IT3 Thermal Cycling Test TR0636E-10026 IT3 Thermal Cycling Test Report (Solder type: Sn63 Pb37) Approved. TY. ARAI June/23rd/2008 Checked . TM. MATSUO June/23rd /2008 Prepared. TY. TAKADA June/23rd /2008 Hirose Electric Co., Ltd . -1- IT3 Thermal Cycling Test TR0636E-10026 CONTENTS 1 OVERVIEW .................................................................................................................................3 2 TEST OBJECTIVES .......................................................................................................................3 3 THERMAL CYCLING TEST PROCEDURE ..........................................................................................4 4 TEST VEHICLES ..........................................................................................................................5 4.1 Connector Type...................................................................................................................5 4.2 Test Vehicle Configuration ...................................................................................................5 4.3 Virgin or Reworked..............................................................................................................9 4.4 Test Variations ...................................................................................................................9 4.5 Number of Test Vehicles and Connectors ............................................................................9 5 ASSEMBLY CONDITIONS .............................................................................................................10 5.1 Test Board Design Detail ...................................................................................................10 5.2 Test Vehicle Assembly.......................................................................................................12 5.3 Rework .............................................................................................................................13 5.4 X-ray Inspection ................................................................................................................14 5.5 Continuity Check...............................................................................................................15 6 THERMAL CYCLING TEST PROCESS.............................................................................................16 6.1 Preconditioning by Isothermal Aging..................................................................................16 6.2 Thermal Cycle Temperature Profile Requirement ..............................................................16 6.3 Thermal Cycling Test Execution.........................................................................................17 6.4 Measurement....................................................................................................................18 6.5 Failure Criteria ..................................................................................................................18 6.6 Identifying for Failure Connector(s) and Failure Point(s) ....................................................18 6.7 Rerouting with Jumper Wire ..............................................................................................18 6.8 Test Duration.....................................................................................................................18 6.9 Test Result ........................................................................................................................19 7 SOLDER BALL SHEAR TEST ........................................................................................................20 7.1 Measurement Method ......................................................................................................20 7.2 Failure Mode.....................................................................................................................20 7.3 Test Result ........................................................................................................................20 8 REVISION RECORD ....................................................................................................................21 9 Attachment _1 : 10 Attachment _2 : 11 Attachment _3: 07-29834-R1 Thermal Cycling Test Report (Trace Laboratories,Inc.) TR0636E-20027 BGA SHEARING TEST REPORT TR0636E-20033 CROSS SECTIONING REPORT -2- IT3 Thermal Cycling Test TR0636E-10026 1 OVERVIEW The following test report is to be considered official documentation for results found during thermal cycle testing of the IT3 series BGA connector system. BGA connection is becoming a key technology for current and next generation high-speed 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-9701. All assembly and re-work processes were performed by Jabil Circuit, Inc. (San Jose, Ca., hereafter ‘Jabil’), and thermal cycling was performed by Trace Laboratories, Inc.(Chicago, Il.). This document includes all processes and test procedures followed, along with who and where they were performed. 