Back-Drill Netnames and XY Regions ------------------------------------ Original Rev. 27-Oct-2016 Current Rev. 30-Jan-2017 This file provides various lists that are used to control the generation of the Hub Back-Drill data: - The list of Netnames that will be considered for Back-Drilling - The list of XY Regions in which Back-Drilling locations must reside - A summary of the various signal layer transitions that occur in each of the Back-Drill Regions and how each of these signal layer transitions will be handled when using only a finite number of Back-Drill depths. - A list of the otherwise unused Mentor Layers where Back-Drill data can be displayed so that we may visually check the locations that will be Back-Drilled. For a location to be back-drilled, that location must be part of a net in this list of netnames and the XY location must be in one of the regions listed. List of Netnames to be considered for Back-Drilling: ---------------------------------------------------- Netname Function / Location ------------------- ------------------------------------- GTH_FO_CH_*_IN FEX Data from Backplane to Fanout GTH_FO_CH_*_OUT_ROD FEX Data from Fanout to MegArray Conn GTH_FO_CH_*_OUT_HUB FEX Data from Fanout to Hub FPGA MINIPOD_TRANS_FIBER_*_DATA From FPGA to Trans MiniPOD REC_MP_FIBER_*_TO_FPGA From Rec MiniPOD Capacitor to FPGA THIS_HUBS_RO_*_CAP_TO_OTHER_ROD From Coupling Cap through DPV to the backplane zone 2 conn THIS_RODS_READOUT_CTRL_TO_GTH_INPUT From the bottom of the S2 MegArray to the Hub's FPGA COMBINED_DATA_FROM_OTHER_HUB From Zone_2 to Hub FPGA MGT Rec. Notes: The _DIR and _CMP suffixes are not included the netnames in this list. The real netnames with both suffixes are to be considered for back-drilling. The * wildcard replaces only one or two numeric characters 0...9 There are many other netnames, e.g. Combined_Data that one assumes would appear in this list. On visual examination these nets have no trace routing that can benefit from back-drilling, e.g. they are routed entirely on the bottom layer of the card. List of XY Regions in which Back-Drill Locations Must Reside: ------------------------------------------------------------- XY Region Name SW Corner NE Corner ---------------- ------------- ------------- FPGA_U1 101.9 114.9 140.1 165.1 Fanout_Main 196.7 76.7 248.2 171.5 Fanout_Top_Row 196.7 177.5 258.5 184.1 Zone_2_MGT 263.1 93.2 278.0 155.9 Meg_S1_Main 139.9 231.8 143.9 280.2 Meg_S2_Main 216.1 231.8 220.1 280.2 Meg_S2_NE 223.7 272.4 225.2 275.2 Meg_S2_SE 223.7 231.7 225.2 232.0 MiniPOD_Trns_MP1 18.0 185.9 26.1 198.1 MiniPOD_Rec_MP2 23.7 159.6 33.5 170.4 Routing_DPVs 182.4 90.5 187.8 95.9 Hub_RO_AC_Caps 167.1 94.5 171.5 97.9 Notes: Some of these XY Regions, e.g. the FPGA_U1, include the Differential Via Pairs that are immediately adjacent to the named object. In general the coordinates of all regions have been made as restrictive as possible. The XY values given above define regions that extend 0.1 mm outside of the area where the back-drill locations are expected to be found, one does not have to worry about > vs =>. List of Signal Level Transitions that Occur in each Back-Drill XY Region: ---------------------------------------- First recall the layout of the Hub design (Ignore the Ground Layers and the pure Power Layers for this list): Mentor Mentor Signal Physical PCB Layer Layer Stackup Function ------ -------- ------- ------- Sig_1 Phy_1 L1 Diff-Pair Top Sig_2 Phy_2 L3 Diff-Pair Sig_3 Phy_3 L5 Diff-Pair Sig_4 Phy_4 L7 Diff-Pair Sig_5 Phy_5 L9 Diff-Pair & Power Sig_6 Phy_9 L14 Diff-Pair & Power Sig_7 Phy_10 L16 Diff-Pair Sig_8 Phy_11 L18 Diff-Pair Sig_9 Phy_12 L20 Diff-Pair Sig_10 Phy_13 L22 Diff-Pair Bot