LOL, yes. But a manufacturer of 480 VAC power distributors is going to have a different view of fine-pitch than a manufacturer of digital Bluetooth hearing aids.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ron Feyereisen
Sent: Thursday, September 06, 2018 2:55 PM
To: [log in to unmask]
Subject: Re: [TN] PTH Fine-Pitch Definition

Hard to believe no one has come up with a definition, IPC or others.

Ron


-----Original Message-----
From: Robert Kondner [mailto:[log in to unmask]] 
Sent: Thursday, September 6, 2018 2:08 PM
To: 'TechNet E-Mail Forum' <[log in to unmask]>; Ron Feyereisen <[log in to unmask]>
Subject: RE: [TN] PTH Fine-Pitch Definition

Ron,

 For whatever it is worth: I would not consider .65mm as fine pitch. .5mm and down is what I consider fine pitch.

Bob K.

-----Original Message-----
From: TechNet <[log in to unmask]> On Behalf Of Ron Feyereisen
Sent: Thursday, September 6, 2018 2:37 PM
To: [log in to unmask]
Subject: Re: [TN] PTH Fine-Pitch Definition

Thanks for the input!

I'm attempting to define (at least in-house) what the definition is so that others cannot keep using the fine-pitch argument as the cause whenever a solder short occurs, regardless of the pitch.

Thanks again!
Ron


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D
Sent: Thursday, September 6, 2018 12:43 PM
To: [log in to unmask]
Subject: Re: [TN] PTH Fine-Pitch Definition

Well, that's close enough for govmint werk, LOL!


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Wayne Showers
Sent: Thursday, September 06, 2018 11:34 AM
To: [log in to unmask]
Subject: Re: [TN] PTH Fine-Pitch Definition

Richard, I am somewhat in your boat, but the definition I was always presented with is .65mm (25.6mil) and smaller is classified as fine pitch.  This is the definition used by Topline for their dummy parts.  I have also seen this number floated about in several papers and equipment manuals.

For lack of clarity, I would propose this as a good guideline based on IPC inspection criteria.
That is, once we are at 0.65mm (and lower), the lead width itself, by necessity, reduces to 10 mils (0.25mm) give or take.
At 10 mil (0.25mm) lead width, Table 1-2 of IPC-A-610 jumps the required inspection magnification from (7.5X to 10X) up to 20X for inspection.