TECHNET Archives

July 2013

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:
Joyce Koo <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Joyce Koo <[log in to unmask]>
Date:
Wed, 10 Jul 2013 09:27:10 +0000
Content-Type:
text/plain
Parts/Attachments:
text/plain (1 lines)
Torsten, can you comment on the size and shape of the punch process?  Any stack up limitation? 
--------------------------
Sent using BlackBerry


----- Original Message -----
From: Torsten Hagge [mailto:[log in to unmask]]
Sent: Wednesday, July 10, 2013 03:09 AM
To: [log in to unmask] <[log in to unmask]>
Subject: [TN] AW: Best Practice Question - Depanelizing

Hi Phil,

punch process with good knife design give very good results with  less than 500µm/m, is best practice for several automotive OEM.

Our tools are qualified by Audi, Daimler, Ford, GM, Nissan, Renault, Porsche, VW. 

VW/Porsche requirement is less 500µm/m for complete PWB process (printer, placement, oven, AOI, ICT, depaneling & EOL-test)...

Torsten

Best Regards

KRISTRONICS GmbH
Torsten Hagge
team leader HW development & 
tech. projectmanager
Gewerbegrund 5-9
24955 Harrislee
Telefon +49 (0) 461 7741-624
Telefax +49 (0) 461 7741-642
[log in to unmask]
www.kristronics.de
Place of jurisdiction: Flensburg, commercial register: HRB 1433 FL
CEO Dipl.-Ing. oec. Thormod Ohm
VAD-Id DE 811182059
Bank account: Deutsche Bank AG Flensburg, account 4216610, bank number 21570011
IBAN: DE32 2157 0011 0421 6610 00, BIC: DEUT DE HH 215
 Please consider the environment before printing this e-mail




-----Ursprüngliche Nachricht-----
Von: TechNet [mailto:[log in to unmask]] Im Auftrag von Phil Bavaro
Gesendet: Mittwoch, 10. Juli 2013 01:51
An: [log in to unmask]
Betreff: [TN] Best Practice Question - Depanelizing

I have been asked to determine what the best practice is for depaneling PWAs from an array (more than one PWA per panel run down the assembly line), or in other words...

....how should we be depanelizing PWAs, a) v-score, b) pin router, or c) mouse bite/punch.

I do have a personal opinion (listed below), but my experience was with commercial Class 2 and not Hi-rel Class 3 hardware.  I am looking for input from others that have years of experience in the Hi-rel arena:

a) V-scoring was always the easiest but required that the score go all the way across the panel.  The result was that there were a few glass bundles (.012" approx) which were sheared left over while the area of the v-score was smoothly finished by the original router.  The mechanical stress, if performed using the round blade to shear while supporting the v-score from the bottom, in minimal.  The solder joints keep away is a minimum of .080" away from the top edge of the V, but ceramic caps might need further distances and special orientation.  Proper singulation method is important so this is not a high volume production type method.  I have always discouraged jump scoring.

b) The pin router method results in a nicely milled edge but it requires ESD controls (ionized air) as well as excellent FOD controls (vacuum for the dust) to control the process.  The resultant board edge is identical to what a PWB fabricator would supply and one advantage is that the copper to board edge pull back area is less than with a v-score.  We don't have room for tooling pins to hold the boards so vacuum hold down is a requirement and that applies mechanical stress to the PWA as well.  This method is suited well to high volume.

c) The mouse bite punch method leaves the entire board edge thickness exposed for glass bundles and is the least desired due to this.  If the mouse bites are not spaced optimally, the punch or nipping process can impart the highest stresses of all of these methods.  The edge copper pull back is from the edge of the mouse bite holes which is close to the amount needed for v-scoring.  The other drawback is that some people tend to want to flex the mouse bites to failure and that causes unknown but excessive stresses.

Please feel free to respond with your preferences as well as point out any disagreements you might have given that this process needs to be used with hi-rel hardware (non-space, but definitely airborne).


Thanks in advance,

Phil
________________________________
 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] ______________________________________________________________________

______________________________________________________________________
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 transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful.

______________________________________________________________________
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