Small quantity dummy SMD components - Page 1
Forum section: electronics / general

author: JohnnyMalaria
author_rank: Super Contributor
timestamp: February 04, 2021, 09:52:21 pm
content: Hi,I'm looking for a supplier of small quantities (e.g, 10) of various types of SMD components including common IC packages so I can practice my hand soldering. I've seen kits that include boards but I don't need those since I plan to get JLCPCB to fabricate boards so I'll have some spare anyway.Any suggestions?Thanks,John.

author: thm_w
author_rank: Super Contributor
timestamp: February 04, 2021, 10:13:40 pm
content: www.lcsc.comjust order whatever parts you need.orhttps://www.aliexpress.com/item/32909277203.html

author: richnormand
author_rank: Unknown
timestamp: February 05, 2021, 07:21:00 pm
content: Since you are based in the USA you could try these folks:https://www.goldmine-elec-products.com/prodinfo.asp?number=G18955

author: phil from seattle
author_rank: Super Contributor
timestamp: February 05, 2021, 08:04:39 pm
content: I learned by building real projects. Soldering SMDs is actually really easy after you have done a couple. Seriously. "Dummy" parts are going to cost about the same as real ones (as long as you don't use super fine pitch parts or high end stuff), especially once you add in shipping costs. For what it's worth, when I first started out, I thought the same as you - need to practice. But I didn't. Just jumped in and was glad I did. My biggest regret was stocking up on 1206 parts because I thought it would be hard solder smaller. Pretty much right off the bat I was doing 805s with ease and I can easily do 603s and have managed 402s.Pick a small project with 10-20 components. Use SOICs, 805 Rs & Cs and maybe a few SOT-23 parts. After the first one or 2 parts, I bet you will agree that you didn't need practice boards. Maybe a simple 555 based flasher. Or an ATTiny based project (if micros are your cup of tea). There are hundreds of possibilities if you look back in the past couple of years of forum posts. The parts cost will be maybe $2-3. Maybe even less. The win here is that you will get satisfaction of making something that actually works.And by the way, I shop at Goldmine and similar places but they often are not cheaper than buying from a distributor like Mouser or Digikey.

author: tooki
author_rank: Super Contributor
timestamp: February 09, 2021, 07:27:06 pm
content: Quote from: richnormand on February 05, 2021, 07:21:00 pmCrikey that’s expensive for a few cents worth of random scrap components (not as in recovered from scrap boards, but the unused waste components that accrue in pick and place machines).I agree that in small amounts, it just makes more sense to buy real components in the case needed. OP, if you have a list of what case types you want to practice with, I can check what we have at work — we have tubs of components we use for practice. (I work at a vocational training center.) If it’s stuff we have, I could probably send you some for the cost of postage.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 09, 2021, 08:39:47 pm
content: With SMD resistors one often ends up buying them 100 pieces at a time anyway (it often hardly makes sense to get less, as one may pay a similar amount for 20) though one hardly needs them all, except maybe for a few very common values like 1 K or 10 K. The resistors are pretty cheap anyway and those that you likely will not need are even lower value.So probably start with a more simple project with not too expensive parts. 0805 size , SOT23 and normal SOIC are relatively easy. It may not look pretty the first time, but is probably still working.The resistors and caps are relatively robust - though reliability goes down when soldering needs very long.TSOP, MSOP, LQFP or 0402 size may need a little practice. The lower pin count ones help with a little faster success. So one could start with something like an OP is SOT23-5 or -6 for a little more difficulty.One can sometimes get cheap chips with odd functions, but even the good old LM358 is OK for practice.

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: February 09, 2021, 10:41:00 pm
content: One thing to mention as well:Get a decent used soldering iron, but more importantly one with an SMD well tip. Yes, you can solder SMD w/o an SMD tip, but it is much easier to use the SMD tip. Do some youtube videos on "drag soldering" as well. Dave actually has some nice vids on YT under microscope.That and flux. Lots of flux. Flux is your friend. You can never have too much flux. If your components permit it (and most do), get water wash flux/solder to make cleanup easier.Careful with water wash flux/solder: some is no-clean while some is must-clean. I typically use no-clean from Chip Quick. It isn't the cheapest, but I get good consistent results and very easy cleaning.Make sure you have some solder wick around as well, you will need it here and there to fix bridges.

author: NorthGuy
author_rank: Super Contributor
timestamp: February 10, 2021, 02:57:46 am
content: Try soldering 0.4mm pitch components. If you have old computers/cards, you can salvage lots of them. You don't even need to unsolder them at first - learn how to apply solder and how to remove unwanted bridges. Experiment with different tips, temperatures, angles etc. Then unsolder few with a hot air gun, clean and solder back in. You'll find out that it's not that bad really. After few sessions with these parts, SOICs will look really huge to you, and easy to deal with.Discretes are much harder to solder (but easy to buy in huge quantities for training). My hands are too shaky for 0402 - I can solder them somehow, but it will look ugly. It took me years until I could solder 0603 quickly and reliably. I don't solder that much though. If you solder more, you'll learn faster.