Vertical Compliant Probe Assembly for Oxide-Layer Die Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The formation of a metal oxide layer on die pads due to oxidation affects conductance during electrical testing, requiring probes to penetrate this layer with precise force, which can lead to probe burnout or pad damage if not managed correctly.
Innovation Solution
A vertical probe assembly with resilient compliant probes and guide plates formed from non-conductive materials, featuring a stopper structure and deformable design to apply controlled contact force, minimizing damage and ensuring consistent electrical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the probe applies sufficient force to penetrate the oxide layer, then electrical contact is achieved, but the contact pad may crack
Solution Approach 1:
The probe incorporates a compliant element that changes the mechanical parameters of the probe tip, allowing it to deform and distribute contact force. This compliance transforms the rigid contact into a controlled deformation process, enabling oxide penetration while limiting peak stresses on the contact pad to prevent cracking
Solution Approach 2:
The probe is constructed as a composite structure with a rigid body portion and a separate compliant element portion. This composite design combines the advantages of rigidity (for structural integrity and positioning) with compliance (for controlled force application and oxide penetration), resolving the contradiction between achieving electrical contact and preventing pad damage
2Reliability
If the probe applies excessive force to ensure contact, then electrical connection is established, but the probe may become burnt
Solution Approach 1:
The compliant element modifies the force parameter applied by the probe, transforming excessive concentrated force into controlled, distributed deformation. This parameter change ensures sufficient contact force for electrical connection while preventing the excessive current density that would cause probe burnout
3Strength
If the contact force is reduced to prevent damage, then probe and pad integrity is maintained, but oxide layer penetration is insufficient
Solution Approach 1:
The compliant element introduces controlled deformation as a new parameter, allowing the probe to achieve oxide penetration through elastic/plastic deformation of the compliant portion rather than through excessive force. This transforms the force-penetration relationship, enabling sufficient penetration while maintaining pad integrity
Solution Approach 2:
The compliant element is designed with a curved or flexible geometry that allows it to deform under load. This curvature enables the probe tip to progressively penetrate the oxide layer through controlled deformation, achieving reliable electrical contact without applying excessive force that would damage the contact pad
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 solution allows for effective penetration of the oxide layer without damaging the die pads, maintaining consistent electrical contact and reducing probe wear, thereby improving test accuracy and reliability.
Implementation Method 1
a first resilient compliant probe formed from a conductive material... The upper and lower portions of the first probe are configured to separately deform in response to external forces
Data Source
AI summary
A vertical probe assembly having a resilient compliant probe, a first guide plate, a second guide plate, and a third guide plate is disclosed. The probe may include an upper portion, a lower portion, and a stopper structure positioned between the upper and lower portions of the first probe. The first, second, and third guide plates may be formed from a non-conductive substrate and separated by one or more spacers. The first, second, and third guide plates may also include a first, second, and third hole, respectively. The first, second, and third holes may be vertically aligned. The probe may be positioned within the first, second, and third holes such that the upper portion extends through the first hole, the lower portion extends through the second and third holes, and the stopper structure contacts a surface of the second guide plate that faces the first guide plate.