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SMT electronics assembly manufacturing forum.


Type 4 powder

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#83055

Type 4 powder | 23 July, 2019

If you were going from a type 3 to type 4 powder, would you do a full blown documented evaluation ?

Flux and alloy remain the same.

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#83056

Type 4 powder | 23 July, 2019

It depends on what you mean by "going from....to....".

If I just decided that I wanted to try a Type 4 paste on something that I'd been having problems printing, I'd probably just grab one (edited to add that we have a couple of recipes where the only difference is powder size, and this is my scenario) out of the fridge and throw it on the stencil (after allowing the paste to warm, and cleaning the stencil and the blades), and inspect like crazy.

If I was actually considering making a change from T3 to T4 across the board, then definitely yes.

That said, we don't build AS9100 or ISO13485 boards here, either. That would be a different story.

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#83072

Type 4 powder | 25 July, 2019

In “J-STD-001 Rev G Amendment 1 Process Qualification” Debbie Carboni, Global Product Line Manager, KYZEN Corp, Nashville, TN said:

What change constitutes a need for requalification?

Major/ Level 1 – Flux or flux-bearing materials (e.g. flux, solder paste, paste flux, cored wire solder) [Requalification Required]

■ Different residues, different activators, different solubilities – Cleaning agents (e.g. solvents, aqueous detergents, topical cleaners)

■ Differences in surface tension, ability to get under low standoff devices – Changes in manufacturing suppliers

■ There may be a reason they are half the price – Changes in solder mask type

■ Changes in porosity, surface energy, etc. – Changes in printed board fabrication processes or surface metalization

■ See IPC-5703 – Geographic change in manufacturing location

■ Change in cultures, training, supply chains

Minor/ Level 2 -Intent was to be a lesser effort - Changes in cleaning parameters: [Requires Supporting Evidence]

■ Increase in belt speed (in-line cleaning systems), or decrease in cycle time (batch systems).

■ Decrease in pressures or flow rates.

■ Decrease in the wash or rinse temperatures.

■ Any changes in these process parameters that are beyond the recommended process windows for the equipment or chemistry suppliers. - Changes in reflow, wave solder, or selective solder recipes

■ Beyond the recommended process windows established by the equipment, flux, or paste suppliers - Changes within a manufacturing location

■ Moving a line from Plant A to Plant B or Location A to Location B

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Conformal Coating Machine under 40000

SMT feeders