, of 30,000, 50,000, 100,000, from multiple suppliers. That's basically it. Thank you very much. Yes, gentleman here. Why do I not buy from Aliexpress or Taobao only? The reason is because those suppliers, they're eBay. They may not supply directly. They may rip me off. So I have a trusted factory owner whom I have a good relationship with. I have met him. I know he exists. And he even takes credit. He even gives credit. I'm not going to give you his name because I don't want people to take advantage of him. But if you really need an introduction and you're serious, I can walk you through the process. Can't find my email address on Yoma68 or rhombustech or lkcl.net. You can find me and contact me and I will walk you through the process and introduce you to him. Okay. I think in case you're only needing a few single components, then it's totally different story. Absolutely. Right. Very good. Very good point. If you're buying only like 10 or 20 components rather than 1000, then it's okay to use Aliexpress. I would strongly recommend that you try and inch Taobao because they buy it and they don't check it but they buy it and make sure it goes on. It's a risk. It's a hidden risk risk. If you can find somebody who is prepared to buy a thing, it is a pain in the neck. I cannot even get quantity 20 samples within a few days because it's not worth their time or money to do it. So what Mike does for me is he has a big order of 50,000 and he says, oh, and incidentally could you look for this 20 for me? Okay. Then he knows that he's doing them a favor by getting lots of money. So it's very, very different. That's why Bunny suggests going over there personally. For dissolving this problem of I just want 20 components, you really need somebody to go round the markets personally who has the time or do it personally yourself and that's where Bunny's book takes over from this talk.