Semiconductor Through Hole Insulation Film Removal via Protective Tape
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Solution Overview
Problem
The yield of semiconductor chips with through vias electrically coupled to electrode pads is degraded due to over-etching during the removal of insulation films using wet etching methods, which can damage electrode pads and result in incomplete coverage of through hole side walls.
Innovation Solution
A method involving the use of insulation film removing tape to cover the opening portions, allowing for precise formation of thinner insulation films on the side walls of through holes, enabling accurate removal and improving the yield by breaking the insulation film at step portions, thus ensuring accurate coverage and reducing damage to electrode pads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wet etching method is used to remove insulation film from electrode pads, then the insulation film can be removed, but over-etching occurs causing damage to electrode pads and degradation of yield
Solution Approach 1:
The patent divides the insulation film removal process into two distinct stages: first removing the insulation film from the electrode pad surface, then removing the insulation film from the through-hole side walls. This segmentation allows each etching step to be optimized independently, preventing over-etching damage to the electrode pads while ensuring complete removal from side walls.
Solution Approach 2:
The patent applies a protective film to the electrode pads before the etching process. This preliminary protective action prevents the electrode pads from being damaged during etching, allowing the insulation film to be removed from the side walls without risking pad integrity. The protective film is removed after etching is complete.
2Productivity
If wet etching method is used to remove insulation film, then the process can be completed, but through hole side wall coverage becomes incomplete
Solution Approach 1:
The patent segments the etching process into two steps: first etching the insulation film from the electrode pad area, then etching the insulation film from the through-hole side walls. This allows the side wall etching to be performed with precise control, ensuring complete coverage without over-etching, while maintaining overall manufacturing efficiency.
Solution Approach 2:
The patent uses a protective film as an intermediary element during the etching process. This protective film is applied to areas that should not be etched, allowing the etching solution to selectively remove insulation film from the through-hole side walls while protecting other areas. The protective film is then removed after etching.
3Device complexity
If insulation film is removed using conventional methods, then the process is simple, but yield of semiconductor chips degrades
Solution Approach 1:
The patent divides the insulation film removal into two sequential etching steps with different objectives: the first step removes insulation from the electrode pad surface, and the second step removes insulation from the through-hole side walls. This segmentation improves chip yield by preventing over-etching damage while maintaining reasonable process complexity through systematic organization.
Solution Approach 2:
The patent applies a protective film to the electrode pads as a preliminary action before etching. This simple additional step prevents over-etching damage to the pads during the etching process, significantly improving chip yield without adding substantial complexity to the overall manufacturing process.
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 method enhances the yield of semiconductor chips by ensuring high accuracy in covering the through hole side walls with insulation films, preventing over-etching and pad damage, thereby improving the manufacturing process efficiency.
Implementation Method 1
an insulation film removing tape pasting step of pasting an insulation film removing tape on the metal film so as to cover the upper end portions of the opening portions
Implementation Method 2
the case of removing the insulation film 103 provided on the electrode pads 102 by using the wet etching method
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An insulation film removing tape 38 is pasted on a metal film 34 so as to cover an opening portion 32, then an insulation film 17 is formed so as to cover the side wall of a through hole 21 from the second major surface 11B side of the semiconductor substrate 11, and thereafter the insulation film removing tape 38 is removed.