Ramping up through hole board production - Page 1
Forum section: electronics / general

author: Szewczykm
author_rank: Regular Contributor
timestamp: November 05, 2012, 09:37:05 pm
content: I have a board that I'm making in small quantities. It's a roughly 3" x 4" board with through hole components on it that I assemble and solder by hand. Does anyone have any advice about small dip soldering tanks for the workshop?I've had a hard time finding anything in the small range. I either find something that's really meant for wire tinning or a $100,000 machine. Does anyone have experience with this they can share?Thanks!Mike

author: Simon
author_rank: Unknown
timestamp: November 05, 2012, 09:38:37 pm
content: Do you really need one ? if you want to save on labor you could consider using SMD parts that don't need holes drilling in the board.

author: george graves
author_rank: Super Contributor
timestamp: November 05, 2012, 09:48:39 pm
content: Is there a specific reason you can't convert to SMD?I've been in the same boat for a while now, and an in the process of switching over to SMD. That's really the only thing that can speed things up. You can hand place a smd much faster then you can insert a TH, bend the leads, flip the board over, solder, and trim the leads. You'll spend more time getting set up - but you'll gain that back with really fast assembly times.

author: Szewczykm
author_rank: Regular Contributor
timestamp: November 05, 2012, 09:49:22 pm
content: I forgot to add that. I understand that I can switch to SMD and maybe bake the boards in a toaster oven like I've seen. But there are over 30 through hole solder points that I can't make SMD, they are for screw terminals and other on board connectors. I'd like to see if there's a small scale dipping product available out there.

author: Simon
author_rank: Unknown
timestamp: November 05, 2012, 09:51:44 pm
content: drilling large holes is probably faster than all of those 0.5, 0.7 and 1mm holes and constantly changing drill bits, unless of course you subbing out the boards. But at least SMD saves you from having to keep flipping the board over and cuts board costs.

author: Szewczykm
author_rank: Regular Contributor
timestamp: November 05, 2012, 09:57:09 pm
content: The boards were subbed out. No drilling.I'm placing through hole parts, bending the leads to hold them in place, snipping them, then soldering them by hand. I'm not sure if there's any way to save time with placing the parts in the board and snipping the leads, but I've seen processes where you spray or dip the board in flux then dip it in solder to make a hundred nice solder joints in a few seconds. But most of the stuff I've found is for high volume robotic dipping stuff.

author: Simon
author_rank: Unknown
timestamp: November 05, 2012, 09:59:33 pm
content: all you need is a container of molten solder, find a shallow container you can heat, fill it with solder, heat it up and then dip the board holding it with pliers, works for the Chinese making PC power supplies for 5 bucks

author: Szewczykm
author_rank: Regular Contributor
timestamp: November 05, 2012, 10:04:11 pm
content: Quote from: Simon on November 05, 2012, 09:59:33 pmWell, I don't have any Chinese workers at my disposal, so I'd prefer to find a commercial device.

author: george graves
author_rank: Super Contributor
timestamp: November 05, 2012, 10:10:04 pm
content: I've never seen anyone that does DIY wave soldering - or "board dipping" - but DX has a few soldering pots, I guess you could try.http://dx.com/p/300w-temperature-controlled-soldering-pot-blue-golden-220v-48764?item=2

author: george graves
author_rank: Super Contributor
timestamp: November 05, 2012, 10:12:22 pm
content: Here's some good info on a DIY wave soldering set up:Quotehttp://www.electro-tech-online.com/electronic-projects-design-ideas-reviews/110619-diy-wave-solder-possible.htmlAnd there is this guy. Looks totally impracticable - apparently he built it to desolder components.:http://www.damir-pavkovic.iz.hr/index.php?option=com_content&view=article&id=30&Itemid=37

author: Szewczykm
author_rank: Regular Contributor
timestamp: November 05, 2012, 10:30:22 pm
content: I did find this:http://www.esicotriton.com/pots/If you look down the page some you'll see the Model 75T and the 80T. The 75T would suit my current needs at $300 or so, but the 80T might be best at about $800 to make sure it fits whatever board size I might deal with in the future.I'm wondering if anyone has experience with these.

