Optical Package Through-Mold Light Path for Thinner CIS Modules
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Solution Overview
Problem
Existing optical device packages face limitations in reducing thickness due to the use of opaque printed circuit boards (PCBs) as substrates, which hinder light transmission and complicate packaging processes, especially for complementary metal-oxide semiconductor (CMOS) image sensors (CIS), leading to increased size and complexity.
Innovation Solution
A method involving molding a chip with a light-transmissive encapsulating material, forming a redistribution layer with conductive patterns that bypass optical paths, and disposing optical devices for light input/output through these paths, using techniques like laser boring and etching to create optical paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a printed circuit board (PCB) is used as a substrate of an optical device package, then electrical connection and structural support are provided, but the thickness cannot be reduced due to the opaque nature of PCBs
Solution Approach 1:
The patent extracts the optical path requirement from the traditional PCB substrate by using a through-hole structure that removes material along the light path, creating a clear optical channel through the package while maintaining the substrate's electrical and mechanical functions
Solution Approach 2:
The patent changes the physical state of the substrate by creating through-holes that pass completely through the package thickness, transforming the substrate from an opaque blocking structure to a structure with optical transmission capability while maintaining structural integrity
2Reliability
If glass packaging is performed separately on the CIS chip before attaching to PCB, then the micro lens is protected, but the package size increases and process steps become complicated
Solution Approach 1:
The patent merges the glass packaging process with the PCB mounting process by forming the through-hole optical path in the same substrate that will hold the CIS chip, allowing both protection and electrical connection to be achieved in a single integrated structure rather than separate sequential steps
Solution Approach 2:
The substrate is designed to serve multiple functions simultaneously: providing electrical connection through conductive patterns, structural support through the rigid board, and optical transmission through the through-hole path, eliminating the need for separate specialized components for each function
3Reliability
If conductive patterns are formed on the substrate, then electrical connection is established, but light transmission is blocked along the optical path
Solution Approach 1:
The substrate is segmented into distinct functional zones: conductive patterns are confined to specific areas for electrical connection, while through-holes create clear segments for light transmission, allowing both functions to coexist without interference by spatially separating their paths
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 results in a thinner optical device package with improved performance by allowing closer component placement and efficient light transmission, reducing complexity and size.
Implementation Method 1
a light-transmissive encapsulating material
Implementation Method 2
forming an optical path passing through the encapsulating material, and the forming of the optical path may be performed by removing the encapsulating material by any one method of laser boring, drilling, and etching
Data Source
AI summary
There is provided a semiconductor package. The semiconductor package includes: a semiconductor chip; a mold configured to encapsulate the chip; a redistribution layer; and an optical device electrically connected to the chip through the redistribution layer. The mold is formed with an optical path passing through the mold, and light is input to or output from the optical device through the optical path.