CMX PCB Description ------------------------ Rev. 31-Oct-2013 --> Modified On 29-Nov-2013 *** Good for Production **** This note is a description of the bare CMX printed circuit board. Note that we are asking the assembly vendor to obtain the bare pcb to insure that they are comfortable with the quality of the pcb and have included in it all rails and tooling holes that their assembly process may require. For this CMX project we are comfortable paying for a high quality pcb with optimum surface finish to insure that there are no assembly problems. We are happy to discuss any aspects of this card that will make the manufacturing of it easier or facilitate higher yield. The CMX system design requires a complicated pcb but we do not want to needlessly specify an excessively difficult to manufacture card. CMX Bare Circuit Board Specifications: Circuit Board Size: rectangular 400mm in X by 366.7mm in Y Layers: 22 Most of the card is alternating trace and ground plane layers. Material: The laminate dielectric material must be appropriate for carrying high frequency 6.5 GHz digital signals. We assume that this will be a quality high frequency low dielectric loss material that the bare pcb vendor is comfortable working with. Controlled Impedance: The CMX circuit board required 2 types of controlled impedance traces: 60 Ohm single ended and 100 Ohm differential. 60 Ohm single ended traces are used on layers: --> 3, 5, 9, 18, 20. In the gerber files all 60 Ohm traces on these layers were drawn with a trace width of 0.12 mm. All 0.12 mm width traces on these layers should be adjusted to have a 60 Ohm single ended controlled impedance. 100 Ohm differential trace pairs are used on layers: --> 1, 3, 5, 9, 16, 18, 20. In the gerber files all 100 Ohm differential trace pairs on these layers were drawn with a trace width of 0.14 mm and a center to center spacing of 0.4 mm . All 0.14 mm width traces on these layers should be adjusted to have a 100 Ohm differential controlled impedance. Layer Summary: PCB Layer Type Layer Function Controlled Impedance ------- ------------ ----------------------- 1 Signal Layer 100 Ohm Diff 2 Ground Plane 3 Signal Layer 60 Ohm SE & 100 Ohm Diff 4 Ground Plane 5 Signal Layer 60 Ohm SE & 100 Ohm Diff 6 Ground Plane --> 7 Signal Layer 8 Ground Plane 9 Signal Layer 60 Ohm SE & 100 Ohm Diff 10 Ground Plane 11 Power Fills 12 Power Fills 13 Ground Plane 14 Power Fills 15 Ground Plane 16 Signal Layer 100 Ohm Diff 17 Ground Plane --> 18 Signal Layer 60 Ohm SE & 100 Ohm Diff 19 Ground Plane 20 Signal Layer 60 Ohm SE & 100 Ohm Diff 21 Ground Plane 22 Signal Layer Copper Weight: 1/2 oz minimum on all Signal and Ground Plane layers i.e. Layers: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 13, 15, 16, 17, 18, 19, 20, 21, 22. 1 oz minimum on all layers with Power Fills i.e. Layers: 11, 12, 14. Thickness: The nominal thickness will be in the range of 2.6 mm. Milled Strip: A strip along the top edge and another strip along the bottom edge must be milled from the BACK side to a thickness of 1.6 mm to allow insertion into card guides. These two milled strip are 2.0 mm wide and are located right along the top and bottom edge. No traces or planes have been placed in the area of these strips. There is silkscreen that indicates the correct side and area of the card to be mill down to 1.6 mm thickness. Blind Vias: This card has one type of blind via that connects only layers 1 through 6. There are 967 of these blind vias. They have a nominal drill diameter of 0.25 mm. Ground Planes: There are 4 different copper patterns used for the 10 ground planes