TECHNET Archives

June 1998

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Mike Barmuta <[log in to unmask]>
Reply To:
Date:
Thu, 4 Jun 1998 14:28:32 -0700
Content-Type:
TEXT/PLAIN
Parts/Attachments:
TEXT/PLAIN (138 lines)

        Scott: The short answer is yes.
The conformal coating and soldermask needs to be looked at as a system and not
independent materials. There are many soldermask chemistry formulations and
types of surfaces, matte semi-matte, semi-gloss, gloss and variations within.
The same is true for conformal coating chemistries; urethanes, acrylics,
silicones, epoxies and parylene and methods of application, dipping, spraying,
flow coat, brushing, vacuum etc. There is also the issue of assembly operations
heat and chemistry exposures and their influence on the mask or the presence of
no-clean residues. All of these play a role in how sucessful the end product
will be.
The soldermask and conformal coating need to be matched together and qualified
as one to provide optimum wetting, adhesion, CTE, electricals, etc.

                                                Regards
                                                        Michael Barmuta
                                                        Staff Engineer
                                                        Fluke Corp.
                                                        Everett Wa.
                                                        425-356-6076



On Thu, 4 Jun 1998 11:28:00 -0700 Challoner, Scott wrote:

> From: Challoner, Scott <[log in to unmask]>
> Date: Thu, 4 Jun 1998 11:28:00 -0700
> Subject: Re: [TN] ASSEM: MATTE VS GLOSSY
> To: Mike Barmuta <[log in to unmask]>
> Cc: TechNet <[log in to unmask]>
>
>
> Would the same principle apply to conformal coating?
>  ----------
> From: Mike Barmuta
> To: [log in to unmask]
> Subject: Re: [TN] ASSEM: MATTE VS GLOSSY
> Date: Thursday, June 04, 1998 1:15PM
>
>         Robert: Matte soldermask has a higher surface energy than gloss
> mask.
> Because of this it wets more easily and holds a more uniform thicker coating
> of flux than the gloss. You can use the analogy of a waxed car (low surface
> energy)it does not wet and retain a coating of water, it beads up and runs
> off,
> same thing for the gloss mask.
>         Since the matte mask holds more flux, wave solder settings like
> preheat/conveyor speed have to adjusted (more preheat/slower speed)to drive
> off
> the volatiles in the heavier coating of flux before contacting the
> solderwave.
> Also flux applicator settings, especially spray type can be adjusted to
> control
> the amount of flux on the board.
>         Glossy mask run at these same settings could dry out and create
> solder
> webbing or bridging when run thru the wave. Glossy mask also has a greater
> tendency to form solder balls which may require additional adjustments of
> the
> the settings to minimize.
>         With one standard mask your assembler will not have to do as much
> process adjusting and will probably provide a more consistent product. My
> guess
> is they would prefer the matte.
>
>                                         Regards
>                                                 Michael Barmuta
>                                                 Staff Engineer
>                                                 Fluke Corp.
>                                                 Everett Wa.
>                                                 425-356-6076
>
> On Thu, 4 Jun 1998 05:22:57 -0700 Robert Welch wrote:
>
> > From: Robert Welch <[log in to unmask]>
> > Date: Thu, 4 Jun 1998 05:22:57 -0700
> > Subject: [TN] ASSEM: MATTE VS GLOSSY
> > To: [log in to unmask]
> >
> > Hello Technetters,
> >
> > I've been asked to forward this inquiry for a contract assembly
> > person we deal with occasionally.
> > His problem is that he has to adjust his wave solder parameters (more
> > or less preheat??)  when changing between "very shiny" and "very
> > dull" solder mask on the same part number.  He would like some
> > collaboration of this phenomena to help  justify
> > requiring his supplier to keep  all the mask the same.
> >
> > Thanks,
> > Robert E. Welch
> > Process Specialist
> > Email: [log in to unmask]
> > Modem: 804-239-9120
> > Fax:   804-237-3048
> >
> > ################################################################
> > 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 web site (http://jefry.ipc.org/forum.htm) 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 web site (http://jefry.ipc.org/forum.htm) 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 web site (http://jefry.ipc.org/forum.htm) for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################


ATOM RSS1 RSS2