Printed Circuit Board Design Updates Andrew Laundrie and Xu Zhai UW - - PowerPoint PPT Presentation

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Printed Circuit Board Design Updates Andrew Laundrie and Xu Zhai UW - - PowerPoint PPT Presentation

Sep 18, 2023 150 likes •498 views

Printed Circuit Board Design Updates Andrew Laundrie and Xu Zhai UW Physical Sciences Laboratory March 27, 2019 Design Updates Overview Foot Boards and Side Boards - Dimensions stretched to fit larger frame tubes - Multi-layer boards are

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SLIDE 1

Printed Circuit Board Design Updates

Andrew Laundrie and Xu Zhai UW Physical Sciences Laboratory March 27, 2019

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SLIDE 2

Design Updates ̶ Overview

3/27/19 DUNE PCB Design Updates 2

  • Foot Boards and Side Boards
  • Dimensions stretched to fit larger frame tubes
  • Multi-layer boards are required in some locations
  • Head Boards
  • Increased spacing between wire traces
  • Improved interface for electrical testing
  • Hardware Improvements
  • Custom Mill-Max sockets and pins
  • Stronger threaded inserts in boards
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SLIDE 3

X-Layer Foot Boards

3/27/19 DUNE PCB Design Updates 3

Old New

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SLIDE 4

V-Layer Side Boards

3/27/19 DUNE PCB Design Updates 4

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SLIDE 5

U-Layer Side Boards

3/27/19 DUNE PCB Design Updates 5

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SLIDE 6

Head Board Structure

3/27/19 DUNE PCB Design Updates 6

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SLIDE 7

Slots Between CR Boards

3/27/19 DUNE PCB Design Updates 7

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SLIDE 8

Solder Pads (48) X Plane Sockets and Test Pads (48) VSS pass‐throughs V U

X-layer Head Board: ProtoDUNE

3/27/19 DUNE PCB Design Updates 8

V and U signals pass through connected socket pairs

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SLIDE 9

X-layer Head Board: ProtoDUNE

3/27/19 DUNE PCB Design Updates 9

  • Spacing of 0.5 mm

between channels limits the safe voltage that can be applied between adjacent wires (~100 V)

  • Increased spacing is

desired to support voltage differences as high as 400 V

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SLIDE 10

X-layer Head Board: DUNE

3/27/19 DUNE PCB Design Updates 10

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SLIDE 11

X-layer Head Board: DUNE

3/27/19 DUNE PCB Design Updates 11

  • Spacing between U and V

wire channels has increased to 2.5 mm

  • Board edge was moved

4.0 mm to accommodate increased channel spacing

  • Fiducials were added to all

boards to support inspection by automatic vision systems

Fiducial reference point V U

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SLIDE 12

X-layer Head Board: DUNE

3/27/19 DUNE PCB Design Updates 12

  • Landing pads were

added to the bottom side of X head boards (blue traces)

  • Pads allow the

attachment of test headers in place of CR boards

  • Headers use spring-

loaded contact pins

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SLIDE 13

Test Header Concept

3/27/19 DUNE PCB Design Updates 13

  • Four connectors

provide access to all channels on the X, U, and V head boards

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SLIDE 14

CR Board (ProtoDUNE)

3/27/19 DUNE PCB Design Updates 14

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SLIDE 15

New CR Board

3/27/19 DUNE PCB Design Updates 15

Minor changes only

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SLIDE 16

V-layer Head Boards (new / old)

3/27/19 DUNE PCB Design Updates 16

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SLIDE 17

U Layer Head Boards (new / old)

3/27/19 DUNE PCB Design Updates 17

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SLIDE 18

G Layer Head Board: ProtoDUNE

3/27/19 DUNE PCB Design Updates 18

Solder Pads (48) Landing pads for G bias (12 + 6)

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SLIDE 19

G Bias Board: ProtoDUNE

3/27/19 DUNE PCB Design Updates 19

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SLIDE 20

G Layer Head Board: DUNE

3/27/19 DUNE PCB Design Updates 20

Solder Pads (48) Landing pads for G bias (48 + 6)

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SLIDE 21

G Bias Board: DUNE

3/27/19 DUNE PCB Design Updates 21

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SLIDE 22

ProtoDUNE Sockets and Pins

3/27/19 DUNE PCB Design Updates 22

Standard catalog items had some performance issues

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SLIDE 23

DUNE Sockets

3/27/19 DUNE PCB Design Updates 23

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SLIDE 24

DUNE Pins

3/27/19 DUNE PCB Design Updates 24

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SLIDE 25

CE Assembly Installation

3/27/19 DUNE PCB Design Updates 25

  • Captive screws in ProtoDUNE were

meant to pull connectors together in a controlled fashion, but they posed a risk of being dropped into the cryostat during CE installation or removal

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SLIDE 26

CE Assembly Installation

3/27/19 DUNE PCB Design Updates 26

  • Captive screws were eliminated

by changing the angle brackets

  • n CR boards
  • Threaded tools are inserted and

rotated to pull connectors together, then removed

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SLIDE 27

CE Assembly Installation

3/27/19 DUNE PCB Design Updates 27

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SLIDE 28

Hardware Improvements

3/27/19 DUNE PCB Design Updates 28

  • Expanding threaded

inserts have been replaced by broaching fasteners to prevent breaking and reduce metal debris

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SLIDE 29

Process Improvements

3/27/19 DUNE PCB Design Updates 29

  • Improved tools and methods are being evaluated for PCBs
  • Instrumented tips on soldering irons for process control
  • Vapor-phase reflow soldering for CR and G Bias boards
  • Improved board-washing equipment
  • Automated test systems for CR boards and G-Bias boards
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SLIDE 30

Quality Assurance and Control

3/27/19 DUNE PCB Design Updates 30

  • All ProtoDUNE boards were inspected when received
  • Complex mechanical features were frequently out of spec
  • Continued inspection of most boards is probably needed
  • Manual board inspection was time-consuming
  • Vision systems are being evaluated for board inspection
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SLIDE 31

Backup Slides

3/27/19 DUNE PCB Design Updates 31

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SLIDE 32

Mill-Max Pins and Sockets

Pins are fragile and not repairable once bent. Their exposure is minimized during APA assembly. .

CR X V U

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SLIDE 33

In ProtoDUNE the separation between exposed metal through-hole pads is about 0.5 mm.

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