Folks,
Is there a consensus, especially from committee (7-11D) members, on the above inquiry regarding Bow & Twist for raw board and PCBAs (populated boards)?
Ref: IPC-T-50M (May – 2015) ( Victor’s comments )
Bow - (Fabric) Filing yarn that lies in an arc across the width of a fabric.
Twist - The deformation of a rectangular sheet, panel, or printed board, that occur parallel to a diagonal across its surface, such that one of the corners of the sheet is not in the plane
that contains the other three corners.
Victor,
From: Jose A Rios [mailto:[log in to unmask]]
Sent: Wednesday, May 16, 2018 8:35 AM
To: TechNet E-Mail Forum; Hernandez, Victor G
Subject: Re: [TN] Bow and Twist measurements per IPC 650 TM 2.4.22, IPC 600-2.11 Flatness
2.4.22 is only for bare (unpopulated) PWB’s, and the rigid portion of rigid-flex PWB's. Section 1 (Scope) explicitly excludes PCBA’s from being evaluated using this method.
José (Joey) Ríos, Sr QA Engineer
Mission Assurance Manager
Kavli Institute for Astrophysics & Space Research
Massachusetts Institute of Technology
[log in to unmask]<mailto:[log in to unmask]>
(617)324-6272
On May 16, 2018, at 7:17 AM, [log in to unmask]<mailto:[log in to unmask]> wrote:
Fellow TechNetters:
Is there a separate Bow & Twist Test/documentation for Printed Wire Boards, PWB, and Printed Wire Board Assemblies, PWBAs? Are they interchangeable......
Victor,
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