1. 109-IDPU-Chassis-Donakowski 1 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR 109-IDPU-Chassis-Donakowski IDPU Chassis Mechanical Design and Development Bill Donakowski Mechanical Engineer UCB/SSL billd@ssl.berkeley.edu

2. 109-IDPU-Chassis-Donakowski 2 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Requirements Functional –Provide Mechanical Packaging for 4 EFW electronic boards in one card cage box –BEB/DFB/DCB/LVPS Boards –Allow removal of each board layer separately –Provide structure and attachment to S/C –All access to test points following board installation into box Structural –Positive strength margins –First natural frequency greater than 50 Hz Radiation Shielding –External walls to have.35” equivalent thickness Aluminum –LOS requirement from outside to boards Venting –Allow proper venting on ascent Thermal –Survival Temperatures: -30°C to +60°C –Operational Temperatures: -25°C to +55°C Mass –10 Kg Maximum EMI Shielding –Provide metal shielding between each board layer (.030” thick aluminum)

3. 109-IDPU-Chassis-Donakowski 3 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Design Description Standard electronics box/card-cage design –Approx. 6U format circuit boards (160mm x 230mm) –Similar to THEMIS –Aluminum 6061 T6 panels bolted together –gaps prevented at panel interface by step in edges Separate layers for individual boards to slide into box –Each card layer consists of PCB, wedgelocks, connectors, and EMI shield –Cards held in place by wedgelocks on sides and fasteners on front panels –Each panel can be removed by unscrewing bolts, loosening wedgelocks, and sliding out Separate, removable radiation shield over connectors and cables –Installed for testing and at integration to S/C –Aluminum 6061-T6

4. 109-IDPU-Chassis-Donakowski 4 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Overview LVPS DFB DCB BEB HOLES FOR BOLTING TO S/C PANEL #5 (9 X 10-32 bolts) ALL CABLES TO S/C MATE TO FRONT OF BOX TOTAL MASS: CBE 8.3 kg 10” 3 X VENTS 3.5” 7.5” 4.2” REMOVABLE RADIATION SHIELD

5. 109-IDPU-Chassis-Donakowski 5 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Overview WEDGELOCKS ON EACH BOARD EDGE (manuf: CALMARK) EACH BOARD CAN BE REMOVED INDIVIDUALLY.030” THICK EMI SHIELD DFB CARD

6. 109-IDPU-Chassis-Donakowski 6 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Overview REMOVABLE RADIATION SHIELD (INSTALLED FOLLOWING BOX INTEGRATION ONTO S/C) BACKPLANE ACCESS PANEL ALLOWS TEST POINT USE FOLLOWING BOARD INTEGRATION 8 X ATTACH BOLTS (8-32)

7. 109-IDPU-Chassis-Donakowski 7 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR RBSP Chassis Radiation Shielding All external aluminum panels provide shielding –.35” thickness –Interlocking steps to prevent any gaps at connections Removable Radiation Shield covers connectors and cables on front of box –Radiation Shield installs following box installation onto S/C –Provides.35” equivalent thickness radiation shielding line of sight to boards VOLUME FOR CABLE RUN TO S/C.030” ALUMINUM EMI SHIELDS BETWEEN CARDS

8. 109-IDPU-Chassis-Donakowski 8 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Radiation Scheme for Cables Radiation LOS Maze allows simple cable runs.90” PASS-THRU FOR CABLES CABLE TIE BASES BONDED TO SIDE WALL GLENAIR BACKSHELLS CABLE RUN

9. 109-IDPU-Chassis-Donakowski 9 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Structural Analysis Assumptions/Tools –Limit Loads 100G –CosmoWorks FEM simulation Results –Thick walled sections leads to robust structure –High strength margins throughout Margin= (Strength/(LoadxSF)) - 1 ItemModeMargin Attach Bolts to S/CShear+2.1 Attach legsBending+107 Screws holding Top Plate Tensile+30

10. 109-IDPU-Chassis-Donakowski 10 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Thermal Analysis High power component heat-sunk directly to Chassis Frame –Amplifier Transistor 2N3637 on LVPS (one part) All other electrical components mounted to PCB Thermal path –Components Radiate to interior of IDPU Box –Conductive path from PCB > Wedgelocks > Chassis Frame –Exterior of IDPU Chassis radiates to inside of S/C –Chassis Lower Panel bolted to S/C panel Components Junction Temperatures Analysis –Board Level Analysis performed on all Cards –Assumes hot PCB steady state (65°C) on all boards –Output junction temps compared with component limits –Lowest margin 14.2°C (SDRAM module on DCB) –Analysis performed by SSL (Chris Smith)

11. 109-IDPU-Chassis-Donakowski 11 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Thermal Treatments EXTERNAL SURFACES BLACK KAPTON XC TAPE BOX INTERIOR SURFACES GOLD ALODINE BOTTOM PANEL GOLD ALODINE INTERFACE TO S/C PANEL INCORPORATES CHO-SEAL GASKET (PROVIDED BY APL)

12. 109-IDPU-Chassis-Donakowski 12 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Prototype Testing Completed Complete build-up with Electronics –fit-check with all electrical cards –Verified grounding Preliminary Vibration Testing –PCB dummies in lieu of actual PCB –Sine sweep –qualification random –First Natural Frequency 820 Hz –No issues to report Vibration Qualification to take place on first Flight Unit as Protoflight

13. 109-IDPU-Chassis-Donakowski 13 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Design Changes from PDR KA98 Backplane Connectors Replace DIN96 –DIN96 Connectors Rejected by APL –All Boards and Mechanical Hardware changes completed Electrical Layouts –Small changes based on electrical layouts –Keep-out zones, connector locations Removable Radiation Shield –Added 2X attach feet (and bolts) to S/C –Removed gap below Shield (no longer cantilevers above S/C panel) No other design changes from PDR No Items from Peer Review

14. 109-IDPU-Chassis-Donakowski 14 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Drawing/Purchasing Status Mechanical ICD, RBSP-IDP-MEC-500 –Drawing completed –Submitted to APL 23-Sep-2009 Individual Board ICDs completed –Showing connectors, board geometry, keep out zones –All components laid out according to ICDs Long Lead Items –CALMARK wedgelocks (10 weeks lead) –Ordered July 2009 (delivery: 01 Oct 2009) Mechanical Parts Drawings –All detail part drawings and assemblies completed –All drawings released Flight Fab –Drawings and RFQs sent out to machine shops for pricing –All Purchase Orders to be Placed Early October 2009

15. 109-IDPU-Chassis-Donakowski 15 30 Sep – 01 Oct 2009DRAFT RBSP EFW ICDR IDPU Chassis Flight Fab Flow Receipt of Machined parts Cleaning Build-Up of IDPU Card Cage Card Instl Electrical Checkout Instrument CalEMC Testing PCB Coat and Stake Qual Vibration Testing Electrical Checkout Qual TVAC Testing Electrical Checkout Apply Thermal Coatings Weigh/Mass Props Ship