Thanks to everyone for their insights on this process. Your comments have
been very helpful.
Steve
-----Original Message-----
From: Peter Swanson [mailto:[log in to unmask]]
Sent: Tuesday, March 25, 2003 3:50 AM
To: [log in to unmask]
Subject: Re: [TN] Adhesive bonding for ferrite cores
It is quite common for this to be done with an activator cured acrylic
adhesive (c.f. Dymax, Loctite or Permabond). This method took over from
mechanical clips some years ago for the reasons which Brian described. I
would be careful about using a cyanoacrylate; check temperature resistance
of the adhesive against your service and bondline operating temperature.
Regards,
Peter
--
--------------------------------------------------------
Peter Swanson [log in to unmask]
INTERTRONICS http://www.intertronics.co.uk
INTERTRONICS is dedicated to providing quality
material, consumable and equipment solutions to the
electronics manufacturing and other technology based
industries, with the highest levels of technical
support and customer service.
-----Original Message-----
From: Brian Ellis [mailto:[log in to unmask]]
Sent: 21 March 2003 9:36
To: [log in to unmask]
Subject: Re: [TN] Adhesive bonding for ferrite cores
Steve,
Using viscous adhesives with a large polymerised molecule, such as
epoxies, will inevitably create gaps in the magnetic circuit, thereby
reducing the inductance. The object of the exercise is to minimise the
gap. In another life, I used a very liquid cyanacrylate of a type used
by restorers for repairing ceramics. I believe it was made by Eastman
Kodak, if I remember correctly. A tiny microdrop dispensed on each of
the ends of the three arms of the E will do the trick. Almost
instantaneous bonding and minimal loss of inductance.
Brian
Shoda, Steve wrote:
> Does anyone have any experience bonding ferrite cores? I am working on
> developing a process for bonding an e-core to an i-core. They are 0.8" x
> 1.2" and sandwich the winding in the pwb. So the bond must be done once
the
> assembly is populated. I'm applying a high viscosity epoxy, but it can
be
> difficult to control. I attempted a 0.002" epoxy preform, but the outcome
> was reduced inductance, so we are still using the high viscosity epoxy.
Why
> would they result in such different inductance properties? In either
case,
> the cure time at 250F is 1 hour and production is requesting a material
> which has a very short cycle time.
>
> Steve Shoda
> BAE SYSTEMS Controls
>
> ---------------------------------------------------
> Technet Mail List provided as a free 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/html/forum.htm for additional
> information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
> -----------------------------------------------------
>
>
>
>
>
---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------
|
