Mike,

When I was involved in assembly operations, it was a defacto standard to run the wave solder at 500F with a dwell in the wave of ~ 4 seconds. Although we ran eutectic solder, colleagues who ran 60/40 also ran the wave at 500F. Running at lower temperatures sometimes led to poor solder quality (i.e. grainy solder). I agree with Pete that you should not see lifted lands at 500F. 

The thermal stress test (550F for 10 seconds) was created to test the robustness of the board design and manufacture, since it represented thermal conditions the board would theoretically never see. The only aspect of Pete's response I would differ with is that the specifications (IPC and mil specs) allow lifted lands (up to the thickness of the land) after thermal stress. There are no lifted lands allowed before thermal stress.

Hope this helps.

Alan Exley
Director of Quality
Cosmotronic
949-660-0740
 

-----Original Message-----
From: Menuez, Pete [mailto:[log in to unmask]] 
Sent: Monday, August 08, 2005 4:54 AM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] "Typical" Wave Soldering Temperatures

Mike,

The 6012 test method (TM-650 2.6.8) requires thermal stress of 550 F for 10 seconds; with no visible lifted lands.  (Ref. paragraphs 3.3.4 and table 3-6).  In my experience with higher Tg materials (170 C) you will not see lifted lands. The peel strength you site is very low.  Even low profile copper should provide 4 pounds per inch. (reference IPC-4101/24)

Pete

-----Original Message-----
From: Michael E. Hill [mailto:[log in to unmask]]
Sent: Friday, August 05, 2005 11:36 AM
To: [log in to unmask]
Subject: Re: [IPC-600-6012] "Typical" Wave Soldering Temperatures




Happy Friday everyone!

Constantino J. González and 610 committee,



I have an assembly question that I could use some help.


 What is the "normal" (or "normal range") wave soldering temperature used
for standard 60/40 solder?


Note: I have a customer that is getting some minor lifted lands with
Hi-Temperature FR4 (170C) multilayers and they are using 500F for the pot
temperature. I checked with two assembly houses and they both use 485F.  I
thought 500F was a little on the high side. The boards are all through hole
technology .062 to .073 inch thick. The foil bond strength to epoxy is 2.5
to 2.8 pounds per inch.


Please let me know what wave soldering temperatures are generally used and
any comments.

thanks
Mike Hill