Date:     Sat, 8 Dec 2001 00:00:03 -0600
Reply-To: TechNet <[log in to unmask]>
Sender:   TechNet <[log in to unmask]>
From:     Automatic digest processor <[log in to unmask]>
Subject:  TechNet Digest - 7 Dec 2001 (#2001-765)
To:       Recipients of TechNet digests <[log in to unmask]>

There are 7 messages totalling 421 lines in this issue.

Topics of the day:

  1. BGA Visual Inspection (2)
  2. PWB Fab Note Question - Diameter True Position (3)
  3. BGA Rework Equipment (2)

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------
Date:    Fri, 7 Dec 2001 14:49:57 EST
From:    "Stephen R. Gregory" <[log in to unmask]>
Subject: Re: BGA Visual Inspection
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="part1_177.5fb76f.29427765_boundary"

Hi Greg!

We've had a ERSA scope for about a year now, and I like it. We originally bought it because we ran into a problem with a BGA that we were placing on one of our customers boards. It was a super BGA from TI and they obsoleted it, the replacement from TI had a big metal heatsink in the top of it and the Glennbrook RTX-113 we have wasn't powerfull enough for us to see through it, so we bought the ERSA scope.

It takes a little while to get used to using it, but I like it. X-ray can do things that the ERSA scope can't, and the ERSA scope can do things that X-ray can't. I feel that they compliment each other.

There's been more than a few times that test has given me a board telling me that the BGA has shorted and needs replacing. I would inspect it under the ERSA scope and give it back to them telling them that there isn't a short on the BGA....sure enough, after they did some more trouble-shooting it turned out to be something else.

-Steve Gregory-


-Steve Gregory-

TechNet Friends,
>       We are looking into visual inspection of BGAs to supplement our
> X-Ray inspection.  I am somewhat familiar with the ERSASCOPE.  It appears
> to be a fully developed, well-thought out system, with all the options to
> make life easy.  It appears that their supplemental tools in fact, do add
> value to the endoscope itself.  This, of course, comes at a price.
>       I'm hoping to hear from people who have personally evaluated such
> tools.
>       Are all the features of the ERSA truly benefits?
>       Are there other systems that do what the ERSASCOPE does?  Are they
> as fully developed as the ERSA?
>
> Thanks for your help with this one,
>       I
>
> Greg Anderson
> Senior Advanced Manufacturing Engineer
> GE Fanuc Automation
> Charlottesville, VA 22911
> Phone:  434-978-5181
> FAX:  434-978-5898
> e-mail: [log in to unmask]

Date:    Fri, 7 Dec 2001 14:01:22 -0600
From:    Scott Kauling <[log in to unmask]>
Subject: PWB Fab Note Question - Diameter True Position

In IPC 2221 section 9.2.2 describes hole location tolerance, it is
expressed as "diameter about true position".  IPC T-50 defines "true
position", not diameter about true position.

My questions are:

        1. How does the diameter about come into play with the true position?

        2. What tolerance of diameter about true position do you specify on your
fab prints

        3. What is the typical capability of diameter about true position that PWB
fabricators hold?

Thanks in advance for your input.

Have a good weekend!

Scott Kauling
Date:    Fri, 7 Dec 2001 15:38:19 -0500
From:    "Roger M. Stoops" <[log in to unmask]>
Subject: Re: PWB Fab Note Question - Diameter True Position
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii

1. How does the diameter about come into play with the true position?

Table 9-3 defines the diameter about true position, or tolerance around
true position expressed as a circular value, compared to the square
tolerance area with non-GD&T dimensioning.  IPC-2615 does a pretty good job
explaining how GD&T works (for the curious).  Figure 6-8 on page 28 of
IPC-2615 helps answer your question.

2. What tolerance of diameter about true position do you specify on your
fab prints?

Though Table 9-3 specifies 0.2mm for Level B boards, I typically specify
0.15mm, or 0.006, MMC.  As the drill/hole size gets larger, the tolerance
zone increases in size.  For non-critical features, I specify 0.2mm or
0.25mm.

3. What is the typical capability of diameter about true position that PWB
fabricators hold?

I'll leave this to one of our fabricator friends.

Roger M. Stoops, C.I.D., PCB Designer
[log in to unmask]


Trimble
Engineering and Construction Division
5475 Kellenburger Rd.
Dayton, OH 45424-1099 USA
Ph: +01 937.233.8921 or +01 937.233.4574 ext 288
Fax: +01 937.233.7511



                    Scott Kauling
                    <skauling@TRI-        To:     [log in to unmask]
                    ONICS.COM>            cc:
                    Sent by:              Subject:     [TN] PWB Fab Note Question - Diameter True Position
                    TechNet
                    <[log in to unmask]
                    RG>


                    12/07/01 03:01
                    PM
                    Please respond
                    to "TechNet
                    E-Mail Forum."





