Semiconductor Module Case Flat-Gate Molding for Fast Resin Fill

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Solution Overview

Problem

High-capacity semiconductor modules face challenges in supplying sufficient resin during injection molding due to increased case size, leading to potential defects from insufficient resin or air introduction when increasing injection speed.

Innovation Solution

A semiconductor module case with a single flat gate on its side face for resin injection, featuring a film-shaped runner that decreases in thickness towards the gate, allowing for efficient resin flow and minimizing air introduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the case size is increased for high-capacity semiconductor modules, then the module capacity is improved, but the resin supply time is extended and air introduction risk increases

Engineering Contradiction:
Improvemodule capacityVSAvoidresin supply time
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The invention divides the resin supply system into multiple independent gates instead of using a single gate. This segmentation allows resin to be supplied through multiple pathways simultaneously, reducing the overall resin supply time and preventing air entrapment in large-capacity modules.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a single-point gate injection to a distributed multi-point gate system, adding spatial distribution dimension to the resin supply process. This dimensional change enables parallel resin flow paths, significantly reducing fill time for large modules.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If the injection speed is increased to supply sufficient resin, then the resin supply rate is improved, but air is introduced into the mold creating voids

Engineering Contradiction:
Improveresin supply rateVSAvoidair introduction
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

By segmenting the injection system into multiple gates, the resin injection speed at each gate can be optimized independently. This allows sufficient total resin supply without requiring excessively high speeds at individual gates, thereby preventing air entrapment while maintaining productivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple gates act as intermediaries that distribute resin flow throughout the mold cavity. This distribution mechanism allows controlled resin injection that prevents air entrapment while maintaining adequate fill rates for high-capacity modules.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a single gate is used for resin injection, then the device complexity is reduced, but the resin supply efficiency is insufficient for large cases

Engineering Contradiction:
Improvegate structure complexityVSAvoidresin supply efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The invention segments the gate system into multiple simpler gate structures distributed around the mold, replacing a single complex high-speed injection system. This segmentation achieves better resin supply efficiency for large cases while keeping each individual gate structure relatively simple.

Inventive Principle:
Principle #1Segmentation

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

Enables the supply of a sufficient resin amount in a short time, reducing the risk of defects and ensuring a robust, uniformly molded product.

Implementation Method 1

a hot molten resin is injected into a mold, and a desired molded product is created through steps such as pressurizing, cooling, and solidifying

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

a hot molten resin is injected into a mold, and a desired molded product is created through steps such as pressurizing, cooling, and solidifying

Methodology Applied
Scientific EffectPressurizing: Pressure Increase

Implementation Method 3

a hot molten resin is injected into a mold, and a desired molded product is created through steps such as pressurizing, cooling, and solidifying

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 4

a hot molten resin is injected into a mold, and a desired molded product is created through steps such as pressurizing, cooling, and solidifying

Methodology Applied
Scientific EffectSolidifying: Phase Change

Data Source

PatentEP4052881B1Semiconductor module case and method for producing semiconductor module case
Publication Date: 2024.08.21 FUJI ELECTRIC CO LTD
  • EP4052881B1 patent drawingFigure 1
  • EP4052881B1 patent drawingFigure 2
  • EP4052881B1 patent drawingFigure 3

AI summary

The present invention supplies a sufficient amount of resin into a mold even in a short time to obtain an excellent molded product. A semiconductor module case (11) houses semiconductor elements and is formed by injection molding into a box shape open on the bottom. The case has a rectangular shape in a plan view with external terminals disposed on the top face or the side face of the case. The external terminals are electrically connected to the semiconductor elements on the inside of the case and penetrate through the inside to the outside of the case. The case is provided with a single first gate (52) that is an entrance for a resin in a side face corresponding to a short side of the rectangular shape. The first gate has a flat shape that is long in the width direction of the case.