TECHNET Archives

January 2006

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:
Jeffrey Bush <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Jeffrey Bush <[log in to unmask]>
Date:
Tue, 24 Jan 2006 08:54:46 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (81 lines)
Gloss mask 

- will increase the propensity for solderballs in assembly
- may have issues with conformal coat wetting
- may have issues is resolving covered fiducials due to high reflection
- material tends to hide defects/conditions on the PCB surface
- Gloss mask does offer a cleaner surface since the profile is lower 

Matte mask

- prevents solderballs as surface tension is low
- has good wetting/adhesion for confomal coating
- has good resolution for fiducial recognition - low reflection
- shows PCB surface conditions readily
- is more difficult to clean, ionics are high - although I think looks
better with no-clean

We lean to a mask that is middle of the road in light absorption - ~
45-55%.  This seems to satisfy the spectrum of needs in fab and by our
users.   
   

Jeffrey Bush
Director, Quality Assurance and Technical Support
VERMONT CIRCUITS INCORPORATED 
           76 Technology Drive - POB 1890 
              Brattleboro, Vermont 05302
                Voice - 802.257.4571 ext 37 
                    Fax - 802.257.0011
                       <http://www.vtcircuits.com/> 
                           

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Chris Ball
Sent: Monday, January 23, 2006 1:03 PM
To: [log in to unmask]
Subject: [TN] LPI - matte vs. gloss or semi-gloss

Hello All-

For many years we have specified matte finish LPI soldermask. Have a
supplier asking us to switch to gloss or semi-gloss to avoid 'solder
smear'
issues.

Any input as to the pros and cons of each would be appreciated.

I think I remember issues finding fiducials with glossy mask but I might
just be making that up, and all the equipment has changed since then
anyway.....

Thanks in advance,
-Chris

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text
in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at:
http://listserv.ipc.org/archives
Please visit IPC web site
http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100
ext.2815
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------

ATOM RSS1 RSS2