Steve,
 
We have made audits before and after the wave soldering,
and we have found that really the components are being lost in the wave soldering.
We lost some components in prior the wave but they are very few.
 
Alejandro
-----Original Message-----
From: [log in to unmask] [mailto:[log in to unmask]]
Sent: Wednesday, March 13, 2002 7:05 PM
To: [log in to unmask]
Subject: Re: [TN] Glue Dot Size (missing parts)

Hi Alejandro!

Are you SURE the components are being lost in the wave? Are you SURE they were there just prior to putting the assembly in the conveyer into the wave?

From past experience, that was an assumption that was made because the components were there after curing in the oven at surface mount, and then missing after they came out of wave solder. Truth of the matter was that they were knocked off during the handling during PTH stuffing, pre-wave masking, prior to actually waving the assembly...there usually isn't any sort of inspection step to ensure all the bottomside SMT components are there in between bottomside SMT inspection until after wave solder. So it is sometimes missed that the components were knocked off from all the handling that gets done prior to wave.

Problem is, when most production people hear the word "epoxy" (as in epoxied SMT components on the bottomside of a board), they equate that to the two-ton stuff that you would use to repair a chair leg with...not understanding that the epoxy that is used for SMT components has very little strength, and don't handle the assemblies with the care that they should...

My two-cents (with a coupon)..hehehe

-Steve Gregory-


We are having issues with 0603 components attached with glue (Glue printed with Pump printing)
that are being fallen in the wave soldering equipment.
The average dot size that we are having in these components is 0.025" and the average torque value is 1 N-cm.
What could be possible causes for this issue?

Regards,

Alejandro Becerra
Thomson multimedia Inc