People just don't realize that J-STD-001 and IPC-A-610 and not design standards.
Jack Crawford
Certification and Assembly Technology
IPC – Association Connecting Electronic Industries®
3000 Lakeside Dr. Suite 309S
Bannockburn, IL 60015
847-597-2893
Fax 847-615-5693
[log in to unmask]
www.ipc.org
www.ipc.org/status www.ipc.org/certification www.ipc.org/downloads
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Whittaker, Dewey (EHCOE)
Sent: Tuesday, March 18, 2014 9:41 AM
To: Technet
Subject: Re: [TN] Confusion about conformal coating area
Conformal coating is art on to itself. When PBAs are designed with specific coating systems in mind; relative bliss. When your ISC department gets hold of them and outsources them to Benny and Gill's Hash House; indigestion is the least of your worries. All the PBAs should (I really wanted to say shall) be controlled by the Drawing and Engineering support documentation. Below is set of Conformal Coat notes for PBA drawings.
NOTE 7. COAT ASSEMBLY PER Item/FN (Manufacturing specification for Conformal Coating listed in the BOM) USING Item Item/FN (Material Code Number of the Conformal Coat material), UNLESS OTHERWISE SPECIFIED:
7.1. OMIT COATING FROM AREA OUTSIDE OF PHANTOM LINE,
ALL AROUND, BOTH SIDES.
7.2. OMIT COATING FROM BODY OF Item/FN (part identification on BOM).
7.3. OMIT COATING FROM PRIMARY SIDE OF Item/FN (part identification on BOM).
7.4. OMIT COATING FROM ADJUSTING SCREW ON Item/FN (part identification on BOM).
7.5. OMIT COATING THIS AREA, BOTH SIDES.
7.6 COATING MAY OR MAY NOT BE PRESENT IN NON-CRITICAL
LAMINATE AREAS OF Item/FN (part identification on BOM) OR ON THE TOP AND SIDE
OF THE NON-CRITICAL, NON-CONDUCTIVE SURFACES OF
LARGE SCALE PACKAGES, UNLESS OTHERWISE
SPECIFIED. THIS EXCEPTION IS FOR THE COATING
COVERAGE REQUIREMENT AND SHALL NOT BE USED TO
ACCEPT UNCOATED AREAS DUE TO BUBBLES, VOIDS AND
OTHER WORKMANSHIP ISSUES.
This appeases Engineering that all critical areas are covered and is simple enough that even ISC and the Supplier can understand the requirement.
Dewey
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of lduso - Diamond-MT.com
Sent: Monday, March 17, 2014 2:37 PM
To: [log in to unmask]
Subject: Re: [TN] Confusion about conformal coating area
That's always been the confusing part, there needs to be a third area in the "plain language". Coating where it *needs* to be, no coating where it
*cannot* be, and areas where coating *can* be, but doesn't *have *to be.
Coating can (and often does) de-wet on top of component or de-wets out in the middle of the soldermask, no place that requires coating but somewhere that is not worth masking. Is that a reject?
Lloyd Duso
Diamond-MT
Plant Manager
(814) 535-3505
www.Diamond-mt.com
On Mon, Mar 17, 2014 at 5:15 PM, Jack Crawford <[log in to unmask]> wrote:
> The plain language requirements for conformal coating are:
> Coating shall be where it is required to be, and there shall not be
> any coating where it isn't required.
>
> J-STD-001E Clause 10.1.1 Application Coating shall [D1D2D3] be applied
> in a continuous manner TO ALL AREAS DESIGNATED FOR COVERAGE ON THE
> ASSEMBLY DRAWING/DOCUMENTATION.
>
> IPC-A-610E Clause 10.8.2 Acceptable - Class 1,2,3 Coating only in
> those areas WHERE COATING IS REQUIRED. Defect - Class 1,2,3 Coating is
> on areas required to be free of coating, e.g., mating surfaces,
> adjustable hardware, wicking into connector housings, etc.
>
> If the drawings/documentation don't require coating J-STD-001 and
> IPC-A-610 don't separately cause a requirement for coating.
>
> Jack Crawford
> Certification and Assembly Technology
> IPC - Association Connecting Electronic Industries®
> 3000 Lakeside Dr. Suite 309S
> Bannockburn, IL 60015
> 847-597-2893
> Fax 847-615-5693
> [log in to unmask]
> www.ipc.org
> www.ipc.org/status www.ipc.org/certification www.ipc.org/downloads
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Richard Kraszewski
> Sent: Sunday, March 16, 2014 5:44 PM
> To: Technet
> Subject: Re: [TN] Confusion about conformal coating area
>
> You and your organization are not the only ones being driven crazy by
> this these specifications. Current J-Std-001 leads you to believe all
> must be coated. The A610 seems to make better use of the acronym AABUS (as
> agreed between user and supplier). In my experience, you can sometimes
> explain and convince the customer that there is little value in
> coating the side of molded components. Only try electrical conductors.
>
> More often than not, this is easier done at the start of a program
> rather than after the fact.
>
> Rich Kraszewski
> PLEXUS
> (920)969-6075
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Çetin Yegin
> Sent: Friday, March 14, 2014 3:02 AM
> To: [log in to unmask]
> Subject: [TN] Confusion about conformal coating area
>
> Dear All,
>
> We have a confusion about conformal coating area. Our quality
> department rejects some boards because edges of some high components were not coated.
> These edges are non-conductive and I think there is no need to coat
> non-conductive areas. IPC-A-610 10.5.2 says that "Conformal coatings
> should be transparent, uniform in color and consistency and uniform
> cover the board and components".
>
> 1. Does it mean we have to coat all areas unless specified in design
> document?
>
> 2. Is there any requirement to coat non-conductive areas?
>
> 3. Do we have to coat non-conductive areas of components?
>
>
> Thanks.
>
> Best Regards
>
> Çetin YEĞİN
> Senior Engineer
>
> ASELSAN A.S. \ ASELSAN INC.
> Microelectronics, Guidance and Electro-Optics Division (MGEO) Çankırı
> Yolu, 7. km, 06750 AKYURT, ANKARA, TURKEY
> Phone: +90 (312) 847 53 00 Ext:4071
> Fax: +90 (312) 847 53 20
>
>
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