IPC-CM-770 paragraph 23.3 is a great place to start for Wire Bonding
information. Most of your questions will be answered.
thom
______________________________ Reply Separator _________________________________
Subject: Chip On Board Survey...
Author: [log in to unmask] at Internet
Date: 4/29/97 11:07 AM
Received: by ccmail
Received: from uunet by xl.com (UUPC/extended 1.11) with UUCP;
Tue, 29 Apr 1997 11:07:42 EDT
Received: from simon.ipc.org by relay1.UU.NET with SMTP
(peer crosschecked as: www.ipc.org [209.42.29.3])
id QQcnjn18215; Tue, 29 Apr 1997 10:55:44 -0400 (EDT)
Received: from ipc.org by simon.ipc.org via SMTP (940816.SGI.8.6.9/940406.SGI)
id JAA18097; Tue, 29 Apr 1997 09:41:04 -0700
Resent-Date: Tue, 29 Apr 1997 09:41:04 -0700
Received: by ipc.org (Smail3.1.28.1 #2)
id m0wMDIY-000BjFC; Tue, 29 Apr 97 08:50 CDT
Resent-Sender: [log in to unmask]
Old-Return-Path: <[log in to unmask]>
Message-Id: <[log in to unmask]>
X-Sender: [log in to unmask]
X-Mailer: Windows Eudora Light Version 3.0.1 (32)
Date: Tue, 29 Apr 1997 09:56:53 -0400
To: [log in to unmask]
From: "Lang, Michael" <[log in to unmask]> (by way of Patrick Ducas
<pa [log in to unmask]>)
Subject: Chip On Board Survey...
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Resent-Message-ID: <"MmZu_2.0.4sE.OoVPp"@ipc>
Resent-From: [log in to unmask]
X-ccAdmin: NOBODY@uunet
X-Mailing-List: <[log in to unmask]> archive/latest/12311
X-Loop: [log in to unmask]
Precedence: list
Resent-Sender: [log in to unmask]
Micheal, I'm not able to answer all these questions but I can suggest you
the following:
You might look towards High Frequency Ultrasonic Gold Ball Bonding. It will
allow you to do wirebonding to a PCB at very low temperature. FR-4 material
may be used in that type of packaging.
Regards.
I am looking for information regarding Chip On Board (COB) and other
packaging schemes which rely on wirebonding to a PCB. If you can, please
answer the following:
1) Do you currently use COB or other packaging schemes which rely on
wirebonding directly to a PCB? If not, is it because of previous bad
experience or other problems?
2) What temperature is wirebonding to PCB's performed at?
3) How it the heat applied (heated stage of wirebonder, heated N2 blowing on
site, etc). If a heated stage, is the PCB placed directly on the stage?
4) What PCB materials can be used for this type of packaging (polyimide,
Kevlar, FR-4)? What are the driving characteristics (Coefficient of Thermal
Expansion in the Z direction leading to barrel cracking, glass transition
temperature, etc)
5) Can wirebonds survive outside of a hermetic environment (assuming they
are protected from physical damage)? Will they survive salt fog, etc.?
This question assumes the wirebond is NOT used for connection to a chip,
but instead to another PCB, I/O pin, etc.
Thanks,
Michael Lang
[log in to unmask]
***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To subscribe/unsubscribe send a message <to: [log in to unmask]> *
* with <subject: subscribe/unsubscribe> and no text in the body. *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] *
***************************************************************************
***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To subscribe/unsubscribe send a message <to: [log in to unmask]> *
* with <subject: subscribe/unsubscribe> and no text in the body. *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] *
***************************************************************************
***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To subscribe/unsubscribe send a message <to: [log in to unmask]> *
* with <subject: subscribe/unsubscribe> and no text in the body. *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] *
***************************************************************************
|