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This specification establishes the performance and qualification

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This specification establishes the performance and qualification

LAT-PS-01132 DRAFT Page 1 of 29

    Document # Date Effective

    7 Nov. 2002 LAT-PS-01132

    Prepared by(s) Supersedes

    N. Virmani None

    Subsystem/Office GLAST LAT PROCESS SPECIFICATION

    Tracker Subsystem

    Document Title

    LAT Tracker Tower Flex Cable Procurement, Quality Assurance, and

    Qualification Requirements

    GLAST LAT

    Tracker Tower Flex Cable Procurement,

    Quality Assurance, and Qualification Requirements

LAT-PS-01132 DRAFT Page 2 of 29

    DOCUMENT APPROVAL

Prepared by:

     Nick Virmani Date

    Naval Research Lab

Approved by:

Dave Nelson Date

    TKR Chief Electrical Engineer

    SLAC

Robert Johnson Date

Thomas Borden Date

    LAT-PS-01132 DRAFT Page 3 of 29

    CHANGE HISTORY LOG

    Revision Effective Date Description of Changes DCN #

    1 Developmental Release

LAT-PS-01132 DRAFT Page 4 of 29

    TABLE OF CONTENTS

    1.0 SCOPE ...........................................................................................................................7 2.0 APPLICABLE DOCUMENTS .....................................................................................7 2.1 GOVERNMENT/MILITARY SPECIFICATIONS AND STANDARDS .........................................7

    2.2 OTHER PUBLICATIONS ..................................................................................................7

    2.3 ORDER OF PRECEDENCE ................................................................................................8 3.0 REQUIREMENTS ........................................................................................................8 3.1 GENERAL REQUIREMENTS .............................................................................................8

    3.1.1 LAT Tracker Kapton Flex Cable Flex cable drawing............................................8 3.1.2 Conflicting requirements ......................................................................................8 3.2 DESIGN ........................................................................................................................8 3.2.1 Tolerances of Flex Cable Design..........................................................................9 3.2.2 Flex Cable Lay-up................................................................................................9 3.2.3 Impedance Specification .................................................................................... 10 3.2.4 Surface Mount Design Consideration ................................................................. 10 3.2.4.1 Parts .................................................................................................................. 11 3.2.4.2 Connectors ......................................................................................................... 11 3.3 MATERIALS ................................................................................................................ 12

    3.3.1 Flexible .............................................................................................................. 12 3.3.2 Flexible Metal Clad Dielectric ........................................................................... 12 3.3.3 Coverlayer ......................................................................................................... 12 3.3.4 Adhesives ........................................................................................................... 12 3.3.5 Flexible Adhesive Bonding Films (Cast) ............................................................. 12 3.3.6 Dielectric Materials ........................................................................................... 12 3.3.7 Copper Foil Thickness ....................................................................................... 13 3.3.8 Cover Coat......................................................................................................... 13 3.3.9 Plated Metallic Layers and Finishes .................................................................. 13 3.4 MECHANICAL DESIGN REQUIREMENTS ........................................................................ 14

    3.4.1 Conductor Spacing ............................................................................................. 14 3.4.2 Balanced Conductors ......................................................................................... 14 3.4.3 Conductor to Edge Spacing ................................................................................ 14 3.4.4 Conductor Thickness and Width ......................................................................... 15 3.4.5 Via Hole ............................................................................................................. 15 3.4.6 Land Requirements ............................................................................................ 15 3.4.7 Test Points ......................................................................................................... 15 3.4.8 Flexible Areas .................................................................................................... 15 3.4.9 Tear Restraints................................................................................................... 15 3.4.10 Bend Areas......................................................................................................... 15 3.4.11 Minimum Bend Radius ....................................................................................... 16 3.4.12 Flexural Life Bend Radius Considerations ...................................................... 16 3.4.13 Bends and Creases ............................................................................................. 16 3.4.14 Structural Strength ............................................................................................. 17 3.4.15 Vibration ............................................................................................................ 17

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LAT-PS-01132 DRAFT Page 6 of 29

