Reliability Qualification Report SGA-9189 Products Qualified by Similarity SGA-9289 March, 2001 522 Almanor Ave., Sunnyvale, Ca 94086 Phone: (800) SMI-MMIC http://www.stanfordmicro.com SGA-9189 Reliability Qualification Report Introduction Stanford Microdevices’ SGA-9189 is a high performance amplifier designed for operation from DC to 3500 MHz. With optimal matching at 2 GHz, TOI = 39 dBm and P1dB=26 dBm. This RF device uses the latest Silicon Germanium Heterostructure Bipolar Transistor (SiGe HBT) process. The process has a V BCEO =8V and an f T =25 GHz. The SGA-9189 is cost-effective for applications requiring high linearity, even at moderate biasing levels. Fabrication Technology These amplifiers are manufactured using a Silicon Germanium Heterojunction Bipolar Transistor (HBT) technology. This patented self-aligned emitter, double poly HBT process has been in production by our foundry since 1998. The process has been successfully used for a wide range of RFIC products including GSM PAs, DECT front end transceivers, LNAs & VCOs. This process offers comparable performance to GaAs HBTs with the added advantages of mature and high producible Silicon wafer processing. Package Type The SGA-9189 power amplifier is packaged in a plastic encapsulated SOT-89 package that is assembled using a highly reproducible automated assembly process. The die is mounted using an industry standard thermally and electrically conductive silver epoxy. The die is mounted directly to the exposed paddle to provide a low thermal resistance path for heat conduction out of the package. Figure 1 : Photograph of SOT 89 Encapsulated Plastic Package SGA-9189 Reliability Qualification Report Qualification Methodology The Stanford Microdevices Qualification Procedure consists of a series of tests designed to stress various potential failure mechanisms. This testing is performed to ensure that Stanford Microdevices products are robust against potential failure modes that could arise from the various die and package failure mechanisms stressed. The qualification testing is based on JEDEC test methods common to the semiconductor industry. For the tests requiring full RF and DC testing to determine PASS/FAIL, the manufacturing test specifications are used as the PASS/FAIL criteria. Qualification By Similarity A device can be qualified by similarity to previously qualified products provided that no new potential failure modes/mechanisms are possible in the new design as compared to the qualified design. The following product has been qualified by similarity to SGA-9189 SGA-9289 Qualification Results Group Test Description A0 A1 A2 C E G Moisture Preconditioning / IR Reflow Simulation Temp Cyle -65°c to 150°c 1000 cycles High Temp Operating Life 1000 hrs. Autoclave 121°c 15 PSI 96 hrs. Solderbility Steam Age High Temp Storage 1000 hrs T= 150°C Test Standard JEDEC 22-A113B JEDEC 22-A104A JEDEC 22-A108A JEDEC 22-A102B JEDEC 22-B102C JEDEC 22-A103A Table 1: Qualification Test Results for SGA-9189. Quantity Quantity Results In Out 650 120 189 80 44 83 650 120 189 80 44 83 PASS PASS PASS PASS PASS PASS SGA-9189 Reliability Qualification Report Junction Temperature Determination One key issue in performing the qualification testing is to accurately determine the junction temperature of the device. Stanford Microdevices uses a 3µm spot size infrared camera that allows a device to be measured at its normal operational parameters. The 3µm spot size allows for very good resolution compared to the heated area of the transistor, which in this case is approximately 1-2µm. The results for the device, running at maximum operational current of 180mA, a device voltage of 5.0V, and a base plate lead temperature of 85.5 oC. Tlead = 85C Id = 180mA Vd = 5.00V Tj = 125C Figure 2: Infrared Thermal Image of SGA 9189, Vd = 5.0V, Id = 180mA, Tlead = 85C SGA-9189 Reliability Qualification Report Operational and Accelerated Life Testing The purpose of the operational life test is to statistically show that the product operated at 125oC will be reliable. This is accomplished by operating several hundred devices for a total test time of 1000 hours. The results for this test are expressed in device hours which are calculated by multiplying the total number of devices passing by the number of hours tested. Operational Life Test Results The results for SGA-9189 High Temperature Operating Life Test are as follows: Group Test Time (hours) A2 1000 Quantity Quantity In Out 189 189 Device Hours 189,000 Table 2: High Temperature Operational Life Test Results Accelerated Life Test Results The following data demonstrates the results from accelerated life tests performed on the Stanford 4A SiGe HBT Process. The test was performed on 77 units running at a peak junction temperature of 195oC. The test exceeded 10,000 hours (1.14 years) with no failures. The FIT rate / MTTF calculation can be found below. The FIT rates were generated assuming 1 failure. In reality, there were no failures, making this a very conservative calculation. Stanford Microdevices Process 4ASiGe HBT FIT Rate / MTTF Calculation SGA Series Devices Parameters *Ea = 0.7 eV Junction Temp C FIT Rate 55 0.053 125 4.136 MTTF (hrs) 1.89E+10 2.42E+08 *The Ea of 0.7eV is conservative, 0.85eV is the activation energy for electomigration which is assumed to be the primary failure mechanism for the SiGe process. **Stanford Microdevices does not assume any liability arising from the use of this data.