author: george graves
author_rank: Super Contributor
timestamp: November 05, 2012, 10:36:01 pm
content: Besides them being temp controlled, I wonder if you when out and got one of those dorm room single style burners, a old pot, and a bunch of solder, and give it a go.Have fun stuffing a whole board at once and keeping everything in place. I don't mean to be negative - just I can't see how this would work - but if would be cool if it did.You might do something like this on your terminal blocks to help them stay in place.http://www.sparkfun.com/tutorials/114Anyways, I'll shut up and let others chime in.

author: David_AVD
author_rank: Super Contributor
timestamp: November 05, 2012, 10:40:15 pm
content: How many boards do you want to make at once? I'd say hand soldering would be more reliable than any DIY (or el-cheapo) solder bath.

author: Szewczykm
author_rank: Regular Contributor
timestamp: November 05, 2012, 10:52:41 pm
content: One board at a time. I have also turned these products up:http://www.wenesco.com/static.htmWhen I'm done placing my parts, I can flip the board over without a problem. Holding things in place hasn't been a big problem. Also, I would probably build a jig to hold the board up off the table for placing thing parts where I'm not bending leads.

author: EEVblog
author_rank: Unknown
timestamp: November 06, 2012, 12:44:35 am
content: Have you priced getting an assembly house to do it?They will either do it by hand or machine or selective wave solder.Even here in Australia I'm only paying $0.35/minute for hand solder/assembly work.Dave.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 06, 2012, 01:02:09 am
content: FYI the way they do TH boards in moderate volume is to hand or machine place parts, with the PCB panel sitting on steel plate which has the same hole pattern as the PCB. The PCB+Plate is then put on a machine which runs a blade over the plate surface to crop the leads the same length (the thickness of the plate).It then goes through a wave soldering machine.Sometimes shrink-wrap is used to hold parts in place during handling and soldering.

author: Szewczykm
author_rank: Regular Contributor
timestamp: November 06, 2012, 01:50:27 am
content: I've tried three different places. One place wanted $45 per board to assemble. I can assemble 3 boards an hour at this point, I can't justify that huge cost.One place didn't call me back and anoth said that my volumes were too low to be of interest to them. So... I figured I'd become my own assembly house and employ friends and relatives and do it cheaper.So, if there's a place I can go, that information would be appreciated also.I can easily picture the way the shear off the leads, that's pretty cool. Shrink wrap is interesting but I'm having a hard time picturing it unless the plastic ends up moving through the pool of solder too.

author: mariush
author_rank: Super Contributor
timestamp: November 06, 2012, 02:08:19 am
content: I saw a youtube video just yesterday, it was actually in a thread here on the forum :???4Check at around 1:00, see how they put the board over flux and then just move the board and flex the sides a bit over the solder.Otherwise, I nice method of speeding up the process would be to skip the bending of the leads, which also makes it harder (in the sense of taking longer time) to cut the leads after the components are soldered.I guess you could get some foam style material and cut holes in it to match the height of the components you use. Put the PCB on some supports (so that the component leads will have room under the pcb) , put all components on the board, put the foam shape over so that components will not fall out when the pcb gets rotated, turn the pcb on the other side (the foam will keep the parts in place) and solder each leg of the components... then cut all the legs to size.You could probably get some pliers that form the leads of components to a specific shape, therefore you'd be sure all parts would be at the same distance away from the board, making the shape easier to make.You could probably make the shape out of some lego pieces.Or even some cardboard springs to mind. Just grab a few cardboard pieces, use a blade to cut rectangles or squares into as many as needed (picture them stacked one on top of the other)See this instructable below, or the article about autodesk, just picture the 3d model being a block of material with holes where the components would be, a sort of a negative of the area above the pcb.. :http://www.instructables.com/id/Model-complex-solid-shapes-with-cardboard/#step1http://autodesk.blogs.com/between_the_lines/2012/05/autodesk-123d-make-available-make-3d-models-real.html

author: EEVblog
author_rank: Unknown
timestamp: November 06, 2012, 02:45:09 am
content: Quote from: Szewczykm on November 06, 2012, 01:50:27 amWe need to know where you are based, country and city...Dave.

author: Szewczykm
author_rank: Regular Contributor
timestamp: November 06, 2012, 02:53:52 am
content: US. 50 miles northwest of Chicago.

