Sensor Package Shielding Structure for Miniaturized Crosstalk Control
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Solution Overview
Problem
Conventional packaging methods for proximity and ambient light sensors face challenges in miniaturization due to mold manufacturing difficulties for miniaturized shielding elements, misplacement issues, and space occupation for wire bonding, leading to crosstalk and inefficient use of circuit space.
Innovation Solution
A packaging structure and method involving a first opaque material on the light sensing chip, sealed in a transparent molding material, with a second opaque material forming a shielding element through a shaping space, avoiding direct light interference and reducing space occupation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metal cover or plastic cover is used as the shielding element, then crosstalk is prevented, but manufacturing difficulty increases significantly when miniaturizing
Solution Approach 1:
The shielding element is divided into two distinct parts: a first opaque material directly on the light sensing chip and a second opaque material filled into a shaping space within the transparent molding material. This segmentation allows each part to be manufactured and positioned independently, avoiding the need for a single complex miniaturized mold while maintaining effective light shielding.
Solution Approach 2:
The shielding approach transitions from a conventional three-dimensional miniaturized cover to a two-dimensional planar configuration where the first opaque material is deposited on the chip surface and the second opaque material fills a space within the molding material. This dimensional change simplifies manufacturing while maintaining shielding effectiveness.
2Object-affected harmful factors
If the transparent molding material is cut to form grooves for the shielding element, then light interference is blocked, but wire bonding space is occupied
Solution Approach 1:
The first opaque material is applied to the light sensing chip before the transparent molding material is cured. This preliminary action allows the shielding function to be established without requiring post-molding cutting operations that would occupy wire bonding space, thus preserving the full circuit area for electrical connections.
3Volume of moving object
If the shielding element is miniaturized, then device size is reduced, but the shielding element becomes hard to fix and easily misplaced
Solution Approach 1:
The first opaque material and the second opaque material are merged to form an integrated shielding element. The first opaque material is directly applied to the chip surface where it is inherently fixed, and the second opaque material fills a shaping space within the molding material that connects to the first opaque material. This merging ensures the shielding element remains securely positioned without requiring separate fixation mechanisms, even in miniaturized configurations.
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 solution effectively reduces crosstalk and enables miniaturization by maintaining circuit space and allowing for closer proximity of components without structural damage, enhancing operational flexibility and practicality.
Implementation Method 1
a first opaque material set on the light sensing chip... a second opaque material set within the transparent molding material and connected to the first opaque material... to form a shielding element
Data Source
AI summary
A complex sensing device packaging structure and packaging method are disclosed. The packaging structure includes a substrate disposed with a light emitting element and a light sensing chip. A first non-transparent material is disposed on the light sensing chip. A transparent molding material surrounds the light emitting element, the light sensing chip and the first non-transparent material. A second non-transparent material is disposed inside the transparent molding material, and the second non-transparent material is connected with the first non-transparent material.