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wave soldering + header connector assembling problem

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#52296

wave soldering + header connector assembling problem | 5 November, 2007

We have a problem with soldering of a 96 pin header connector(9001-11961c00l1a from kingmate) we use 3 different wave soldering but in all of the machines we have many short circuit between the pins . the wave soldering machines that we use is from NIHON,ERSA & SEHO we think that the problem is from the manufacturing & designing of this pcb but another company Has been Assembled these boards without any difficulties so we doubt that it might be of the wave soldering machines parameter s definition . if anybody needs the picture of the place that the connector should be assembled I can send it for you . Please let me know any suggestion that you have for solving this problem . Thanks

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#52306

wave soldering + header connector assembling problem | 5 November, 2007

You need to send the connector perpendicular through the wave not parallel.

Patrick

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#52311

wave soldering + header connector assembling problem | 5 November, 2007

Call me jaded, but this sounds suspiciously like the classic "our other supplier didn't have this problem" but the other supplier was hand soldering the headers, and finally requoted the job with that in mind so the customer moved on.

Granted, there's not a lot of info. here regarding lead pitch, solder type, header location, etc., and Patrick may very well have hit on the issue. I wonder if the board CAN be oriented properly or if other circumstances force the issue (parallel orientation of the header to direction of travel).

Link to pic, maybe?

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#52313

wave soldering + header connector assembling problem | 5 November, 2007

That's where this website falls short. Sorry to b*tch, but there's lots of people who post here whose primary language is NOT english, and you know what they say... "a picture is worth a thousand words."

Original Poster guy...try "Image Shack" to share your picture with us. Take an overhead shot of the entire board and then let us know which direction it's travelling into the wave. Then post it on an image file-sharing site.

Ol' chap Patrick is correct in saying that the connector should be perpendicular and not parallel to wave direction. If parellel, you've got a bunch of conductors making contact with the wave at the same time, which causes the connector to act as a "rake", thus causing the solder shorts. The peelback of the wave from the board is better when the direction is perpendicular.

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#52315

wave soldering + header connector assembling problem | 5 November, 2007

Maybe the "other" company runs a different wave, or flux, or pallet, or touches up every board. Assumptions are like brains - every claims they have one, but very few use em.

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#52380

wave soldering + header connector assembling problem | 8 November, 2007

please download the picture from the link below . we have two picture . picture1 is the place of the 96 pin connector that we have problem with it and i should say that we use parallel & perpendicular direction for sending the board to the wave soldering machine but the problem doesn`t solve . please also have a look at picture2 with this place of connector with don`t have any problem . in wave soldering machine . please let me know your suggestion

http://www.4shared.com/file/28653288/e9badeb8/connector_picture.html

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#52382

wave soldering + header connector assembling problem | 8 November, 2007

please download the picture from the link below . we have two picture . picture1 is the place of the 96 pin connector that we have problem with it and i should say that we use parallel & perpendicular direction for sending the board to the wave soldering machine but the problem doesn`t solve . please also have a look at picture2 with this place of connector with don`t have any problem . in wave soldering machine . please let me know your suggestion

http://www.4shared.com/file/28653288/e9badeb8/connector_picture.html

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aj

#52390

wave soldering + header connector assembling problem | 8 November, 2007

Hi,

I have just taken a look at the Connector Images.

Is there a difference in pitch between both connectors ?

From the photo it looks like the Annular Rings are oversized on Image #1 especially around the centre area ( this might be the image ).

We have some products here where we just have to grin and bear it as we have tried everything possible to eliminate the shorts but if its a board design issue well there is very little you can do apart from advise the customer to fix it.

Check out the IPC spec and see if the design meets the standard.

aj...

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#52394

wave soldering + header connector assembling problem | 8 November, 2007

Where are the shorts occurring on the 96 pin connector? Are they consistently in the same areas?

It looks as though there are a number of pins connected by traces on the board, and/or the ground plane. This would cause a lot of repeatable shorts in wave. The amount of copper poured around the area may also cause some difficulty. I note that the plane is poured on the board edge side of the connector, and I can't see why from this picture (ie. I can't see any of the connector pins on that side of the connector connected to the plane).

Other notes in this thread are all valid, as well. Just because another company was successful...doesn't mean that they were truly successful. Customers have a habit of assuming success based upon delivery of quality units/lack of discussion about the issues. It's possible that the other company has been reworking this area as a matter of course, and has never addressed the design of the board as a potential cause of problems.

Different equipment and processing could have an effect. For solder shorts...flux application, temperature rise, and availability of a hot air knife could all impact the results.

cheers ..rob

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RDR

#52401

wave soldering + header connector assembling problem | 8 November, 2007

Annular rings are too big, it is acceptable to have shorts on the common conductors. I would be willing to say the "other" supplier may have modified the artwork as well.

Good fluxing, preheat and proper immersion depth are key to eliminating shorts as well. I notice these are very close to edge, wave fingers may be disrupting the laminar flow of nozzle or you may have a parallelism issue with wave

Russ

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#52407

wave soldering + header connector assembling problem | 8 November, 2007

We've got lots of connectors at my place of employment like this.

What I do is... I run these "slower than molasses in January" - we're talkin' 2 Ft/Min. conveyor speeds. Obviously this will have an effect on your thermal profile so compensate accordingly on your preheat zones.

Anywho, going slower effectively reduces your contact length. So the slower you go, you are contacting less solder as the assembly traverses across your wave, and this makes peelback from the wave smoother. Also if you can, shut the chip wave off completely. You will preserve activator if the wave is in contact with just one wave. And, if you're good enough at the artform, reduce the pump speed as much as you can get away with w/out sacrificing anything else.

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#52416

wave soldering + header connector assembling problem | 9 November, 2007

how about applying solder resist on the area where you have bridging occurs..you may ask your pcb supplier the possibility.

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#52420

wave soldering + header connector assembling problem | 9 November, 2007

You're joking rite? I mean the pitch between these two connectors is night and day. Of course you will get shorts on the 96 pin connector because your leads are right on top of each other.

Now, what to do about it: You took a picture of the top of the board - assuming the annular ring is the same top and bottom, you can decrease this. Go with a matte finish and make sure your resist is between each thru-hole pin of the connector. Last, you can try decreasing the pin protrusion. Without seeing the connector, this may also be a problem.

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