author: David_AVD
author_rank: Super Contributor
timestamp: November 06, 2012, 06:11:30 am
content: Quote from: EEVblog on November 06, 2012, 12:44:35 amThat's very cheap. We charge a lot more than that. At that price $21 / hr price point, I guess that the assemblers are not skilled in electronics as such (apart from soldering)?

author: Bored@Work
author_rank: Super Contributor
timestamp: November 06, 2012, 06:56:51 am
content: For hand soldering you could use a jig likehttp://www.newark.com/ideal-tek/pcsa-2/pcb-assembly-jig-esd/dp/40K2016Put as many PCBs between the bars as possible. Place all components, then close the lid. Foam in the lid keeps the components in place. Swing around. Cut the leads. It is easier to cut the leads now before soldering, especially if you use a flush cutter or similar which you have rigged to keep a certain distance from the PCBs. It also somewhat reduces the risk of cracked solder joints. After cutting, hand solder all components.For bending the leads of axial components you could use a hand operated bending and cutting machine likehttp://www.cutbend.com/html/english/frame_e.htmto save some time.

author: EEVblog
author_rank: Unknown
timestamp: November 06, 2012, 07:34:34 am
content: Quote from: David_AVD on November 06, 2012, 06:11:30 amThat's why they are called assemblers!You generally don't have TO's or engineers assembling boardsAlthough the caveat is that that price is part of my assembly package, so some of it may be subsided by other work, I don't know, but that's what the itemised quote showed.Dave.

author: mariush
author_rank: Super Contributor
timestamp: November 06, 2012, 07:41:34 am
content: @BoredAtWork: Looks like what I was describing a few posts above.. But man, 400$ for that.... if you're handy with some screws and some pieces of wood, there's no reason you shouldn't be able to build that yourself.As for bending leads, the machines are also kind of expensive, maybe too much for a few boards. Not to mention it takes 10-20 minutes to prepare them for desired width and all that and then you really need to form hundreds at a time to be worth it, otherwise you're better off with those plastic bands :http://evilmadscience.com/productsmenu/partsmenu/68-benderIf you want something simpler to do more complex shapes on the leads, something I've had my eye on fpr some time are the tools from Piergiacomi :http://www.piergiacomi.com/piergiacomi/en/products/hand-tools.html?ja_color=defaultSee the Special Tools section at the bottom.I've seen them sold at various stores, at reasonable prices, like 10 euro for one tool, for example here:http://www.renex.ro/pokaz_kategorie.php?cid=331http://www.olamefusa.com/e_forming_handtools.htm(this page has probably the whole collection with nice pictures showing the way the leads are bent)Hakko also used to have some of these tools, but I think they were OEM tools from some company and I couldn't find them anywhere at the well known online stores.

author: David_AVD
author_rank: Super Contributor
timestamp: November 06, 2012, 09:33:37 am
content: $45 a board sounds too much to be paying when you can do 3 boards an hour yourself.Maybe there's ways to reduce the build time. The layout of the board can influence this too. Resistors in rows, same values next to each other (where possible), component values on the silk screened all make a difference.We bought a axial bender/cutter machine years ago and it's paid for itself many times over. You can process 1000 resistors in about a minute. Imagine the RSI you'd get using a hand tool!Loading the boards into frames (flip over type with a clip on foam cover) also improves production speed. A good frame takes hardly any time at all to configure for a batch of boards as they have sliding rails and knurled nuts.Using the right type of solder and soldering iron can make a massive difference to the speed of hand soldering too.

author: EEVblog
author_rank: Unknown
timestamp: November 06, 2012, 10:38:26 am
content: Quote from: David_AVD on November 06, 2012, 09:33:37 amI agree.Have you quizzed them on why they think it takes over an hour per board (even at very high $45/hour?)They do tend to overestimate things at first, and often come down in price once they have actually timed it themselves and know the numbers.Dave.

author: Simon
author_rank: Unknown
timestamp: November 06, 2012, 11:25:32 am
content: Quote from: EEVblog on November 06, 2012, 10:38:26 amQuite, they know there is a sucker born every minute, guess why i decided to go self employed. Why work by the hour when I can charge as much as per hour per board and still be reasonable.

