SMD Assembly Box - Seeking advice from SMD assemblers - Page 1
Forum section: electronics / projects

author: UncleSam
author_rank: Newbie
timestamp: June 19, 2014, 06:40:01 pm
content: I have become adventurous enough to work with SMD parts again.YAY!I am ready to build my first Minty Boost kit. This charge controller is made of SMD components.I don't have reserve components. Therefore, I decided to make an assembly box. The top of the box is a glass pane 16 x 20 in. The purpose of the box is to prevent SMD components from disappearing as I solder them onto a PCB, one at a time, and they pop loose from the restraining tool. The box will have a white interior.I am putting three holes into the sides of the box. One is for a 6 in. diameter duct to suck the solder fumes outdoors. The other two holes are so I can put my arms into the box. My arms measure 18 in. from wrist to elbow. Obviously, I must make the box tall enough to fit hold-down devices underneath the glass pane.I might put a fourth hole in the box to run in the soldering iron cord. II plan to let the solder station outside the box.I have two questions to start:1. Which do you think would be more comfortable 16" side-to-side or 20" side-to-side, literally, as I face the glass-topped box?2. I plan to put high-power LEDs inside the box to illuminate its interior. Obviously they will all point down. Do you have another reccomendation for orienting the LEDs? or for any other user considerations? If this is a bad idea, say so.If you have learned anything else that I should take into consideration making this box, please let me know. Thank you. No sense in repeating a mistake that somebody else made.

author: SirNick
author_rank: Frequent Contributor
timestamp: June 19, 2014, 07:01:07 pm
content: Sounds like a cool idea, and like your ideas are on the right track. However... after using paste and a hot air rework station to solder a few SMD parts to a board, I'm not entirely sure why people still use an iron.If you're willing to hack a toaster oven, even better. Then the iron is just for through-hole parts and the occasional touch-up or two.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 19, 2014, 11:09:58 pm
content: Anything like this will just get in the way and be a total pain. You'll probably end up losing more.SMD parts are cheap - get spares.

author: calexanian
author_rank: Super Contributor
timestamp: June 20, 2014, 02:08:52 am
content: when making a small run of some boards (Typically 10 or so, i did 12 today) I have lately become a fan of masking tape and making a little areas on the bench for all the various parts and counting out exact numbers of each. The BOM of our products is not particularly long. It makes it nice for keeping track. For example I am less likely to forget to place a part if one is leftover. Also i find the anti static mat tends to keep parts from going too far if the flick out of the tweezers or something. Just a bare desk, or a pane of glass would be like a skating rink.

author: poorchava
author_rank: Super Contributor
timestamp: June 20, 2014, 06:12:59 am
content: From time to time I'm doing small hand assembly jobs, up to 20 boards or something. I've found out that what works the best for me is a small metal lid from a jar, shoepaste or something similar. I just tap the metal lid so that the components flip over.I have tried gluing cut tape onto my workbench with double-sided tape, but it works ok only if you have components in one orientation only.As soon as you have to pick up a component from a tape and turn it 90 degrees, it becomes cumbersome.

author: UncleSam
author_rank: Newbie
timestamp: June 22, 2014, 04:12:59 pm
content: Thank you, all, for your comments. Yes, I watched the video.Will definitely get some solder paste..

author: UncleSam
author_rank: Newbie
timestamp: June 25, 2014, 02:43:00 pm
content: What kind of fan should I use to suck the air out through a 4- inch diameter hose that is 6 feet long, to the window? AC or DC? Is an AC fan too noisy? How many cubic feet per minute?

author: jmole
author_rank: Regular Contributor
timestamp: June 28, 2014, 12:33:41 am
content: As far as parts organization goes, I've found this to be super useful:http://www.amazon.com/AideTek-BOX-ALL-Enclosures-Capacitor-Organizer/dp/B00A15YHJY/ref=sr_1_1?s=hi&ie=UTF8&qid=1403915543&sr=1-1&keywords=boxall

author: UncleSam
author_rank: Newbie
timestamp: July 10, 2014, 03:59:49 pm
content: Just saw Ben Heck's SMT tutorial video here:This looks more practical than my way.Instead of a box, all I'll need would be a toaster oven, dust masks, and solder paste in a syringe/tube. And a loupe, which I'll need for either method.Thanks for your recommendation on plastic boxes, jmole.

author: Kjelt
author_rank: Super Contributor
timestamp: July 10, 2014, 06:10:28 pm
content: yeah if you assemble one board a week or so that is doable. If you need more and as I did last month do three boards simultaneously it can get messy (touching the solderpaste on board 3 with your hand while assembling board 1 or 2). There are a lot of manual DIY pick and place machines where you slide the boards horizontally and your hand vertically over the boards, things likethis onewhich is much too expensive but can be build for not too much money by yourself if you google around. But for first starts do as everyone before you by hand without help. However instead of using the tweezers buy a vacuum pincet for a couple of tenners

author: zapta
author_rank: Super Contributor
timestamp: July 10, 2014, 10:08:26 pm
content: Quote from: Kjelt on July 10, 2014, 06:10:28 pmI had very poor experience with those manual vacuum pens (including a fancy one from Digikey, don't recall the model). What does work well for me is a small vaccume pump connected to syringe with flexible tube. I also added an electric vacuum valve from ebay and an activation pedal to have more stable part release but this is not necessary.

author: SirNick
author_rank: Frequent Contributor
timestamp: July 10, 2014, 10:34:20 pm
content: Throw some pics at us, Zapta.

author: Kjelt
author_rank: Super Contributor
timestamp: July 11, 2014, 07:19:00 am
content: Quote from: zapta on July 10, 2014, 10:08:26 pmIndeed that is garbage and not what I meant. Those are a few $ and crap. I mean a kind of aquarium vacuumpump with a flexible tube and turning pincet like the Conrad 189200 see pic below.A DIY syringe with hotglue tube connected also works pretty well but there the tube does not unwind (turn) so now and then you have to untangle it.I myself build a small vacuum project: a good vacuumpump sucking a few litres vacuum barrel to -0.9 bar (restart vacuumpump at -0.6 bar with vacuumswitch) and the barrel is connected to footpedal controlled valves, one for the vacuumpincet/pipet the other one for my desoldering iron. The advantage is working without noise unless the vacuum is too low and the pump activates again.