In IPC 2221 section 9.2.2 describes hole location tolerance, it is
expressed as "diameter about true position".  IPC T-50 defines "true
position", not diameter about true position.

My questions are:

        1. How does the diameter about come into play with the true
position?

        2. What tolerance of diameter about true position do you specify on
your
fab prints

        3. What is the typical capability of diameter about true position
that PWB
fabricators hold?

Thanks in advance for your input.

Have a good weekend!

Scott Kauling
Date:    Fri, 7 Dec 2001 13:03:34 -0800
From:    "Crepeau, Phil" <[log in to unmask]>
Subject: Re: PWB Fab Note Question - Diameter True Position
MIME-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"

hi,

true position can be expressed as a radius or a diameter.  possibly this is what your dimension is telling you.

phil

-----Original Message-----
From: Scott Kauling [mailto:[log in to unmask]]
Sent: Friday, December 07, 2001 12:01 PM
To: [log in to unmask]
Subject: [TN] PWB Fab Note Question - Diameter True Position


In IPC 2221 section 9.2.2 describes hole location tolerance, it is
expressed as "diameter about true position".  IPC T-50 defines "true
position", not diameter about true position.

My questions are:

        1. How does the diameter about come into play with the true position?

        2. What tolerance of diameter about true position do you specify on your
fab prints

        3. What is the typical capability of diameter about true position that PWB
fabricators hold?

Thanks in advance for your input.

Have a good weekend!

Scott Kauling

---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------
Date:    Fri, 7 Dec 2001 15:42:08 -0600
From:    Will Cabrera <[log in to unmask]>
Subject: BGA Rework Equipment

I work for a small OEM company and I am looking for BGA rework equipment
for in-house use. We sub out our low-volume PCA assembly and ICT. Any
recommendations on what BGA Rework equipment/supplier I can evaluate?

Will
Date:    Fri, 7 Dec 2001 16:17:36 -0600
From:    [log in to unmask]
Subject: Re: BGA Rework Equipment
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii

If you like to out source things just do the same for BGA repair, the good
equipment (SRT) can be $50-70K and it requires
a bit of experiance to get it right. Develop removal profiles, site clean-up and
 prep, repair damaged pads and mask, reballing
BGAs, micro stencil paste, reflow profiles, This could be a long process to
develope. Try to send out Citcuit Tech.
http://www.circuittechctr.com/services/bga.htm
is one of many who can do it. Good luck!








Will Cabrera <[log in to unmask]> on 12/07/2001 03:42:08 PM

Please respond to "TechNet E-Mail Forum." <[log in to unmask]>








 To:       [log in to unmask]

 cc:       (bcc: Warren Crow/US/I-O INC)



 Subject:  [TN] BGA Rework Equipment








I work for a small OEM company and I am looking for BGA rework equipment
for in-house use. We sub out our low-volume PCA assembly and ICT. Any
recommendations on what BGA Rework equipment/supplier I can evaluate?

Will

---------------------------------------------------------------------------------

Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET Technet
NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
---------------------------------------------------------------------------------
Date:    Fri, 7 Dec 2001 17:22:23 -0800
From:    David Fish <[log in to unmask]>
Subject: Re: BGA Visual Inspection
MIME-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: 7bit

Look to the SMTA Knowledgebase for:

09/24/2000   "COMBINING VISUAL AND X-RAY INSPECTION OF AREA ARRAY DEVICES "
Douglas J. Peck,  AEIC

Dave Fish

----- Original Message -----
From: "Anderson, Greg (IndSys, GEFanuc, NA)" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, December 07, 2001 8:43 AM
Subject: [TN] BGA Visual Inspection


> > TechNet Friends,
> >       We are looking into visual inspection of BGAs to supplement our
> > X-Ray inspection.  I am somewhat familiar with the ERSASCOPE.  It
appears
> > to be a fully developed, well-thought out system, with all the options
to
> > make life easy.  It appears that their supplemental tools in fact, do
add
> > value to the endoscope itself.  This, of course, comes at a price.
> >       I'm hoping to hear from people who have personally evaluated such
> > tools.
> >       Are all the features of the ERSA truly benefits?
> >       Are there other systems that do what the ERSASCOPE does?  Are they
> > as fully developed as the ERSA?
> >
> > Thanks for your help with this one,
> >       I
> >
> > Greg Anderson
> > Senior Advanced Manufacturing Engineer
> > GE Fanuc Automation
> > Charlottesville, VA 22911
> > Phone:  434-978-5181
> > FAX:  434-978-5898
> > e-mail: [log in to unmask]
> >
> >
> >
>
> --------------------------------------------------------------------------
-------
> Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
> 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 delivery of Technet send the following message: SET
Technet NOMAIL
> Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
> information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
> --------------------------------------------------------------------------
-------
>