Everyone you are mistaken. At first when I read the comment I thought as you
did. Plating thickness. 0.4mm is 15.7 mils. If you can make .016 of Cu
connect there is a big problem here. I believe he is referring to the
diameter of the hole. He has used the word barrel which is deceiving. What
you have here my friend is a ring void. The fact that the PCB's have been
processed with Immersion Tin finish is apparent the boards have not been
through a thermal stress related process at the board vendors end. My
recommendation is a solder float 5x @ 10 second intervals @ 500F. This will
emulate the process of the wave soldering process when assembling the parts.
It will also give you a good indication whether or not the vias can
withstand that type of punishment. However most of the comments stated are
true. 8 tenths of a mil is the minimum. 1 ounce (1.4mils) preferred.

Merry X-Mas Everyone. Here's hoping 03 is better than 02.

Regards,

Damon A. DeSilva
Engineering Manager
Lazer-Tech Ltd.
PH#(416)291-7727 EXT:271
FAX(416)291-0325
[log in to unmask]


-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of [log in to unmask]
Sent: Thursday, December 19, 2002 11:44 AM
To: [log in to unmask]; [log in to unmask]
Subject: [TN] Plated Through Holes


Hi everyone
Can anyone tell me what the recommended thickness of the barrels of PTH's
is?
We have a minor problem with 0.4mm dia. barrels not giving good ground from
top of board to ground plane on underside.
Boards are double sided PTFE / copper track / Emersion tin RF boards.

Richard Brennan
Manufacturing Support Manager
Health & Safety Manager
Aerial Facilities Ltd
Aerial House
Asheridge Road
Chesham
Bucks
HP5 2QD
01494 777000
Direct line
01494 777052

[log in to unmask]

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