Bill,
There is a possible exception to this blanket "ok to use leaded solder"
statement.
There are possible issues when using SAC/lead-free BGAs or solder bumps.
These need to be liquefied which means higher temperatures, different
fluxes, profile changes, ect...
You are into a lead-free "build" with leaded solder so very careful
qualification/testing is needed.
David A. Douthit
Manager
LoCan LLC
Brooks,Bill wrote:
>I talked with our ME's here and they inform me that the current process of
>using tin/lead solder WILL BE COMPATIBLE with the new 'lead free' parts that
>are being manufactured... So why change processes if you don't need to deal
>with the EU...?
>
>The ME's say they have real issues with inspecting high temp solder joints
>that do not wet or wick like tin/lead solders... I would expect more trouble
>with the ductility of other alloys too, so if your surface mount board is
>undergoing thermal excursions and getting stressed at the solder joints due
>to CTE mismatches the other alloys are more likely to crack due to work
>hardening... and less ductility.
>
>How much real research has been done into these alternative alloys? Do you
>want to ride in a Space Shuttle with lead free solder joints? Or put a pace
>maker in your chest that has lead free solder joints? Are they truly
>reliable?
>
>Who's really driving the move to lead free?
>
>I still maintain that leaded car batteries are a much greater threat to the
>environment than cell phones with solder on the small parts they carry
>inside. Look at how many cars there are that have to change their batteries
>every 5 years or less...
>
>
>
>Bill Brooks
>PCB Design Engineer , C.I.D., C.I.I.
>Tel: (760)597-1500 Ext 3772 Fax: (760)597-1510
>http://pcbwizards.com
>
>
>-----Original Message-----
>From: Dehoyos, Ramon [mailto:[log in to unmask]]
>Sent: Wednesday, September 08, 2004 11:13 AM
>To: [log in to unmask]
>Subject: Re: [TN] Lead free
>
> Since Japan is almost 100% lead free, what have they chosen as their
>best alloy? or Europe?
> Just a thought.
> Ramon
>
>-----Original Message-----
>From: David Bergman [mailto:[log in to unmask]]
>Sent: Wednesday, September 08, 2004 1:28 PM
>To: Dehoyos, Ramon
>Subject: RE: [TN] Lead free
>
>
>Hi Ramon,
>
>It will be interesting to see what Technet response is to this. My
>personal opinion is that the industry is narrowing on the SAC alloy
>(Tin/Silver/Copper). I also believe that the SAC 305 (3% Silver 0.5 %
>copper, balance tin) will be the leading alloy. There is a significant
>amount of R&D work looking at lower temperature alloys including Bismuth
>and Zinc, but none of these are mainstream options yet.
>
>Dave
>
>
>David W. Bergman, CAE
>Vice President, Standards, Technology and International Relations
>IPC
>2215 Sanders Road #250
>Northbrook, IL 60062-6135
>Phone 847-790-5340 Fax 847-504-2340
>Mobile 847-867-1388
>email [log in to unmask] www.ipc.org
>
>
>IPC IS MOVING: On Friday, September 17, IPC will be moving to a new
>office location: 3000 Lakeside Drive, Suite 309 S, Bannockburn, IL,
>60015. All phone, fax, web and e-mail service will be down from the
>close of business on the 16th until Monday, September 20th. The new main
>telephone number will be 1-847-615-7100 and the new main fax number will
>be 1-847-615-7105. Direct phone numbers are not yet available. A
>complete listing of all new direct phone numbers will be available when
>confirmed by the phone company at www.ipc.org/move.
>
>-----Original Message-----
>From: TechNet [mailto:[log in to unmask]] On Behalf Of Dehoyos, Ramon
>Sent: Wednesday, September 08, 2004 12:15 PM
>To: [log in to unmask]
>Subject: [TN] Lead free
>
> Technetters:
> Last time I checked there were more than a dozen different types
>of lead free solders. Has the industry chosen the best one? Or is it
>still experimenting with different types?
> Regards,
> Ramon
>
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