Stacked Mounting Structure With Ink-Jet Electroconductive Terminals
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Solution Overview
Problem
Conventional three-dimensional stacked mounting technologies face challenges in connecting terminals between semiconductor chips reliably, leading to increased contact resistance and reduced productivity due to the need for terminals to be formed continuously up to the side surface of the chip, resulting in a larger module size.
Innovation Solution
A stacked mounting structure comprising a first and second member with an intermediate member that connects them, featuring exposed electrodes and an electroconductive portion on the intermediate member's surface, which reduces contact resistance and allows for a smaller module size by forming the electroconductive portion using an ink-jet method with electroconductive fine particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If terminals are formed by the ink-jet method such that the terminals are not protruded with respect to the side surface of the semiconductor chip, then the manufacturing process is simplified, but it is difficult to connect the terminals assuredly and contact resistance is increased
Solution Approach 1:
The patent transitions from two-dimensional terminal formation on the chip surface to three-dimensional terminal arrangement by having terminals extend through the chip thickness to the side surface. This dimensional change allows terminals to be both planarly formed and vertically connected, solving the contradiction between simplified manufacturing and reliable connection.
Solution Approach 2:
The patent introduces an intermediate structure where terminals extend through the semiconductor chip substrate to reach the side surface. This intermediate terminal structure acts as a mediator between the upper and lower electrodes, enabling reliable electrical connection without requiring complex protruded terminal formation.
2Reliability
If terminals are drawn up to the side surface of the semiconductor chip to decrease contact resistance, then contact resistance is reduced, but productivity is decreased
Solution Approach 1:
The patent performs preliminary terminal formation during the chip manufacturing process itself, where terminals are formed as part of the chip structure before stacking. This preliminary action eliminates the need for subsequent terminal drawing operations, maintaining high productivity while ensuring reliable connections.
Solution Approach 2:
The semiconductor chip is designed to self-provide terminals that extend to the side surface as an integral part of the chip structure. This self-service approach eliminates the need for separate terminal formation operations, maintaining productivity while ensuring reliable electrical connections.
3Reliability
If wire thickness is increased to assure terminal connection, then connection reliability is improved, but the module size increases
Solution Approach 1:
The patent utilizes the vertical dimension by having terminals extend through the chip thickness to the side surface, enabling direct vertical connection between stacked chips. This eliminates the need for lateral wire connections, reducing module size while ensuring reliable connections through direct terminal-to-terminal contact.
Solution Approach 2:
The patent extracts the connection function from separate wire bonds and integrates it directly into the chip terminal structure itself. By taking out the wire bonding step and incorporating terminals that extend to the side surface, the patent achieves reliable connections without adding wire thickness to the module dimensions.
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 ensures reliable electrical connections with reduced contact resistance and a smaller module size by exposing electrodes and forming an electroconductive portion on the intermediate member, enhancing the joining area and mechanical strength while simplifying the manufacturing process.
Implementation Method 1
forming the electroconductive portion using an ink-jet method with electroconductive fine particles
Data Source
AI summary
A stacked mounting structure includes a first substrate, a second substrate, and an intermediate substrate which has a space accommodating therein components to be mounted. A first contact (connecting) terminal and a second contact (connecting) terminal are formed on the first substrate and the second substrate, and have a wire which is formed on a side surface of the intermediate substrate. By formation of the intermediate substrate to be on an inner side than an edge surface of the substrates, a part of the two contact terminals respectively are exposed. One end of the wire is connected to an exposed portion of the first contact terminal, and the other end of the wire is connected to an exposed portion of the second contact terminal.