    4.1 QUALITY REQUIREMENTS ........................................................................................... 25 4.2 QUALIFICATION REQUIREMENTS ................................................................................. 25 4.3 SOURCE INSPECTION ................................................................................................... 26 4.4 QUALITY CONFORMANCE ........................................................................................... 26 4.5 INSPECTION LOT ......................................................................................................... 26 4.6 WORKMANSHIP .......................................................................................................... 26 4.7 ACQUISITION REQUIREMENTS ...................................................................................... 26

    5.0 PACKAGING AND SHIPPING ................................................................................. 26

    5.1 HANDLING AND STORAGE ........................................................................................... 26 5.2 HANDLING FIXTURES .................................................................................................. 27 5.3 SUPPORT .................................................................................................................... 27 5.4 PACKAGING ................................................................................................................ 27

    5.5 MARKING ................................................................................................................... 27 5.6 TRACEABILITY ........................................................................................................... 28

    5.6.1 Test Coupons ..................................................................................................... 28

    5.7 DOCUMENTATION AND QUALITY TEST SPECIMEN ........................................................ 28

    6.0 SUPPLIER RESPONSIBILITY ................................................................................. 28

LAT-PS-01132 DRAFT Page 7 of 29

1.0 SCOPE

    This specification establishes the procurement, quality assurance, performance and qualification requirements for flex cable used on the Tracker (TKR) subsystem. Verification of flex cable is accomplished through the use of product assurance provisions defined herein. Detail requirements, specific characteristics, and dimensions of the flex cable, are specified in the flex cable drawing. This specification does not address flex cable parts and connector assembly and installation of the cable to the tracker.

2.0 APPLICABLE DOCUMENTS

    2.1 Government/Military Specifications and Standards

    The following specifications and standards form a part of this specification to the extent specified herein. Unless otherwise specified, the applicable issues of these documents shall be those listed in the issue of the Department of Defense Index of Specifications and Standards (DoDISS), and the applicable supplement thereto, in effect on the date of the procurement.

    Evaluation of Multilayer Printed Wiring Boards by NASA-RP-1161 Metallographic Techniques

2.2 Other Publications

    The following documents forma a part of this specification to the extent specified herein. The applicable issues of these documents shall be that or those in effect by the responsible industry association or society on the date of the procurement documents.

    IPC-2221 Generic Standard on Printed Board Design

    IPC-2223 Sectional Design Standard for Flexible Printed

    Boards

    IPC-6013 Qualification & Performance Specification for Flexible

    Printed Boards

    IPC-A-600 Acceptability of Printed Boards

    IPC-TM-650 IPC Test Methods

LAT-PS-01132 DRAFT Page 8 of 29

    2.3 Order of Precedence

    In the event of a conflict between the procurement document(s), the text of this document and the references cited herein, the following order of precedence, shall apply:

    1) Contract or purchase order.

    2) Flex cable drawing

    3) This specification

    4) Other documents referenced herein

3.0 REQUIREMENTS

    3.1 General requirements

    Flex cable furnished to this specification shall conform to the requirements of the LAT Tracker Kapton Flex Cable drawing, this specification, and IPC-6013. The detailed requirements contained in this section are determined by examining specific quality conformance test circuitry (test coupons) and sample flexible cable, shall apply to all coupons, sample flexible cable, and delivered flexible cable. Defects or anomalies noted on coupons or sample cables (or both) when performing the inspections defined herein shall be recorded and the proper corrective actions shall be initiated to eliminate the defects or anomalies.

    3.1.1 LAT Tracker Kapton Flex Cable Flex cable drawing

    Flex cables delivered under this specification shall be of the material, design, and construction specified on the flex cable drawing. If individual design details are not specified on the drawing, then the baseline design parameters shall be as detailed in the design standard IPC-2223.

    3.1.2 Conflicting requirements

    In the event of conflict between the requirements of this specification and other requirements of the drawing, the precedence in which documents shall govern, in descending order, is as follows:

    a. The drawing. Additional acquisition requirements may be provided in the

    order or contract. Any deletion of any of the performance requirements or

    performance verifications of this specification not approved by the activity, will

    result in the flex cable being deemed noncompliant with this specification.

    b. This specification.

    c. The applicable IPC design standard.

    d. Specifications, standards, and other documents referenced in section 2. 3.2 Design

LAT-PS-01132 DRAFT Page 9 of 29

    Flex cable shall be of the design as specified on the drawing. If individual design details are not specified on the applicable drawing, then the baseline design parameters to be used for acceptability of finished product requirements shall be as detailed in IPC-2223 that was used to design the flexible cable.

