The PPT process is very useful for controlling solder deposits
especially on fine pitch and micro-BGA parts as well as on very fine designs
used for direct chip attach using a CC-4 approach.
This process provides a very defined volume of solder which cannot be
accomplished by normal stencil printing and if that is your goal, I think
that the economics work out very well. The cost is a lot less than you will
get with other
solder deposit methods I have looked at!
Contact: JoAnne DeBlis
714-557-3383
[log in to unmask]
-----Original Message-----
From: Paul Klasek [SMTP:[log in to unmask]]
Sent: Wednesday, May 13, 1998 3:45 PM
To: [log in to unmask]
Subject: Re: [TN] HASL alternatives
Scott
The PPT is formed with a mesh process ; leaving the checkered imprint
on
the surface ; supposedly keeping the flux in place .
You still pay for the stencil ; only shift the process to bare board
.
The polished rollers process sounds intriguing .
I've send a reply to this topic few moths back ; it'll be in files ,
incl. the contacts .
From cost , no clean , double sided application , ( you do need a
reflow
with chiller of bottom side ), etc. , it is impractical for most of
the
assy spectrum . Very limiting and complex on the mix TH & SMD as well
.
There are better and cheaper ways how eliminate stencil process ,
pending the application .
See you paul ; ResMed
>----------
>From: Lolmaugh, Scott (AZ15)[SMTP:[log in to unmask]]
>Sent: Thursday, 14 May 1998 0:15
>To: [log in to unmask]
>Subject: Re: [TN] HASL alternatives
>
>All,
>There was an interesting article in the February issue of SMT
Magazine
>(IHS Publishing Group) on page 56, entitled: "End Paste Defects with
>Solid Solder Deposits". This is a technique where the PWB
Manufacturer
>applies solder to the board, then runs the boards through polished
>rollers to flatten the solder coating into a flat surface roughly
the
>same height as the soldermask. Then a tacky flux is applied and
finally
>an easy peel cover sheet. They claim the boards retain
solderability
>well and the paste stencil process is eliminated.
>
>There have been similar / identical techniques touted in the past,
known
>as:
>"Sipad" (R) Siemens AG, (solderpaste application method)
>"Optipad" (R) Viele Circuits Inc. and Burkle USA, (liquid solder
>application method) and
>"Precision Pad Technology or PPT (R) Mask Technology Inc.
(solderpaste
>application w/ textured finish)
>
>If anyone knows of domestic (USA) Manufacturers offering this
technology,
>I'd like to hear who they are.
>Thanks
>Best Regards,
>Scott Lolmaugh
>SMT Production Engineering
>Honeywell IAC, Inc.
>602.313.3551 /FAX: 3402 (Please call first)
>
>
> -----Original Message-----
>From: [log in to unmask]
>Sent: Wednesday, May 13, 1998 8:39 AM
>To: [log in to unmask]
>Subject: [TN] HASL alternatives
>
>To All,
>We are now making a comparison between different alternatives to
HASL.
>The
>chosen alternative will have to meet the following criterias
criterias.
>
> - flat coating
> - compatible with No-clean process and mixed technology
> - resistant to 2-3 reflow (multiple heat cycle)
> -and MINIMUM 1 year shelf life (storage before assembly)
>
>These are the alternatives we think can meet our needs:
>
>* OSP
> - Benzimidazole (?)
>
>* IMMERSION
> - Silver
> - Bismuth
> - Au-Ni
> - Palladium
>
>
>Q: Wich one do you think could be the best meet to our criterias ?
>
>Q: And what would be its advantage(s) compared to the others ?
>
>Q: OTHERS ? (is anyone using other coating alternative )
>
>
>Thanks for all for your help
>
>
>Nicolas van der Heyden
>
>################################################################
>TechNet E-Mail Forum provided as a free service by IPC using
LISTSERV
>1.8c
>################################################################
>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://jefry.ipc.org/forum.htm) for
additional
> information.
>For the technical support contact Dmitriy Sklyar at [log in to unmask]
or
> 847-509-9700 ext.311
>################################################################
>
>################################################################
>TechNet E-Mail Forum provided as a free service by IPC using
LISTSERV 1.8c
>################################################################
>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://jefry.ipc.org/forum.htm) for
additional
>information.
>For the technical support contact Dmitriy Sklyar at [log in to unmask]
or
>847-509-9700 ext.311
>################################################################
>
>
################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV
1.8c
################################################################
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://jefry.ipc.org/forum.htm) for
additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or
847-509-9700 ext.311
################################################################
################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
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://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################
|
