Which SMD components to stock up on? - Page 1
Forum section: electronics / beginners

author: garymck
author_rank: Contributor
timestamp: May 07, 2017, 09:46:07 pm
content: Hi,After multiple trips to the local hobbyist store to by 1 resistor, 2 caps etc, I decided to stock up on bits and pieces. Spent under a $100 on evilbay and have mass quantities of resistors, caps, zeners, transistors, ic's etc on a slow boat from China. These are all through hole stuff.What would be the suggestions for stocking up on SMD stuff? Should I even do it? Can spare another $100 or so if it's worth it..Which series are most useful etc? Like the look of the sample book kits offered....Note, I am a beginner, building up the bits to create my home "lab", joining the local electronics/radio club and spending hours watching electronics relation tube videos....cheersGary

author: tautech
author_rank: Super Contributor
timestamp: May 07, 2017, 10:12:28 pm
content: Quote from: garymck on May 07, 2017, 09:46:07 pmLook for SMD folder/binders with lots of pages and pockets for cuttings of taped componentry. When I got mine it was cheaper to get the binder and the SMD assortments separately. 0805 is as small as you want to start with and assortments of 20ea of the common values of resistors and caps can be had for a few $ each.You won't really know which SMD IC's to start collecting, it all depends on your interest, logic, uC or whatever.IC tape is generally wider and won't fit the slots/pockets in the binders but some like SOT-23 and SMD diodes do.The SMD binder books can easily fit a resistor, cap and a good # of diode, LED's etc. selection.Sometimes it's cheaper to buy 100's of things like SMD 1N4148 and cut a lot of 20 off to have in your "working" binder and have the rest in some other storage.

author: jpanhalt
author_rank: Super Contributor
timestamp: May 07, 2017, 10:15:07 pm
content: Why would you expect what you "need" for SMD would be any different than for the TH counterparts?Moreover, SMD parts for the same function, e.g., a resistor, are often cheaper, particularly when purchased in sets.You may also want to get some SMD to TH miniature PCB converters so you can use SMD on your breadboard(s). SOICX (X=8) and SOT23-X (X=3,5,6) are probably the most common ones needed.John

author: KL27x
author_rank: Super Contributor
timestamp: May 07, 2017, 10:39:12 pm
content: A full reel of 0603 decoupling caps, haha. Why? Cuz it's $10.00 to by a reel. And you might use them someday. Beyond that, it depends on what is your specialization/interest. If you are using thru hole parts for prototyping, why would you stock any SMD parts? You might need them to verify footprint sensitive pcb circuitry... but in this case you probably are going to buy project-specific parts.

author: rstofer
author_rank: Super Contributor
timestamp: May 07, 2017, 11:02:53 pm
content: I have a bunch of SMD parts but I couldn't sort them out if I tried. Every time I use SMDs, it is because I just ordered a PCB and the parts will get here first. So, I order by the project with extras that I can never find. Except for that reel of 4000 0.1 ufd ceramic capacitors.Those binders sound like a good way to go. I may give them a try.As to SMD ICs, I usually buy one or two extras just in case but I don't try to 'stock' them.

author: garymck
author_rank: Contributor
timestamp: May 07, 2017, 11:45:05 pm
content: Quote from: jpanhalt on May 07, 2017, 10:15:07 pmhi John,I was referring to the size range - was not sure which was the most common - I may have misunderstood, but I thought there were different size packages of SMD's? Not referring to values.cheersgary

author: sokoloff
author_rank: Super Contributor
timestamp: May 07, 2017, 11:58:22 pm
content: There are indeed different sizes.For hand work, absolutely stay away from anything 0402 or smaller. (By the time you can do 0402, you'll know it. That might be never.) The only thing I'll sometimes use in 0402 are decoupling caps.Many people can do 0603 by hand; 0805 is more comfortable/easier. Start with an assortment or a practice PCB to learn your own personal skill level. (It depends partly on your equipment, but also your hand steadiness and patience.)Something like:https://www.aliexpress.com/item/5-sets-Electronic-2014-New-DIY-Kit-SMT-SMD-Component-Welding-Practice-Board-65-53mm/1920705186.html?If you absolutely can't wait to stock up, I'd start with 0805, but it would be better to know your own ability level.

author: rdl
author_rank: Super Contributor
timestamp: May 08, 2017, 12:00:26 am
content: Unless you're planning to mass produce something, just buy the biggest you can find and don't duplicate anything you already have in through hole. That's my plan anyway.

author: KL27x
author_rank: Super Contributor
timestamp: May 08, 2017, 04:30:24 am
content: There's no reason to stock smd parts, unless you are designing pcb, other than perhaps caps and common resistors for use on protoboard.The reason 0402 is a pain is because they will stick to your tweezers no matter what you do. The 0603 and larger are manageable. Note that we're talking about imperial measurements. You can buy them in same size, metric, and they are much smaller.Ceramic caps are a little heavier, plus you can get lower ESR for cheaper by going smaller. So you might consider going smaller on those.

author: jpanhalt
author_rank: Super Contributor
timestamp: May 08, 2017, 05:23:12 am
content: Hi Gary,I started with 1206/1210 and quickly went to 805 for many things. But then, I only hand solder and am in my 70's. The old hands just are not as steady as when you are younger.I still use 1206's for prototyping as they have the nice property of being about the right size to solder on various protoboads/stripboards that are cut or drilled 0.1" on center.805's are reserved for when I am working on an etched PCB.John

author: garymck
author_rank: Contributor
timestamp: May 08, 2017, 10:40:32 am
content: Thanks guys, for taking the time to offer suggestions. I think I may put off getting the smd's until I have a bit more experience, and even the start with the larger varieties as I build up my soldering skills. It's very hard to know exactly what to get when one is starting out, but at least component s are really cheap so mistaken purchases don't blow the budget!cheersGary

author: lapm
author_rank: Frequent Contributor
timestamp: May 09, 2017, 05:32:45 am
content: Personally i stock up only components i usually use lots of. Such as certain bypass capasitors, certain resistor values, etc..

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: May 09, 2017, 05:49:37 am
content: As others have said, SMD is really quite cheap, so you can get one of the binders to get started. I personally don't get SMD unless I need it. I usually use TH for prototyping (if possible). If I go to PCB I go for SMD components.An exception to this is if you do a lot of repair work - getting some resistor/capacitor binders can be usefull.Unless space is an issue, 1206 can be nice in the begging. I default to 0805, 0402 for RF/high density. I do however tend to stock up by default, because most places I order from have minimum order quantities of 10-20 resistors. I'm still working on how to sort them tho - but I do try to write the value on the tape of capacitors (resistors sizes 0805 and up generally have the value printed on them).Of course, all this might change if you don't have access to a distributor like Farnell, RS, ... and you need to get your parts through Amazon bundels or something.

author: cowana
author_rank: Frequent Contributor
timestamp: May 09, 2017, 01:59:55 pm
content: Quote from: evb149 on May 08, 2017, 12:34:24 amThat's a good list. Most of these jellybean components (NPN/PNP transistors, small MOSFETs, signal diodes etc) are amazingly cheap (<£0.50) when purchases in 100x quantities from Aliexpress - well worth keeping a bunch around to incorporate into designs.