Wettable Flank Component Fabrication Using Resin Thinning Cavities

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing processes for manufacturing wettable edge electronic components are inadequate in ensuring reliable electrical connections, particularly in critical applications like automotive and medical fields, where visual inspection of solder quality is necessary.

Innovation Solution

A method involving soldering connection pads onto chip connection pads, coating with insulating resin, thinning the resin layer, forming cavities, depositing a conductive material on the sides, and separating the chips to create electronic components with wettable sides.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If connection metallizations are extended to the sides of components to enable visual inspection of solder quality, then reliability of electrical connections is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvereliability of electrical connectionsVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The manufacturing process is divided into distinct sequential steps: soldering connection pads to chip connection pads, coating with insulating resin, thinning the resin layer, forming cavities, depositing conductive material on sides, and separating chips. This segmentation allows each step to be optimized independently while achieving the overall goal of creating wettable flanks for visual solder inspection

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The insulating resin layer is applied and thinned before the final separation step, and the conductive material is deposited on the sides before separation. This preliminary action ensures that the wettable flanks are properly prepared with conductive material in advance, allowing visual inspection of solder quality without requiring additional post-processing steps

Inventive Principle:

Principle #10Preliminary action

2Ease of operation

If insulating resin layer is thinned to reach connection pads to enable side access, then accessibility of connection pads is improved, but structural integrity deteriorates

Engineering Contradiction:

Improveaccessibility of connection padsVSAvoidstructural integrity of insulating layer

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The insulating resin layer is thinned locally only in the regions where connection pads are located, rather than thinning the entire layer uniformly. This localized thinning provides access to connection pads for forming cavities and depositing conductive material while maintaining the structural integrity of the insulating layer in other critical areas

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The insulating resin layer is thinned to the extent necessary to reach the connection pads, but not completely removed. This partial action maintains sufficient structural integrity of the insulating layer while providing adequate access to the connection pads for subsequent manufacturing steps

Inventive Principle:

Principle #16Partial or excessive 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 method enhances the reliability of electrical connections by allowing visual inspection of solder quality and ensures consistent manufacturing of surface-mount components with wettable sides, critical for high-reliability applications.

Implementation Method 1

soldering connection pads onto the connection pads of the chips

Methodology Applied

Scientific EffectSoldering: Soldering

Implementation Method 2

depositing a layer of conductive material on the sides of the components and on the connection pads

Methodology Applied

Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Data Source

PatentEP4571825A1Method for producing electronic components with wettable flanks

Publication Date: 2025.06.18 STMICROELECTRONICS INT NV

Figure 1~2B
Figure 2C~2F
Figure 3~6

AI summary

Method for manufacturing electronic components with wettable sides from a substrate (301) covered by connection pads (107) and in which chips (103) are formed, the method comprising the following steps: a) soldering connection pads onto the connection pads (107), b) coating the connection pads with a layer of insulating resin (121), c) thinning the layer of insulating resin (121) until it reaches the connection pads, d) forming cavities by removing part of the connection pads and part of the layer of insulating resin (121), so as to make part of the sides of the components accessible, e) depositing a layer of conductive material (122) on the sides of the components and on the connection pads, f) separating the chips (103).