Advice on setting up a low-mid volume SMT line for <$130k?

[jmelson]

As far as remaining concerns, the Heller reflow oven and MPM stencil printer I really am clueless about. I assume I can find manuals and stuff, the oven itself shouldn't be terribly complicated. Even so I haven't looked into available service nearby. I am just crossing my fingers on these, they will be demonstrated working prior to shipment but then it's on me to get those up and running.

I know NOTHING about stencil printers, except that I am a "manual" printer, i do it by hand.  But, I suspect gentle handling is important.

Ovens are likely to be fairly tough, but make sure you get all the manuals (or CAN get them from somebody).  Again, I know nothing, but have heard scuttlebutt.  And, that is that the entire oven is kind of a consumable.  You will have heating elements, controllers, and fans fail over time, as well as conveyor parts.  It is all pretty simple mechanics and electrical tech. but it is all pretty highly stressed by the temperatures.  So, having worked out in advance where to get parts, and where as many parts can be found from McMaster-Carr, PLC Center and such will be a help.  You might even want to check with other users and get in some of the most often needed spare parts in advance, to save days of down time when the inevitable happens.  Heating elements and SSRs should not be terribly expensive unless the maker went to extremes to make sure you couldn't use commodity parts.

Jon

[jmelson]

One other area is insurance.  I have heard MANY, MANY horror stories of totally disastrous shipping accidents where the machines were badly damaged or destroyed, and the shipper was able to walk away with no liability due to some ridiculous fine print stuff.  Like the machine fell off the back of the truck while unloading at the destination, and because it was on the recipient's property, "Not our problem".

So, when you are talking about a $100K delivery, you want to make sure the insurance really covers all possible events.  I don't know much about this, but as I say, I've heard stories!

Jon

[SVFeingold]

Just found out the machines also come with the off-line programming tool as well as a feeder calibration rig. Music to my ears!

Anyone here with experience using one of these? I've read good things about them, one is available here for $1k. Apparently it works but won't save programs. I'm OK with that if it's a good oven, would be great for running small boards or leaded boards that I don't want in the big oven.

Now I'm looking for a dip-solder machine, apparently Manncorp no longer offers those models despite being listed on the website. That pretty much just leaves China as far as I know. Not a big issue with that, unless anyone has suggestions.

jmelson: I'm pretty adept at reading the fine print, after a few startup experiences. Nobody is touching anything unless the insurance covers it. Once the machines have been safely transported, powered up, and checked out with the approval of a service tech, then I will sign off.

[forrestc]

To start, Macrofab wants to charge $60k for these boards for assembly alone. And that will be the case on every. single. batch. China is "cheaper" if your time is free and you have the expertise to do it. Many people allude to this magical CM that can take the files and pump out 1k boards for $1 each without any back and forth. Please find them for me!

Sorry for the late reply, but really want to reply to this one.

This is my experience as well.    We've been assembling in-house for this reason for at least 10 years now.

5-6 years ago we had one of those years that we needed to spend some money at the end of the year.   Ended up spending $80K for a complete line + dry box from manncorp, which allowed us to switch from 100% through hole to SMD.   It's been one of the best purchases I've made.   If I was in the market for a second machine, I sure wouldn't count them out (although I would definitely make sure I evaluated the entire market).   Like any purchase there are trade-offs, but for the relatively lower tech boards (0.5mm pitch/0402 and larger), this has worked well for us, and the pick and place machine has been remarkably trouble free.

As we've slowly increased our volume, I continue to look at outsourcing assembly of some of the products.   So far, I haven't been able to find anyone anywhere who can manufacture the volume we do (500-1000pcs) for the cost

[SVFeingold]

Yes, of course I agree with you hence this project.

I've always been big on vertically integrating. I think too many industry professionals look at things from their POV and decide in-sourcing is a bad idea. There are many ways to look at it, and for small business it's IMHO not as easy to put in terms of "ROI" as far as pure tangible dollars are concerned. Being able to turn things around quickly, when the cost of mistakes is low, has a huge impact on your operating mindset. You don't have to take 2 weeks to pore over every detail to MAKE SURE everything is perfect (and it still won't be) because each prototype is costing you several thousand dollars + 1-2 weeks. This applies to mechanical things as well as electrical. I recall Apple themselves dropping a few million on some high-dollar CNC equipment to live right next to their design lab in California. There's a reason they did that instead of just out-sourcing. Of course, if I had their resources...

