Fingerprint Sensor Package Layout Using Anisotropic Conductive Film

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Fingerprint sensor packages face challenges in achieving reduced size and thickness while maintaining reliability and sensitivity, and there is a need for compact and cost-effective designs.

Innovation Solution

A fingerprint sensor package design featuring a first substrate with bonding pads and a second substrate with sensing patterns, connected by conductive wires and covered by a molding layer, includes an external connection pad with anisotropic conductive film for improved connectivity and space efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the fingerprint sensor package uses traditional connection pad designs, then the structure is simple, but the space efficiency is insufficient and reliability is compromised

Engineering Contradiction:

Improveconnection reliabilityVSAvoidconnection pad structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The external connection pad is divided into multiple patterns (first outer pattern, first inner pattern, second outer pattern, second inner pattern) arranged in different directions. This segmentation allows each pattern to independently establish connections through conductive balls, improving connection reliability while distributing the structural complexity across multiple simple geometric shapes rather than one complex pad design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner patterns are positioned inside the outer patterns, creating a nested configuration where the first inner pattern is within the first outer pattern and the second inner pattern is within the second outer pattern. This nesting optimizes space utilization and allows compact arrangement of multiple connection paths within a confined area, improving space efficiency without compromising connection reliability

Inventive Principle:

Principle #7Nested doll (Nesting)

2Volume of moving object

If the fingerprint sensor package uses compact design, then the size is reduced, but the connection reliability and sensing performance may deteriorate

Engineering Contradiction:

Improvepackage sizeVSAvoidfingerprint recognition reliability

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The connection patterns are arranged in multiple directions (first direction and second direction perpendicular to each other) rather than a single linear arrangement. This multi-dimensional layout allows connections to be established in various orientations, maximizing space utilization while maintaining adequate spacing and connection quality for reliable fingerprint recognition in a compact package

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The external connection pad uses asymmetric pattern arrangements with different outer and inner patterns positioned strategically in different directions. This asymmetric design optimizes the distribution of conductive balls and connection paths within the limited space, ensuring reliable connections without requiring a larger package area, thus maintaining fingerprint recognition reliability in a compact form

Inventive Principle:

Principle #4Asymmetry

3Ease of manufacture

If the external connection pad uses a single pattern design, then the manufacturing is simple, but the space efficiency and connection reliability are insufficient

Engineering Contradiction:

Improveconnection pad manufacturing simplicityVSAvoidconnection pad area efficiency

Core Design Contradiction:

Ease of manufactureVSArea of stationary object

Solution Approach 1:

Multiple connection patterns (outer and inner patterns in different directions) are merged into a single integrated external connection pad structure. This combining of multiple functional patterns into one unified pad design achieves efficient space utilization and multiple connection paths without requiring separate manufacturing processes for each pattern, maintaining manufacturing simplicity while improving space efficiency and connection reliability

Inventive Principle:

Principle #5Merging (Combining)

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

The design achieves increased space efficiency and reliability, enabling compact fingerprint sensor packages suitable for smart cards with enhanced fingerprint recognition capabilities.

Implementation Method 1

the external connection pad is in contact with an anisotropic conductive film including a conductive ball

Methodology Applied

Scientific EffectAnisotropic conduction: Anisotropy

Implementation Method 2

the external connection pad includes an outer pattern having a bar shape in a plan view and an inner pattern inside the bar shape, and the external connection pad is in contact with an anisotropic conductive film including a conductive ball

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

Fingerprint sensors acquire users' fingerprint information using an optical method, a capacitive method, an ultrasonic method, a heat detection method, or the like

Methodology Applied

Scientific EffectCapacitance sensing: Capacitance

Data Source

PatentUS12517609B2Fingerprint sensor package and smart card including the same

Publication Date: 2026.01.06 SAMSUNG ELECTRONICS CO LTD

AI summary

Provided is a fingerprint sensor package including an anisotropic conductive film including a conductive ball.