ADIS16265 Assembly Tips

Question

What are the most common issues associated with mounting the ADIS16265 on a PCB?

NevadaMark · Accepted Answer

The ADIS16265 is a fully-calibrated, digital MEMS gyroscope that comes in a 20-pin, 11.2mm Land Grid Array package, which supports standard, Pb-free, solder-reflow assembly techniques. The most common process oversights associated with their assembly are: 
 
 Moisture ingression prior to solder reflow .. The ADIS16265 are classified as MSL5, per JEDEC J-STD-033. The ADIS16265 BCCZ are stored and shipped in JEDEC-compliant trays, which are vacuum-sealed with moisture absorbing materials, inside of an anti-static bag. J-STD-033 describes the floor life (time between bag opening and solder reflow), environment (temperature, humidity) and pre-reflow bake requirements. If these parameters are not well-controlled, baking these devices for 24-48 hours at +125 ° C, inside of a dry oven (nitrogen), will help remove any residual moisture and reduce its impact on assembly yields. J-STD-033 is availalbe for download at http://www.jedec.org/standards-documents . 
 Solder-reflow time/temperture profile . The ADIS16265 has been qualified to support the Pb-free solder reflow profile in J-STD-020. Prior to running parts through an oven, use an accurate thermocouple, placed at the DUT on the PCB, to verify compliance with the reflow profile in J-STD-020. J-STD-020 is available for download at: http://www.jedec.org/standards-documents . 
 Peeling stress can cause the ADIS16265 leads to fracture. This is a common sensitivity for LGA and BGA packages. A common cause of peeling stress is PCB separation techniques, which causes the PCB to bend and places the lead interfaces in "tension." In producing the ADIS16265/PCBZ breakout boards, the individual PCBs are cut out of the array using a rotating bit, while the PCB material is clamped. This process has produce more than 1000 boards, with zero yield loss due to lead fracture. PCB mounting hole location, thickness, width, length and material rigidity; along with the ADIS16265 's proximity to natural bend points, can impact exposure to peeling stress. Another common technique for managing peeling stress is the use of an underfill compound, which help distribute peeling stress across the entire bottom of the package. The following materials, provided by Hysol, have been used with success: FP4470, FP4545FC, FC4502, and FP4548. The following tips may help in developing an under-fill process:
 
 Pre-heat the PCB to +90 ° C, to help the material whick under the ADIS16265 's package bottom. 
 Deposit under-fill material on two adjacent edges of the ADIS16265 and allow the material to wick under the package, for approximately 30 minutes 
 Bake at +125 ° C for 30 minutes to help the material set 
 Bake at +160 ° C for 90 minutes to fully cure the material

This information applies to all iSensor BGA and LGA devices: ADIS16003 , ADIS16006 , ADIS16060 , ADIS16201 , ADIS16203 , ADIS16204 , ADIS16209 , ADIS16220 , ADIS16240 , ADIS16260 and ADIS16265 .)

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ADIS16265 Assembly Tips