Semiconductor Package Light Shielding for Cross-Talk Reduction
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Solution Overview
Problem
In semiconductor package devices, cross-talk interference occurs due to direct light transmission from light-emitting components to light detectors, leading to potential malfunctions in sensors, particularly in optical modules like proximity sensors.
Innovation Solution
Incorporating a separation wall and light shielding layers within the semiconductor package device to prevent direct light transmission between the emitter and detector, utilizing a metal bar under the wall structure to enhance light blocking and a light shielding layer that extends from the separation wall to the detector area, and using light-absorbing materials in the solder mask to further reduce unwanted light transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the emitter and detector are disposed close to each other on the carrier, then the device size is reduced, but cross-talk interference increases due to direct light transmission
Solution Approach 1:
The patent divides the space between emitter and detector by introducing a separation wall that extends from the top surface downward, and light shielding layers that extend horizontally between the emitter and detector regions. This segmentation creates distinct optical zones that prevent direct light transmission while maintaining compact device dimensions.
Solution Approach 2:
The patent applies light-absorbing materials specifically in the solder mask layer and introduces light shielding structures at critical positions between the emitter and detector. This localized application of light-blocking properties prevents cross-talk interference only where needed, without affecting other device functions or requiring complete redesign of the entire structure.
2Object-affected harmful factors
If light shielding structures are added to block cross-talk, then cross-talk interference is reduced, but device complexity increases
Solution Approach 1:
The patent integrates light shielding functionality into existing device components rather than adding completely separate shielding structures. The solder mask layer is formulated with light-absorbing materials to provide shielding, and the separation wall is incorporated into the carrier structure itself. This merging approach reduces the number of discrete components and simplifies manufacturing.
Solution Approach 2:
The separation wall serves multiple functions: it provides mechanical support, creates physical separation between emitter and detector, and acts as a light-blocking barrier. Similarly, the solder mask layer simultaneously provides electrical connection, mechanical support, and light shielding. This multi-functionality reduces the need for additional dedicated shielding components.
3Object-affected harmful factors
If light-absorbing materials are added to the solder mask, then cross-talk interference is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent incorporates light-absorbing materials directly into the solder mask compound, creating a composite material that simultaneously provides the solder mask's traditional functions (electrical connection, mechanical support) and additional light-absorbing properties. This integration eliminates the need for separate light-absorbing layers and simplifies the manufacturing process by using a single material deposition step.
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
Effectively reduces cross-talk interference by blocking undesired light, enhancing the performance and reliability of optical devices by preventing light from the emitter from reaching the detector, thereby improving the accuracy of proximity sensors and other optical modules.
Implementation Method 1
The light shielding layer is disposed adjacent to the top surface of the carrier and extends from the separation wall to the second portion of the carrier
Data Source
AI summary
An electronic device comprises a carrier, an emitter, a detector, a separation wall and a light shielding layer. The emitter is disposed on a first portion of the top surface of the carrier. The detector is disposed on a second portion of the top surface of the carrier. The separation wall is disposed on the top surface of the carrier between the emitter and the detector. The light shielding layer disposed adjacent to the top surface of the carrier and extends from the separation wall to the second portion of the carrier.