IGBT Control Terminal Positioning via Resin Block Interlock

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Solution Overview

Problem

Conventional IGBT modules face issues with the control terminal sinking into or being pulled out of the resin case due to compressive or tensile loads, leading to inaccurate positioning and potential damage to the patterned insulating substrate.

Innovation Solution

A semiconductor device design featuring a control terminal with projections and a resin case with corresponding concave portions, along with a resin block that fits into the resin case to securely position and fix the control terminal, preventing vertical movement and ensuring precise positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the control terminal is not fixed to the resin case (using independent terminals), then the assembly process is simpler, but the control terminal sinks into or is pulled out of the resin case under load, causing positioning inaccuracies and potential substrate damage

Engineering Contradiction:

Improveassembly process simplicityVSAvoidcontrol terminal positioning stability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The invention introduces a resin block as a separate component that segments the fixation function from the resin case. The resin block contains positioning protrusions that engage with the control terminal, while the resin case provides structural support. This segmentation allows the control terminal to be securely fixed without complicating the overall assembly process, as the resin block can be pre-formed and then integrated into the resin case.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The resin block acts as an intermediary component between the control terminal and the resin case. It provides the positioning protrusions that directly engage with the control terminal, while the resin case provides the overall structural support. This intermediary structure resolves the contradiction by providing secure fixation without requiring complex integration of the control terminal directly into the resin case.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If the control terminal is allowed to move freely in the resin case, then the assembly process is easier, but the position of the control terminal cannot be determined precisely, especially when the arm portion is long

Engineering Contradiction:

Improveassembly easeVSAvoidcontrol terminal position accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The resin block is pre-formed with positioning protrusions at specific locations before being integrated into the resin case. These positioning protrusions are designed in advance to engage with the control terminal at precise positions. This preliminary preparation of the fixation structure allows for accurate positioning without requiring complex adjustment procedures during assembly.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention replaces the need for complex mechanical adjustment mechanisms with a simple geometric interlocking system. The positioning protrusions on the resin block engage with corresponding features on the control terminal through geometric constraints, providing precise positioning without requiring adjustable mechanisms or complex alignment procedures.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If the control terminal is welded to the patterned insulating substrate, then the joint strength is improved, but the patterned insulating substrate can be damaged by compressive loads applied to the control terminal

Engineering Contradiction:

Improvejoint strengthVSAvoidsubstrate damage from compressive load

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The resin block serves as an intermediary that absorbs and distributes compressive loads applied to the control terminal. Instead of these loads being transmitted directly to the welded joint on the patterned insulating substrate, the resin block's positioning protrusions and the surrounding resin material distribute the forces, protecting the substrate from damage while maintaining joint strength.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The resin block provides beforehand cushioning against compressive loads. The soft resin material of the block acts as a cushion that absorbs and distributes compressive forces before they can reach the welded joint on the substrate. This protective function is built into the structure in advance, preventing substrate damage under load conditions.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP2750187B1Semiconductor device and semiconductor device manufacturing method

Publication Date: 2020.01.01 FUJI ELECTRIC CO LTD

Figure 1(a)~1(d)
Figure 2(a)~2(b)
Figure 3(a)~3(b)

AI summary

Provide is a semiconductor device configured such that a control terminal (13) is soldered onto a patterned insulating substrate (42) which is fixedly attached to a heat dissipating base (41). A resin case (1) is bonded to the rim of the heat dissipating base (41) to cover the patterned insulating substrate (42) of the heat dissipating base (41). The control terminal (13) is exposed to the outside of the resin case (1) from an opening (2) of the resin case (1). First and second projections (16, 17) provided on a side end surface (14) of the control terminal (13) are fitted to a convex step portion (26) of a resin block (21) inserted into the opening (2) of the resin case (1). According to the above configuration, even when external force such as a compressive load or tensile load is applied to the control terminal (13), the control terminal (13) can be prevented from sinking into the resin case (1) or being pulled out of the resin case (1).