Semiconductor Package Height Alignment via Working Table

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Solution Overview

Problem

Conventional semiconductor devices face issues with variations in thermal resistance and excessive stress on control terminals due to height discrepancies between packages and heat sinks, leading to potential thermal destruction and faulty electrical continuity.

Innovation Solution

A method is implemented where first and second terminals are connected via a bonding material in a clearance, ensuring packages are aligned at the same height, reducing thermal resistance variations and suppressing excessive stress on control board mounting parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If heat sink is attached to the back side of the insert case, then heat dissipation function is provided, but the back side becomes warped and flatness cannot be obtained

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidflatness of back side
Core Design Contradiction:
TemperatureVSShape

Solution Approach 1:

A working table is introduced as an intermediary component between the heat sink and the insert case. The working table has a flat surface that receives the heat sink, and the insert case is mounted on this working table. This intermediary structure supports the heat sink in a fixed position and prevents warping of the insert case back side, while still enabling effective heat dissipation through the heat sink.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If packages are mounted on the insert case without height alignment, then manufacturing is simplified, but thermal resistance varies and excessive stress occurs on control terminals

Engineering Contradiction:
Improvepackage mounting simplicityVSAvoidthermal resistance consistency and electrical connection stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The working table provides a flat, level surface that ensures all packages mounted on it are at the same height. This equipotential approach eliminates height discrepancies between packages, ensuring uniform thermal resistance to the heat sink and preventing excessive stress on control terminals during connection to the control board.

Inventive Principle:
Principle #12Equipotentiality

3Ease of manufacture

If heat sink grease thickness varies due to height discrepancies, then application is easier, but heat dissipation efficiency decreases

Engineering Contradiction:
Improveheat sink grease applicationVSAvoidheat dissipation efficiency
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

By mounting all packages on the flat surface of the working table, the invention ensures that the back surfaces of all packages are at the same height. This allows heat sink grease to be applied with uniform thickness across all package mounting surfaces, optimizing thermal contact and heat dissipation efficiency while maintaining ease of application.

Inventive Principle:
Principle #12Equipotentiality

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 achieves consistent thermal resistance and reduces stress on control board connections, enhancing the reliability and performance of semiconductor devices by ensuring even heat dissipation and stable electrical connections.

Implementation Method 1

a clearance is formed between a first terminal of a case placed on a working table and a second terminal of a package placed on the working table, and the first terminal and the second terminal are electrically connected to each other via a bonding material in the clearance formed in parallel with the working table

Methodology Applied
Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 2

a heat sink attached to the back side of the insert case may be warped depending upon the module size or structure

Methodology Applied
Scientific EffectThermal Conduction: Conduction (thermal)

Data Source

PatentEP2851951B1Method for manufacturing semiconductor device and semiconductor device
Publication Date: 2019.11.13 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2851951B1 patent drawingFigure 1(a)~1(b)
  • EP2851951B1 patent drawingFigure 2(a)~2(d)
  • EP2851951B1 patent drawingFigure 3~4(b)

AI summary

In a method for manufacturing a semiconductor device according to the present invention, as shown in FIG. 2(a), a case (2) including a first terminal (1) is placed on a working table (3) with an opening (30) formed at the bottom of the case (2). Subsequently, as shown in FIG. 2(b), a plurality of packages (6,6,6) including second terminals (4) are placed on the working table (3) through the opening (30) of the case (2), forming a clearance (31) between the first terminal (1) and the second terminal (4). As shown in FIG. 2(c), a bonding material (7) is disposed in the clearance (31) so as to electrically connect the first terminal (1) and the second terminal (4). Thus, the exposed surfaces of the packages (6,6,6) in the opening (30) of the case (2) are aligned at the same height, thereby reducing variations in thermal resistance among the packages (6,6,6).