Is there a solder mask matrix by vendor stated which solder mask is compatible with which raw board/card final surface finish, besides with experience?
Not that I am aware of outside of the Material TDSs for the various soldermask products.
Does the solder mask literature make reference to this finish application?
Yes, usually in the TDS from a general perspective, but this requires knowledge of the fabrication process and the end-use requirements also.
For example for Taiyo PSR-4000BNB, it lists compatibility with ENIG and Immersion Tin finishing and provides information on that. Some plating finishes are applied prior to masking and thus are redundant. But the soldermask vendors such as Taiyo cannot possibly list all of the different specific applications their products are "appropriate" or "qualified for use". They can only provide all of the material characteristics, and it is up to you, the fabricator, and the end-use customer to determine which soldermask product is best suited for the particular design and PWB material.
Can a raw board supplier inadvertently use the wrong SM due to cost? Is there a test for solder mask beside the Peel/Scratch Test?
Yes to both. Paying attention to both process requirements and end-use requirements is critical when it comes to soldermask. The Design Engineer and the PWB Fabricator must review these with the end-use customer and agree on which is best. Quite often the choice of soldermask (and sometimes the entire PWB fab notes!) are boilerplated from one design to another without the proper review and questioning of assumptions and appropriateness.
Both IPC-SM840E and IPC HDBK-840 reference all of the Test Methods used, including both those in IPC-TM-650 and the ASTM specifications also, and there are many of them besides just the Peel/scratch test.
Ultimately though, the IPC cannot provide a chart for you that does the material selection and the design characteristics for you, as there are simply too many applications, exceptions, differing customer requirments, etc. Sometimes we simply have to step up as both manufacturing engineers and design engineers, and work with the fabricator and customer to ensure all of the design and end-use requirements are met.
And yes, sometimes it helps to have 50 years of experience in doing that, but I don't think it is a necessary qualification; good engineering principles and gap analysis, mixed with a small amount of common sense, are requirements in material selection for every single application whether you started on the Apollo Space program or you graduated yesterday. You should be able to understand the end use and look at the material specifications in the soldermask TDS and determine whether the product meets both the requirements and is compatible with the PWB materials selection as defined within IPC 4101 slash sheets.
The best advice I can give you is to ask these questions of your fabricator and your customer. You may be shocked at the ignorance of one, the other, or both!
Or you may not, in which case you do not need documents like SM840 to get to sleep at night.
Odin
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Victor Hernandez
Sent: Monday, October 05, 2015 1:33 PM
To: [log in to unmask]
Subject: Re: [TN] Solder mask type versus raw board/card finish
Is there a solder mask matrix by vendor stated which solder mask is compatible with which raw board/card final surface finish, besides with experience. Does the solder mask literature makes reference to this finish application? Can a raw board supplier inadvertently use the wrong SM due to cost.? Is there a test for solder mask beside the Peel/Scratch Test.
Victor,
From: Douglas Pauls [mailto:[log in to unmask]]
Sent: Monday, October 05, 2015 12:01 PM
To: TechNet E-Mail Forum; Hernandez, Victor G
Subject: Re: [TN] Solder mask type versus raw board/card finish
Victor,
Solder mask can be impacted by the application of the final finish. Gold, for example, is a very harsh plating process on solder mask. So chemical compatibility between the solder mask and the finish applied can be an issue.
If the solder mask is not fully cured or completely cross linked prior to exposure to these plating baths, the process fluids can be absorbed into the polymer matrix where they are not found by conventional ROSE testing. They come out later with disastrous results.
Doug Pauls
Principal Materials and Process Engineer Rockwell Collins
On Mon, Oct 5, 2015 at 11:04 AM, Victor Hernandez <[log in to unmask]<mailto:[log in to unmask]>> wrote:
Now, I understand that there are many solder mask vendors globally. What I am not clear on is why does raw card surface finish impact SM performance. Besides adhesions properties and HDI. Any comments and/or papers out there...
Victor,
-----Original Message-----
From: TechNet [mailto:[log in to unmask]<mailto:[log in to unmask]>] On Behalf Of Stadem, Richard D.
Sent: Friday, October 02, 2015 10:19 AM
To: [log in to unmask]<mailto:[log in to unmask]>
Subject: Re: [TN] Solder mask removal, SMOBC
Yes, and they would have the proper environmental controls and safety equipment, etc.
Even if you attempted to remove it using a conformal coat blaster, you still have the safety issues to deal with. You don't want to breathe that stuff.
Excuse me while I go outside for a cigarette.
Odin
-----Original Message-----
From: Ed Popielarski [mailto:[log in to unmask]<mailto:[log in to unmask]>]
Sent: Friday, October 02, 2015 10:16 AM
To: TechNet E-Mail Forum; Stadem, Richard D.
Subject: RE: Solder mask removal, SMOBC
In addition to Richard's sage advice and rationalization is the fact they are set up to deal with harsh chemistry like this and probably do so on a regular basis.
Ed Popielarski
Engineering Manager
970 NE 21st Ct.
Oak Harbor, Wa. 98277
Ph: 360-675-1322<tel:360-675-1322>
Fx: 206-624-0695<tel:206-624-0695>
Cl: 949-581-6601<tel:949-581-6601>
"It's one kind of victory to slay a beast, move a mountain, and cross a chasm, but it's another kind altogether to realize that the beast, the mountain, and the chasm were of your own design."
https://maps.google.com/maps/myplaces?hl=en&ll=48.315753,-122.643578&spn=0.011188,0.033023&ctz=420&t=m&z=16&iwloc=A
-----Original Message-----
From: TechNet [mailto:[log in to unmask]<mailto:[log in to unmask]>] On Behalf Of Stadem, Richard D.
Sent: Friday, October 02, 2015 5:36 AM
To: [log in to unmask]<mailto:[log in to unmask]>
Subject: Re: [TN] Solder mask removal, SMOBC
Perhaps you can ask your board fabricator? I would imagine they have methods for doing this. Perhaps also they may be able to do it for you cheaper than you could set yourself up to do it? Doesn't hurt to ask.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]<mailto:[log in to unmask]>] On Behalf Of Victor Hernandez
Sent: Friday, October 02, 2015 6:52 AM
To: [log in to unmask]<mailto:[log in to unmask]>
Subject: [TN] FW: Solder mask removal, SMOBC
Fellow TechNetters:
I did not receive very much feedback on my initial inquiry. Therefore, I ask again. Additionally I also ask if Solder mask and conformal coating the same Product/Term (IPC-7711.21 section 2.3.1. I want to removal/strip solder mask. At this point I do not known the solder mask vendor or type.
Victor,
From: Hernandez, Victor G
Sent: Thursday, October 01, 2015 10:56 AM
To: TechNet E-Mail Forum
Cc: Hernandez, Victor G
Subject: Solder mask removal
Fellow TechNetters:
I have been asked to see if that is a satisfactory method for removing/stripping solder mask from sample coupons chemically and/or mechanically.
Victor,
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