And as typical with single part epoxies, it needs to be stored in the fridge and brought up to room temperature for use. It has a high viscosity, but also shear-thins, because it is designed for high speed dot dispensing. I'd be surprised if it has a super strong peel strength to PVC, as this is not a common characteristic of epoxies. Surface mount adhesives tend to have low Tg's to help with reworkability, and they are not designed to have much structural strength after the soldering process - they are just there to keep components in place until that point. However, it may be absolutely OK for this application. As with all things, you will need to test in your application, including temperature cycling. My comment about cure is that most people at this stage of the assembly are reluctant to go back through a reflow or other oven. These "securing" jobs are mostly done during a final part of the process, well after any soldering. Regards, Peter -------------------------------------------------------- Peter Swanson [log in to unmask] INTERTRONICS http://www.intertronics.co.uk Tel: +44 1865 842842 Oxfordshire, England INTERTRONICS is dedicated to providing quality material, consumable and equipment solutions to the high technology, high performance assembly industries, incorporating outstanding levels of technical support and customer service. Read our news! http://www.intertronics.co.uk/blog/blog.htm -----Original Message----- From: Stadem, Richard D. [mailto:[log in to unmask]] Sent: 21 November 2007 18:53 To: TechNet E-Mail Forum; Peter Swanson Subject: RE: [TN] Epoxy application Loctite 3621 requires a "substantial heat bump" of 150 seconds at 150 deg. C to fully cure. It is designed to adhere to almost any component. It can be applied with a manual syringe or automated dispenser, does not seep away but stays in place until cured. It can be cured as part of a wave solder or reflow process. It has super strong peel strength, is impervious to most chemicals, and is a very low outgassing single part epoxy. Good stuff. And it does not stink. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Peter Swanson Sent: Wednesday, November 21, 2007 9:59 AM To: [log in to unmask] Subject: Re: [TN] Epoxy application Peter, You don't say how many of these you are making, but with that proviso: 1) A single part "chipbonder" or surface mount adhesive like the one mentioned will require a substantial heat bump to cure. 2) Rather than an epoxy, maybe a methacrylate adhesive would be better - often less brittle, but good all round adhesion. Something like Araldite 2022 is a two part product, but in a cartridge, so easy to apply. Might still me a bit smelly through.... 3) If you have, or can justify the purchase of the equipment, then a UV acrylic adhesive does this job well. No mix, fast cure, good adhesion, choose your viscosity and the right resiliency to give the stress relief. Regards, Peter -------------------------------------------------------- Peter Swanson [log in to unmask] INTERTRONICS http://www.intertronics.co.uk Tel: +44 1865 842842 Oxfordshire, England INTERTRONICS is dedicated to providing quality material, consumable and equipment solutions to the high technology, high performance assembly industries, incorporating outstanding levels of technical support and customer service. Read our news! http://www.intertronics.co.uk/blog/blog.htm -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D. Sent: 21 November 2007 13:28 To: [log in to unmask] Subject: Re: [TN] Epoxy application Hello, Peter I have a client using Loctite 3621 epoxy in a very similar application. It bonds to the mylar sleeving very well. Try it. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Peter L Sent: Tuesday, November 20, 2007 6:00 PM To: [log in to unmask] Subject: [TN] Epoxy application Hello, I would like to ask for opinion on an epoxy application. We apply RTV to bond and secure 2 electronic devices on a PCB. But after noticing the RTV bond breaking off during vibration test, our customer has specs in a 5min 2-part epoxy (made by http://www.devcon.com/techinfo/5_MINUTE_FR.pdf) to replace the RTV. The problem is that the Devcon epoxy is fast cure, requries 2 part mixing, and carries a strong, irritating odor. I would like to move away from using Devcon and expect that there must be more process friendly epoxy for such application. The 2 materials to be joined were a flat ferrite inductor and round capacitor having a PVC sleeve. Due to positioning of the 2 devices there is generally a ~0.25" gap between them for the epoxy to fill. The epoxy bead deposit is about .75" long x 0.5" wide. (see following link to the assembly http://members.shaw.ca/ppwlee4/Epoxy_appl.JPG) I am looking for recommendation of a suitable epoxy to allow: - 5-10 min working life before it starts curing - process friendly (smell, preferrable no pre-mix) - good adhesion to the component/PCB surfaces. Any suggestion is appreciated. Thanks. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------