Grant Main

Technical Sales Manager

Fineline VAR Ltd

40 Years in PCBs. Large and small companies in the UK and the US. Experienced Process Engineer, DFM, Materials, Impedance Control, Surface Finishes, etc. Working with Fineline now across the portfolio of manufacturers covering rigid, flex, rigid flex, ATE, Load Boards, MSAP, and other existing and emerging technologies.

Grant Main has submitted responses to the following questions.

IPC 610 Class 3 with Missing Non-functional BGA Pads
I would suggest that those PCB's are not per design and consequently do not meet requirements. Removal of unused pads ...

Delamination After V-cut
Without knowing more about the affected PCB, difficult to say for sure but a number of things that could affect ...

Acceptable Conductor Repair
As a PCB person and going on comments from the persons above, my line of attack would be "what confidence ...

Allowable Bow and Twist on Round PC Fab
I agree - the fact that the PCB is routed should make no odds to bow and twist. What will ...

Matte Black Solder Mask Defects
Whilst the imperfections and marking are worse than would be expected, from a PCB manufacturing perspective I would ask the ...

Controlling Creep Corrosion
Not sure this is best directed at PCB manufacturers but my tuppence would be; Conformal coating of the PCB would ...

Baking Old PCBs Prior To Reflow
You don't make reference to whether these are rigid pcb's, flexis or rigid flex. Assuming these are rigid then they ...

Tented Via Options and Tradeoffs
When you say "tented" is this genuinely tented, or a partial covering? To tent in the old fashioned sense, you ...

Tented Via Options and Tradeoffs
When you say "tented" is this genuinely tented, or a partial covering? To tent in the old fashioned sense, you ...

Contamination From Anti-static Foam
I agree with a few of the comments above. Same as we do at PCB level in the case of ...

Solution for Warped PCBAs
Warp/Twist happens for a reason. Unless you identify what that reason (or reasons) is, you may in all probability get ...

Moisture Sensitivity Level for Bare Boards
Some excellent comments and recommendations here but another couple of points which should and need to be understood and appreciated. ...

Bottom Terminated Components and Vias
Tenting in the true sense pretty much doesn't exist any longer as the industry has almost entirely ditched dry film ...

Exposed Copper Risk
Exposed copper is never recommended, no matter what the environment. The modification looks to be a manual soldering process, presumably ...

Adhesion Problems with Conformal Coating
Another point to consider (irrespective of the actual coating), is to ensure that the CTE of the coating is well ...

HASL Surface Finish and Coplanarity
As has been said, a 0.60mm suggests quite a large pitch device. Previously, I would have said down to 0.80mm ...

Via Wall Thickness Test
To the best of my knowledge, there is no failsafe way to verify the plated thickness of copper in a ...

Removal of Non-functional Pads from Inner Layers
There are many aspects and matters that should be considered with this. On a rigid PCB of 1.6mm thickness, not ...