Experimental Study of Temperature Cycling Test Chamber in Integrated Circuits
Integrated circuit temperature cycling is an environmental test that verifies the normal functioning of a product by subjecting it to repeated cycles in alternating high and low temperature environments. The test principle is that when a product cycles within a set upper and lower temperature limit, thermal expansion and contraction cause alternating expansion and contraction, resulting in thermal stress and strain.
To investigate the effects of rapid temperature changes on integrated circuits, we use a Temperature Cycling Test Chamber to perform temperature cycling tests. The main test content is as follows:
Test Equipment: Temperature Cycling Test Chamber
Test conditions: -65℃ to 150℃, high and low temperature transition time 15 minutes, temperature change rate approximately 14.3℃/min. High and low temperatures each lasted 15 minutes. Electrical parameters were tested and confirmed every 100 cycles.
Test samples are shown in the table below:
| Product | Material | Dimensional Data | Elastic Modulus (N/mˆ2) | Coefficient of Thermal Expansion (10⁻⁶/°C) | Chip Thickness (µm) |
| CW7388CZ-1 | Molding compound | KH9100/22mm | / | 37 | 300 |
| Chip | 4.38 * 4.93mm | / | 2.6 | ||
| Bonding wire (CU) | 38um | 1.27E+11 | 16.7 | ||
| CW7388CZ-2 | Molding compound | EMG400/22mm | / | 26 | 300 |
| Chip | 4.38 * 4.93mm | / | 2.6 | ||
| Bonding wire (CU) | 38um | 8.1E+10 | 14.2 | ||
| CS2003CB-1 | Molding compound | EME-G630AY/10mm | / | 47 | 300 |
| Chip | 1.74 * 0.97mm | / | 2.6 | ||
| Bonding wire (CU) | 25um | 1.27E+11 | 16.7 | ||
| CS2003CB-2 | Molding compound | CEL-8240/10mm | / | 30 | 300 |
| Chip | 1.74 * 0.97mm | / | 2.6 | ||
| Bonding wire (CU) | 25um | 7.8E+10 | 14.2 |
The experimental results are shown in the table below:
| Product | Expected Solder Joint Lifespan M | Expected Chip Lifespan Nf | Actual Failure Lifespan Nf | Number of Failures |
| CW7388CZ-1 | 2953 | 341 | 300 | 2 |
| CW7388CZ-2 | 8810 | 877 | 1000 | 3 |
| CS2003CB-1 | 1516 | 2039 | 1800 | 2 |
| CS2003CB-2 | 4522 | 6591 | 4200 | 4 |
Test Results:
The test results show that for large-size chips, the estimated diagonal lifespan is shorter than the solder joint lifespan, while for small chips, the opposite is true. The actual lifespan performance matches the calculated results. Analysis of the failed samples shows that the failed CW7388 samples were indeed all damaged at the diagonal positions, while the CS2003 failures were all due to solder joint breakage or detachment. The FA condition of the failed samples is shown in the following figure:
Summary:
Temperature cycling testing is an indispensable part of integrated circuit reliability testing. However, temperature cycling is a destructive test, and the test conditions must be matched to the product's design specifications. Especially during reliability screening, strict attention must be paid to preventing overstress and the development of new failure modes. Therefore, the product's design parameters must be understood during screening, and the number of temperature cycles should not be excessive to avoid fatigue failure.
For any questions regarding integrated circuit reliability testing, please consult the relevant technical personnel at Huanyi Instruments.