Semiconductor Substrate Resin-Layer Through-Hole Orthogonal Grinding
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Solution Overview
Problem
The existing methods for manufacturing micromachines with semiconductor elements on silicon substrates face challenges in forming recesses with orthogonal side surfaces, leading to variations in the exposed area of electrodes due to grinding, which increases processing costs and variability.
Innovation Solution
A semiconductor device with a substrate having a through-hole and a resin-layer through portion with orthogonal surfaces, where the resin-layer is made of polyimide resin and interposed between the column and the inner wall of the through-hole, ensuring consistent cross-sectional shape regardless of grinding variations, and a method involving photolithography and electroplating for manufacturing this device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If batch etching using chemical solution is employed to reduce processing cost, then manufacturing cost is reduced, but the recess cannot have a side surface orthogonal to the substrate
Solution Approach 1:
The patent applies preliminary action by forming a resin layer within the recess before etching the substrate. This resin layer acts as a mask that defines the recess boundaries and ensures orthogonal side surfaces are formed during the batch etching process, thereby achieving both cost reduction and shape precision
2Shape
If anisotropic etching from (100) surface is used to form recess with orthogonal side surface, then side surface orthogonality is achieved, but variations occur in the area of the exposed portion of the electrode depending on the degree of grinding
Solution Approach 1:
The patent uses an intermediary approach by introducing a resin layer that extends to the back surface of the substrate. This resin layer serves as a mediator that compensates for grinding variations, ensuring that the exposed electrode area remains consistent even when the grinding degree varies, thus resolving the precision issue
3Manufacturing precision
If single-wafer etching using plasma is employed to form recess, then processing precision is improved, but processing time increases and device cost increases
Solution Approach 1:
The patent replaces the plasma etching mechanism with a chemical solution-based batch etching process. By using chemical etching combined with a resin mask layer, the system achieves comparable precision without the time-consuming and expensive plasma process, thereby reducing both processing time and device cost
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 reduces variations in the exposed area of the electrode, allowing for more precise control over the semiconductor device's dimensions and reducing processing costs by maintaining consistent cross-sectional shapes during grinding, thus enhancing manufacturing efficiency.
Implementation Method 1
a resin layer, which includes a resin-layer through portion having an orthogonal surface orthogonal to the back surface, interposed between the column and an inner wall of the through-hole
Implementation Method 2
cross sections of the column parallel to the mounting surface all have the same shape regardless of the inclination of the inner wall of the through-hole
Implementation Method 3
a column formed within the through-hole and electrically connected to the front-surface wiring line
Data Source
AI summary
A semiconductor device includes a substrate having a front surface and a mounting surface that are separate from each other in a thickness direction. The substrate is formed with a through-hole that penetrates through in the thickness direction. A semiconductor element is mounted on the front surface of the substrate, and a front-surface wire line is formed on the front surface of the substrate to be electrically connected to the semiconductor element. A column is provided inside the through-hole, and is electrically connected to the front-surface wiring line. An electrode pad is provided on the mounting surface of the substrate, and is electrically connected to the column. A resin-layer through portion is also provided inside the through-hole. The semiconductor element is covered with a sealing resin. The resin-layer through portion has an orthogonal surface in contact with the column. The orthogonal surface is orthogonal to the mounting surface.