Recessed Adhesive Layer for Stacked Semiconductor Chip Bonding
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Solution Overview
Problem
The challenge in semiconductor package manufacturing is the overflow of non-conductive films during the bonding process, leading to overhangs and insufficient filling, which can result in defective bonds and reduced reliability, especially when these films are not properly recessed from the side surfaces of the semiconductor chips.
Innovation Solution
The use of a hydrostatic bonding process with pressurized fluid to cure the non-conductive films, ensuring their side surfaces are recessed from the semiconductor chips, preventing overflow and enhancing the bond strength between the films and the molding member, thereby improving the reliability of the semiconductor package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-conductive films are used during bonding process, then bonding between semiconductor chips is enabled, but film overflow and overhangs occur leading to defective bonds
Solution Approach 1:
The side surfaces of the non-conductive film are recessed from the side surfaces of the semiconductor chips before the bonding process. This preliminary shaping prevents the film from overflowing during bonding, eliminating overhangs that would cause defective bonds and short circuits.
Solution Approach 2:
By pre-recessing the film sides, the invention creates a preventive structure that counteracts the natural tendency of the film to overflow during bonding. This preliminary anti-action stops the harmful overflow effect before it can occur during the bonding process.
2Reliability
If non-conductive films are applied generously to ensure coverage, then complete bonding coverage is achieved, but insufficient filling and voids occur
Solution Approach 1:
The non-conductive film is designed with different geometries at different locations: the top surface extends beyond the chip edges to ensure complete coverage and bonding, while the side surfaces are recessed to prevent overflow. This local differentiation of film geometry solves both coverage and filling issues simultaneously.
Solution Approach 2:
The film is pre-shaped with recessed side surfaces before bonding, ensuring that during the bonding process the film will fill the gap uniformly without creating voids or insufficient filling, while still maintaining adequate coverage area.
3Manufacturing precision
If film viscosity is increased to prevent overflow, then film control is improved, but film application and spreading become difficult
Solution Approach 1:
Instead of modifying the film's viscosity to control overflow, the invention pre-shapes the film with recessed side surfaces. This allows the use of lower viscosity films that are easier to apply and spread, while the pre-formed geometry prevents overflow during bonding.
Solution Approach 2:
The invention changes the geometric parameters of the film (side surface recession) rather than the material parameter (viscosity). This parameter substitution maintains overflow control while preserving ease of film application and processing.
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 approach effectively prevents overhangs and ensures a uniform, reliable bond between the semiconductor chips and the molding member, increasing the overall reliability and structural integrity of the semiconductor package by controlling the viscosity and processing conditions of the non-conductive films.
Implementation Method 1
The use of a hydrostatic bonding process with pressurized fluid to cure the non-conductive films
Implementation Method 2
The first temperature is above a curing temperature of the first uncured adhesive layers
Data Source
AI summary
A semiconductor package includes a first semiconductor chip having a first through substrate via (TSV), a second semiconductor chip stacked on the first semiconductor chip and a first adhesive layer disposed between the first semiconductor chip and the second semiconductor chip. The second semiconductor chip includes a second through substrate via connected to the first through substrate via. A side surface of the first adhesive layer is recessed from side surfaces of the first and second semiconductor chips.