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Terry Munson
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President/Senior Technical Consultant
Foresite
Mr. Munson, President and Founder of Foresite, has extensive electronics industry experience applying Ion Chromatography analytical techniques to a wide spectrum of manufacturing applications.

Terry Munson has submitted responses to the following questions.
No-Clean Flux Residue After Selective Soldering
If the no clean SMT paste flux residue is still gooey and connecting pads or pat to via it may ...
Specific Solder To Control Dendritic Growth
I hope you found that the root cause was due to paste residue, but the reality is that any of ...
Using Solder Paste Beyond the Expiration Date
It typically is not considered in the expiration date as to cleanability but the solder wetting and reflow conditions that ...
Components Falling Off During Wave Soldering
Let me ask the question are you following the glue manufacturer's ramp time and rate of cure, or are you ...
Tough Hand Soldering Problem
The cooling may be causing more of an issue. Remember the grid pattern is a heat sink. If you are ...
QFN Test Failures Caused by Flux
This is a correct statement. We have been reporting on this failure mechanism for 10 years. The QFN is pulled ...
Hot Air Solder 0201s and 01005s
I would suggest you rework with an IR rework station and dispense paste with a syringe. Check out the DAGE ...
Overlap Solder Joint Failures
I would evaluate using solder preforms and hot bar soldering or IR heating. ...
Cleanliness Testing
If you want to understand the cleanliness of a process with typical components doing the average cleanliness of the total ...
Removal of Coatings from PCBs
It will depend on the coating type for the right approach and if you want specific areas removed or total ...
MELF Component Misalignment
It appears that you are curing the chipbonder epoxy during reflow. This will cure faster because the ramp rate is ...
Adhesion Problems with Conformal
To address the issue with the conformal coating adhering to large gold surfaces we would suggest using a plasma surface ...
Production Floor Temperature and Humidity Loggers
Wouldn't it make sense to put temp/humidity monitors in critical locations, such as board and component storage areas, near the ...
Excess Flux Residue After Hand Soldering
The answer is it depends but this appears to be excessive on the contact, but was a different amount of ...
Burned Chip Repair
From the photo my recommendation would be to spend the money on the new board sorry. Something in the system ...
Bottom Side Chip Bonding
There should not be a normal situation where the components are glued to the bottom side of a PCBA if ...
Challenging Cleaning Problem
The use of no clean flux will create residue opportunities that must be designed out of the assembly process. To ...
BGA Joint Voids - Accept or Reject?
This is a difficult call on a generalization of voids, but I would remind you this is a thin section ...
Long Term Component Storage
It has been our experience that dry cabinets that hold 25 C at 0% RH with or without nitrogen work ...
Dross Particles Sticking to PCBs
Typically if you are getting dross or webbing you are using to little flux. The flux acts a lubricant between ...
Tacky Substance Under Zero Clearance Parts
I am sorry to tell you that you're right and your flux vendor is wrong!!! That is exactly what is ...
Can Solder Joint Geometry Change Resistance?
Typically these types of higher current draws are due to flux or fabrication residues on the capacitors or at the ...
White Discoloration After Ultrasonic Cleaning
The white residue is uncleaned no clean flux residue. Ultrasonic cleaning does not clean well for most water soluble fluxes ...
Insufficient Plated Hole Fill with Electrolytic Capacitors
We would first recommend that you assess the solderability of the board and component leads, at the same time check ...
HASL vs. Immersion Gold
The Gold is a better finish for the corrosive environment if it is clean going into the field. HASL will ...
Cleaning PCB's of Oxidation
We have seen great success using EnviroGold 816 at 5% in DI at 60 C or use of plasma to ...
Options for Reducing Dross
My recommendation is to use the MS2 product from PK Metal. Contact Larry Kay at larrykay@pkaymetal.com We have done extensive ...
Cleaning No-Clean Solder Paste
We have been cleaning no clean fluxes for 9 years and it requires some good cleaning energy, flux cleaner and ...
Re-plating lead-free components for tin/lead assembly
The re-plate and solder dipping processes depend on the type of component. There are companies such as Corfin and Meehan ...
Cause of Unusual Contamination?
Unusual contamination? The photos show what appear to be contamination below the soldermask from the etch process not properly rinsed. ...
Flux Residue Visible After 3 Months
First your description of the conditions does appear to be the reaction of partially heat activated flux that is able ...
Hard Water Contamination
We have recoved bare boards using sapoinified DI water with our Aquastorm 200 removing tap water residues and recovered solderability ...
Wave soldering of fine pitch through hole components
We have seen very tight pitch wave soldering when the MS2 material is used on the solderpot. The MS2 works ...
Ultrasonic Cleaning Causing Damage
We use saponifier and steam to effectively clean no clean. ...
What is the Proper DI Water Resistivity
Using high resistivity water has been the most effective cleaning with both batch and in line cleaning. We use 18.2 ...
Problem with 'No Clean' Solder Flux Residue
This is white residue around all the SMT pads and on the bottom selective wave solder areas. This is flux ...
DI Resistivity for Wafer Dicing and Cleaning
We have been effective at using 14-18 meg ohm resistivity DI water for our clients dicing wafers. The lower the ...
Cleaning PCB's after long-term storage
As a consulting service and test laboratory we get this question regularly. We have use a specific saponifier at 5% ...
Board cleaning problem
I response to your question about improved cleaning under the 0603 low standoff components we would recommend presoaking the boards ...
Idle Time Between Soldering and Cleaning
Typically the only two that are critical are reflow to clean and clean to coating and it depends on what ...
How many types of pad contamination are there?
We have found pads with high levels of sulfate, sodium, ammine, rosin, and nitrate besides the chloride and phosphate contamination. ...
DI Water resistivity
To answer your question, the better the water quality the less garbage you put on your wafers. Why only 0.5 ...
IR Reflow Issue
This sounds like a combination of a oxidized lead surface and a low thermal profile. Check the solderability of the ...
What is the correct coupon for moister and insulation test
The B-24 is a single sided coupon with only 4 comb patterns 20 mil spaced (16 mil) line, while the ...
Best Board Cleaning Methodology
We have found that a low pressure (35 -40 psi) saponified cleaning with a 50 psi rinse removes more solderballs ...
Ultrasonic Cleaning Considerations
Cleaning in an ultrasonic cleaner, bare boards, assembled boards and raw parts will poorly clean even with the most expensive ...
Resistivity and Cleaning
To address the DI water resistivity question for proper defluxing with water the higher the resistivity the better (we currently ...
Deflux Eutectic and Lead-Free Assemblies
Cleaning Leaded and Lead Free assemblies with a good saponifier and DI water in an in-line aqueous cleaner using a ...
Cleaning "no-clean" flux
We have published on cleaning a No Clean (it is a Circuits Assembly Article). It doesn't work well with just ...
Cleaning Military Circuit Boards Contaminated with Sand
Cleaning of this type can effectively be done with a low pressure (25 PSI) wash system with a weak 1% ...