2 T EST 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. -3- IT3 Thermal Cycling Test TR0636E-10026 3 T HERMAL CYCLING T EST PROCEDURE Virgin assembly (5.2) Test samples (4.5) Eutectic X-ray inspection (5.4) Continuity check (5.5) Rework (5.3) Test samples (4.5) Jabil Eutectic 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 (6.3) Monitor the resistance increase to initial resistance (6.4) Yes (Failure): Five consecutive reading scans or more 20 % or more increase to the initial resistance is detected for five consecutive reading scans (6.5) Suspend thermal cycling test. Detect failure points. (6.6) Trace Labs No (Pass) Thermal Cycling Test Report (9) Rerouting to skip the failure points with jumper wire (6.7) Resume Test NO (Failure): More than 50 % of all solder joints Failure points =< 50% (6.5) YES (Pass) Test duration (6.8) 3500 cycles Hirose & Jabil Terminate test Solder ball sheer test (7) Cross Section at BGA joints Jabil Hirose -4- Solder Ball Sheer Test Report (10) Cross Sectioning Report (11) TR0636E-10026 IT3 Thermal Cycling Test 4 T EST VEHICLES The following parameters were applied to simulate various manufacturing and connector usage situations. 4.1 Connector Type Mezzanine Connector: Hirose IT3 series Receptacle IT3M-300S-BGA(57)…Mounted on Mother Board Receptacle IT3D-300S-BGA(57)…Mounted on Daughter Card Interposer Assembly Interposer assembly IT3-300P-17H(03)…17 mm Stacking Height IT3-300P-32H(03)…32 mm Stacking Height IT3 Connector 4.2 Test Vehicle Configuration Boards were designed to a thickness of 3.3 mm (125 mils) per IPC-9701 4.2.1 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 connector mounting in various configurations. Config. 1 Config. 2 Config. 3 Config. 4 Numbers of connectors / Daughter card 1 2 2 4 Remarks Individual X Direction(2 CN) Y Direction(2CN) Quad(4 CN) -5- IT3 Thermal Cycling Test TR0636E-10026 4.2.2 Test Board Examples IT3 mezzanine connectors were assembled to the board and tested . Each test board has four IT3 connectors 300 mm IT3M-300S-BGA (57) 300 mm Mother Board 300 mm IT3D-300S-BGA (57) 300 mm Daughter Card（Config.4） -6- IT3 Thermal Cycling Test 4.2.3 Test Board Configurations Config. 1 ---One connector per daughter card Spacer Position Config. 2 ---Two connectors per daughter card (X direction) Spacer Position -7- TR0636E-10026 IT3 Thermal Cycling Test Config. 3 ---Two connectors per daughter card (Y direction) Spacer Position Config. 4 --- Four connectors per daughter card Spacer Position -8- TR0636E-10026 TR0636E-10026 IT3 Thermal Cycling Test 4.3 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 Eutectic Eutectic Solder Paste Eutectic Eutectic 4.5 Number of Test Vehicles and Connectors For 3.3mm (125 mil) thick test boards, the following number of connectors were used. IT3-300S Totals Height Config 1 Config 2 Config 3 Config 4 Total # of Connectors 17H 6/2 6/2 6/2 6/2 24/8 32H 6/2 6/2 6/2 6/2 24/8 12/4 12/4 12/4 12/4 48/16 Note: 12/4 represents 12 Virgin and 4 Reworked -9- TR0636E-10026 IT3 Thermal Cycling Test 5 ASSEMBLY CONDITIONS 5.1 Test Board Design Detail Test Board Design Details per IPC-9701 Item Requirement Remarks 1 Thickness 3.3mm (125 mils) per IPC-9701 − 2 # of Metal Layers 16 layers − 3 Layer Structure 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 6 Signal Layer Remaining 30% copper weave 7 Daisy Chain On top layer only − Pads for probing on the bottom layer through via For failure analysis purposes, pads are connected by jumper cable to continue rest of the cycles if any failure is found. Simulate mechanical strength of actual PCBs with vias. 8 Pad and Via Ground plane on even # layers Signal traces on odd # layers Passed 9 Surface Finish High Tg OSP (Organic solderability preservative) IPC-S-804B solderability test IPC-TM-650 insulation resistance test IPC-6012(0.75%) warp and twist test 10 Pad Type 11 Copper Thickness NSMD (Non-solder mask defined) − Outer layer: 35 microns Inner ground: 35 microns − Inner signal: 18 microns 12 Trace Width 200 microns (8 mils) 13 # of Connectors 10 connectors per board maximum 150 microns (6 mils) minimum (IPC-9701) − 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. - 10 - TR0636E-10026 IT3 Thermal Cycling Test Top layer (daisy chained) Layer Top 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th 13th 14th 15th Bottom Ground (meshed. 70% copper) Signal (weaved 30% copper) Bottom layer (Probing pads for failure analysis and jumper cable) Fig. 1 * 16 Layers in Total PCB Layer Structure IT3* – 300S-BGA Foot Pattern 270-φ0.65+/0.05 (Solder Mask) Fig. 2 BGA Land Design - 11 - 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 IT3 Thermal Cycling Test TR0636E-10026 5.2 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. 