TECHNET Archives

September 2000

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Brian Ellis <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Fri, 22 Sep 2000 10:57:02 +0300
Content-Type:
text/plain
Parts/Attachments:
text/plain (68 lines)
A thick film "board" is generally a ceramic substrate on which successive conductor,
insulating and resistive frit pastes are silk-screened. After each frit is deposited,
it is melted in a furnace to form the pattern with the desired electrical
characteristics. A frit is a suspension of a fine low melting point glass powder in a
suitable solvent/rheological additives vehicle, to which is added a metallic or
resistive powder. As it goes through the furnace zones, the solvents are firstly
evaporated, the other organics are oxidised to gases and finally the glass melts,
bringing the metal particles into contact to form a homogeneous conductor or fusible
metal oxide particles to form a ceramic/glass resistor (e.g. cermet). Each successive
layer uses a glass of a slightly lower melting point. Nearly any metal or alloy with a
melting point higher than that of the glass can be thus deposited. It is common to use
noble metals for the conductors, but copper is also much used and is cheaper. With the
correct choice and proportions of metal and glass, the resultant fired deposit is also
solderable or bondable for adding components.

There are probably thousands of jobbing shops of variable quality throughout the world,
capable of doing this work at either proto or production stages or both. If there is
one close to you who seems capable of doing what you want, then this may be the best
bet. Otherwise, one of the larger specialist companies (C-MAC in West Palm Beach, Fl is
one example that springs to mind) will produce both your proto and production
quantities. There is a list of producer-members on the www.imaps.org site.

Hope this helps.

Brian

Mark Hargreaves wrote:

> Hi All,
>      Can anyone suggest a source for thick film boards in prototype
> quantities.
> Also, would someone kindly give me the short definition of thick film
> boards.
>
> Thanks,
> Mark Hargreaves
>
> P.S. This is my 1st post, although I've been watching from the shadows for a
> few weeks. Useful & interesting subjects; timely & friendly responses.
>
> ##############################################################
> TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d
> ##############################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
> the body:
> To subscribe:   SUBSCRIBE TECHNET <your full name>
> To unsubscribe:   SIGNOFF TECHNET
> ##############################################################
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
> information.
> If you need assistance - contact Keach Sasamori at [log in to unmask] or
> 847-509-9700 ext.5315
> ##############################################################

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################

ATOM RSS1 RSS2