Who has a selective solder machine? - Page 1
Forum section: electronics / general

author: forrestc
author_rank: Unknown
timestamp: November 08, 2019, 08:34:45 am
content: I've about had it trying to get this soldering robot to work with any consistency, not to mention the fixturing challenges in a lowish-volume medium-mix environment. And I'm at the stage I either need to do something or hire another employee just to solder connector pins (our boards have lots and lots of pins, some having around 300 pins due to the high number of RJ45 and other connectors).So I'm thinking about a selective soldering machine again....I suspect there are at least some of you who have (or have worked with) a selective solder machine out there. If so, I'm curious to hear random feedback about the experience, brands, problems, expectations, realities, and so on....Quite a while ago (before we switched to SMD), we were using a wave solder machine. When we switched to SMD for everything but the connectors, we found that the wave was taking more time when you factored in the care and feeding of the wave. Plus, due to it having a foam fluxer, the flux tended to wick up the connector pins and into the connectors themselves causing flux residue issues. Once we figured out that we could hand solder and end up with a better result with a similar amount of time spent per board, we switched to hand soldering connectors. Plus the old machine having a tin-lead pot sort of put the nail in the coffin there. I really only mention this to provide some context about our experiences here.Sorry, I don't have any more specifics about what information that I'm looking for, I'm hoping to gain a bit more information before I decide to go buy something at random in desperation.-forrest

author: Mangozac
author_rank: Frequent Contributor
timestamp: November 08, 2019, 10:11:16 am
content: You're not the only person who has switched to hand soldering connectors. I've seen several high volume operations where they solder the odd through hole part by hand - even in western countries with high labour costs.Selective soldering is very expensive. Have you considered semi-automatic dip soldering?

author: Reckless
author_rank: Frequent Contributor
timestamp: November 08, 2019, 11:47:05 am
content: Are you planning for an inline or offline solution? I have been heavily warned against RPS by someone very influential in the industry. He swore up and down they are the biggest POS as he was hired to fix some.I have a Jade Pilarhouse which is pretty good runs windows xp. We have been debating on selling it as we dont have a current need for it. Our boards need to be depanelized before soldering. Ace Kiss are also highly regarded in the industry. Both companies really defined the small selective solder market and own most market share. Personally for small standalone solutions these are the two I trust. I have been intrigued by ddm novastars solution but havent heard any feedback on their selective. After using their wave solder I am not too impressed with their quality. I almost purchased a monstrous size ersa but was told they are expensive to fix being european.I just got my solder robot, trying to figure out how to power it properly. Manufacturer claims its 110V 30 amps 360 watt. Need to build a custom jig for it as well.

author: IconicPCB
author_rank: Super Contributor
timestamp: November 08, 2019, 12:59:46 pm
content: 30 Amp?

author: pk7639
author_rank: Newbie
timestamp: November 08, 2019, 01:31:12 pm
content: We use a generic soldering iron robot, a bit like this onehttps://www.alibaba.com/product-detail/International-soldering-robot-for-pcb-soldering_60514425721.html?spm=a2700.7724838.2017115.57.195970fcfHyrTeit's takes a little longer than hand soldering, but the results are pretty consistent. We machine fixtures from delrin.

author: Reckless
author_rank: Frequent Contributor
timestamp: November 08, 2019, 03:08:31 pm
content: I keep arguing with them if they mean 3 amp. They sent 220V soldering irons instead of 120V. I will make a seperate post once I get it running.I'm thinking to order some kind of adjustable rail system that will screw into their holes.

author: forrestc
author_rank: Unknown
timestamp: November 08, 2019, 10:14:42 pm
content: Quote from: Mangozac on November 08, 2019, 10:11:16 amI'd probably just go get a used wave machine if I went that route since the main problem I had with the wave is flux application issues, and you end up with similar issues with the dip soldering method.

