Pressure cooker test

Figure 18.21 Comparison of hydrolytic stability. Pressure cooker test under 120 CC steam atmosphere. SPS (30% GF), PBT (30% GF), PA66 (30% GF), PPS (40% GF)...

Recently in the industry, requirements on cured state Tg and related phenomena have begun to be requested of the resin suppliers. One of two types of tests has been added over the NEMA FR4 requirements listed in Figure IV. This test is either a measurement of the cured state Tg or a pressure cooker test. 

The Tg requirement has increased from about 115-120°C. to a level of 120-130°C. for the cured laminate. The pressure cooker test is run by subjecting the test laminate to 15 psi steam in a conventional pressure cooker for 20-40 minutes. The test laminate is removed from the pressure cooker, conditioned one hour at room temperature and immediately placed in a hot solder bath (about 500°F.). The laminate is then tested for water blistering between the laminate plies. Any visible blistering is considered a failure. 

COMPARISON OF LAMINATE Tg AND PRESSURE COOKER TEST RESULTS... 

Modified cyclo-olefin thermoset (MCOT) resins are liquids that cure when heated at 150 °C for a minimum of 30 minutes to form the general polymer structure shown in Figure 3.14. The monomers cure by an addition polymerization and, as such, no water or other by-products are evolved. The molecular structures are essentially nonpolar which impart very low moisture absorption properties. For two formulations developed by Johnson-Matthey, water absorptions of 0.05% were recorded when exposed to 85 °C/85% RH conditions for 168 hours. Only 0.1% water absorption was measured even after pressure cooker testing at 150 °C, 85% RH, for 168 hours. These low moisture absorption values make MCOT adhesives and molding... 

Leak tests Hermetic seal tests MIL-STD-883 method 1014 JIS C 7022 A-6 lEC PUB 68 Test Q [Pressure cooker test (PCT) to evaluate moisture resistance in a short period of time EIAJ IC-121 18] Final seal Performance degradation, shorts or opens caused by chemical corrosion or moisture, intermittents... 

Pressure cooker test - temperature 120°C, humidity 100 RH%, testing time 50 h... 

Highly accelerated stress testing unlike the pressure cooker tests, this test uses unsaturated steam, varying from 50 to 100%, at temperatures of 105-150°C, the experimental data being extrapolated to any temperature-humidity conditions by using theoretical models based on the usual Arrhenius equation. 

---