I just received a quote for an industrial control board I designed for my day job, from RushPCB. $33k for 100 boards with a 20 day turn. These are not super special RF magic boards...commonplace tech nowadays. About 400 components, mostly passives, nothing smaller than 0402, a single 1mm pitch BGA, a few through-holes, etc... I can get 100x of these PCBs made in China, with superb quality, for <$1k. The BOM cost is ~$100 per board. That comes out to $11,000 for 100 boards. If I could get these boards programmed in a couple of days, I can do the whole run for them within a week, charge 1/4 what they do, and be quite happy with a week's work. Now granted, RushPCB is probably not the cheapest but they aren't the most expensive either. Every new CM I try in the US ends up being equally expensive. Maybe I'm just bad at finding the good + affordable ones.

I'm still waiting for that "a-ha" moment where I realize how utterly stupid my plan is but I haven't gotten there yet. The math checks out, all that is left is for me to study and learn this equipment like my life depends on it.

[SVFeingold]

Interesting development on the through-hole front...has anyone used a Bismuth containing solder paste such as this: http://alphaassembly.com/Products/Solder-Paste/CVP-520

Seems like a great option for through hole. I just read an article in the Printed Circuit Design & Fab magazine about Bismuth solder and how it fell out of favor when leaded solder was commonplace for some reason (I think it was material compatibility with lead) but now is coming back into favor. I'd of course love to do a second pass with this paste but that may be difficult with a populated board, so I'd need to solder all the parts with it.

Too risky?

[jmelson]

Just found out the machines also come with the off-line programming tool as well as a feeder calibration rig. Music to my ears!

Anyone here with experience using one of these? I've read good things about them, one is available here for $1k. Apparently it works but won't save programs. I'm OK with that if it's a good oven, would be great for running small boards or leaded boards that I don't want in the big oven.

$9000 Crazy!  $1000, well, that's a bit high, I have no idea how accurately it controls temperature.  I use a big toaster oven from WalMart, with a ramp and soak temperature controller patched in.  I poke a micro thermocouple into a through hole in one of the boards.  I can do boards up to about a regular US sheet of paper in it, or 6 small boards.

Now I'm looking for a dip-solder machine, apparently Manncorp no longer offers those models despite being listed on the website. That pretty much just leaves China as far as I know. Not a big issue with that, unless anyone has suggestions.

I do it by hand, with a custom kind of tongs that holds the board without touching any of the through hole components either top or bottom.  I got a Chinese 5 x 7" solder pot.  I use lead free solder in this.  I'll bet, if one were to use it for leaded solder, you'd find it much easier to get perfect soldering.

jmelson: I'm pretty adept at reading the fine print, after a few startup experiences. Nobody is touching anything unless the insurance covers it. Once the machines have been safely transported, powered up, and checked out with the approval of a service tech, then I will sign off.

Yes, sounds good.  But, shipping insurance may not cover oopses on your property.  Just something to check.

Jon

[jmelson]

Interesting development on the through-hole front...has anyone used a Bismuth containing solder paste such as this: http://alphaassembly.com/Products/Solder-Paste/CVP-520

Seems like a great option for through hole. I just read an article in the Printed Circuit Design & Fab magazine about Bismuth solder and how it fell out of favor when leaded solder was commonplace for some reason (I think it was material compatibility with lead) but now is coming back into favor. I'd of course love to do a second pass with this paste but that may be difficult with a populated board, so I'd need to solder all the parts with it.

Have you checked the brittleness and fracture strength of these solders?  I think this may be a real problem with it.

Jon

[SVFeingold]

After doing some research it seems that the brittleness is indeed a problem. Probably not an experiment I'd want to undertake at this point.

For shipping I'm not anticipating any major oopsies after it's off the truck and on pallet jacks on the ground. However, as long as they're handling the equipment be it truck or forklift, it needs to be their responsibility. Surely this can't be an uncommon request but we'll see.

