Circuit Module Molding Material Dicing to Prevent Cracking

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Solution Overview

Problem

The existing methods for manufacturing miniaturized circuit modules with semiconductor chips mounted on wiring substrates and molded with a molding material face issues such as cracking of the molding material during cutting, leading to manufacturing defects and contamination from residue, especially when using transfer molding and dicing techniques.

Innovation Solution

A circuit module design where the wiring substrate is elongated, allowing for end faces of the molding material to be formed by dicing along the lengthwise direction, intersecting with the lateral direction of the substrate, enabling the removal of molding material without cracking and reducing contamination by avoiding cuts in other regions, with the option to use different cutting methods for different substrate regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the molding material and mother board are cut by punching with a die or scribing method, then the wiring substrates are separated, but cracking is likely to occur in the molding material

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidcut surface quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent divides the cutting process into two distinct stages: first cutting the mother board to separate wiring substrates using punching or scribing, then subsequently cutting the molding material using dicing. This segmentation allows each cutting method to be optimized for its specific task, preventing cracks in the molding material while maintaining manufacturing efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs the cutting of the mother board before the cutting of the molding material. By preliminarily separating the wiring substrates from the mother board, the subsequent dicing process can focus solely on the molding material without the constraint of cutting through the entire assembly, thereby preventing cracks.

Inventive Principle:
Principle #10Preliminary action

2Volume of moving object

If the wiring substrates have a small width, then the circuit module is miniaturized, but the molding material spreads over the widthwise sides and is undesirably cut by the die

Engineering Contradiction:
Improvemodule sizeVSAvoidmolding material integrity
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent separates the cutting operations into two stages: first cutting the mother board to create individual wiring substrate units, then subsequently cutting the molding material with dicing. This segmentation allows the dicing blade to cut only the molding material without affecting the already-separated wiring substrates, even when they have small widths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs the mother board cutting operation before the molding material cutting operation. By preliminarily separating the wiring substrates, the subsequent dicing process can accurately cut the molding material without the risk of the die cutting into the narrow wiring substrates.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If the molding material is cut by dicing along the entire length of the mother board, then the molding material is removed, but a large amount of residue is generated causing contamination

Engineering Contradiction:
Improvemolding material removalVSAvoidcontamination from residue
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes only the excess molding material from the end faces of the wiring substrates using dicing, rather than cutting the entire length of the mother board. This selective removal minimizes the generation of residue and reduces contamination while still achieving the necessary molding material removal.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies dicing only to specific regions where molding material removal is necessary (the end faces of the wiring substrates), rather than uniformly cutting the entire mother board. This localized approach reduces waste and contamination while maintaining manufacturing effectiveness.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS9252124B2Circuit module having a substrate, semiconductor chip, and molding material formed by dicing
Publication Date: 2016.02.02 CRYSTAL LEAP ZRT

AI summary

A circuit module including: a wiring substrate having a shape elongated in one direction; a semiconductor chip mounted on the wiring substrate; and a molding material that molds the semiconductor chip, wherein end faces of the molding material that extend along a lengthwise direction of the wiring substrate and intersect with a lateral direction of the wiring substrate are formed by dicing performed along end faces of a partial region of the wiring substrate.