The layer transitions are listed separately for each of the Back-Drill XY Regions. The layer transitions are listed by their Mentor Physical Layer. Transition To the FPGA's Top P1 Layer From: P2, P3, P4, P5 FEX Data P13 Comb-Data, Hub Readout P11, P12 data to MiniPOD Transmitter P2, P3 data from MiniPOD Receiver P5 ROD's Readout Control data Transition To the MiniPOD's Top P1 Layer From: P11, P12 data to Transmitter MiniPOD P2, P3 data from Receiver MiniPOD Transition To the Fanout's Top P1 Layer From: P2, P3, P4, P10, P12 FEX DATA NO transitions to Fanout Top P1 from: P5, P9, P11 Transition To the Fanout's Bottom P13 Layer From: P3, P4, P5, P9, P11 FEX Data NO transitions to Fanout Bottom P13 from: P2, P10, P12 Transition To the MegArray's Top P1 Layer From: P5 ROD's Readout Control P9, P10, P11, P12 FEX Data P13 Comb-Data and Hub Readout Transition To the Backplane Zone 2 Connector From: P2, P3, P4, P9, P10, P11, P12, P13 NO transitions to the Backplane Zone 2 Conn from: P5 Transitions in the two Routing Differential Via Pairs: P13 transitions to P9 Hub Readout 0 to Other Hub P13 transitions to P2 Hub Readout 1 to Other Hub Now divide up the above layer transitions into the actual Back-Drills Depths that will be used in the Hub PCB: Notes: We do not want stubs more than 0.5 mm long. We can conveniently have up to 4 Back-Drill Depths per PCB Side during the PCB Manufacturing. It looks like ONLY transitions To the Fanout's Bottom P13 layer and the transitions To P13 in the Routing Differential Via Pairs will Require Back-Drills from the Top side of the PCB. Back-Drills in the Backplane Zone 2 Connector area must be from the Bottom and must leave a minimum 1.40 mm tunnel of metal adjacent to the Top surface of the card. The expected thickness of the Hub PCB is 3.05 mm. The expected spacing in the actual PCB between the Mentor Physical layers under discussion is the following: From P1 To P2: 0.2539 mm From P2 To P3: 0.2996 mm From P3 To P4: 0.2996 mm From P4 To P5: 0.2996 mm From P5 To P9: 0.6197 mm Thick Center Power From P9 To P10: 0.2996 mm From P10 To P11: 0.2996 mm From P11 To P12: 0.2996 mm From P12 To P13: 0.2539 mm Putting all of the above together gives the following selection of Back-Drill Depths: Back-Drills from the TOP When the Signal is Going To Bottom Layer P13: to P13 from P1: No Back-Drill Possible to P13 from P2: Ideal - cut down through L2 keep connection to L3 expected stub is 0.0711 mm to P13 from P3: Ideal - cut down through L4 keep connection to L5 expected stub is 0.0711 mm Settle for - cut down through L2 keep connection to L3 expected stub is 0.3707 mm to P13 from P4: Ideal - cut down through L6 keep connection to L7 expected stub is 0.0711 mm to P13 from P5: Ideal - cut down through L8 keep connection to L9 expected stub is 0.0711 mm Settle for - cut down through L6 keep connection to L7 expected stub is 0.3707 mm to P13 from P9: Ideal - cut down through L13 keep connection to L14 expected stub is 0.0775 mm to P13 from P10: This transition pair is not used in the Hub design. to P13 from P11: Ideal - cut down through L17 keep connection to L18 expected stub is 0.0787 mm to P13 from P12: This transition pair is not used in the Hub design. Summary of the Back-Drill Depths from the TOP: cut down through L2 keep connection to L3 cut down through L6 keep connection to L7 cut down through L13 keep connection to L14 cut down through L17 keep connection to L18 Back-Drills from the BOTTOM When the Signal is Going To Top Layer P1: to P1 from P13: No Back-Drill Possible to P1 from P12: Ideal - cut up through L21 keep connection to L20 expected stub is 0.0711 mm to P1 from P11: Ideal - cut up through L19 keep connection