VCSEL Chip Package Sidewall Light Shielding
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Solution Overview
Problem
Traditional vertical-cavity surface-emitting laser (VCSEL) devices face challenges in integrating light emitters and receivers within a single package, leading to increased device volume and potential light interference due to metal caps and adhesives.
Innovation Solution
A chip package design featuring a sidewall structure with light-shielding layers and a cover, where the light emitter and receiver are positioned in aperture areas, with the first light-shielding layer ensuring vertical light emission and blocking non-vertical light, and the second light-shielding layer replacing adhesive for bonding and preventing lateral light interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a metal cap is used for light shielding in traditional VCSEL packages, then light emission directionality is improved, but device volume cannot be reduced and light interference may occur
Solution Approach 1:
The patent divides the light-shielding function into multiple segments: the sidewall structure with first light-shielding layer provides lateral shielding, the second light-shielding layer provides bonding and additional shielding, and the cover provides top shielding. This segmentation allows each component to be optimized for its specific function while reducing overall device volume compared to a traditional metal cap.
Solution Approach 2:
The patent implements a nested structure where the second light-shielding layer is positioned between the chip and the sidewall structure, creating a multi-layer nested arrangement. The cover is then positioned on the sidewall structure, forming another nested layer. This nested configuration maximizes space utilization and reduces device volume while maintaining effective light shielding.
2Strength
If adhesive is used to bond metal cap to device, then bonding is achieved, but laser may pass through adhesive and irradiate outward in unexpected direction
Solution Approach 1:
The second light-shielding layer serves as an intermediary between the chip and the sidewall structure, replacing the traditional adhesive. This intermediary layer provides both bonding functionality and light-shielding functionality, eliminating the risk of laser passing through adhesive while maintaining strong bonding between components.
3Volume of stationary object
If light emitter and light receiver are integrated in single package, then device volume is reduced, but light interference between emitter and receiver may occur
Solution Approach 1:
The patent applies local quality by providing light-shielding layers at specific locations: the first light-shielding layer on the sidewall structure blocks lateral light, the second light-shielding layer between the chip and sidewall structure blocks light from below, and the cover blocks light from above. This localized shielding approach effectively prevents light interference between the emitter and receiver while allowing them to be integrated in a single compact package.
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 ensures vertical light emission, blocks external interference, reduces device volume by integrating components, and protects the light receiver from infrared, while maintaining effective bonding without traditional adhesives.
Implementation Method 1
at least one surface of the sidewall structure has the first light-shielding layer... a tangled external light (i.e., a non-vertical light) can also be blocked by the first light-shielding layer of the sidewall structure
Implementation Method 2
The second light-shielding layer is located between the chip and the sidewall structure... The second light-shielding layer not only can bond the chip to the sidewall structure
Implementation Method 3
the cover that covers the light receiver may ensure that the light receiver does not receive an infrared entering from a direction of a target object
Data Source
AI summary
A chip package includes a chip, a sidewall structure that has a first light-shielding layer, a second light-shielding layer, and a cover. The chip has a light emitter and a light receiver that are located on a top surface of the chip. The sidewall structure is located on the top surface of the chip and has two aperture areas. The light emitter and the light receiver are respectively located in the two aperture areas. The sidewall structure surrounds the light emitter and the light receiver, and at least one surface of the sidewall structure has the first light-shielding layer. The second light-shielding layer is located between the chip and the sidewall structure. The cover is located on a surface of the sidewall structure facing away from the chip, and at least covers the light receiver and the sidewall structure that surrounds the light receiver.