Jerry Karp

Jerry Karp has submitted responses to the following questions.

Solder Paste Print Test Boards
IMO nothing serves better than the real board. Test boards do not provide representations of the actual product. ...

Full Aqueous Clean or Local Spot Clean
IMO, spot cleaning can create additional contamination to the PCB. Re-cleaning the entire PCB is my opinion. ...

Trays for MLS Baking
If using glass use laboratory grade Pyrex. ...

Question About ESD Ionizer Guns
The answer is yes. Utilizing pressurized air is moving particulate matter across the surface and, air is not clean per ...

Storage To Prevent Corrosion
My recommendation would be a vacuum seal utilizing a nitrogen purge with a large desiccant pack. ...

Conformal Coating Bubbles
Just from reading your supplied information related to the bubbles being present & the clear language of the IPC spec, ...

Solder Joint Blow Holes
I do not believe that the epoxy "bump" you refer to would be the cause. Creating an airtight seal would ...

Moisture Barrier Bag Calculation
I'm not sure of what he is referring to when he states "volume of vacuum-sealed bag?" It's nebulous. Without knowing ...

Challenge Wetting Solder to Brass Pins
There is only one solution that I could recommend. As you are trimming and forming the leads you are exposing ...

Hand Sanitizer Contamination
IMO not a good idea. The ammonium , per SE, is a urea product. Urea contains calcium. Calcium is a ...

Point to Pint Soldering vs Drag Soldering
I think you have answered your own question! When you were soldering each pin individually you were not experiencing shorts. ...

Looking for Long-term Component Storage Options
10 years... Wow. Are these IC's in the original tubes? Hopefully they were provided in ESD compliant products. From moisture ...

ESD Ground Wire Gauge
18 gauge stranded wire is commonly utilized for grounding. The center screw on an outlet is the preferred contact, using ...

Pad Missing ENIG Plating
It's the fabricators problem, not yours... return the entire batch as "rejected, does not meet spec". ...

Adding Chlorine to a DI (Deionization) Water System
Time out! First of all adding anything to your DI system will kill your DI beds. Chlorine, especially, what you ...

Reflow Oven - 5 Zone or 8 Zone
An age old question... How many zones do I need. Speed, profile, components, etc. Personally I will defer to my ...

Moisture Sensitive Components in Flooded Storage Facility
OK, so we know that these components were exposed to excessive moisture for an extended period of time. My belief ...

Stainless Steel Benches and ESD
The use of SS or metal benches is dangerous to your component and more so to your employees. Stainless steel ...

PCBA Inspection Process Causing Damage
I am not aware of any specific studies that were done on the movement of a PCB on a"relatively" hard ...

Stencil Cleaning Frequency
I would recommend you obtain, IPC-7526, which covers all aspects of stencil cleaning... ...

Cleanliness Testing
Ionic contamination testing is still the most cost-effective method available. There are several commercial systems available. ...

Exposed Copper Risk
Absolutely. Bare copper? Ever leave a penny outside? Green in no time. Either go with conformal coating for the entire ...

Control Electronic Static Discharge
If you are referring to ESD events caused by the motion of the handling devices then the only method is ...

Contamination Using Solvent Dispensers
What type of solvent dispenser are you using? There are products on the market that prevent the solvent from being ...

MSD Components Baked Too Long
The answer begs the question. Are you asking because you have already baked the parts at the longer stated time ...

Production Floor Temperature and Humidity Loggers
First & foremost..."your customer audit" They are making the request. Customers are hard to come by. Monitors are relatively inexpensive. ...

ESD Grounding - 1 Meg Ohm Resistor
The resistor protects the operator from becoming the path to ground in the event there is contact with live voltages. ...

Soldering Station Calibration
A lot depends upon the type of station utilized. Is it a military application? If so there are different requirements. ...

ESD Conductive Floor Tile Worry
Any time there is a high voltage situation the operator should be isolated/insulated from the potential to be the path ...

Selective Printing for BGA Components
At what cost to the integrity , structural, of the component. Could you do it... sure. Should you do it ...

PCBA Transport Between Facilities
The movement of PCB's from one facility to another presents a set of circumstances requiring specialhandling procedures. I will assume ...

ESD and Humidification
Additional humidification of an assembly area is not necessarily required when other measures are in place. Obviously, it is imperative ...

Spotting After DI Water Cleaning
Have you changed flux?There is something obviously fouling the beds if they are going bad in 2 weeks. Having sold ...

Long Term Component Storage
My first question would be "why do you need to store components for 10 years". I am going to assume ...

Solder Paste Life on the Stencil
Simplicity is always the way to go in my opinion.Are you seeing issues related to leaving the paste on the ...

Zip-lock Bags vs. Heat Sealed Bags
The correct answer would be no. From the fact that air cannot be fully evacuated from a zip lock ESD ...

Silver Solder for Audio Circuits
I would venture to say following.If you are an OEM then I don't see that Silver solder is going to ...

Improve DPPM for Wave Soldering Using Nitrogen
In all probability, yes. Nitrogen will significantly reduce the amount of "air" contacting your PCB, dependent on the quality & ...

Deionized Water Sample Testing
You indicate that you are getting a reading of 15 mOhms. Is that at the discharge from the point where ...

Wire Tinning Dispute
When tinning wire it hasalways been my understanding that no solder should "creep" under theinsulation.Solder flowing under thejacketing on a ...

Mixing Different SAC305 Solders
As long as the assay reports on the two different vendors materials are of the same chemical levels there should ...