author: Szewczykm
author_rank: Regular Contributor
timestamp: November 06, 2012, 03:58:44 pm
content: Thanks, there have been some great suggestions on this thread.I did ask them what was driving the cost so high. I'm not regarded as an abrasive person and I thought the way I asked was nice, but after I asked what was driving the cost of $45 per board, they never followed up. I guess anything less wasn't worth their time, I don't know." But man, 400$ for that.... if you're handy with some screws and some pieces of wood, there's no reason you shouldn't be able to build that yourself."Yea, maybe. I don't have any containers laying around that would work efficiently and I don't know what I'd use as a heating element. I appreciate the go getter do it yourself thing, I have a hard time paying anyone to do something I could do myself, but in this case I think I'd be spending a lot of time that I don't have to make something that would probably inferior to the commercial product, which I think I can afford.I have done some things like laying the resistors out near each other. Actually I've replaced 3 rows of resistors with a bussed resistor network to simplify things.I feel I'm really at the point where I want to make placing, trimming, and soldering more efficient. All of the parts are bent and ready to go, placed in bins along the table in assembly line fashion. I'm not sure how to make that more efficient without somehow going robotic. So the next places for improvement are lead trimming and soldering."Otherwise, I nice method of speeding up the process would be to skip the bending of the leads, which also makes it harder (in the sense of taking longer time) to cut the leads after the components are soldered."I did try this, but I found navigating the forest of leads trying to solder around them before trimming them took me longer than trimming then soldering.While you may not be able to offer up a specific builder, maybe some keys for seeking them out would be helpful. If you have someone you work with for short runs, 50 - 100 boards, how did you find them? I think the problem I'm running into is that big outfits are, well, big. They're easy to find but they're not altogether interested in my small project. Small guys who are interested in helping are.. small.. harder to find.

author: Szewczykm
author_rank: Regular Contributor
timestamp: November 06, 2012, 04:22:54 pm
content: And those Piergiacomi tools are very cool. I'm looking into getting a few of those now. I love the cut/bend all in one idea.Thanks!

author: EEVblog
author_rank: Unknown
timestamp: November 06, 2012, 09:45:14 pm
content: Quote from: Szewczykm on November 06, 2012, 03:58:44 pmI used to have my uWatches and uCurrent hand assembled in batches of 50-100 by a local guy who works in his garage.He just charged based on time, and was happy to do one or a hundred boards, SMD or through-hole.I'd simply keep looking and asking around.Your time should not be spent assembling boards IMO, that's just a too generic a task to waste time doing yourself.Things like testing and tweaking etc may be different.Dave.

author: jeroen74
author_rank: Frequent Contributor
timestamp: November 06, 2012, 10:02:16 pm
content: QuoteMaybe a deep fryer would work? Possibly modded to get higher temps?

author: ampdoctor
author_rank: Frequent Contributor
timestamp: November 07, 2012, 01:27:12 am
content: I've found that often times when you get silly numbers it's a subtle way of them saying they don't want the job. If you bite and accept the offer it's a cash cow for them.Hell, I'd charge you 45/hr as many boards as I can stuff, unless there's something really quirky going on. btw, I'm 120 miles north west of Chicago so if you want to drop me a pvt message feel free.

author: Smokey
author_rank: Super Contributor
timestamp: November 26, 2012, 07:56:05 am
content: There are a few things that would give us a better idea of how much it should cost to stuff your boards:Maybe I just missed it, but did you say what actual quantities you are looking to build? Also how many components per board total and how many unique component values/types? Any requirements like ROHS? Do you need the boards washed or can you live with solder residue? Do you have adequate assembly documentation (BOMS, Drawings, Specific instructions, fully assembled example)? Is the silkscreen clear and organized as far as where all the parts go?It does kind of sound like you might have got a "no bid" by way of silly quote. Running small quantities of through hole boards can be a pain since someone (or many) has to be trained to do your specific boards based on your documentation. It's not as easy as programming the pick and place. Kind of like human setup time that makes small runs expensive, especially if the documentation isn't all there the way the assembly house is used to.

author: daedalus
author_rank: Regular Contributor
timestamp: March 05, 2013, 09:43:46 am
content: Hi, I still think you would be better off looking at an smt redesign. If you post a pic of the pcb maybe we can suggest suitable smt connectors. You can get smt screw terminals rated up to 24A.