HSROCB Design Details --------------------------- Rev. 30-SEPT-1998 Special Mentor Layer Usage: --------------------------- DAM_1 Overall Label Text DAM_2 Cut trace in the GROUND Plane DAM_3 Cut trace in the Power Plane DENSITY_1 Cosmic Copper added to the component side traces PROBE_1 Geometric constructions for curved traces Gerber Plots ------------ Details of Gerber generation are listed in the Default_Artwork_Order ASCII Geometry. The basic scumbag method of generating plots for multiple power supplies sharing a common physical plane is used. That is, separate layers in the Mentor system, hand drawing cut traces on a separate layer, and putting it all together in the gerber plot. Test Plot DAM_1, BOARD_OUTLINE Comp Side Traces DAM_1, SIGNAL_1, PAD_1, DENSITY_1 Ground Plane DAM_1, DAM_2, POWER_1 Brd Edge = 0.025 Power Plane DAM_1, DAM_3, POWER_2, POWER_3 Brd Edge = 0.025 Solder Side Traces DAM_1, SIGNAL_2, PAD_2 Comp Side Silkscreen DAM_1, SILKSCREEN_1 Solder Side Silkscreen DAM_1, SILKSCREEN_2 Comp Side Solder Mask DAM_1, SOLDER_MASK_1 Solder Side Solder Mask DAM_1, SOLDER_MASK_2 Thermal Aperatures ------------------ for 33 mil vias D-Code 71 Position 12 want + orientation for 35x45 rectangle D-Code 20 Position 13 want X orientation ? Oval Pads --------- The oval pad is 35 mil x 45 mil The plane relief around this pad is 45 mil x 60 mil The Thermal relieved pad is 45 mil x 60 mil outside dimension with 5 mil air gap and 12 mil ties The solder mask relief is 40 mil x 50 mil i.e. normal 5 mil over the pad size. D-Code vs Plot File ------------------- Plot Plot Name File D-Codes Udes ------------ ---- -------------------------------------------- Test Plot 1 10 Comp Side 2 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 23 Gnd Plane 3 10, 70, 71, 20, 21, 22 Power Plane 4 10, 70, 71, 20, 21, 22 Sold Side 5 10, 11, 12, 14, 15, 16, 23, 24 Comp Silk 6 10, 14 Sold Silk 7 10, 14 Comp Sold Msk 8 10, 13, 15, 16, 17, 18, 19 Sold Sold Msk 9 10, 15, 16, 24 Geometry for the HP HDMP-1012 ------------------------------ From the HDMP-1012 Data Sheet: "package dimensions conform to JEDEC plastic QFP (80) specification" lead pitch 0.80 mm foot width 0.35 mm outside dimension (i.e. toe to toe) along long edge 23.2 mm outside dimension (i.e. toe to toe) along short edge 17.2 mm From the IPC SMD design book for the QFP-14x20-80 Component Identifier we find: it is a 16 pin by 24 pin device Device outside dimension (i.e. toe to toe) along long edge 22.95 - 23.45 mm outside dimension (i.e. toe to toe) along short edge 16.95 - 17.45 mm length of foot 0.70 -1.05 mm Pad Pattern outside dimension of pads along long edge 23.80 - 24.00 mm inside dimension of pads along long edge 20.40 - 20.60 mm outside dimension of pads along short edge 17.80 - 18.00 mm inside dimension of pads along short edge 14.40 - 14.60 mm center of pads along long edge 22.20 mm center of pads along short edge 16.20 mm pad length 1.80 mm pad width 0.40 - 0.60 mm Mentor Geometry that was made for this part center of pads along long edge 22.40 mm center of pads along short edge 16.40 mm pad length 2.00 mm pad width 0.40 mm Conclusions: In the Mentor Geometry pads are about 0.20 mm i.e. 0.008" longer than necessary. In the Mentor Geometry center of the pads are about 0.10 mm i.e. 0.004" further out than necessary. All pad positions are OK. We may want to plot them as 0.45 mm wide pads. Pads at plot time were specified to be: 2.00 mm = 0.0787 became 0.079 = 2.007 mm <-- just fine 0.40 mm = 0.0157 became 0.017 = 0.432 mm <-- could be even wider ? Impedance Match --------------- So THE-Card has about 3 kinds of traces. The outer two layers on the surfaces of the cards, microstrips, look like either about 60 Ohms for the trace next to the Gnd Plane or else about 85 Ohms for the trace on the surface of the card. The inner layers of traces are always asymmetric between 2 Gnd Planes are are about 50 Ohms. Note this is all from just calculations, i.e. not measured. For the HSROCB microstrips we can guess the following trace widths vs Zo for various mat thinknesses. MICROSTRIP Trace Trace Board Construction Trace Width Thickness Layers, Mat thickness Z in Mills in oz and Mills Mills WRT Gnd -------- --------------- --------------------------- -------- 10 1 oz 1.4 mil GND, 15 mil mat, Trace 86 Ohm 10 1 oz 1.4 mil GND, 20 mil mat, Trace 98 Ohm 10 1 oz 1.4 mil GND, 25 mil mat, Trace 105 Ohm 12 1 oz 1.4 mil GND, 15 mil mat, Trace 81 Ohm 12 1 oz 1.4 mil GND, 20 mil mat, Trace 90 Ohm 12 1 oz 1.4 mil GND, 25 mil mat, Trace 101 Ohm 19 1 oz 1.4 mil GND, 10 mil mat, Trace 50 Ohm 30 1 oz 1.4 mil GND, 15 mil mat, Trace 50 Ohm 40 1 oz 1.4 mil GND, 20 mil mat, Trace 50 Ohm 49 1 oz 1.4 mil GND, 25 mil mat, Trace 50 Ohm 58 1 oz 1.4 mil GND, 30 mil mat, Trace 50 Ohm Finisar says that besides the Impedance match that you want the two traces to have a length match within 0.100". The actual 2 dimensional trace length (plus pad and C34 component) match is within 0.025" with the hop over trace being longer. If you add 0.55mm height for the zero Ohm C34 hop over then the match is within 0.068". TO-DO ----- x Mark pins to solder in silkscreen on the solder side. x Add J1, U2 pin numbers to the silkscreen on the solder side. Add spare vias to unused terminator resistors ? x Remove the solder mask relief from all the 33 mil vias on both sides. Add alignment marks for the parts placer. Parts to purchase: ------------------ Qty Needed ------ ----------------------------------------- -------- --------------- 80 p HP G-Link chip HDMP-1012 U1 ordered 4 then 4 80 p Laser Module Finisar FTM-8510-1-0-1 U2 ordered 6 15 . Connector AMP 104068-6 J1 0 h Chip Resistor 10 Ohm R1 :R4 Vee ByPass 200 . Chip Resistor 51 Ohm R11:R12 Terminate STRBIN 0 h Chip Resistor 1k Ohm R21 HCLKON pull down R22:R24 Laser Mod Lines 200 . Resistor Network 51 Ohm CTS 766-161-510 R31, R32 Terminator 0 h Chip Capacitor 0.1 uFd bypass quality C1 :C6 Vee C11:C18 Vtt C21:C22 Vcc 400 . Chip Capacitor 0.1 uFd 10% good quality C31:C32 Strobe AC Couple C33 Loop Filter C34 DOut-Tx hop over 100 . Ferite or Filter Inductor (SMD ?) L1 200 . 2-56 hex nuts and 2-56 by 1/2" allen screws 100 Heat Sinks