Following from the EMPF HelpLine In Indianapolis; prepared by Pat Kane:

You might try these ideas for investigating the pinholes and blowholes.

Check manufacturer spec for topside temp for the flux being used, may be
too cool.

Check solder height (contact to PCB) and verify even contact of PCB during
travel (use a lev-check plate)

Check that flux is not contaminated, excessive moisture content, and
correct specific gravity.

Experiment with slower conveyor speed to allow flux activation to occur
correctly (temperature concern).

Check for PCB contamination and component solderability.

Check the hole- to- lead ratio.

When they did the microsections, did the side walls of the barrel show
sufficient and even thickness?  Was there evidence of rupturing of the side
walls?

EMPF can perofm these tests and evaluations if required.

>----------
>>Resent-Date: Mon, 7 Apr 1997 13:06:26 -0700
>>Resent-Sender: [log in to unmask]
>>Old-Return-Path: <[log in to unmask]>
>>Date: Mon, 07 Apr 1997 12:59:00 -0400
>>From: Ed Gavin <[log in to unmask]>
>>To: [log in to unmask]
>>Subject:  Assembly - Wave Solder Pinholes
>>Resent-From: [log in to unmask]
>>X-Mailing-List: <[log in to unmask]> archive/latest/11745
>>X-Loop: [log in to unmask]
>>Precedence: list
>>Resent-Sender: [log in to unmask]
>>
>>Trying to elimenate pinholes(many) and blowholes(some)
>>
>>Situation:
>>Through hole technology, 0.062 double side PCB
>>OA 20% solids flux, .905 spec gravity
>>Wave Temp - 500*F  Preheat top side temp of 190*F
>>Speed 4.5 FPM
>>
>>Have tried baking 215*F for 2 hours
>>Have microsectioned board, copper in holes looks good
>>
>>Believe some components could be contaminated, could this cause the
>>condition?
>>Looking for suggestions

***ALL NEW EMPF PHONE NUMBERS***

Jack Crawford, HelpLine Coordinator
Electronics Mfg. Productivity Facility
****NEW--317.655.3688
****FAX  317-655-3699
714 N Senate Ave, Suite 100
Indianapolis IN  46202-3112
VISIT OUR HOME PAGE AT: http://www.empf.org
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