Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Wavesolder bridges

Michael N

#13710

Wavesolder bridges | 23 October, 1998

I need some info on how to stop the bridges I'm having on radial and axial parts that are in the same place on every board. I'm also having problems with sot-25 bridging. I'm using a Electrovert E-pak. I tried leveling the machine,solder pot, and the nozzles. I ran the optimizer profiler throught there and I got a top temp at 210 F and board depth in main wave at 50% of board thickness. I'm having so much problems and I'm running out of resources to fix the problem. My thru-hole Parts are place by machine clinch. If anyone can give me some ideas or direct to get some info.

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Earl Moon

#13711

Re: Wavesolder bridges | 23 October, 1998

| I need some info on how to stop the bridges I'm having on | radial and axial parts that are in the same place on every board. I'm also having problems with sot-25 bridging. I'm using a Electrovert E-pak. I tried leveling the machine,solder pot, and the nozzles. I ran the optimizer profiler throught there and I got a top temp at 210 F and board depth in main wave at 50% of board thickness. I'm having so much problems and I'm running out of resources to fix the problem. My thru-hole Parts are place by machine clinch. If anyone can give me some ideas or direct to get some info. | What are your real numbers? What's your flux and required activation temperature? Time your conveyor (stop watch ruler at between 4-6 fpm). Measure your flux density (without adds), measure your top side board temp (with profilometer of some kind). Correlate top side with preheater temperautre and the results are? What's your real wave temperature? What is your angle over the wave? What type devices run? Pre chip wave and laminar wave? Contact time/area on wave? Etc. You know your parallelism, right?

In other words, calibrate and characterize the entire process, its sub processes, and operator dependent activities (where most variabilities occur)

There must be some more things to consider, but the rest of the crew will get it right,

Earl Moon

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tom Gervascio

#13712

Re: Wavesolder bridges | 26 October, 1998

| | I need some info on how to stop the bridges I'm having on | | radial and axial parts that are in the same place on every board. I'm also having problems with sot-25 bridging. I'm using a Electrovert E-pak. I tried leveling the machine,solder pot, and the nozzles. I ran the optimizer profiler throught there and I got a top temp at 210 F and board depth in main wave at 50% of board thickness. I'm having so much problems and I'm running out of resources to fix the problem. My thru-hole Parts are place by machine clinch. If anyone can give me some ideas or direct to get some info.

Earl gave some good advice. Other things to consider are these design related? Longer leads closer together probably would not help- have you tried to cut the lead length and see if this help.

Also could it be related to board sagging- if the board sags it might make these parts go not as deep into the wave and couses the bridges. Immersion depth across the board is probably important but board layout has the biggest impact.

| | | What are your real numbers? What's your flux and required activation temperature? Time your conveyor (stop watch ruler at between 4-6 fpm). Measure your flux density (without adds), measure your top side board temp (with profilometer of some kind). Correlate top side with preheater temperautre and the results are? What's your real wave temperature? What is your angle over the wave? What type devices run? Pre chip wave and laminar wave? Contact time/area on wave? Etc. You know your parallelism, right? | | In other words, calibrate and characterize the entire process, its sub processes, and operator dependent activities (where most variabilities occur) | | There must be some more things to consider, but the rest of the crew will get it right, | | Earl Moon |

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Dave f

#13713

Re: Wavesolder bridges | 26 October, 1998

| I need some info on how to stop the bridges I'm having on | radial and axial parts that are in the same place on every board. I'm also having problems with sot-25 bridging. I'm using a Electrovert E-pak. I tried leveling the machine,solder pot, and the nozzles. I ran the optimizer profiler throught there and I got a top temp at 210 F and board depth in main wave at 50% of board thickness. I'm having so much problems and I'm running out of resources to fix the problem. My thru-hole Parts are place by machine clinch. If anyone can give me some ideas or direct to get some info. |

Michael: It's tough, as other responders have said, to determine the source of your problem. Is it:

1 Process setup 2 Problem board profiling 3 Problem board soldering materials, board, and components 4 Problem board design layout 5 One or more of the above

TTYL

Dave F

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