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Robert "Bob" Lazzara

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President
Circuit Connect, Inc.

Bob has been in PCB design and fabrication since 1976. He has held elected positions with the SMTA, is a member of the MSD Council, has served as a committee member for various IPC standards and is a Certified IPC Trainer.

Robert "Bob" Lazzara has submitted responses to the following questions.
Exposed Copper Defect
YES: Exposed copper is a class 3 defect per IPC-A-600 EXCEPT for card edge connectors. Remember those? ...
IPC-A-610 Class 3 - IPC-A-600 Class 2
"If the PCB Assembly inspection requirement is IPC-A-610 Class 3, does it mean that the PCB inspection IPC-A-600 also has ...
Bottom Terminated Components and Vias
Single sided via protection -- be it tenting, plugging or something other -- is to be avoided. Such features are ...
ENIG Solderability Issues
"The nickel thickness measured with an XRF is around 400 microinches." That is impressive thickness for electroless nickel. Are you ...
Manual or Automated Assembly?
Here's a different idea:Buy your PCBs pre-pasted. Pre-pasted PCBs come with assembly-thickness solderready-to-go right out of the box. No stencil ...
V - Scoring PCB Question
You will generatepost-assembly dust that will include metal (copper) particulates. Otherwise,going sufficiently deep to depanel with a 90-degree cutter will ...
Adhesion Problems with Conformal Coating
For your review andconsideration: http://www.circuitnet.com/articles/article_102459.shtml ...
Proper method to bake PCB's
The IPC-1601, Printed Board Handling andStorage Guidelines, has 34 references on the subject of baking PCBs. The IPCanswers the questions ...
Concave Via Fillets Causing Problems
Maintain your pad size,but reduce the via size to the smallest diameter your board house can providewithout driving-up cost. ...
Reduce Glare During Assembly
Virtually all solder maskmanufacturers offer matte and semi-matte formulations. In addition tomitigating glare these reduced-gloss masks arguably improve conformal coatingbond, ...
Circuit Board Bow and Twist
Given that the circuit pattern and assembly processing are unchanged, bare board processing can be considered. If the manufacturer fails ...
Blow Holes and Disturbed Joints
In the case ofmultilayer PCBs it is unlikely that moisture trapped deep within the boardswill be fully released. Baking schemes ...
Silkscreen as a Masking Layer?
Becauseyou're re-purposing the material from Marking feature to Insulatorfunction, you might first check with UL (presuming the end-product performs toUL). ...
HASL Surface Finish and Coplanarity
HASL coplanarity will vary by method(horizontal vs. vertical) and by alloy (Pb-free versus SnPb). I'm sure you wantrepeatability; to that ...
White Legend Ink Turning Pink
Gold salts (e.g., from ENIG surface finish) left on the surface(typically from a dirty final rinse) will react with titanium ...
Issues with BGA Components Near PCB Edges
When the PCB is post-assembly separated frompallet/panel form to individual form, the various methods of"depanelizing" will load different levels of ...
Delamination Causing Scrap
The #1 cause of delamination is moisture. And by-far. Whileother failure modes exist (e.g., inadequate bonding layer cure) they do ...
Can Solder Joint Geometry Change Resistance?
Determine whetherthe intermetallic differs between two electrically-differing joints (micro-sectionanalysis). If cross-sectional views indicates the intermetallic isvisually thicker on the higher ...
Flux Oozing from Insulated Wires
Are your wiresstranded or solid? Stranded wires have a higher propensity for wicking flux,which can later reflow at elevated assembly ...
Reflow Causing Warp
"We have a 20 layer PWB that is notbalanced..." That really says itall. Your only recourse will be to restrain ...
Gold Plated Hole Defects
There's a variety ofcauses for the solder not to fully wet to pads & hole walls, and none ofthem are ...
HASL vs. Immersion Gold
Immersion gold is notintended as a final finish. Rather, it's purpose is to preserve thesolderability of the metal it covers, ...