Substrate Support Plate Pits with Bending Portions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional substrate supporting apparatuses face issues with spacer members slipping out or breaking due to thermal expansion coefficient differences and contamination from particulate dust during semiconductor manufacturing processes.
Innovation Solution
A substrate supporting apparatus with a metallic plate member featuring pits for spacer members, where the open edge portion is plastically deformed to create a bending portion and a V-shaped groove, preventing spacer member slippage and contamination by using a groove and bumps to restrain dust from transferring onto the spacer members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the spacer members are tightly fitted into the pits to prevent slipping, then the anti-slipping capability is improved, but the thermal stress increases causing breakage of brittle spacer members
Solution Approach 1:
The patent changes the geometric parameters of the pit structure by adding a bending portion that protrudes into the pit. This creates an optimized fit between the spacer member and pit that provides anti-slipping capability while accommodating thermal expansion differences, preventing excessive stress concentration that would cause breakage of brittle ceramic spacer members
Solution Approach 2:
The bending portion in the pit acts as a cushioning element that anticipates and absorbs thermal stress before it can cause damage. By pre-positioning this geometric feature in the pit structure, the design compensates for thermal expansion differences between metal plate and ceramic spacers, preventing stress-induced breakage before it occurs
2Device complexity
If the upper end of spacer members simply projects from the plate surface, then the structure is simple, but particulate dust can move from the plate surface to the spacer members causing contamination
Solution Approach 1:
The patent segments the originally simple projecting upper end of the spacer member into multiple functional portions: a first portion that projects from the plate surface and a second portion that extends into the pit. This segmentation allows the structure to simultaneously maintain simplicity while preventing dust contamination by creating a geometric barrier at the critical interface
3Ease of manufacture
If the opening width of the pit is larger than the spacer member diameter, then assembly is easy, but the spacer member can slip out during thermal cycling
Solution Approach 1:
The patent applies local quality by creating a bending portion with specific geometric properties at a localized position within the pit. This local structural modification provides the necessary retention force to prevent slippage during thermal cycling, while the rest of the pit maintains its original dimensions for easy assembly, thus combining assembly ease with operational reliability
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 effectively prevents spacer member slippage and breakage while maintaining a clean substrate environment by ensuring the spacer members remain securely in place and preventing particulate dust from adhering to the substrate.
Implementation Method 1
a bending portion which is formed by plastically deforming the open edge portion toward the spacer member
Implementation Method 2
the plate member and the spacer members may be considerably different in thermal expansion coefficient. If the substrate supporting apparatus is exposed to high temperature... the spacer members, which are lower in thermal expansion coefficient than the plate member, may possibly slip out
Data Source
AI summary
A substrate supporting apparatus includes a plate member of an aluminum alloy having a flat upper surface, bottomed pits formed in the plate member, and spacer members held in the pits, individually. The spacer members are sapphire spheres. The diameter of each spacer member is a little smaller than that of each pit. The upper end of each spacer member projects from the upper surface of the plate member. A spot facing is formed in a region that includes the open edge portion of the pit. A bending portion which is obtained by plastically deforming the open edge portion of the pit toward the spacer member is formed on a bottom surface of the spot facing. A V-shaped groove is formed behind the bending portion.