IT3D(M)-300S-BGA (37) Lead-Free THERMAL CYCLING TEST REPORT

Transcription

1 TR066E-018 ITD(M)-00S-BGA (7) Lead-Free THERMAL CYCLING TEST REPORT - Post 6000 Cycles Report - APPROVED TY.ARAI Nov. 18, 009 CHECKED TM.MATSUO Nov. 17, 009 CHARGED TY.TAKADA Nov. 17, 009 HIROSE ELECTRIC - 1 -

2 CONTENTS 1 OVERVIEW... TEST OBJECTIVES... THERMAL CYCLING TEST PROCEDURE TEST VEHICLES Connector Type Test Vehicle Configuration Multiple Connector Mount Virgin or Reworked Type of Solder Test Vehicles Varieties ASSEMBLY CONDITIONS Test Board Design Detail Test Vehicle Assembly Rework X-ray Inspection Test Board Design Detail Continuity Check THERMAL CYCLING TEST PROCESS Preconditioning by Isothermal Aging Thermal Cycle Chamber Profile Thermal Cycling Test Execution Measurement Failure Criteria Identifying Failed Connector(s) and Failure Point(s) Rerouting with Jumper Wire Test Duration Test Result THERMAL CYCLING TEST REPORT REVISION RECORD...0 ATTACHMENT _1 : THERMAL CYCLING TEST REPORT (TRACE LABORATORIES,INC.) - -

3 1 OVERVIEW The following test report is to be considered official documentation for results found during thermal cycle testing of the IT series BGA connector system. BGA connection is becoming a key technology for current and next generation high-speed, high-density transmission. It is crucial to perform accelerated life time testing to both simulate actual applications and prove BGA attachment reliability. All processes described herein, including test board design and thermal cycling test conditions, are based on and conform to IPC All assembly and rework processes were performed by Jabil Circuit, Inc. (San Jose, Ca., USA, hereafter Jabil ), and thermal cycling was performed by Trace Laboratories, Inc.(Chicago, Il., USA, hereafter Trace Labs ). This document includes all processes and test procedures followed, along with who and where they were performed. TEST OBJECTIVES The test samples and processes were prepared to simulate various applications that included: Both virgin and rework assemblies, connector configurations, and both single and multiple connector mounts. - -

4 THERMAL CYCLING TEST PROCEDURE Virgin assembly (5.) Test samples (4.5) Lead Free X-ray inspection (5.4) Continuity check (5.5) Rework (5.) Jabil Test samples (4.5) Lead Free X-ray inspection (5.4) Continuity check (5.5) Two combinations of assembled test samples [1 virgin, 1 reworked] Thermal cycling test (6) Thermal cycling test start (6.) Monitor the resistance increase to initial resistance (6.4) 0 % or more increase to the initial resistance is detected for five consecutive reading scans (6.5) Yes (Failure): Five consecutive reading scans or more Trace Labs No (Pass) Suspend thermal cycling test. Detect failure points. (6.6) Rerouting to skip the failure points with jumper wire (6.7) Thermal Cycling Test Report (7) Resume Test NO (Failure): More than 50 % of all solder joints Failure points =< 50% (6.5) YES (Pass) Test duration (6.8) 6000 cycles Terminate test - 4 -

5 4 TEST VEHICLES The following parameters were applied to simulate various manufacturing and connector usage situations. 4.1 Connector Type Mezzanine Connector: Hirose IT series Lead-Free Receptacle ITM-00S-BGA(7) Mounted on Mother Board Receptacle ITD-00S-BGA(7) Mounted on Daughter Card Interposer assembly IT-00P-17H(0) 17 mm Stacking Height IT-00P-H(0) mm Stacking Height Interposer Assembly IT Connector 4. Test Vehicle Configuration Boards were designed to a thickness of. mm (15 mils) per IPC Multiple Connector Mount In many applications, multiple connectors are mounted on one daughter card which can create potential alignment issues and different stresses on solder joints. This test covers multiple connectors mounting in various configurations. Numbers of connectors / Daughter card Config. 1 Config. Config. Config Remarks Individual X Direction( CN) Y Direction(CN) Quad(4 CN) - 5 -

