In-Line Testing of Highly Panelized PCBAs with Parallel Functional Test
Electrochemical Reliability as a Function of Component Standoff
Reliable Nickel-Free Surface Finish for High-Frequency-HDI PCB
Enclosed Media Printing as an Alternative to Metal Blades
Risk for Ceramic Component Cracking Dependent
Nanocopper Based Paste for Solid Copper Via Fill
Fluxless Die Attach by Activated Forming Gas
Embracing a New Paradigm: Electronic Work Instructions (EWI)
Latest Industry News
Global Chip Shortage Is Impacting Carmakers
VIEWPOINT 2021: Raymond M. LaFleur, General Manager of Overseas Sales and Marketing, DEN-ON
VIEWPOINT 2021: Mark Cottom, Vice President of Sales & Marketing, National Circuit Assembly
Geely and Foxconn form partnership to build cars for other automakers
Samsung Debuts World's First Wi-Fi 6E Mobile Phone
IBM tops US patent list for 28th year in a row with more than 9,100 patents granted
5G Makes Waves At CES 2021
4 Reasons a Retreat Into Nature Will Increase Productivity

Modify Rework Procedures for Assemblies Fabricated Using OSP?

Modify Rework Procedures for Assemblies Fabricated Using OSP?
Should we modify any rework or repair procedures for circuit board assemblies fabricated using OSP, organic solderability preservatives, bare boards? Jim Hall and Phil Zarrow, the Assembly Brothers, share their own thoughts on this scenario.
Board Talk
Board Talk is presented by Phil Zarrow and Jim Hall of ITM Consulting.
Process Troubleshooting, Failure Analysis, Process Audits, Process Set-up
CEM Selection/Qualification, SMT Training/Seminars, Legal Disputes
Phil Zarrow
Phil Zarrow
With over 35 years experience in PCB assembly, Phil is one of the leading experts in SMT process failure analysis. He has vast experience in SMT equipment, materials and processes.
Jim Hall
Jim Hall
A Lean Six-Sigma Master Blackbelt, Jim has a wealth of knowledge in soldering, thermal technology, equipment and process basics. He is a pioneer in the science of reflow.


Welcome to Board Talk with Jim Hall and Phil Zarrow of ITM Consulting, the Assembly Brothers. Coming to you today from the ITM Consulting failure analysis cave, high atop Mount Rialto.

We are here to talk about electronic assembly, materials, equipment, components, practices and procedures, among other things. Jim, let's see.

There is another thing, today we have a rework question. This is from J.N.

J.N. asks should we modify any rework or repair procedures for circuit board assemblies fabricated using OSP, organic solderability preservatives, bare boards? That is a good one.

First off, I want to say if you are working with a completed assembly then there should no longer be any OSP on that board because all of the surfaces covered with OSP should have been covered with solder at one step of the assembly process. They should not have finished boards that have any OSP exposed, like test points or something else.

OSP is not a long term protection for copper on finished boards. It is strictly protection between the PC fab and the time you solder it. Everything should have solder on it.

It should just be an ordinary board. Perhaps you are doing touch-up after the first side of a double-sided SMT assembly.

So you haven't gone through wave soldering, you haven't gone through second side, and you may have some OSP pads which are not soldered at that point. Understand that it is not a physically robust surface.

It should take soldering temperature, but you don't want to expose it to any extreme temperatures. But most importantly you don't want to scratch it. OSP is not like a metallic finish that is robust.

When you are in there with soldering irons and soldering wicks and so forth if there is an OSP through hole nearby that hasn't been soldered yet you want to make sure that you do not scratch that OSP. You can very easily go right through that surface, expose some copper and then have a soldering problem in your next soldering step.

Very good. I hope we answered your question and anyone else who has been pondering the same thing in the wild world of OSPs.

You have been listening to Board Talk, with Phil and Jim the Assembly Brothers. Although the SMTA denies any responsibility for our actions, we are the Assembly Brothers.

Also, whatever you do please don't solder like my brother.

And don't solder like my brother.


Per Phil's comments on covering any exposed copper surface with solder on OSP board, there will be board vias not covered by solder. Would there be any long term functional negative effect caused by them?
Phuong T Huynh, Flex

Submit A Comment

Comments are reviewed prior to posting. You must include your full name to have your comments posted. We will not post your email address.

Your Name

Your Company
Your E-mail

Your Country
Your Comments

Board Talk
Is There a Spacing Spec for SMD Components?
Maximum Board Temperature During Tin-Lead
Is HASL a Good Choice for Surface Finish?
Connector Bowing During Reflow Process
Has My Flux Expired?
Long Term Component Storage
Processing Circuit Boards with BGAs On Both Sides
What Causes Solder Balls During Hand Soldering?
Ask the Experts
Mixing Different SAC305 Solders
Dross Particles Sticking to PCBs
Cleaning with Sodium Bicarbonate
Conformal Coating Over Heat Sinks
Flux Oozing from Insulated Wires
Conformal Coating in Low Humidity Environments
Tiny Solder Balls After Reflow
Solder Paste Alloy Check