Probe Head Guide Plate Bumps for Probe Overpressure

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Solution Overview

Problem

The existing probe cards face issues with probe overpressure during assembly, leading to potential cracking or sinking of probes into the upper guide plate, which results in reduced test yield.

Innovation Solution

The proposed probe head design features an upper guide plate with bumps and a locking structure that limits probe rotation, ensuring proper alignment and preventing overpressure issues by maintaining a gap between the probe tails and the space transformer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the upper guide plate is made with large application area, then the coverage is improved, but the parallelism difference increases causing probe overpressure

Engineering Contradiction:

Improveapplication areaVSAvoidparallelism

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

The upper guide plate is segmented into multiple regions with independent support structures (bumps or ribs) distributed across the large area. This segmentation allows each local region to maintain its parallelism independently, preventing cumulative parallelism errors across the entire large application area while still providing extensive coverage for probe card operations.

Inventive Principle:

Principle #1Segmentation

2Reliability

If the probe head is disposed on the space transformer, then the electrical connection is established, but the pressure between probe tails and space transformer becomes uneven causing probe damage

Engineering Contradiction:

Improveelectrical connectionVSAvoidprobe integrity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

Support structures (bumps or ribs) are pre-installed on the upper guide plate at strategic locations corresponding to probe tail positions. These support structures act as cushioning elements that distribute and absorb assembly pressure before it reaches the probe tails, preventing overpressure damage during the assembly process while maintaining reliable electrical connections between the probe heads and space transformer.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The support structures (bumps or ribs) serve as intermediary elements between the upper guide plate and the probe tails. During assembly, these intermediaries bear the mechanical load and distribute it evenly, preventing direct concentration of force on the probe tails. This mediation protects the probes from damage while still allowing proper electrical contact to be established.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the probe penetrates the upper guide plate, then the electrical connection is formed, but the probe may crack or sink into the guide plate

Engineering Contradiction:

Improveelectrical connectionVSAvoidprobe damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Strength

If the probe body is rigid, then the structural strength is improved, but the probe cannot accommodate parallelism differences and becomes stuck

Engineering Contradiction:

Improvestructural strengthVSAvoidparallelism adaptation

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The probe structure employs local quality differentiation: the probe body maintains high rigidity and strength for structural integrity, while the probe tail section incorporates flexibility or compliance features. This allows the rigid probe body to provide structural strength while the flexible tail can accommodate parallelism variations in the upper guide plate, preventing the probe from becoming stuck during assembly or operation.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3715866B1Probe head and probe card

Publication Date: 2025.03.05 MPI CORP

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AI summary

This disclosure discloses a probe head (PH), including an upper guide plate (10), a lower guide plate (20), and a plurality of probes (30). The upper guide plate (10) includes a groove (15), and the upper guide plate (10) is provided with an upper surface (11) and a lower surface (12) that are opposite to each other and a plurality of probe holes (13) vertically penetrating the upper surface (11) and the lower surface (12) along a first direction (D1). The groove (15) is depressed from the upper surface (11), and the groove (15) is provided with a groove bottom surface (151). In the first direction (Dl), the groove bottom surface (151) is located between the upper surface (11) and the lower surface (12). The lower guide plate (20) is disposed on the upper guide plate (10) and located on the side of the lower surface (12). The probe (30) is provided with a probe tail (31), a probe body (32) and a probe tip (33) that are connected in sequence, and the probe (30) is disposed in the groove (15). In the first direction (D1), an end portion of the probe tail (31) is located between the groove bottom surface (151) and the upper surface (11). This disclosure further discloses a probe card, including a circuit board (PCB), a space transformer (ST) and the probe head (PH).