What does the internal die do to the test?

> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Doug Pauls
> Sent: Wednesday, October 29, 2003 12:21 PM
> To: [log in to unmask]
> Subject: Re: [TN] IPC Cleaning Evaluation using B-36 coupons
>
>
> Jack,
> 1.    Qualify the cleaning process to what standard?  That
> may restrict
> what you can or cannot use as a component.
> 2.    If you will be doing SIR testing, you have to make sure that the
> component package HAS NO INTERNAL DIE, or a true mechanical
> dummy.  Many of the Practical Components or TopLine dummy
> components are packages with blown die, which can mess up
> SIR.  Both companies do have these true dummies as available
> part numbers, but you may have to wait 6-8 weeks if they have
> to have them made for you.  If you are doing only cleanliness
> testing, such as ROSE or IC, this distinction is irrelevant.
> 3.    The B-36 board should come with solder mask on four
> points under the
> LCC which should give you a 5 mil standoff.  You can have
> them made with thicker solder mask for greater standoff, but
> your solder volume may need to be increased, although the
> B-36 is not used as a solder demonstration platform.  The
> PLCC is rather high in standoff.  If you can find a gull wing
> with the proper I/O go for it.
> 4.    The issue of whether the B-36 board is an accurate
> representation of
> product has always been a difficult one.  The standard B-36
> has minimal solder mask and exposed metal, usually bare
> copper, under the components. Usually not indicative of
> actual product.  Who are you trying to convince with the data?
>
> Doug Pauls
> Rockwell Collins
>
>
>
>
>                       Jack Evans
>                       <jack.evans@AEROF        To:
> [log in to unmask]
>                       LEX.COM>                 cc:
> (bcc: Douglas O Pauls/CedarRapids/RockwellCollins)
>                       Sent by: TechNet         Subject:  [TN]
> IPC Cleaning Evaluation using B-36 coupons
>                       <[log in to unmask]>
>
>
>                       10/29/2003 10:44
>                       AM
>                       Please respond to
>                       "TechNet E-Mail
>                       Forum."; Please
>                       respond to Jack
>                       Evans
>
>
>
>
>
>
> Hello,
> I am getting ready to qualify a new cleaning process using
> IPC B-36 test coupons and I am looking for suitable
> components for the test. The board was designed for the use
> of a 68 pin LCC or PLCC. The footprint is about .800 mils
> inside pad to pad square. The pad length is apx .100 mils.
> The problem with the components mentioned above are: The PLCC
> from Practical Components has a standoff height of about .020
> mils and the LCC fits tight to the board with no stand off at
> all. If I use the LCC I will likely fail the SIR testing
> because I don't think I can get under it to clean completely.
> If I use the PLCC, I will clean it ok, but I don't feel that
> it is a practical representation of what we see in
> production. I would really like to find a QFP that would fit
> this footprint and that I can form to a more realistic
> standoff height. Does anyone have any suggestions?

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