author: forrestc
author_rank: Unknown
timestamp: November 08, 2019, 10:26:29 pm
content: Quote from: Reckless on November 08, 2019, 03:08:31 pmI'll be interested in hearing how you do with this. I'm still not 100% given up on the soldering robot.I'm still dealing with two main issues: Better component support (I haven't yet found the perfect solution, the current method I've come up with seems to be functional, but it still doesn't feel right), and the biggie is process repeatability. I can take 5 boards, and all 5 will solder fine, then the next five will be full of defects. Same program, same process, same day, same room temperature, same batch of boards, same bag of connectors, etc. I'm feeling like this might be a solder/flux issue, but I've tried various cores and methods and haven't found any to be extremely reliable.Both of these *should* be solved with a selective soldering machine. The problem is that new ones are north of $50K US, and probably more like 80-100K. Plus nitrogen becomes something you should probably do to minimize dross production. And so on - but in the end it comes down to producing decent quality boards.

author: forrestc
author_rank: Unknown
timestamp: November 08, 2019, 10:31:09 pm
content: Quote from: pk7639 on November 08, 2019, 01:31:12 pmMine is pretty close to that exact model as well. What cored wire are you running?I'm ok with it taking longer - as long as the human time is less. There are lots of options for balancing a line with a slow machine....How do you do component support in the delrin? Pictures would be nice

author: Mangozac
author_rank: Frequent Contributor
timestamp: November 08, 2019, 10:35:01 pm
content: Quote from: forrestc on November 08, 2019, 10:14:42 pmYes, that's true.Honestly, if it's a limited number of through hole pins I'd be inclined to keep it simple and just pay someone to hand solder them. It saves a LOT of headache.

author: forrestc
author_rank: Unknown
timestamp: November 08, 2019, 10:45:37 pm
content: Quote from: Reckless on November 08, 2019, 11:47:05 amThanks for the info. Seems to match what I've heard as well. Well except the pillarhouse - in the USA it seems like the Ace KISS machines are the preferred machines to use. The pillarhouse is a bit less used/known. So I appreciate the perspective.Offline is fine as that's the way we run today.The wave we used to use was a Novastar - I have similar opinions about their quality. When I've looked at pictures of the selective solder it sure looks like a very similar engineering style to the wave, so I haven't really went down that path.

author: forrestc
author_rank: Unknown
timestamp: November 08, 2019, 10:54:17 pm
content: Quote from: Mangozac on November 08, 2019, 10:35:01 pm'Unfortunately, it's not a limited number. A typical board has over 200 pins. Some close to 400. It's at a point where it's consuming pretty much a full-time employee...So, we're reaching the point where we're going to be spending more labor+benefits on soldering pins than the cost of a selective soldering machine. Especially if I can find a good used machine.I really wanted this robotic soldering machine to work, but so far no dice. I'm going to spend some serious time on it again this weekend to see if I can figure out what is going on.

author: Mangozac
author_rank: Frequent Contributor
timestamp: November 09, 2019, 03:59:31 am
content: Quote from: forrestc on November 08, 2019, 10:54:17 pmAhh yes with those numbers hand soldering really isn't economical. Having played with wave solder in the past it's definitely something I would do my best to avoid in the future.Hang on, doesn't selective soldering have the same fluxing issue as wave and dip? You're still going to have to spray flux.What model of robot are you playing with? I saw so many of them on display in Shenzhen this week (at several price points) so the process itself must be sound. I'd really love to see an upside-down soldering robot so that fixturing isn't necessary, but I have to assume there's a reason they aren't done this way.

