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Subject: RE: [Homebrew_PCBs] Re: Slightly OT: What are these called?

From: "Bertho" <boman33@...>
Date: 2017-10-15

Note:  For joining top to bottom layers as is normally done, you do not want perfect little tubular eyelets.  You should use eyelets that are formed from a strip and rolled into the eyelet shape.  It will have a desirable vertical slit in it.

I know it sounds backwards the reasons are valid.

Many decades ago Motorola used eyelets on PCBs instead of through hole plating.  Originally nice round eyelets were used and there were a lot of field failures.  The solder properly solders the bottom section to the runner, it wicks up through the eyelet and solders the component lead but there is no capillary action to draw the solder over the eyelet’s top edge onto the top runner so it only makes mechanical contact.  The eyelets with a vertical slit avoids that problem.

Bertho

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
Sent: Sunday, October 15, 2017 16:19
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: Slightly OT: What are these called?