Probe Card Guide Plate Capacitor Structure for Signal Integrity
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Solution Overview
Problem
Existing probe cards face issues with instantaneous voltage drops due to large parasitic inductance between the device under test and the de-coupling capacitor, leading to power integrity problems during testing.
Innovation Solution
A probe card design incorporating a guide plate with a capacitor structure and multiple probes, including first and second ground probes and power probes, forms a current loop with the capacitor structure to provide real-time power supply, reducing parasitic inductance and improving test signal integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the de-coupling capacitor is placed close to the device under test on an adapter plate or printed circuit board, then the power supply response is improved, but the probe wiring design becomes difficult and parasitic inductance cannot be sufficiently reduced
Solution Approach 1:
The patent merges the capacitor support function directly into the guide plate structure. The guide plate includes a capacitor receiving space that accommodates the de-coupling capacitor, eliminating the need for separate adapter plate modifications or complex PCB wiring designs. This integration resolves the contradiction by maintaining close capacitor placement while simplifying the overall structure.
Solution Approach 2:
The guide plate acts as an intermediary structure between the device under test and the capacitor. It provides both mechanical support for the device and a dedicated receiving space for the capacitor, enabling optimal capacitor placement without complicating the probe wiring design. The guide plate mediates between the conflicting requirements of close capacitor placement and simple wiring.
2Object-affected harmful factors
If shorter pins are selected to reduce parasitic inductance, then the inductance of the probe path is improved, but the overall probe structure becomes more compact with limited design flexibility
Solution Approach 1:
The patent segments the probe structure into distinct functional components: the probe body, the guide plate with capacitor receiving space, and the support structure. This segmentation allows each component to be optimized independently - the pins can be kept short to reduce inductance while the guide plate provides design flexibility through its modular capacitor accommodation space.
Solution Approach 2:
The patent utilizes three-dimensional space by creating a capacitor receiving space within the guide plate structure. This vertical/dimensional arrangement allows the capacitor to be positioned optimally close to the device under test without constraining the horizontal probe wiring layout, thereby reducing parasitic inductance while maintaining design flexibility.
3Reliability
If the probe path length is reduced to minimize parasitic effects, then power integrity is improved, but the wiring design becomes more constrained and difficult to implement
Solution Approach 1:
The patent combines the capacitor mounting function with the guide plate structure. The guide plate includes an integrated capacitor receiving space that accommodates the de-coupling capacitor in optimal position. This merging eliminates the need for separate wiring extensions or complex routing to reach distant capacitor locations, thereby minimizing probe path length while simplifying wiring design and manufacturing.
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 design effectively addresses instantaneous voltage drops by providing real-time power, enhancing the identification of test high voltage (VIH) and preventing interpretation errors from blurred signals, thus improving test signal integrity.
Implementation Method 1
the capacitor structure is disposed in the second guide plate portion and connected to the second guide plate portion... the power probes draw current through the capacitor structure
Data Source
AI summary
A probe card includes an adapter plate, a guide plate and a plurality of probes. The guide plate incudes a first guide plate portion, a second guide plate portion and a capacitor structure. The probes include at least one first ground probe, at least one second ground probe and a plurality of power probes. The first ground probe penetrates through the first guide plate portion and is connected to the capacitor structure and the adapter plate. The second ground probe and the power probes penetrate through the first guide plate portion, the capacitor structure and the second guide plate portion and are connected to the adapter plate. The first ground probe is used to provide voltage to the capacitive structure to generate a potential difference. The power probes draw current through the capacitor structure and form a current loop with the second ground probe.