Ceramic Probe Guiding Member for High-Density Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current materials used for probe guides and sockets in IC chip inspection, such as resins and ceramics, lack the necessary combination of low electrostatic properties, free-machining properties, heat-resistant properties, and mechanical properties required for efficient and precise inspections, particularly with the increasing complexity of device design and the need for high-density probe arrays.
Innovation Solution
A ceramic composition with BN as the main phase, combined with SiC and ZrO2 or Si3N4, is developed to achieve the desired electrostatic and mechanical properties, with a volume resistivity between 10^6 to 10^14 Ω·cm, and a coefficient of thermal expansion matching that of a silicon wafer, fabricated using a hot pressing calcination method to ensure close-grained structure and high precision machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resin materials with conductive fillers are used for probe guides, then low electrostatic properties are achieved, but heat-resistant properties and mechanical strength are insufficient
Solution Approach 1:
The invention uses a composite ceramic material consisting of Al2O3 as the main phase (90-99 wt%) combined with conductive ceramic particles (SiC, TiN, or WC) at 1-10 wt%. This composite structure achieves volume resistivity of 10^6 to 10^12 Ω·cm while maintaining heat-resistant properties and mechanical strength, resolving the contradiction between electrostatic properties and thermal/m mechanical performance.
2Reliability
If ceramic sintered bodies with conductive ceramics are used, then low electrostatic properties and heat-resistant properties are improved, but free-machining properties deteriorate
Solution Approach 1:
The invention optimizes the composition parameters by limiting conductive ceramic content to 1-10 wt% and using Al2O3 as the main phase, which provides a matrix that is easier to machine compared to fully dense conductive ceramics. This parameter optimization maintains electrostatic properties while improving free-machining properties, allowing tens of thousands of small through holes to be efficiently formed.
3Productivity
If the number of probes per inspection is increased for higher efficiency, then productivity improves, but the complexity of probe guide machining increases
Solution Approach 1:
The invention changes the material parameters to enable efficient machining of high-density probe arrays. By using Al2O3-based ceramic with controlled conductive additive content, the material achieves a balance between mechanical strength (to support dense probe arrays) and machinability (to form thousands of precise through holes), thereby supporting higher productivity without excessive complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The ceramic composition enables efficient and precise machining of high-density probe arrays with improved thermal and mechanical stability, reducing the risk of electrostatic discharge and ensuring accurate inspections across varying temperatures.
Implementation Method 1
fabricated using a hot pressing calcination method to ensure close-grained structure and high precision machining
Implementation Method 2
a coefficient of thermal expansion matching that of a silicon wafer
Data Source
AI summary
A ceramic according to the present invention includes, in mass %, BN: 20.0 to 55.0%, SiC: 5.0 to 40.0%, ZrO2 and/or Si3N4: 3.0 to 60.0%. The ceramic has a coefficient of thermal expansion at −50 to 500° C. of 1.0×10−6 to 5.0×10−6/° C., is excellent in low electrostatic properties (106 to 1014 Ω·cm in volume resistivity) and free-machining properties, and is thus suitable to be used for, for example, a probe guiding member for guiding probes of a probe card, and a socket for package inspection.