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What is the acceptable Halide content of

Kelvin Chow


What is the acceptable Halide content of "Halide Free" Flux ?? | 25 February, 2002

We always talk about the halide free fluxes and solder pastes. Is there anyone tell me what is the industrial acceptable level of halide content or contamination in flux residue? All comment are welcome !!!


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What is the acceptable Halide content of | 25 February, 2002

Kelvin, You can find the Standard acceptable levels and testing procedures from IPC. Here's a little advice from the fellas' over at PCFAB: As a guideline, we recommend that for assemblies processed with low-solids flux technology and that are not cleaned, chloride levels do not exceed 2.0 (mg/in2) and bromide levels do not exceed 20 (mg/in2). In our experience, halide residue content higher than these levels is an indicator of progressively greater incidence of electrochemical failures.

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What is the acceptable Halide content of | 25 February, 2002

No, none of us can tell you what is the acceptable level of halide content or contamination in flux residue. The level of harmful residues on your product helps determine the reliability of your product. We know nothing of your product, its customers, their requirements, or their end use of the product. The product requirements for a garage door opener are far different than those for a under hood electronics.

From previous conversations on SMTnet, we know �Activators get jiggy wit flux.� Activators can be: * Linear dicarboxylic acids * Mono-dicarboxylic acids * Halide salts * Organic bases, such as amines.

Water-soluble fluxes wet better due to their higher activity attributed to halide additions. This is important for those using lead-free alloys. But some people get very nervous about halides. So, they specify fluxes that are �halide �free�. In some cases, a low residue halide free flux based on adipic acid as its primary activator provides acceptable wetting and hole fill. In other cases, the adiptic acid requires non-halide activators to provide acceptable results using a halide-free flux.

To be �halide-free�, a flux should be able to pass IPC/Bellcore copper mirror tests and show no sign of halides.

Taking a bit of a right turn, consider: * Getting your hands on some product that has seen a fair about of customer use similar to what you�d expect your product to see. * Taking that product to a lab like Trace, CSL, or Robisan [contacts follow]. * Having them do some ion chromatography testing to determine the level of ionic material on those boards. * Determining in-process standards based on those levels.

Alternate test laboratories are: * Trace Laboratories 1150 W. Euclid Ave Palatine,IL 0067-7397 847-934-5300 Fax 4600 Jeffry Schutt * Contamination Studies Laboratory Kokomo IN 765.457.8095 Terry Munson * Robisan Laboratory 6502 East 21st St Indianapolis, IN 46219 317-353-6249 fax 317-917-2379 Susan Mansilla

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What is the acceptable Halide content of | 25 February, 2002

This sounds like information bantied-about by the fine folk at CSL [Contamination Studies Laboratories in Kokomo, IN]. If so, this includes the sum of the halides from the following sources: * Fabricated board * Components * Processing of the assembly

CSL posts papers on their site that are interesting to read.

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