Mike, there is a page in the back of (most) all IPC documents called "Standard
Improvement Form".  All users are encouraged to copy that page, add whatever
suggestions they have, and fax or mail it to us.  We then route it to the appropriate
committee working on the documents.  Alternately, you can e-mail us, providing the
same information requested on the form.

Note that comments received "This doesn't work for us" or "Our company doesn't agree
with..." don't get action because there is no action to take.  Provide your
suggestion AND provide valid technical reasons for your suggestion. If you are
suggesting something that is contrary to an existing requirement, you may be offered
the opportunity to share supporting data to substantiate your suggested change.

Standards developed by members of IPC are industry consensus documents that anyone is
free to review during draft development and invited to ballot for
acceptance/rejection.  Notices regarding availablility of drafts for review are
published in the IPC Monthly Newsletter "REVIEW" and are provided as press releases
to most major industry magazines.  IPC members that attend any committee meeting for
a specific document automatically receive draft copies when they are ready to be
circulated. Non-IPC members that attend a committee meeting do NOT automatically
receive draft copies, but they are provided on request.  (Non-members must
specifically request for each draft circulation.  It's a benefit of membership,
folks.) Comments are accepted from anybody anytime.  Balloting for acceptance is done
by everyone, IPC member or non-member, that has participated in any part of the
document development or who otherwise advises us that they want to ballot.  NO votes
on a ballot require technical substantiation or the committee has the right to
discard the NO vote.  The total process is much more involved than I can go into
here, but it is ANSI approved.  jack

IPC/SMTA Electronics Assembly Expo
Technical Committee Meetings, Conference, Exhibits
Providence RI   October 24-29
More info at http://www.ipc.org

Jack Crawford, IPC Project Manager - Assembly
2215 Sanders Road, Northbrook IL  60062-6135
[log in to unmask]      847-509-9700 x 393     fax 847-509-9798

>>> "McMonagle, Michael R." <[log in to unmask]> 07/02/98 09:21AM >>>
Jim,
        You mention at the bottom of your post that ANSI & IPC are
currently under revision. How would one go about submitting revision
suggestions to the committees? As a contract manufacturer, we see a
variety of situations that current standards can leave open to broad
interpretation both internally and externally.

Mike McMonagle
K*Tec Electronics

> -----Original Message-----
> From: [log in to unmask] [SMTP:[log in to unmask]]
> Sent: Thursday, July 02, 1998 8:54 AM
> To:   [log in to unmask]
> Subject:      [TN] ReDewetting
>
> A couple of comments regarding dewetting:
> - Dewetting is a problem in ANY product, not just high reliability
> products.
> - IMHO you should be looking for causative factors instead of looking
> for
> references in the manufacturing standards (presumably to confirm/deny
> that
> dewetting is a defect).
> - Your questions didn't give a clue as to whether the problem is
> associated
> with leaded components in pth, or with surface mount, so I'll try to
> cover
> both briefly.  In answer to your questions, what standards apply and
> what
> paragraphs of which standard can be applied to dewetting, the
> following
> information, based on ANSI/J-STD-001B (Requirements for Soldered
> Electrical
> and Electronic Assemblies) and IPC-A-610B (Acceptability of Electronic
> Assemblies) is provided.
> - For plated through holes:
> 1) ANSI/J-STD-001B.  Defect #  6 of Table 11-1 (Hardware Defects)
> refers to
> par. 9.2.5.1 which says "The solder joint MUST provide evidence of
> good
> wetting and plated through hole solder fill MUST meet the requirements
> of
> Table 9-1 and Figure 9-3."   Table 9-1 and Figure 9-2 provide detailed
> information regarding solder coverage and percent of wetting required.
> Note
> that when the word MUST is used it means that the requirement is
> mandatory for
> all 3 Product classes.
> 2) IPC-A-610B.  Paragraph 4.1 includes Table 4-1 (comparable to Table
> 9-1 of
> J-STD-001) which describes wetting requirements.  The text below
> Figure 4-3
> requires an acceptable solder connection to have evidence of wetting
> and
> adherence when the solder blends to the soldered surface or be
> considered a
> Defect for all 3 Product classes.  Text below Figure 4-9 lists a
> solder
> connection which has poor wetting as a Defect for all 3 Product
> classes.
> A-610 includes multiple references to the effect that wetting is a
> required
> attribute for a connection to be considered acceptable, but does not
> specifically list dewetting as a Defect.
> - For Surface Mount:
> 1) ANSI/J-STD-001B:  Wetting is not broadly or universally "required"
> for SMT
> by the J-STD-001B.  Bear in mind that only the items listed as
> Hardware
> Defects by Table 11-1 are actually considered "defects" (words in the
> text of
> the document are essentially advisory in nature and failure to meet
> the
> requirements of the text does not constitute a defect unless the
> condition is
> listed in Table 11-1).    The solder connection criteria which can be
> applied
> to SMT are in Table 11-1, Defect # 20 which references paragraph
> 9.2.4.1
> (wetting is not a requirement of par. 9.2.4.1).  You can find some
> limited
> requirements for wetting of SMT solder connections in the notes
> associated
> with Tables 9-2 through 9-9 inclusive.
> 2) IPC-A-610B.  Par. 10.2.1 says (below Figure 10-9): "A properly
> wetted
> fillet is not evident" is a Defect for all 3 Product classes.  Par.
> 10.2.2
> says (below Figure 9-15): Dewetted or nonwetted joint is a Defect for
> all 3
> Classes.  Also below Figure 10-22 absence of a properly wetted fillet
> is
> defined as a Defect for all 3 Product classes.  The IPC-A-610B
> document
> continues to require a properly wetted fillet for all classes of
> product
> throughout Section 10 (Surface Mount Assemblies).
> - Hope the above helps identify the source of the requirements.  Note
> that
> both ANSI/J-STD-001B and IPC-A-610B are presently being revised.  One
> of the
> goals of the revision committees is to clarify the requirements so
> that the
> documents can be more easily understood and used.  If you can find
> time your
> participation in the revision process would be welcomed.
> Regards, Jim Moffitt, Moffitt Enterprises
>
> ################################################################
> 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's web site (http://www.ipc.org) "On-Line Services"
> section for additional information.
> For technical support contact Hugo Scaramuzza at [log in to unmask] or
> 847-509-9700 ext.312
> ################################################################

################################################################
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's web site (http://www.ipc.org) "On-Line Services" section for
additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700
ext.312
################################################################

################################################################
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's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################