I have a Controleo2 modified toaster reflow oven as well that's worked pretty flawlessly so far. Had some issues on the last batch with rather ugly solder joints and inadequate wetting. I think the cause for this is two-fold: 1) Chip Quik paste seems to work great most of the time but it's been less consistent for me than Kester. 2) One issue with the ControLeo2 is that my oven is relatively large and so takes a little longer to heat up. The Controleo seems to get a little more aggressive on each learning cycle until it just hits the profile but stops there. As a result my reflow cycle times are like 6+ minutes. Just on the edge of acceptability. You can tweak this in the Controleo firmware but I haven't gotten around to it. They're coming out with a new control unit soon which looks pretty badass and has more features, might be able to make these adjustments easily.

Not only that but in the new space I can modify the oven to run off of 240 which should add some much-needed oomph.

Anyone have stories to share regarding preferred solder paste? I feel OK about ChipQuik, Kester I've had pretty good luck with. I seem to hear unanimous good things about Alpha, and Loctite seems well regarded as well.

[jmelson]

Chip Quik paste seems to work great most of the time but it's been less consistent for me than Kester. 2)

Yes, I have also found the ChipQuik seems to go bad in short order, while some other pastes work OK without refrigeration and other care for a year or more.  My last batch of ChipQuik seems to have turned into hard chunks, even after adding some solvents to it, and massive attempts to re-mix it.

Anyone have stories to share regarding preferred solder paste? I feel OK about ChipQuik, Kester I've had pretty good luck with. I seem to hear unanimous good things about Alpha, and Loctite seems well regarded as well.

I got some lead-free paste from Warton Metals in the UK (VERY expensive to import to the US) and it was wonderful stuff!  I have since gotten some lead-free Shen Mao Formosa-brand solder cream that is pretty good.  I occasionally have to add a little liquid flux and Butanol to it to keep it working right.

At the rate I use solder paste, it eventually turns to crud and I have to replace it.  But, I usually can use 80% of the jar before it gets really bad.  But, it was more like 50% of the ChipQuik.  But, then I do a lot more lead-free work, and rather few with leaded solder.

Jon

[mikeselectricstuff]

Henkel GC10 is supposed to be a very good LF paste with very long life - I think there is a thread here somewhere about it

[Kjelt]

IMO If you are running a pro setup you just don't take any risk with the paste beyond its expiry date.
The cost of time and components of a couple up to tens of wrong reflowed boards is much higher than a new jar. Not to speak of return failures in the field after months.

Amateurs and hobbieists like me can buy the old still sealed containers for old metal price.
But guess what, even I buy 250g new jars of paste Whats $50 ?
If the stuff is unusable I melt it around 300C on a fire in a metal pan till all the flux has dissapeared and add the metal to my solderpot.

[rx8pilot]

Henkel GC10 is supposed to be a very good LF paste with very long life - I think there is a thread here somewhere about it

I just switched to GC10 - AMAZING! I was using one of the Kesters before.

Every metric of the GC10 is better - very long stencil life, temp stable, very easy to print fine pitch (type 4 paste), excellent finished joints, very low residue.

[jmelson]

Henkel GC10 is supposed to be a very good LF paste with very long life - I think there is a thread here somewhere about it

I just switched to GC10 - AMAZING! I was using one of the Kesters before.

Every metric of the GC10 is better - very long stencil life, temp stable, very easy to print fine pitch (type 4 paste), excellent finished joints, very low residue.

Who did you buy it from?  It is probably just about time to refresh my lead-free paste.

Jon

[forrestc]

Anyone have stories to share regarding preferred solder paste? I feel OK about ChipQuik, Kester I've had pretty good luck with. I seem to hear unanimous good things about Alpha, and Loctite seems well regarded as well.

On our p&P machine, one of the options was a high precision dot dispenser (martin brand).  We use this for very low production boards (<100/yr), and for prototypes.   We tried lots of different types of pastes and eventually settled on an Indium paste specifically designed for air dispensing, since many others would do bad things in this application.   Many pastes are actually non-newtonian fluids and this causes problems when you're "impacting" them with air pressure and trying to get the paste to go through a small needle.   I understand others will separate.

