Mike Scimeca

Mike Scimeca has submitted responses to the following questions.

Copper Dissolution Rate
There are many factors which effect the rate of Cu dissolution such as solder flow rate, alloy type,copper type and ...

Solution for Grape Effect
There are a few ways to combat graping. Use a solder paste with higher activity. Graping can be caused by ...

Test Probe Problems After Pin-In-Paste
My suggestion is to use a real pin probable solder paste. From our development work it isn't easy to make ...

What causes black pad?
Black pad is basically a reaction of the chemistry in Immersion Gold with the Electroless Nickel. This can be caused ...

White Discoloration After Ultrasonic Cleaning
Some no clean solder pastes are very difficult to clean. Typically this is due to making a paste pin probable ...

Solder Paste Viscosity
You should be able to return the sample as long as there is no contamination when running viscosity. Today's pastes ...

Wave Solder Pot Contaminated with Lead
Yes. You can dilute your pot to get to the right level. For instance if your pot size is 1,000 ...

Delay Before Washing Water Soluble Flux
This depends on the type of water soluble flux that you used. If you are talking about a wave solder ...

Pros and Cons of Cleaning No-clean
I believe that there are a lot of new cleaning chemistries in the market today that do clean off no-clean ...

Flux Residue Causing Test Issues
First question is are you running lead or lead free and is the residue left behind tacky? If the answer ...

Advantages Using OSP Surface Finish
The big advantage with OSP as a surface finish is that it is coplanar unlike Hot Air Leveling. OSP is ...

What is the Shelf Life for a Syringe of Solder Paste
This depends on the type of solder paste as well as the manufacturer. For our No Clean pastes we typically ...

Humidity Inside Our Screen Printer
Some of the older generation pastes were more susceptible to drying out in low humidity environments and slumping in high ...

Recommendation for PCB Surface Finish
I would suggest that you use Lead Free (SN100CL) Hot Air Leveling as this is one of the most robust ...

Which to Use - Rosin Flux or Water Soluble?
Typically water soluble fluxes have a higher activity than the rosin based fluxes so if you are looking for wetting ...

Cause of Yellow/Brown Discoloration
Yellow / Brown color on silver is silver tarnish which is a combination of silver sulfide and silver oxide which ...

What Is The Ideal HASL Thickness?
The ideal thickness is to be thick enough for good solderability, yet thin (flat) enough for part placement. Because of ...

Tacky Flux Residue Problem
Typically what you are left with is the residual tacky flux that didn't evaporate off. If this is a no ...

Concerns with High Humidity
High humidity can have an effect on reflow soldering. This is typically the case for Water Soluble Solder pastes. When ...

Hard Water Contamination
I am not an expert when it comes to cleaning but I do know a little bit about chemistry as ...

Solder Joint Void Limit for BGA Components
Solder joint void limit for BGA components is 12.25 % area for lead free class 2 circuit board assemblies. Most ...

Technology to Measure Oxidation Levels
Yes. We use an instrument from ECI Technology to measure oxidation on certain types of surface finishes. The technology is ...

Difference between shiny and matt solder resist
Yes, there are process differences between the two types of mask although there isn't a difference in the price. The ...

Nickel Barrier Thickness Requirement
The the normal spec for Nickel thickness is 100 micro-inches minimum (39.4 microinches/micron). Normally the Nickel minimum thickness is done ...

Leaded components in a no lead process
It isn't going to be an issue of lead contamination so much as it might be an issue with reliability. ...

SAC lead Free Solder Tear
I would say that we don't know whether they are a long term reliability issue if exposed to harsh environment ...

Screen Print Shelf Life
Usually we want people to reflow as soon as possible with water soluble pastes. If the Relative humidity isn't extreme, ...

IPA to clean 'lead-free'
No clean fluxes are designed to stay on the board. These residues are non conductive and non corrosive. I would ...

Ideal humidity for circuit board assembly
Solder pastes react differently to temperature and humidity levels. Low humidity levels can exacerbate the driving off, or drying of ...

Re-certify a reflow oven
Critical requirements for your specific reflow oven will be outlined by the oven manufacturer. Normal requirements generally consist of:A clean ...

Problem with 'No Clean' Solder Flux Residue
There are different classes of no clean flux. Ones that are a low solids containing no rosin and ones that ...

Type III vs. Type IV solder paste
The major reason to choose a Type-4 powder over Type-3 is to improve printing in small apertures. As a general ...

Set up for lead-free wave soldering
While optimal process settings will be determined by the alloy, flux, equipment type and individual assembly being processed, some good ...

Oxidation on Immersion Silver PCB's
Silver naturally tarnishes in open air, especially with chemicals present like in a PWB shop. There are a few recommendations ...

Micro-balling with lead-free HASL and SAC alloy
Micro-balling can be attributed to the print process, placement process, reflow process, the environment or the solder paste itself. Verify ...

IPA cleaning precautions
I recommend following the standard precautions for IPA. It is flammable, so keep heat and spark sources away from it. ...

Cleaning PCB's after long-term storage
63/37 HASL finish degrades with the growth over time of an intermetallic layer Cu6SN5. Usually the thickness of the HASL ...

Cleaning methodology and options
In the past people would use vapor degreasers that had solvents which were both polar and non-polar. An example of ...

Cleaning No-clean Flux
Residues of no clean fluxes are meant to be left on the board. The reason is that paste residues have ...

Tin-lead and no-lead compatibility issues
There is no problem associated with running Lead-free HASL boards using leaded paste. Nihon Superior, the patent holder on the ...

Solder to a think flexible circuit
Soldering to flex circuitry can be accomplished in several ways. Flex circuits are prone to de-lamination, a direct result of ...

PCB Cleaning
The benefit to pre-wiping a mis-printed board would be that it keeps the cleaning equipment from being quickly contaminated with ...

Lead Free Dross Removal
Dross is formed through oxidation when the molten alloy is exposed to the oxygen-rich environment. There are many variables that ...

Lead Free Flux
Lead-free alloys wet slower, have a greater surface tension, and operate at higher temperatures compared to tin/lead. There are older ...

What is the correct coupon for moister and insulation test
If you are testing liquid or paste flux residues, you will need to use the IPC-B-24 test coupon. B-24 is ...

Voids in leadless packages
Pages have been, and still could be written on this subject. There are basically two types of voids; a) gas ...

Through Hole Soldering on 24 Layer Board
24 layers is a lot of material to heat up for a soldering iron. My first suspicion would be that ...

Recover Solder from Dross
You have to evaluate on a case by case basis and as well determine what type of ROI you are ...