Mark Northrup

Fellow

Raytheon

Mark has over 35 years of experience in electronics fabrication, quality, and reliability while working for Raytheon RMD, IEC Electronics, GE, Motorola, ORS, etc. He has most recently taken the role as a Fellow at Raytheon in Tucson, AZ; prior to that, he established IEC Electronics Analysis and Testing Laboratories (IATL), LLC in Albuquerque, NM, for electronics and material analysis testing in the military, medical, and industrial industries. His expertise includes PCB, PCBA, components, and analytical and electrical analysis techniques.

Mark Northrup has submitted responses to the following questions.

Removing Cleaning Residues Under BTC Packages
Great question C.G. Typically I like to perform Ion Chromatography (IC) extractions from components ( e.g., bottom terminated ) for ...

Pad Missing ENIG Plating
If you apply OSP to the pads you have two different finishes, unacceptable by both IPC and customer drawing requirements ...

Tarnished OSP Circuit Boards
The OSP(Organic Solderability Preservatives)Process consists of the following high level steps: OSP Process Steps *reclean/ Microetch *Prefix/Acid *Organic Coating *Rinse ...

Adding Chlorine to a DI (Deionization) Water System
My colleague Joe Russeau at Precision Analytical Labs(PAL) and myself recommend the following SOP to address bacteria issue:Place a large ...

IPC SOIC Defect Question
The issue with "IPC SOIC Defect" relative to if solder touches the body of a Metal, Ceramic, or Plastic component ...

How to Detect Counterfeit Components?
Many of my customers ask me about a counterfeit components risk mitigation testing strategy. Typically, there are several industry testing ...

Inspection for Hidden Solder Joints
Great question. You indicate a complex mechanical arrangement with 50 through-hole solder joints to be inspected. Your concern is if ...

Contamination From Anti-static Foam
Your question involves two steps: Identifying the unknown contaminationRemoval of the unknown contaminationStep one will require FTIR if organic in ...

What's Causing Cloudy Conformal Coating
You explain that you are experiencing electrical faults with an assembly. What are the IPC -TM-650-2.3.28 Anions(Na, K, Ca, Li, ...

Allowable Bow and Twist on Round PC Fab
B.D. great question I hope I have a good answer. Both the IPC-A-600 and IPC-6012 documents state the bow and ...

Moisture Sensitive Components in Flooded Storage Facility
If the parts were flooded (e.g., exposed to 100%RH for several days via immersion under water) then my recommendation is ...

Insufficient Barrel Fill on Through-hole Components
My experience has identified "Insufficient Barrel Fill" on Through-hole Components can be attributed to the following : First, have you ...

Is Component Lead Damage Reparable?
First I recommend you address the poor lead forming process that left gashes in the component leads. Goal should be ...

Requirements for Installing Leaded vs. Lead-free Press Fit Connectors
Yes there are different requirements between a leaded press fit connector, and a lead free press fit connector. Check with ...

What Caused SMT Pads to Oxidize After Reflow
Your question is quite common with many who specify ENIG PCB Surface Finish. Do you require IPC-4552 Specification for Electroless ...

Specific Solder To Control Dendritic Growth
Specifying a specific type of solder paste of your choosing to electronics suppliers to be compliant especially in a Class ...

Moisture Sensitivity Level for Bare Boards
The JEDEC industry standard (J-STD-033) for electronic components requires they must also be stored and handled correctly. Specifically, attention should ...

Solder Balling Splash After Reflow
Your "Solder Balling Splash After Reflow" description and associated pictures are a good start. But unfortunately, I need more information ...

IPC-A-610 Class 3 - IPC-A-600 Class 2
Great question, many times I am asked about mixing and matching between IPC Class 3 and 2 requirements across specifications ...

Two Year Component Date Code Mandate
At IEC Electronics, also an electronics services manufacturer (CM), we too are routinely confronted with quality mandates on components purchased ...

What Is This Contamination?
The images from a failed position-sensor used in your power plant, appear to be potted or staked with some kind ...