author: forrestc
author_rank: Unknown
timestamp: November 09, 2019, 04:44:44 am
content: Quote from: Mangozac on November 09, 2019, 03:59:31 amThe operative word here is: drop jet fluxing.My experience with wave soldering was with foam fluxing. Generally, you pump enough air through flux to make it foam, and then you run the board through the head of foam. It's almost impossible to consistently get the correct amount of flux applied, and the popping bubbles tend to create an aerosol that the whole board ends up going through, so you often end up with little top side spots if you've got the air set too high. Plus, with it too high, you end up with a lot of flux in everything. If you turn it down, you find that by the time you turn it low enough to solve these issues, you're often not getting enough flux in some areas. It's just one of those things which are almost impossible to consistently get right.Spray fluxing would have helped a lot, but at the time we abandoned the wave I wasn't interested in spending the $$$$ on a spray fluxer.In selective soldering, you generally will get a *selective* spray fluxer, or in my case, I'd want to end up with a drop jet fluxer. The spray ends up with some overspray, which is a problem if you're trying to not clean the boards (we generally try to run no-clean until we rework, then we clean reworked boards). The overspray ends up not activated, and so it doesn't end up inert in a selective soldering system. (The non-inert nature of non-activated flux is another reason we abandoned the wave).The drop jet fluxers allow you to be much more precise as to how much and where the flux is applied. My understanding from vendors and others I have talked to about this is that you can generally control this well enough to avoid most of the issues. But since I haven't used one yet, I can't vouch for the realities of this. Maybe someone else has used one...There's a video by RPS about their fluxing options:Annoying background music. Don't know why companies do that. But a good overview of the options.

author: Mangozac
author_rank: Frequent Contributor
timestamp: November 09, 2019, 05:10:16 am
content: Foam fluxing is a giant headache. I don't imagine many people use it any more?The drop jet fluxing looks very cool but I don't imagine is a very affordable option. It would be nice if you could test out a spray fluxer first to see if it might be adequate.

author: forrestc
author_rank: Unknown
timestamp: November 09, 2019, 05:28:01 am
content: Quote from: Mangozac on November 09, 2019, 05:10:16 amOddly, it seems like foam fluxing is a standard option on many current-production wave solder machines. I would have though that spray would have taken over.I went back and looked and the drop jet fluxer is a $2K USD option on the last Selective solder machine quote I got (on a $65K machine).

author: IconicPCB
author_rank: Super Contributor
timestamp: November 09, 2019, 06:20:34 am
content: Foam fluxers are really not suitable for no clean or low solids fluxes. These fluxes simply do not foam up. If they do ( with excessive air ) solvents tend yo evaporate and since the flux is a low solids variety the hygrometer measurement is unable to determine precisely how much solvent to add to a flux whose density is not far off the solvent density.No clean flux is ideally to be sprayed on.To protect the board from over spray a palette may be used ( product specific fixture) either as a part of the carrier frame or finger handled fixture.IN some cases a bit of high temperature adhesive tape can be used to protect the leading edge of the PCB from excessive flux or misttimed flux application as well as mistimed solder wave front.

author: forrestc
author_rank: Unknown
timestamp: November 09, 2019, 07:21:45 am
content: Quote from: IconicPCB on November 09, 2019, 06:20:34 amKester 951 and 959 are no-clean fluxes designed for foam application. I can definitely say they foam quite well with minimal air.Back when we ran these in the wave, we started out by titrating the mixture with a Kester PS-22 test kit. After an extended period of this and discovering that the way we managed the flux tank resulted in never needing to thin the mixture, we didn't bother near the end.

author: pk7639
author_rank: Newbie
timestamp: November 10, 2019, 10:39:37 pm
content: Quote from: forrestc on November 08, 2019, 10:31:09 pmHere's a little overview:

author: jmelson
author_rank: Super Contributor
timestamp: November 11, 2019, 12:01:19 am
content: Quote from: forrestc on November 08, 2019, 08:34:45 amI have one board I make that has 40 connectors of varying type and size. It was suggested I try dip soldering. It took a few tries to dial in the technique, but I now get very good results. I manually paint water soluble flux on the board. I think some kind of spray/foam fluxing would work better, but this is what I have right now, I made a "claw" that holds the edges of the board, and dip it at a slight angle into the solder pot, then tilt it level and hold it in the solder for 8 seconds, then tilt it slightly the other way and lift very slowly from the solder. This is with lead-free solder. Oh, I pre-heat the board at 100C for 2 minutes before the solder dip.It seems the VERY slow lift out of the solder is a major trick to preventing icicles.I've done close to 400 of these boards so far, and my results are getting better all the time.Jon

author: IconicPCB
author_rank: Super Contributor
timestamp: November 11, 2019, 03:28:12 am
content: I guess it would be silly to think You do not skim the dross off the surface prior to dipping?

