Semiconductor Back-End Test Data Sheets
Semiconductor • Back-End Test
What to Look for on a Data Sheet for Back-End Test Applications
When optimizing material choices for Semiconductor plastics applications, it becomes critical to know how to sift through the data to make the right choice. Standard material data sheets contain a wealth of useful information but can also include data that’s irrelevant to your specific application. Each segment of semiconductor manufacturing has its own set of relevant properties—further complicated by the fact that each application’s requirements differ. For back-end test sockets and related fixtures, start your material selection process by evaluating these five key properties.
Five Critical Material Properties
1. Tensile Elongation
Determines accuracy of hole placement when drilling micro-holes. Testing shows that the lower the elongation value (expressed as a percentage), the more capable the material is of maintaining precision in micro-drilled patterns.
2. Flexural Modulus
Often the most influential data point in material selection. Tight array patterns remove a high percentage of base material, reducing resistance to flex. Therefore, a higher flexural modulus is preferred for improved stiffness and dimensional stability.
3. Moisture Absorption
Imagine machining a perfect hole pattern only to have the part grow out of tolerance later due to moisture uptake. A lower moisture absorption rate ensures long-term dimensional accuracy.
4. Coefficient of Thermal Expansion (CTE)
Test sockets and fixtures undergo wide temperature swings during chip testing. A lower CTE helps maintain dimensional integrity throughout the temperature range.
5. Melt Temperature
The thermal properties of the material determine its ability to resist burr formation. Micro-drilling uses very small bits at high speeds, producing frictional heat. A higher melt temperature allows the plastic to resist burrs and maintain cleaner hole finishes.
Why These Data Points Matter
Each of these properties directly impacts machinability, dimensional stability, and longevity in semiconductor back-end test environments. The goal is to ensure high-precision results across machining, assembly, and actual chip testing—where performance failures translate to significant production losses.
Typical Property Comparison Table
The following data illustrates how material properties vary among common engineering plastics used in back-end test socket applications. Use this as a guideline when reviewing supplier data sheets.
| Property | Ideal Value Range | Why It Matters |
|---|---|---|
| Tensile Elongation | < 10% | Improves hole accuracy and pattern consistency |
| Flexural Modulus | > 400,000 psi | Provides stiffness, resists flexing during micro-drilling |
| Moisture Absorption (24h) | < 0.20% | Prevents dimensional growth post-machining |
| CTE (in/in/°F) | Low (2–4 ×10⁻⁵) | Maintains dimensional stability during temperature cycling |
| Melt Temperature | > 500°F | Resists burr formation under high-speed drilling heat |
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