TECHNET Archives

November 2012

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:
Phil Bavaro <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, [log in to unmask]
Date:
Mon, 26 Nov 2012 17:17:57 +0000
Content-Type:
text/plain
Parts/Attachments:
text/plain (89 lines)
Hi Steve,

In a former life, I have seen production type non-stepped down stencils last for far more than 10K prints.  Let's put it in perspective....10k (200 prints/day)(5 days/wk)(5 wks) is not a lot to expect from a regular high volume stencil.  I have seen stencils used for many more prints before being retired due to wear.

Regards,

Phil

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
Sent: Friday, November 23, 2012 9:55 PM
To: [log in to unmask]
Subject: Re: [TN] Stencil Life...

Hi Ahne,

I know that "it depends". I was just looking for what can be expected from a stencil as long as it hasn't been dinged, and the mesh is still intact and the stencil is taut.

The reason that I'm asking is that we have a stencil that has been used many times (probably around 10,000 prints or more) and we're having trouble with bridging on some tiny QFN footprints in the stencil. It's a stepped stencil because we have to place some RF fences around the most populated areas on the board and that's at 7-mils, and the inside area is stepped down to 5-mils. There probably has been some extra pressure put on the stencil in order to get the step to work. I can see the outline of the board coined into the stencil. I think it's time to get a new stencil and just wanted to know if expecting the stencil to last more than around 10,000 prints is asking a lot...

Steve

P.S. I did think about how to spell Bob's last name for a bit and almost spelled it with a "J", but then changed it to a "G"...


-----Original Message-----
From: [log in to unmask]
Sent: Friday, November 23, 2012 1:42 PM
To: [log in to unmask] ; [log in to unmask]
Subject: FW: [TN] Stencil Life...

Short answer: Yes, why not.
Long answer: It depends...........how the stencil is treated. If you use the
proper squeegee pressure, if you clean it well regularly, if you don't drop
tools on it, if you don't bang it against hard objects, you don't use a
screwdriver to clean apertures, etc.
I have seen stencils returned where I could see the pattern of runs of the
circuit board pressed into the stainless steel. Obviously the squeegee
pressure had been too high. Some came back with tears in the mesh (and in my
eye) and many times you could find dings and dents in the metal. So, misuse
is the worst enemy of a long stencil life.

Ahne.

PS: It's Bob Jillings, was CEO

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of steve gregory
Sent: 22 November, 2012 19:28 PM
To: [log in to unmask]
Subject: [TN] Stencil Life...

Hi all!

First, let me wish everyone a happy Thanksgiving. I think that all of us can
sit back and be thankful for something in our lives, no matter how small it
is, and that's what this day is all about.

Now to my question; how long, or what is the useful life of a stainless
steel stencil? I know there is a lot of "It depends" that will figure into
the answer. But seem to recall someone telling me that a stencil should last
for 10,000 prints...I think I remember Bob Gillings of SMT (before Alpha
bought him out) telling me that.

What do you think? Should a stencil last that long?

Steve
Sent via BlackBerry by AT&T


______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________



______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
________________________________
 This message and any attachments are solely for the use of the addressee and may contain L-3 proprietary information that may also be defined as USG export controlled technical data. If you are not the intended recipient, any disclosure, use or distribution of its content is prohibited. Please notify the sender by reply e-mail and immediately delete this message and any attachments.

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

ATOM RSS1 RSS2