Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Lead free

newf

#6397

Lead free | 20 July, 2000

How are Component manufactuers addressing the PB free solder inititive? Since I am told higher processing Temps will be required to reflow the pb-free alloy.

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Bob Willis

#6398

Re: Lead free | 20 July, 2000

Yes there will be higher process temperatures on the currently preferred alloys of tin/silver.

There are not that many companies highlighting they have the solutions although many parts will be fine. If all components meet the requirements of the IPC or IEC Component Compatibility for SMT specifications then this will go a long way to eliminating the issue.

I do however see so many companies just buying parts and never asking the questions on the rating of parts. As a simple example there are a number of TSOP parts only rated at a max temp of 215C, how many people can say there reflow and rework systems are below this temperature ?

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newf

#6399

Re: Lead free | 20 July, 2000

Will component manufactuers need to look at possible new coatings for pins when to be used in a PB- free enviroment?

PT 2 Will new solder joint inspection criteria have to be developed for the use of lead free solder?

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Bob Willis

#6400

Re: Lead free | 20 July, 2000

Yes if we are going to be lead free than lead will have to go. There are alternative plating finishes, Shipley have been doing a lot of work in this area. Also have a look at the NPL web site.

Some people say that new crieria is necessary but I think in most cases existing criteria will do. There does not seem to be any real issues with lead free and x-ray either.

Bob

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armintan

#6401

Re: Lead free | 20 July, 2000

Do present reflow and wave solder equipment currently processing tin-lead process need to be replaced when migrating to lead free process ? Is there any equipment (reflow or wave) out there capable of processing both leaded and unleaded processes which is something that companies have to consider buying when they plan to move to lead free.

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Bob Willis

#6402

Re: Lead free | 20 July, 2000

Many machines for both reflow and wave are quite capable to run lead free but you are generally talking about the high end systems not the light weight units.

Bob

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joevo2k

#6403

Re: Lead free | 20 July, 2000

Bob, Is Nitrogen a "MUST" for reflow and wave soldering of the Lead-Free Solder Alloys ? And is post cleaning be a great impact when converting to Lead-Free Solders ?

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Bob Willis

#6404

Re: Lead free | 21 July, 2000

You will find that most of the work reported in Europe has been in a nitrogen enviroment. All my trials have been in air so my comments just relate to air.

I feel that most people will still not clean but the residues that are produced seem to be higher than with standard no clean products.

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