author: forrestc
author_rank: Unknown
timestamp: November 11, 2019, 09:18:53 am
content: Quote from: pk7639 on November 10, 2019, 10:39:37 pmThanks for the info.I think we have the same machine, just a bit different age it looks like (coloring is slightly different, the design is the same).In regards to the fixturing, I have the challenge that due to the connector styles, I can't clinch the leads before soldering. Which provides a bit of a problem. Like I mentioned previously, I've got something that works but isn't that efficient.I worked on this over the weekend. When I quit working with it on Saturday, the soldering was working quite well. Today I go out and turn it back on, and now it's back to crap soldering. Not sure if it's a humidity thing or tip oxidation differences, or what..I spent a fair bit of time trying before I gave up in disgust today. I will say that the crap soldering isn't as bad as it was, but it still isn't great. At least not as good as it was. I wish I knew what was changing. I'll probably try again during off-shift times during the week.

author: pk7639
author_rank: Newbie
timestamp: November 11, 2019, 01:09:18 pm
content: We don't see much variability in our process. The extra flux is necessary with the lead free solder we use....... I'll see if I can find some video of it making joints.. Maybe (and I have no knowledge of your experience with the machine) we are just running it differently???

author: forrestc
author_rank: Unknown
timestamp: November 11, 2019, 02:00:00 pm
content: Quote from: pk7639 on November 11, 2019, 01:09:18 pmI expect there's something different that I'm missing here. I've just ordered a spool of 63/37 "highly active" RA with 4% flux just to see if it's a flux thing, although I'm not optimistic since I've added plenty of flux in the past with no apparent long-term difference. I had switched to a different type of solder with more flux (3.3%) and supposedly a more active no-clean formulation earlier in the weekend, and it looked like that had solved the issue, but then resuming the next day things are different. I checked, and temperature/humidity hasn't really changed, so I'm not sure what else would have changed.The failures really look like inconsistent wicking. Sometimes on early pins, sometimes on later ones. Once the solder doesn't wick correctly, then you have a volume on the tip issue, and you end up with solder blobs on the following pins. Or worse, a big blob on top of a couple non-wicked pins. And yes, I've tried using lots of additional flux (even to excess at least once or twice).Then the next day, I make a small change, and everything goes swimmingly for some quantity of boards, then things go badly again. Or things go badly until I've almost given up, and all of a sudden, everything is fine. I've played with temperature settings, tip alignment, tip positioning, solder feeding position, new tip, different tip style, etc.I just realized there is one thing I haven't checked, and that is to measure the actual tip temperature with a tip thermometer. If I've got inconsistent temperatures on the tip, that might make a difference. I'll have to see if I can find my thermometer.I really wish "traditional" selective solder machines weren't so expensive to buy and operate. I'm still hoping to find the right one used at some point.

author: pk7639
author_rank: Newbie
timestamp: November 11, 2019, 06:52:55 pm
content: You mentioned oxide build up as a possible cause. Is your tip cleaning station doing it's thing?Is the tip wetting?We start each joint cycle with a quick feed of solder wire to wet the tip....Video may help, I can't find any on my phone, I'll ask the guys in the morning and we'll shoot some if we draw a blank.

author: IconicPCB
author_rank: Super Contributor
timestamp: November 11, 2019, 07:01:24 pm
content: Are the component leads clean ( not oxidised ) do they boards wet ? Stupid question to ask I know but...

author: forrestc
author_rank: Unknown
timestamp: November 12, 2019, 01:59:32 am
content: Quote from: IconicPCB on November 11, 2019, 07:01:24 pmAll the components are fresh, and come from the same bag from the manufacturer. Same with the RAW PCB's.Quote from: pk7639 on November 11, 2019, 06:52:55 pmAs far as I can tell, the tip is wetting fine and it starts off clean every cycle. That isn't to say that there isn't some oxidized solder left around, maybe I need to try flooding the tip a bit more before the cleaning cycle. Or do two cleaning cycles.The program I currently have in is a cleaning cycle, and the program feeds some solder onto the tip to wet it before starting the first joint.