We originally did 100% dispense for a couple of months, then switched to stencil printing for the higher volume products.  Because we were using a indium paste for dispense, we got a chemically compatible paste designed for printing from them in tubs.   Have had no problems at all, even well beyond the expiration date of the paste (we keep all but the currently operating tub refrigerated).

[rx8pilot]

Henkel GC10 is supposed to be a very good LF paste with very long life - I think there is a thread here somewhere about it

I just switched to GC10 - AMAZING! I was using one of the Kesters before.

Every metric of the GC10 is better - very long stencil life, temp stable, very easy to print fine pitch (type 4 paste), excellent finished joints, very low residue.

Who did you buy it from?  It is probably just about time to refresh my lead-free paste.

Jon

DigiKey -

[jmelson]

DigiKey -

OK, what threw me off is it shows as being Loctite brand, not Henkel.  I guess Loctite is their US distributor.
They also show zero stock.  $101 for 500 g.  But, if it works like a dream, I guess I should just pay the price and enjoy the good soldering performance.

Thanks,

Jon

[forrestc]

OK, what threw me off is it shows as being Loctite brand, not Henkel.  I guess Loctite is their US distributor.

Loctite is one of the Henkel brands.   Kinda like Scotch or Post-it are 3M brands.

[SVFeingold]

Interesting, I'll admit I was biased as it's often cheaper than Kester or Chip Quik. I'll definitely have to pick some up!

[TJ232]

Henkel GC10 is supposed to be a very good LF paste with very long life - I think there is a thread here somewhere about it

Another Henkel GC10 happy user here!

[rx8pilot]

Interesting, I'll admit I was biased as it's often cheaper than Kester or Chip Quik. I'll definitely have to pick some up!

I only recently switched to the GC10, which as you pointed out was a little more expensive than the Kester that I previously used.

What I quickly learned is the GC10 is a fraction of the cost, potentially even paying me to use it. The reason I say that is because I have not had a single bad joint with the GC10, I have not had to re-print a single board, I have left it in the stencil for 12 hours, put it in a bag, pulled it out the next day for another 12 hours in the stencil and it still printed and flowed well.

The Kester was not even close. Harder to print and more susceptible to bridging creates re-work which almost immediately overshadows the savings on the paste. Being able to leave it out for extended periods while I setup or do other things is very convenient and avoids tossing paste in the trash. I did not expect much difference with the GC10, but it has made a considerable improvement in labor and direct costs.

[SVFeingold]

Sounds pretty awesome.

I really have to wonder why there is so much variability. Is it all down to the flux? I would think the metallurgy is pretty much identical but who knows, maybe that extra 0.01% purity makes a tangible impact on the result.

[rx8pilot]

Sounds pretty awesome.

I really have to wonder why there is so much variability. Is it all down to the flux? I would think the metallurgy is pretty much identical but who knows, maybe that extra 0.01% purity makes a tangible impact on the result.

Chemistry is beyond me.

[Kjelt]

The flux should be different because this stuff does not need to refridgerated.
For the rest only the size of the balls is a differentiator. Some paste can not pass 0,3mm syringes.
I thought that was the difference between stencil paste (bigger balls) and syringe paste (smaller balls)?

[forrestc]

The flux should be different because this stuff does not need to refridgerated.
For the rest only the size of the balls is a differentiator. Some paste can not pass 0,3mm syringes.
I thought that was the difference between stencil paste (bigger balls) and syringe paste (smaller balls)?

Every paste has varying composition.   Only part of it is the ball size and the active materials (i.e. the acids which actually clean the oxides so the solder works).  It is true you generally want a smaller ball size for syringe paste.

The rest has to do with how it flows and behaves in certain applications.   The behaviors one would want when screen printing vs pneumatic dispensing can be widely different - which is why manufacturers sell pastes which are specifically designed for pneumatic dispensing.  Occasionally you'll find a paste which works well for both with just a change in the metal load, but usually what works well for syringe dispensing doesn't work so well for screen printing and vice versa.