5.2.1 Virgin Assembly Parameters Process parameters followed for testing. Items Requirements Type of Reflow Equipment Mass-reflow conveyor furnaces Pre Conditioning Dry package Thickness = 0.127 mm (0.005’’) Stencil Frame size X= 736.6 mm, Y= 736.6 mm (29’’ x 29’’) Open area ratio : 90% aperture size by area Solder Ball Composition Sn63 : Pb37 Solder Paste Composition Sn63 : Pb37 (Supplier Part Number) (Kester EP 256 no-clean Eutectic solder paste) DEK-265GSX Automatic screen printer Process Parameters Printing speed = 1’’/second Stencil snap off = 0 Reflow Temperature Profile See details on the next page. Reflow Atmosphere Nitrogen - 12 - IT3 Thermal Cycling Test 5.3 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. 5.3.1 Rework Parameters Items Type of Reflow Equipment Stencil Solder Ball Composition Solder PasteComposition Rework Atomosphere Requirements Hot air rework station Thickness = 0.127 mm (0.005’’) Open area ratio : 90% aperture size by area Sn63 : Pb37 Sn63 : Pb37 (Kester EP 256 no-clean Eutectic solder paste) Nitrogen - 13 - TR0636E-10026 IT3 Thermal Cycling Test 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 : IT3D-300S-BGA (57) - 14 - TR0636E-10026 TR0636E-10026 IT3 Thermal Cycling Test 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. R A A Cross section _ AA Resistance Per Connector Chain IT3 Interposer Height Resistance 17 mm height 25 to 29 32 mm height 38 to 42 Unit : Ohm * Resistance includes one connector assembly plus PCB trace. - 15 - TR0636E-10026 IT3 Thermal Cycling Test 6 T HERMAL CYCLING T EST PROCESS Thermal cycling test performed conforms to IPC-9701 (JESD22-A-104-B). 6.1 Preconditioning by Isothermal Aging Test specimens were subjected to an accelerated thermal aging (e.g. 24 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. 6.2 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 2 boards Thermal cycle profile Tmax = 100 oC (+10 / 0 o C) Tmin = 0 oC ( 0 / -10 oC) o Ramp rate = Approximately 10 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 Ts (max) Nominal Ts (max) Upper Dwell Time Ts T Cyclic Range Temperature ( C) 100 Lower Dwell Time 0 Nominal Ts (min) Ts (min) Cycle Time w/Tolerance Time - 16 - TR0636E-10026 IT3 Thermal Cycling Test 6.3 Thermal Cycling Test Execution TC5 TC2 TC3 TC1 --- AIR Door TC6 TC4 IT3-assembled test board (Refer to 4.2.2 Test board example for test board details.) Thermocouple Locations Air temperature (Yellow Line) Air temperature (Blue Line) Chamber_2 TL 745 Chamber_1 TL 544 Measured Thermal Cycle Profile - 17 - IT3 Thermal Cycling Test TR0636E-10026 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 20% 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 detected, rerouting of the effected area was required. Jumper wires (AWG32, 60mm in length, pre-stripped and tinned) provided by Hirose were inserted approximately 2 mm into the appropriate through-holes and then soldered to complete the bypass. 6.8 Test Duration 3500 cycles - 18 - TR0636E-10026 IT3 Thermal Cycling Test 6.9 Test Result See attached document "07-29834-R1 PRINTED CIRCUIT BOARDS TEMPERATURE CYCLE" prepared by Trace Laboratories, Inc. for more details. No failure was observed up to 3,500 temperature cycles. Initial Final Failure cycle Resistance Resistance & Resistance MB-001 40.9 40.1 MB-002 26.5 MB-003 Board # Configuration Conn-1 Conn-2 Conn-3 Conn-4 No failure Config-1 Virgin Virgin Virgin Virgin 25.8 No failure Config-1 Virgin Virgin Virgin Virgin 40.2 39.7 No failure Config-2 Virgin Virgin Virgin Virgin MB-004 26.0 25.6 No failure Config-2 Virgin Virgin Virgin Virgin MB-005 39.9 39.6 No failure Config-3 Virgin Virgin Virgin Virgin MB-006 25.7 25.2 No failure Config-3 Virgin Virgin Virgin Virgin MB-007 40.2 39.8 No failure Config-4 Virgin Virgin Virgin Virgin MB-008 26.5 26.1 No failure Config-4 Virgin Virgin Virgin Virgin MB-009 41.1 40.1 No failure Config-1 Virgin Virgin Reworked Reworked MB-010 27.5 26.5 No failure Config-1 Virgin Virgin Reworked Reworked MB-011 41.0 40.4 No failure Config-2 Virgin Virgin Reworked Reworked MB-012 26.0 26.6 No failure Config-2 Virgin Virgin Reworked Reworked MB-013 39.8 41.1 No failure Config-3 Reworked Virgin Virgin Reworked MB-014 26.9 27.5 No failure Config-3 Reworked Virgin Virgin Reworked MB-015 40.6 41.5 No failure Config-4 Reworked Virgin Virgin Reworked MB-016 26.4 26.9 No failure Config-4 Reworked Virgin Virgin Reworked Unit：ohm Measurement Result - 19 - IT3 Thermal Cycling Test TR0636E-10026 7 SOLDER B ALL SHEAR T EST Ball shear qualification conforms to IPC-9701. The minimum shear force is defined as the mean minus 3 sigma, for a minimum of three connectors 7.1 Measurement Method Force is applied to the edge of the connector so that the balls receive the shearing force. The height of shearing tool should exceed the height of the connector surface of 50μm minimum. Test speed: 500 micrometer / second 7.2 Failure Mode The failure mode for the sheared balls is defined as either a bulk solder failure or copper pad lift-off. An intermetallic failure between contacts and balls is unacceptable. 7.3 Test Result See the attachment "TR0636E-20027 : IT3D(M)-300S-BGA (57) BGA shearing force test report" No intermetallic failure between contacts and balls was observed in both Initial and Post 3500 cycles specimens. - 20 - TR0636E-10026 IT3 Thermal Cycling Test 8. REVISION RECORD Revision no. Description (Major changes) Date rd Initial release June. 23 , 2008 - 21 -