Yes I understand - where the conductor joins you are allow .002" and
.001" as stated in f.
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: Paymon Sani [mailto:[log in to unmask]]
Sent: Friday, March 30, 2007 3:24 PM
To: TechNet E-Mail Forum; Jeffrey Bush
Subject: RE: [TN] Solder Resist Encroachment onto BGA pads
Hi Jeffry, the criteria that you mentioned below applies to fine pitch
components but not BGAs. In 6012B, the next paragraph just below it
suggests no solder resist encroachment for the NSMD BGA pads. The same
is also said in IPC-600A.
I followed up with the links that Steve provided. In conclusion, the
solder resist is not allowed to encroach on NSMD, BGA pads for 2
reasons:
1- It reduces the product reliability because it creates high stress
points, therefore cracking of the solder joint.
2- The BGA solder joint stresses are balanced between the component and
the PCB; this is achieved by selecting the correct pad dimension. The
encroaching solder resist disturbs the PCB pad geometry causing more
stresses on the solder joint to the PCB.
Cheers,
Paymon Sani
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Jeffrey Bush
Sent: March 30, 2007 1:45 PM
To: [log in to unmask]
Subject: Re: [TN] Solder Resist Encroachment onto BGA pads
IPC-6012 allows .002" for 50 mil or greater pitch and .001" for <50 mil
pitch. 3.7.1.f.1
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 Ian Hanna
Sent: Friday, March 30, 2007 12:26 PM
To: [log in to unmask]
Subject: Re: [TN] Solder Resist Encroachment onto BGA pads
600A 2.9.3.2 "BGA --Copper Defined Lands -- Class I/II/III Acceptable
== 'soldermask does not encroach on the land, except at the conductor
attachment' -- Nonconforming == does not meet...
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D.
Sent: Friday, March 30, 2007 11:16 AM
To: [log in to unmask]
Subject: Re: [TN] Solder Resist Encroachment onto BGA pads
Where does it say that it is not allowed?
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Paymon Sani
Sent: Friday, March 30, 2007 11:02 AM
To: [log in to unmask]
Subject: [TN] Solder Resist Encroachment onto BGA pads
Hello All,
Does anybody know why IPC does not allow any solder resist encroachment
onto the BGA copper defined lands for PCBs?
------------------------------------------------------------------------
---------------
Confidentiality Notice
This e-mail and any attachment(s) are intended for the individual or
entity to which this email is addressed and may contain information that
is confidential. If you are not the intended recipient or an employee
or agent responsible for delivering this e-mail to the intended
recipient, please be aware that any dissemination, distribution or
copying of this communication is strictly prohibited. If you have
received this in error, please notify the sender by telephone at
604.430.4336 or by return e-mail, and please delete or destroy all
copies of this communication. Thank you!
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0
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 15.0
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 15.0
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
-----------------------------------------------------
------------------------------------------------------------------------
---------------
Confidentiality Notice
This e-mail and any attachment(s) are intended for the individual or
entity to which this email is addressed and may contain information that
is confidential. If you are not the intended recipient or an employee
or agent responsible for delivering this e-mail to the intended
recipient, please be aware that any dissemination, distribution or
copying of this communication is strictly prohibited. If you have
received this in error, please notify the sender by telephone at
604.430.4336 or by return e-mail, and please delete or destroy all
copies of this communication. Thank you!
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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
-----------------------------------------------------
|