to L18 expected stub is 0.0711 mm Settle for - cut up through L21 keep connection to L20 expected stub is 0.3707 mm to P1 from P10: Ideal - cut up through L17 keep connection to L16 expected stub is 0.0711 mm to P1 from P9: Ideal - cut up through L15 keep connection to L14 expected stub is 0.0711 mm Settle for - cut up through L17 keep connection to L16 expected stub is 0.3707 mm to P1 from P5: Ideal - cut up through L10 keep connection to L9 expected stub is 0.0775 mm to P1 from P4: Ideal - cut up through L8 keep connection to L7 expected stub is 0.0787 mm Settle for - cut up through L10 keep connection to L9 expected stub is 0.3771 mm to P1 from P3: Ideal - cut up through L6 keep connection to L5 expected stub is 0.0787 mm to P1 from P2: Ideal - cut up through L4 keep connection to L3 expected stub is 0.0787 mm Settle for - cut up through L6 keep connection to L5 expected stub is 0.3783 mm Summary of the Back-Drill Depths from the Bottom cut up through L21 keep connection to L20 cut up through L17 keep connection to L16 cut up through L10 keep connection to L9 cut up through L6 keep connection to L5 Back_Drills for Backplane Zone 2 Connector Only The Back-Drills for the Backplane Zone 2 Connector are all from the BOTTOM. Zone 2 Connector Back-Drills from the BOTTOM When the Signal is Going To Top Layer P1: to P1 from P13: No Back-Drill Possible to P1 from P12: Ideal - cut up through L21 keep connection to L20 expected stub is 0.0711 mm to P1 from P11: Ideal - cut up through L19 keep connection to L18 expected stub is 0.0711 mm Settle for - cut up through L21 keep connection to L20 expected stub is 0.3707 mm to P1 from P10: Ideal - cut up through L17 keep connection to L16 expected stub is 0.0711 mm to P1 from P9: Ideal - cut up through L15 keep connection to L14 expected stub is 0.0711 mm Settle for - cut up through L17 keep connection to L16 expected stub is 0.3707 mm to P1 from P5: This transition pair is not used in the Hub design. to P1 from P4: Ideal - cut up through L8 keep connection to L7 expected stub is 0.0787 mm Must Settle for - cut up through L11 keep connection to L10 1.40 mm min. expected stub is 0.5194 mm to P1 from P3: Ideal - cut up through L6 keep connection to L5 expected stub is 0.0787 mm Must Settle for - cut up through L11 keep connection to L10 1.40 mm min. expected stub is 0.7999 mm to P1 from P2: Ideal - cut up through L4 keep connection to L3 expected stub is 0.0787 mm Must Settle for - cut up through L11 keep connection to L10 1.40 mm min. expected stub is 1.0995 mm Summary of the Back-Drill Depths from the Bottom for the Backplane Zone 2 Connectors. cut up through L21 keep connection to L20 cut up through L17 keep connection to L16 cut up through L11 keep connection to L10 Special Use of Mentor Layers: ----------------------------- The following otherwise unused Mentor Layers will be used to graphically display the Back-Drill data so that we may check the locations that will be Back-Drilled. Mentor Layer Back-Drill Display Function ------------------- --------------------------------------- SHEET_DIELECTRIC_4 From Top Keep L3 to L22 \ SHEET_DIELECTRIC_5 From Top Keep L7 to L22 | SHEET_DIELECTRIC_6 From Top Keep L14 to L22 | SHEET_DIELECTRIC_7 From Top Keep L18 to L22 | All XY | Regions SHEET_DIELECTRIC_8 From BoT Keep L20 to L1 | Except SHEET_DIELECTRIC_9 From BoT Keep L16 to L1 | Zone 2 SHEET_DIELECTRIC_10 From BoT Keep L9 to L1 | Connector SHEET_DIELECTRIC_11 From BoT Keep L5 to L1 | | SHEET_DIELECTRIC_12 All Back-Drills Top & Bot / PREPREG_9 From Bot Keep L20 to L1 \ PREPREG_10 From Bot Keep L16 to L1 | Zone 2 PREPREG_11 From Bot Keep L10 to L1 | Regon | Only PREPREG_12 All Zone_2 Back-Drills /