Collective Printed Circuit Board Segmentation and Localized Sealing

Solution Overview

Problem

The miniaturization and multi-layering of collective printed circuit boards have complicated the manufacturing process, leading to a decrease in yield and an increase in costs, with warpage caused by thermal contraction of sealing resin posing challenges in mounting semiconductor elements on flat surfaces.

Innovation Solution

A collective printed circuit board design where multiple printed circuit boards are independently bonded to a frame with through holes, improving rigidity and minimizing sealing resin usage to prevent warpage, allowing only non-defective boards to be selected and bonded, thus enhancing yield and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If miniaturization and multi-layering are implemented in collective printed circuit boards, then the integration density and functionality are improved, but the manufacturing process becomes complicated and the yield decreases

Engineering Contradiction:

Improveintegration densityVSAvoidmanufacturing process complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The collective printed circuit board is divided into multiple independent small printed circuit boards, each with its own mounting unit. This segmentation allows each board to be manufactured and tested independently, simplifying the overall manufacturing process while maintaining high integration density through the collective arrangement of multiple functional boards.

Inventive Principle:

Principle #1Segmentation

2Reliability

If sealing resin is used to seal the collective printed circuit board, then the sealing and protection are improved, but the thermal contraction causes warpage of the printed circuit board

Engineering Contradiction:

Improvesealing performanceVSAvoidboard flatness

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The sealing resin is applied locally only to the peripheral edges of the small printed circuit boards where they join to the collective board, rather than covering the entire surface. This localized sealing provides adequate protection while minimizing the amount of resin that could cause thermal contraction and warpage of the mounting units.

Inventive Principle:

Principle #3Local quality

3Ease of operation

If warpage is reduced to enable mounting on another circuit board, then the mountability is improved, but the sealing resin usage must be minimized which may affect sealing performance

Engineering Contradiction:

ImprovemountabilityVSAvoidsealing performance

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The sealing resin is applied locally only to the peripheral edges of the small printed circuit boards where they join to the collective board, rather than covering the entire surface. This localized sealing provides adequate protection while minimizing the amount of resin that could cause thermal contraction and warpage of the mounting units.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The collective printed circuit board is divided into multiple independent small printed circuit boards, each with its own mounting unit. This segmentation allows each board to be manufactured and tested independently, simplifying the overall manufacturing process while maintaining high integration density through the collective arrangement of multiple functional boards.

Inventive Principle:

Principle #1Segmentation

4Productivity

If yield is increased by selecting only non-defective boards, then the production efficiency is improved, but the device complexity increases due to selective bonding process

Engineering Contradiction:

Improveproduction efficiencyVSAvoidselective bonding process

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

Each small printed circuit board undergoes electrical testing and appearance checks before being bonded to the collective board. This preliminary quality assessment ensures that only non-defective boards are selected for assembly, increasing yield and production efficiency while the testing process itself is integrated into the manufacturing workflow.

Inventive Principle:

Principle #10Preliminary action

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 design increases the yield of printed circuit boards, prevents warpage, and stabilizes the mounting of semiconductor elements, ensuring efficient and cost-effective production of electronic devices.

Implementation Method 1

upper-surface peripheral edge portions of the printed circuit boards and a through-hole peripheral portion of the frame are bonded to each other

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 2

the sealing resin thermally contracts largely more than the printed circuit board. As a result, the printed circuit board is warped

Methodology Applied

Scientific EffectThermal contraction: Thermal Contraction

Implementation Method 3

the rigidity can be improved by the frame

Methodology Applied

Scientific EffectStructural rigidity:

Data Source

PatentUS9173299B2Collective printed circuit board

Publication Date: 2015.10.27 KYOCERA CORP

AI summary

There is provided a collective printed circuit board including a plurality of printed circuit boards each having a mounting unit on which a semiconductor element is mounted at an upper-surface central portion, and a frame having a plurality of through holes having sizes to surround the mounting portion. Upper-surface peripheral edge portions of the printed circuit boards and a through-hole peripheral portion of the frame are bonded to each other such that the mounting units are exposed from the through holes.