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Wave Solder Bean Bags

Views: 4372

#75852

Wave Solder Bean Bags | 7 June, 2016

Does anyone have a good answer to lifted components?

I read on this site (old thread) that someone designed bean bags to set on top of a PCB to keep the components down on the board. I know that seems like a short cut to eliminate lifted components. However, I have tried to profile these wave solder (kic2000) machines and there doesn't seem to be a problem with the profile. Any help is greatly appreciated.

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#75854

Wave Solder Bean Bags | 7 June, 2016

I remember doing that back in the day. We not only used bags but also wood planks. It was an old solder-cut-solder process without any top side preheaters. I wouldn't do it today because the bags would interfere with the top side preheat let alone a possible fire hazard.

Are you using a cut and clinch machine? If not, why not? Is it all components or just a few types? More insight regarding your process would be helpful.

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#75856

Wave Solder Bean Bags | 8 June, 2016

Some of our components cannot be cut and clinched. We do use one but some of the leads are too thick to clinch.

I was thinking the same thing about the bean bags being on top with top side preheaters. That was one of the reasons I wanted to explore other options. Do you have any other ways in which you reduce your lifted component defects?

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#75857

Wave Solder Bean Bags | 8 June, 2016

I've not seen it done but I've heard talk of using some kind of wrap something like "ShrinkWrap" or "clingfilm"

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#75858

Wave Solder Bean Bags | 8 June, 2016

Lead forming can provide retention during wave soldering. There is the simple offset method, the dimple and compound forms. All of these are outlined in IPC-AJ-820A. It would probably require automated lead forming equipment using special dies. GPD makes equipment for this purpose. There may be other brands but am more familiar with GPD. The front end may seem expensive but you really want to avoid rework which is also costly and degrades quality.

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#75860

Wave Solder Bean Bags | 9 June, 2016

I'm sorry but I don't understand your statement. What is lead forming? What or Who is GPD?

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#75864

Wave Solder Bean Bags | 9 June, 2016

I'm assuming these are two leaded axial components. GPD Global makes fluid dispensing and component prep equipment. Component leads can be formed (or bent) in order to provide some resistance in the hole during insertion. This should prevent the component from lifting out of the hole.

For an example of various forming types, see the link: http://gpd-global.com/co_website/pdf/leadformers/operations/CF8%20Die%20Catalog.pdf

The dies are attached to one of their machines such as their CF-8. Forming component leads in this way is the ideal but it can run into money (I don't know what your volume/budget is). I also don't know if the dies can handle leads that are too thick. Hope this helps.

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#75865

Wave Solder Bean Bags | 10 June, 2016

I appreciate the insight. However, most of our lifted components are from connector's or relays. Basically a component with more than 2 leads. They tend to lift at the front of the component feeding into the wave. The rear end of the component does not lift (in 99% of the cases).

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Tom

#75866

Wave Solder Bean Bags | 10 June, 2016

Haven't had to do this yet but what about an adhesive? Maybe an instand bonding adhesive from loctite or similar? The difficult part would be finding something fast drying with a high enough temperature rating.

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#75867

Wave Solder Bean Bags | 10 June, 2016

Kyle,thank you for steering me back on track. For relays and connectors I like Tom's suggestion provided you are allowed to add materials to your assemblies. An instant adhesive or perhaps a chip bonder (used in SMT) may work if the preheat is high enough. In either case keep it away from the pads.

If you are not allowed to add materials, then you might try making bars that would hold the relays or connectors in place and they would attach to your solder pallet (if you use them) or perhaps set into tooling holes in your board. They would require some design effort but could be reused and probably less labor intensive than an adhesive.

Finally, you could try using a peelable solder mask, either a latex or the pink material (we use Wondermask P). It is not designed to be an adhesive but it would withstand soldering temperatures and is easily removed. It might just be enought tack to work if you can afford to wait 30 minutes or so. That's all I've got. Let us know how you make out.

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#75893

Wave Solder Bean Bags | 17 June, 2016

Great insight guys. I appreciate your input and I will use everything here today to figure out what is best for our manufacturing needs.

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#75935

Wave Solder Bean Bags | 5 July, 2016

Hi have you try to use some type of adhesive like loctite or a solder mask to avoid lifted components, we use both in 2 different products, we use loctite to avoid a hall inserted in a plastic carrier, lift when being solder in the solder wave, the solder mask we use a pink solder mask call wonder mask, we use that one for another hall but this one goes on a pcb, and gets solder in the solder wave, this one we can peel the solder mask after the solder wave and never got any problems with any of them

cheers

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#76114

Wave Solder Bean Bags | 5 August, 2016

Spoke the ladies here a couple years ago, they still will make them for you

Bear Wear Inc.

1114 Spring Creek Lane Lewisville, Texas, 75067 USA Phone 972-315-6457

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