(Just a tidbit… to keep you up at
night)
We found a few errors in the IPC-2221
specification that need correction. (not that we were looking for them)
Note: This is also referenced in the CID
design Guide on page 113.(it is wrong in both places of course, that’s
where we found it first…)
We believe Table 9-1 page 74 of the design
guide has a math error when converting from millimeters to inches… (don’t
feel bad, NASA even has trouble with that sometimes)
Regarding manufacturing tolerances…
Note 1 says ‘add 0.05mm [0.0197
in.] well… that is about 20 mils there isn’t it…? Some
how that raised a flag… do they need 20 mils for mfg tolerances?
Shouldn’t it say… ’add
0.05mm [0.00197] ? (with two zeros following the decimal point) that would be
closer to the 2 mils I think they meant.
The same is true in the table Note 2…
where they convert the same way…
Also at Section 1.6.3 mentioned in note 3,
I went to that section in the IPC-2221 to read about the Producibility levels
and found…(see page 3)
(I was still trying to make sense of note
one and two)
3 producibility levels:
Level A General Design Producibility - Preferred
Level B Moderate Producibility - Standard
Level C High Producibility - Reduced
‘High’ producibility (in English)
implies that the board is very producible when in fact it should be
referencing the ‘least’ producible condition… or MOST
DIFFICULT to produce.
It seems the terminology that was used
earlier in the spec at 1.6.2 was somehow incorporated into this description
when it should not have.
Perhaps it should read Level C Low Producibility
– Reduced…?
That’s my contribution for this year…
I’m done. (Can I go home now?)
J
Everyone have a safe holiday weekend…
J
Bill Brooks |
Datron World
Communications, Inc.
PCB
Designer/Engineer | Office: 760-602-7004| Fax: 760-597-3777 |
From: DesignerCouncil
[mailto:[log in to unmask]] On Behalf Of
Brooks, Bill
Sent: Tuesday, November 16, 2010
1:20 PM
To: [log in to unmask]
Subject: Re: [DC] Rick Hartley
contact info
Thank you all for the great
responses… I got it.
J
I knew I could count on
our community to come thru… J
Bill Brooks |
Datron World
Communications, Inc.
PCB
Designer/Engineer | Office: 760-602-7004| Fax: 760-597-3777 |
From: DesignerCouncil [mailto:[log in to unmask]]
On Behalf Of Brooks, Bill
Sent: Tuesday, November 16, 2010
10:56 AM
To: [log in to unmask]
Subject: [DC] Rick Hartley contact
info
Does someone have Rick Hartley’s
phone number?
I want to talk with him for a minute or
two…
Please send it to me offline…
thanks.
Bill Brooks |
Datron World
Communications, Inc.
PCB
Designer/Engineer | Office: 760-602-7004| Fax: 760-597-3777 |
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