Carrie, I remember some time (way) back where a SIC (SEC) test comparison suggested that matte soldermask tended to yield higher numbers suggesting potential flux residues (or something). I believe this would be due to the additional surface area caused by the matte surface. This may not necessarily be applicable to all matte soldermasks. Just the ones that were ran in the tests. But it does bring up a valid subject on surface tensions associated with surface area. Someone who processes any kind of liquids, pastes, or inks may encounter some variation from the soldermask type. I tend to agree with Mike's statement that most specify "semi-matte/semi-gloss" soldermask type. It's the best of both worlds. Electrical Performance (Speed) is another topic for discussion. Cheers, See you all at IPC APEX/EXPO in Anaheim. David Hoover (aka, Groovy) ----- Original Message ----- From: "Barmuta, Mike" <[log in to unmask]> To: <[log in to unmask]> Sent: Tuesday, January 27, 2004 9:45 AM Subject: Re: [TN] Matte vs. Gloss Finish for Solder Mask > Carrie: First I am assuming your are asking about LPI soldermask only. > > From a board fabrication standpoint there should not be any additional cost > or processing steps. The major difference is in the formulation. So asking > or specifying a matte mask should not effect the bare board cost. > > A full matte finish may be more susceptible to scratching depending on the > filler system and amount of resin in the mask. It is also more prone to > showing surface cosmetics and white haze/residue. Gloss finish boards do not > display this as much. However gloss soldermask can be hard to inspect, TU > and manually load components due to it's high reflectivity. > > There is another issue and that is the electrical performance properties of > the mask. There are "some" matte masks that have reduced electrical > properties than a gloss mask. This can be the result of higher filler > content, less resin, etc. However there are many more things that play into > this than just the matte issue. The formulation, type and amount of resins > and cure can also influence the electrical performance greatly. There are > many matte masks that are comparable to non-matte types. > > Most people specify a semi-matte/semi-gloss as opposed to a full matte. This > provides a good compromise from the two ends of the spectrum. > > > Regards > > Michael Barmuta > > Staff Engineer > > Fluke Corp. > > Everett WA > > 425-446-6076 > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]]On Behalf Of Morse, Carrie > Sent: Tuesday, January 27, 2004 8:24 AM > To: [log in to unmask] > Subject: [TN] Matte vs. Gloss Finish for Solder Mask > > > We are a CM and find that boards with a Matte finish are less susceptible to > solder balls at our wave processes. We have discussed this with our flux > suppliers and equipment suppliers and have read a few articles on why solder > balls are more likely to form on the gloss finish boards. We have received > many recommendations on how to reduce or eliminate the solder balls (change > flux volume, change preheat, change this, change that) -- But, the one theme > from a root cause standpoint that recurs is the mask. > > What are the pro's and Cons of a Matte vs. Gloss finish for solder mask? > Is one easier to apply, less expensive? > Why would one be specified or used vs. the other? > > What is the specification for Gloss? Normally I see "Solder mask per SM-840 > Class T". Is finish an option from a fab standpoint when it is not > specified? > > Ultimately I'd like to be able to specify Matte Finish to the supplier, but, > I do not know how this may affect longevity of the board, cost, or even > perception of quality. I've heard some say that the end customers like the > way that the gloss boards look -- "shinier looks cleaner"? > > Any and all info including personal opinions about matte vs. gloss finish > are welcome. > > Thanks, > Carrie > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 1.8e > 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 or (re-start) delivery of Technet send e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/archives > Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 > for additional information, or contact Keach Sasamori at [log in to unmask] or > 847-509-9700 ext.5315 > ----------------------------------------------------- > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using LISTSERV 1.8e > 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/archives > Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 > ----------------------------------------------------- > --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------