Harold Hyman

Harold Hyman has submitted responses to the following questions.

Component Damage From IR Reflow
It is not entirely clear from the question whether the cracks occur in the solder joint or in the component ...

Rework or Repair
It is all a question of definition. We define these activities as follows: REWORK -- an operation that is carried ...

What is Causing Oxidation?
Initial observation is that the blackening of the silver is more likely due to the creation of Sulphide rather than ...

Flux Recommendation for BGA Rework
The immediate reaction to this question is to suggest the same flux chemistry as is incorporated in the formulation of ...

Cause of Solder Icicles
Since the icicles are appearing on "some leads" and not all of them, the problem is more likely to be ...

Cleaning PCB's of Oxidation
Presumably, the "bare PCB's" have copper surfaces with no protective coating. Even so, it is a good idea to subject ...

What Causes Chip Component Blow Out
Assuming no irregularities in the performance of the reflow oven, the reason that immediately comes to mind is that the ...

Lead-Free Profile on Tin/Lead Assemblies
Subjecting boards that have been assembled with Sn/Pb to a typical Pb Free thermal profile should, in principle, not result ...

BGA Rework Flux Recommendation
The key phrase in the question is "under prolonged heating". In principle, the same flux or flux type as was ...

Lifted Leads on QFP
At all times during the handling and processing of QFPs, special care must be taken to make sure that all ...

Organic Flux Residue Concerns
It depends on the nature of the "organic flux residues." Pure rosin can be described as "organic" but its residues ...

Contamination Prior to Conformal Coating
Although not directly related to the adhesion of conformal coating there have, over the years, been reported instances of compromized ...

Which to Use - Rosin Flux or Water Soluble?
These questions raise more questions! In a few words, the choice is based on how strong the flux needs to ...