6 4.. Test Board Examples IT mezzanine connectors were assembled to the board and tested. Each test board has four IT connectors. Conn_1 Conn_ 94 mm ITM-00S-BGA (7) Conn_4 Conn_ 8 mm Mother Board Conn_4 Conn_ 94 mm ITD-00S-BGA (7) Conn_1 Conn_ 8 mm Daughter CardConfig.4-6 -

7 4.. Test Board Configurations Config One connector per daughter card Spacer Position Config. ---Two connectors per daughter card (X direction) Spacer Position - 7 -

8 Config. ---Two connectors per daughter card (Y direction) Spacer Position Config Four connectors per daughter card Spacer Position - 8 -

9 4. Virgin or Reworked To simulate the actual assembly process, both Virgin and Reworked board samples were tested. Assembly was done by Jabil, using industry standard assembly /rework equipment and processes. Virgin Reworked Test Board Virgin Reuse after connector removal Connector Virgin Virgin 4.4 Type of Solder Virgin Reworked Solder Ball on Connector Sn-.0Ag-0.5Cu Sn-.0Ag-0.5Cu Solder Paste Sn-.0Ag-0.5Cu (No Clean) Sn-.0Ag-0.5Cu (No Clean) Sn-.0Ag-0.5Cu (Water Soluble) Sn-.0Ag-0.5Cu (Water Soluble) 4.5 Test Vehicles Varieties No. Board Tag Assembly Height Conn-1 Conn- Conn- Conn-4 Cingfiguration Solder paste type 1 Pb-Free_MB_001 Assembly Virgin Virgin Virgin Virgin Height Pb-Free_MB_00 Pb-Free_MB_00 Assembly Virgin Virgin Virgin Virgin Height Assembly Virgin Virgin Virgin Virgin Height No clean 4 Pb-Free_MB_004 Assembly Virgin Virgin Virgin Virgin Height Pb-Free_MB_005 Assembly Virgin Virgin Virgin Virgin Height Pb-Free_MB_006 Pb-Free_MB_007 Assembly Virgin Virgin Virgin Virgin Height Assembly Virgin Virgin Virgin Virgin Height Water Soluble 8 Pb-Free_MB_008 Assembly Virgin Virgin Virgin Virgin Height 4 9 Pb-Free_MB_010 Assembly Virgin Virgin Rwk Rwk Height No clean Pb-Free_MB_011 Pb-Free_MB_01 Assembly Virgin Virgin Rwk Rwk Height Assembly Virgin Virgin Rwk Rwk Height 1 Water Soluble *1 1 1 Pb-Free_MB_01 Pb-Free_MB_014 Assembly Rwk Virgin Virgin Rwk Height Assembly Rwk Virgin Virgin Rwk Height No clean Pb-Free_MB_015 Pb-Free_MB_016 Assembly Rwk Virgin Virgin Rwk Height Assembly Rwk Virgin Virgin Rwk Height 4 Water Soluble *1 *1 No clean paste is used for Rework - 9 -

10 5 ASSEMBLY CONDITIONS 5.1 Test Board Design Detail Test Board Design Details per IPC-9701 Item Requirement Remarks 1 Thickness.mm (15 mils) per IPC-9701 # of Metal Layers Layer Structure 16 layers See Fig. 1 on the next page 4 PCB Material High Tg FR-4 IS-410/NP-150TL 5 Ground Layer Remaining 70% copper mesh Ground plane on even # layers 6 Signal Layer Remaining 0% copper weave Signal traces on odd # layers 7 Daisy Chain On top layer only 8 Pad and Via 9 Surface Finish Pads for probing on the bottom layer through via High Tg OSP (Organic solderability preservative) If any failure is found, pads are connected by jumper cable to continue the rest of cycles. Passed IPC-S-804B solderability test IPC-TM-650 insulation resistance test IPC-601(0.75%) warp and twist test 10 Pad Type NSMD (Non-solder mask defined) 11 Copper Thickness Outer layer: 5 microns Inner ground: 5 microns Inner signal: 18 microns 1 Trace Width 00 microns (8 mils) 1 # of Connectors 150 microns (6 mils) minimum (IPC-9701) 4 connectors per board maximum Note: Test boards were designed to measure electrical continuity using the daisy chain circuit only. Vias were not connected to any specific signal or ground layers. Neither ground contacts nor ground layers are connected anywhere