in the CMX card. The upper ground plane pattern is used on pcb layers: 2, 4, 8. The L6 ground plane pattern is used only on pcb layer: 6 The middle ground plane pattern is used on pcb layers: 10, 13, 15, 17, 19. The lower ground plane pattern is used only on pcb layer 21. Drill Information: The CMX card has 3 types of drill holes: Plated through drills Plated drills from layer 1 to layer 6 for Blind Vias Un-Plated through drills There is a separate drill file for each of these hole types: cmx_drill_plated_1_22 cmx_drill_plated_1_6 cmx_drill_un_plated_1_22 All holes sizes are given as finished diameter. Note that as designed the 0.25 mm diameter holes are only used for the blind vias from layer 1 to layer 6. These blind vias have a pad land diameter of 0.56 mm. We are happy to discuss adjusting this hole diameter to optimize the finished pcb yield. Note that as designed the 0.30 mm diameter through holes are only used for vias that have a pad land diameter of 0.60 mm (or 0.65 mm where possible). We are happy to discuss adjusting this hole diameter to optimize the finished pcb yield. Plated through drills Layers 1 through 22 Drill Drill Size Count Function ----- ----- ----- ---------------------------- 2 0.3 7137 small vias and bga pins 3 0.6 1761 bigger vias backplane conn 4 0.7 136 mdr 68 pin front panel conn 5 0.9 16 2x8 front panel connector 6 1.0 32 AWG22 vias SFP Cage pin 8 1.1 36 SFP Cage pins 10 1.2 40 SFP Cage pins 11 1.3 95 DC/DC Converter pins 14 2.0 10 MiniPOD mounting screw pins 16 2.3 2 CF_Socket mounting screw pins 17 2.7 4 m2.5 mounting screw pins 18 3.0 38 4-40 mounting screw pins Plated Blind Via drills Layers 1 through 6 Drill Drill Size Count Function ----- ----- ----- ---------------------------- 1 0.25 967 blind vias layers 1 thru 6 Un-Plated through drills Layers 1 through 22 Drill Drill Size Count Function ----- ----- ----- ---------------------------- 7 1.0 10 CF_Socket Header_2x20 TTCDec 9 1.1 10 LED alignment 12 1.55 17 SFP MiniPOD CAN_Bus Proc Conn 13 1.75 2 CF_Socket 15 2.0 3 Power Conn alignment 19 3.18 2 Backplane Pin Receptacle Traces and Clearances: In the 1 mm pitch BGA breakout there are 0.13 mm traces with a minimum of 0.13 mm clearance to the nearest copper. Outside of the BGA breakout wider traces and clearances are used except where dictated for controlled impedance traces. Surface Finish: The surface finish should be selected to allow optimum SMD component assembly. I assume that this will be gold finish of some type. Bare card electrical test: All cards 100% tested Gerber Files: File Name Content ------------------- ------------------------------- cmx_artwork_1 Layer 1 Trace Top Copper cmx_artwork_2 Layer 3 Trace cmx_artwork_3 Layer 5 Trace --> cmx_artwork_4 Layer 18 Trace cmx_artwork_5 Layer 9 Trace cmx_artwork_6 Layer 11 Power Fill cmx_artwork_7 Layer 12 Power Fill cmx_artwork_8 Layer 14 Power Fill cmx_artwork_9 Layer 16 Trace --> cmx_artwork_10 Layer 7 Trace cmx_artwork_11 Layer 20 Trace cmx_artwork_12 Layer 22 Trace Bottom Copper cmx_artwork_13 Layers 2,4,8 Gnd Plane cmx_artwork_14 Layer 6 Gnd Plane cmx_artwork_15 Layers 10,13,15,17,19 Gnd Plane cmx_artwork_16 Layer 21 Gnd Plane cmx_artwork_17 Overall Assembly Drawing cmx_artwork_18 Silkscreen Top cmx_artwork_19 Silkscreen Bottom cmx_artwork_20 Solder Mask Top cmx_artwork_21 Solder Mask Bottom cmx_artwork_22 Solder Paste Stencil Top cmx_artwork_23 Solder Paste Stencil Bottom Technical Contacts: Dan Edmunds Philippe Laurens Phone: (517) 884-5521 phone: (517) 884-5522 Email: edmunds@pa.msu.edu Email: laurens@pa.msu.edu FAX: (517) 355-6661 FAX: (517) 355-6661