Probe Pin Multi-Layered Structure for Thermal Isolation
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Solution Overview
Problem
Existing probe pins with multiple conductors of different resistivities arranged side by side face issues with mechanical strength degradation due to heat transfer and thermal expansion, leading to potential contact problems during semiconductor device inspections.
Innovation Solution
A probe pin design featuring a multi-layered structure with a high resistance member, a low resistance member, and an air gap or slit, arranged in a specific order perpendicular to the buckling direction, ensuring non-overlapping alignment when viewed from the buckling direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a low resistance conductor is used to increase allowable current, then current flow capability is improved, but heat generation causes thermal expansion and contact with high resistance conductor, reducing mechanical strength
Solution Approach 1:
The probe pin is segmented into multiple conductive layers with different resistivity values. A low resistance conductor is placed at the distal end (contact tip) to handle high current, while high resistance conductors are positioned at the proximal end (shaft) to maintain mechanical strength. This spatial segmentation allows each material to perform its optimal function without compromising the other.
Solution Approach 2:
Different sections of the probe pin are assigned different material properties based on their functional requirements. The distal end uses low resistance material (e.g., copper, gold, or silver) for high current flow, while the proximal end uses high resistance material (e.g., tungsten or stainless steel) for mechanical strength. This local differentiation of material quality resolves the contradiction between electrical performance and mechanical strength.
2Strength
If conductors are arranged side by side to preserve mechanical strength, then structural integrity is maintained, but thermal expansion causes contact between conductors, leading to heat transfer and strength reduction
Solution Approach 1:
The patent transitions from a two-dimensional side-by-side arrangement to a three-dimensional layered structure. Conductors are stacked in multiple layers along the longitudinal axis of the probe pin, with insulating layers separating them. This dimensional change allows conductors to be close for structural integrity while preventing thermal contact through the insulating barrier.
Solution Approach 2:
An insulating layer is introduced as an intermediary between the low resistance conductor and high resistance conductor. This insulating layer prevents direct thermal contact while allowing the conductors to be positioned close together for mechanical strength. The insulator blocks heat transfer from the low resistance conductor to the high resistance conductor, eliminating the harmful thermal effect.
3Reliability
If probe pin is pushed down against semiconductor wafer for contact, then electrode contact is ensured, but buckling displacement causes misalignment of conductors, leading to contact problems
Solution Approach 1:
Insulating layers are positioned beforehand between the conductive layers to cushion and prevent misalignment issues during buckling. When the probe pin undergoes buckling displacement during wafer contact, the insulating layers maintain the spatial separation and alignment of conductors, preventing them from shifting into contact with each other and ensuring stable electrical connections.
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
This design effectively maintains mechanical strength while allowing for high current flow, preventing heat transfer-induced mechanical strength reduction and ensuring reliable contact with semiconductor electrodes during inspections.
Implementation Method 1
a low resistance member (L) consisting of a first metal with a first conductivity
Implementation Method 2
a high resistance member (H) consisting of a second metal with a second conductivity, the second metal having a resistivity higher than that of the low resistance member
Implementation Method 3
the probe pin has a multi layered part between the contact part and the terminal part, where the multi layered part is configured in an order of the high resistance member, a slit of air gap, and the low resistance member
Implementation Method 4
a low resistance conductor generates heat to expand and contacts with a high resistance conductor. Heat is transferred to the high resistance conductor, and thereby, a problem may be caused that the mechanical strength is decreased
Data Source
AI summary
A probe pin includes a low resistance member consisting of a first metal with a first conductivity, and a high resistance member consisting of a second metal with a second conductivity, the second metal having a resistivity higher than that of the low resistance member. The probe pin has a multi layered part between a contact part and a terminal part, where the multi layered part is configured in the order of the high resistance member, a slit of air gap, and the low resistance member, in a first direction different from a buckling direction of the probe pin at the time of inspection of a test object. The low resistance member and the high resistance member are arranged so as not to overlap with each other, when the multi layered part is viewed from the buckling direction.