11 Top layer (daisy chained) Bottom layer (Probing pads for failure analysis and jumper cable) Ground (meshed. 70% copper) Signal (weaved 0% copper) Layer Top nd rd 4th 5th 6th 7th 8th 9th 10th 11th 1th 1th 14th 15th Bottom * 16 Layers in Total Footprint type Daisy chain Ground layer Signal layer Type A Ground layer Signal layer Type B Ground layer Signal layer Type A Ground layer Signal layer Type B Ground layer Signal layer Type A Ground layer Signal layer Type B Ground layer Signal layer Type A Via test points Fig. 1 PCB Layer Structure Fig. IT* 00S-BGA Foot Pattern Φ0.7 mm Solder Mask Aperture Φ0.6 mm BGA Pad Diameter 0.1mm min. Solder Dam* Fig. BGA Land Design

12 5. Test Vehicle Assembly Hirose provided assembly/rework process information that was then adapted by Jabil to conform to industry standard practices. All connectors were assembled / reworked at Jabil Virgin Assembly Parameters Process parameters followed for testing. Items Type of Reflow Equipment Pre Conditioning Requirements Mass-reflow conveyor furnaces Dry package Thickness = 0.17 mm (0.005 ) Stencil Frame size X= 76.6 mm, Y= 76.6 mm (9 x 9 ) Open area ratio : 100% aperture size by area Solder Ball Composition Solder Paste Composition (Supplier Part Number) Paste Printing Parameters Reflow Temperature Profile Sn-.0Ag-0.5Cu Sn-.0Ag-0.5Cu -No Clean : Alpha OM8PT, Type- -Water Soluble : Kester R50A, Type- DEK-65GSX Automatic screen printer - Printing speed = 1 /second - Stencil snap off = 0 See below Reflow Atmosphere Nitrogen (O level : below 00 ppm ) 5.. Reflow Temperature Profile Lead-Free Reflow Profile Specs. Solder Joints: 5 o C _45 o C Typical TAL(17 o C): 60_90sec Component Body: 60 o C Maximum - 1 -

13 5. Rework Rework consists of a series of processes, such as removal of connector by using rework equipment (i.e., SRT), PCB cleaning and placement/reflow of a new connector using rework equipment Rework Parameters Items Requirements Type of Reflow Equipment Stencil Solder Ball Composition Solder PasteComposition Rework Temperature Profile Hot air rework station Thickness = 0.17 mm(0.005 ) Open area ratio : 100% aperture size by area Sn-.0Ag-0.5Cu Sn-.0Ag-0.5Cu -No Clean : Alpha OM8PT, Type- -Water Soluble : Kester R50A, Type- See below Rework Atmosphere Nitrogen (O level : below 100 ppm ) 5.. Rework Temperature Profile Lead-Free Rework Profile Specs. Solder Joints: 0 o C _40 o C Typical TAL(17 o C): 60_10sec Component Body: 60 o C Maximum - 1 -

14 5.4 X-ray Inspection Test Board Design Detail X-ray inspection after assembly was conducted. All connectors passed the X-ray inspection before thermal cycling. X ray Photo : ITD-00S-BGA (7)

