TECHNET Archives

July 2016

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:
"Decker, Scott UTAS" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Decker, Scott UTAS
Date:
Thu, 28 Jul 2016 17:07:28 +0000
Content-Type:
text/plain
Parts/Attachments:
text/plain (1 lines)
Steve,

   Just a thought here, but if the leads are sealed with a glass, bending the leads may break the fret seal and that's why they are concerned. I looked at the part, (but not in depth) to see if it was sealed and it said yes, so that may be why they want it potted. Shearing the leads may cause a shock to the lead and crack the seal? Bending the leads out to match the board pattern would do the same thing, so special fixturing may be needed to hold the leads near the part and bending farther away in addition to lead clipping? From a past company that did space work, leads that are sealed were not allowed to be bent, "sealed" leaded parts, were just soldered, etc. Hope this helps...

Later...



Scott Decker – Senior Analyst, Drafting & Design Services CID+ – Electronic Systems Center

UTC AEROSPACE SYSTEMS

3445 S. 5th Street, Suite 170, Phoenix, AZ 85040 U.S.A.

Tel: 602 308 5957  FAX: 602 243 2347

[log in to unmask]   www.utcaerospacesystems.com



CONFIDENTIALITY WARNING: This message may contain proprietary and/or privileged information of

UTC Aerospace Systems and its affiliated companies. If you are not the intended recipient please 1) do not disclose, copy,

distribute or use this message or its contents, 2) advise the sender by return e-mail, and 3) delete all copies (including all

attachments) from your computer. Your cooperation is greatly appreciated.

This Document Does Not Contain Export Controlled Technology Or Technical Data.



-----Original Message-----

From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory

Sent: Thursday, July 28, 2016 8:12 AM

To: [log in to unmask]

Subject: [External] [TN] Prepping TO-5 can style Relay...



Hi All,



We're building a board for a customer that uses a 8-lead TO-5 style relay.

The footprint on the board requires that the leads are spread out to a larger diameter circle than what diameter is when they come out of the body at the bottom of the relay. Here's the information for one of the relays, there are three others that are the same style:



http://www.digikey.com/product-search/en?lang=en&site=us&WT.z_cid=ref_findchips_standard&mpart=PRMAC-26X



So we have a Simonds CLP274 lead processor with a die that matches the footprint on the PCB:



http://stevezeva.homestead.com/Simonds_CLP274.jpg



We insert the part which spreads the leads out, then step on the pedal and a guillotine style blade shears the leads off. I've used the prep unit many, many time before at previous employers without issues. The customer is saying that prepping the leads in this unit is damaging the relay. So now we are to pot the leads before prepping them with a 2-part epoxy using a tooling fixture as a mold for the epoxy, and the potted relay looks like

this:



http://stevezeva.homestead.com/Potted_Relay.jpg



Has anybody ever heard of this Simonds unit damaging relays like this? Has anybody had to add potting to a relay like this? I can understand wanting to keep the leads coming straight out of the bottom of the body before making the bend to match the footprint on the board, but I think I can use a Bivar permanent spacer and slip it over the lead and accomplish the same thing. Something like this:



https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0ahUKEwiqk8zCt5bOAhWJ1IMKHebaCR8QFggxMAE&url=http%3A%2F%2Fwww.bivar.com%2Fportals%2F0%2Fproducts%2F616-070.pdf&usg=AFQjCNESVvvX6qOo_-0T94sAYNLP8AJ21Q&cad=rja



Or even a nylon washer that matches the diameter of the lead pattern

(.200") coming out of the bottom of the relay. Potting this relay is going to be very time consuming and there's going to be a risk of getting the epoxy on the leads that will ruin the solderability of the part. I'm just trying to understand if it is truly the Simonds prep unit causing the damage, and if this really is, and easier way other than potting them to accomplish the same thing.



Thanks all!



Steve Gregory



-- 





This email and any attachments are only for use by the intended

recipient(s) and may contain legally privileged, confidential, proprietary or otherwise private information. Any unauthorized use, reproduction, dissemination, distribution or other disclosure of the contents of this e-mail or its attachments is strictly prohibited. If you have received this email in error, please notify the sender immediately and delete the original. 


ATOM RSS1 RSS2