    Test coupon design, quantity, placement, and usage shall be in accordance with IPC-2223.

    3.2.1 Tolerances of Flex Cable Design

    Flex cable materials are inherently unstable to some degree, perfect multilayer alignment cannot be achieved. Designs of flex shall accommodate these variations:

     After etch shrinkage: 0.001 in/in

     Artwork variation: 0.0002 in/in form humidity and temperature effects (plotting

    error plus film base instability, unless the base is glass).

     Pinning: each occurrence, 0.002 in.

     Lamination: 0.003 in.

     Hole-to-hole in drilled patterns: 0.002 in.

    Artwork factoring to compensate for material movement after etch is almost mandatory; thoughtful material choice at the design stage, plus clear definition of the material and quality requirements in drawing notes, is essential to close the control loop. Optional alignment to etched fiduciaries is one of the methods for reducing alignment errors, which reduces the effect of artwork pinning errors and after-etch shrinkage. 3.2.2 Flex Cable Lay-up

    Figure 1 shows the lay-up for the four-layer flex cable. The total thickness is 450 ;m

    (18 mils) nominal. The minimum thickness can include the adhesive. The following is the justification for each material thickness:

     All copper are required to be a minimum of 1 oz., Type 3.

     All other dielectrics are a minimum of 0.008” between layer 2 and 3.

     The top and bottom cover layer is a minimum of 0.001”.

     Solder pads shall be left exposed

LAT-PS-01132 DRAFT Page 10 of 29

     LF0210 Kapton Covercoat 0.00100

     Acrylic Adhesive 0.00200

    Layer 1 1 oz. Copper + Plating Rolled/Annealed + ED Copper 0.00350

     Acrylic Adhesive 0.00100

     LF9111 Kapton Basefilm 0.00100

     Acrylic Adhesive 0.00100

    Layer 2 1 oz. Copper Rolled/Annealed + ED Copper 0.00140

     Acrylic Adhesive 0.00100

    AD1 LF0121 Kapton Basefilm 0.00200

     Acrylic Adhesive 0.00100

     Acrylic Adhesive 0.00100

    AD2 LF0121 Kapton Basefilm 0.00200

     Acrylic Adhesive 0.00100

    Layer 3 1 oz. Copper Rolled/Annealed + ED Copper 0.00140

     Acrylic Adhesive 0.00100

     LF9111 Kapton Basefilm 0.00100

     Acrylic Adhesive 0.00100

    Layer 4 1 oz. Copper + Plating Rolled/Annealed + ED Copper 0.00350

     Acrylic Adhesive 0.00200

     LF0210 Kapton Covercoat 0.00100

    Total Thickness 0.03000

    Nominal Dielectric Thickness is .008”

    Table 1.Tracker Flex Cable Lay-up

3.2.3 Impedance Specification

    The ordering of the layers is shown in figure1. The signal traces are nominally 150 Ohm Differential Impedance. The signals NTREQxxx, NTOKENxxx, NSDATAxx, and TEMPxx shall have 10-mil trace width. The signals NRESETxx, CLKx, NTACKx, and NSCMDx shall have 12-mil traces from J1 to two inches from J2 on the main cable, and 8-mils all the rest of the routing. The xxx represents the signal suffixes. Differential pairs shall be routed together and spaced away from other pairs.

    3.2.4 Surface Mount Design Consideration

    The following surface mount design guidelines will be followed:

    1. Pads should be coverlayered or covercoated to prevent solder escape-apertures

    should define the best area for device attachment.

    2. Pads should extend well underneath the coverlayer or covercoat to increase

    resistance to pad lifting form the attach and rework cycles.

    3. Coverlayer of covercoat thickness should be minimal to minimize impact on

    solder-cream deposition and device attachment. Because the coverlayer could

    prevent the device from settling into contact during reflow, it‟s possible that

    apertures should be larger than the component.

    4. Part footprints should be used where possible.

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