15 5.5 Continuity Check Final assembly, including mounting interposer assembly / daughter cards and board spacers, was performed to complete the daisy-chain circuit prior to performing the continuity check. A R A Cross section _ AA Resistance Per Connector Chain IT Interposer Height Resistance 17mm height (x4) 6 to 9 17mm & mm height (x) 1 to 4 mm height (x4) 6 to 9 Unit : Ohm * Resistance includes one connector assembly plus PCB trace

16 6 THERMAL CYCLING TEST PROCESS Thermal cycling test performed conforms to IPC-9701 (JESD-A-104-B). 6.1 Preconditioning by Isothermal Aging Test specimens were subjected to an accelerated thermal aging (e.g. 4 hours at 100 C (-0/+5 C)) in air to simulate a reasonable use period and to accelerate such possible processes as solder gain, growth, intermetallic compound growth or oxidation. Test specimens were stored at room temperature following the artificial aging process and before commencing the thermal cycling test. 6. Thermal Cycle Chamber Profile Dummy boards and connectors were employed to simulate expected thermal mass A minimum of 4 thermal couples near connectors on at least boards Thermal cycle profile T max = 100 o C (+10 / 0 o C ) T min = 0 o C ( 0 / -10 o C) Ramp rate = Approximately 10 o C/min (10% to 90% of test temperature range) Dwell time = 5 to 10 min (Holding time of maximum and minimum temperature) 5 successful cycles were performed before commencing test. w/tolerance 100 Upper Dwell Time Ts (max) Nominal Ts (max) Temperature (C) T Cyclic Range Ts 0 Nominal Ts (min) Lower Dwell Time Cycle Time Ts (min) w/tolerance Time

17 6. Thermal Cycling Test Execution TC5 TC TC1 --- AIR TC6 TC Door TC4 IT-assembled test board (Refer to 4.. Test board example for test board details.) Thermocouple Locations Measured Thermal Cycle Profile Thermal Cycle Profile

18 6.4 Measurement Chamber temperature profile was continuously monitored and recorded during the test. Electrical resistance was monitored and recorded continuously. Maximum scan interval of all chains was one minute during test. 6.5 Failure Criteria Failure was claimed when a 0% resistance increase to initial resistance was monitored for five consecutive reading scans. Failure points could not exceed 50 %. 6.6 Identifying Failed Connector(s) and Failure Point(s) Failed connectors or failed points were identified by probing connector and specific test points and daisy chain test points located on the bottom of all test boards. Failure point(s) and number of cycles were recorded, when failure(s) occurred. 6.7 Rerouting with Jumper Wire Once failure and location was identified, rerouting of the effected area was required. Jumper wires (AWG, 60mm in length, pre-stripped and tinned) provided by Hirose were inserted approximately mm into the appropriate through-holes and then soldered to complete the bypass. This is to connect pads to continue the rest of cycles. Mechanical strength simulation of actual PCB s with vias is needed. 6.8 Test Duration 6000 cycles

19 6.9 Test Result See attached document " Hirose Report 6000 cycles" prepared by Trace Laboratories, Inc. for more details. No failure was observed up to 6,000 temperature cycles. No. Board Tag Initial Post 6000 cycles Cingfiguration Solder paste type 1 Pb-Free_MB_ Pb-Free_MB_00 Pb-Free_MB_ No clean 4 Pb-Free_MB_ Pb-Free_MB_ Pb-Free_MB_006 Pb-Free_MB_ Water Soluble 8 Pb-Free_MB_ Pb-Free_MB_ No clean Pb-Free_MB_011 Pb-Free_MB_ Water Soluble *1 1 1 Pb-Free_MB_01 Pb-Free_MB_ No clean Pb-Free_MB_015 Pb-Free_MB_ Water Soluble *1 Unit : ohm Measurement Result *1 No clean paste is used for Rework

20 7 THERMAL CYCLING TEST REPORT Please refer to Attachment_1: THERMAL CYCLING TEST REPORT (TRACE LABORATORIES, INC.). 8 REVISION RECORD Revision no. Description (Major changes) Date 0 Initial release Feb. 9th, Update Nov. 17th,