Optical Device Opaque Dam Encapsulation
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Solution Overview
Problem
There is a need for efficient and accurate optical devices and methods of manufacturing them, particularly in packaging for optical devices that include optical radiation emitters and sensors, which are used in various applications such as distance measurement, proximity sensing, and imaging, where existing technologies may not provide optimal performance or manufacturing efficiency.
Innovation Solution
The optical device includes a substrate with an optical emitter chip and an optical sensor chip, separated by an opaque dam, with transparent and opaque encapsulation blocks that provide optical isolation and spectral modification, using different viscosities of epoxy materials for encapsulation and coating to prevent light interference and enhance adhesion, and trench formation for precise encapsulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If optical emitter and sensor are placed close together for compact design, then device size is reduced, but light interference between emitter and sensor increases
Solution Approach 1:
The device is segmented into distinct functional regions: an emitter region containing the optical emitter, a sensor region containing the optical sensor, and an opaque region separating them. This spatial segmentation prevents light interference while maintaining compact overall device size by clearly defining boundaries between functional zones.
Solution Approach 2:
An opaque dam or opaque structure is introduced as an intermediary element between the optical emitter and optical sensor. This intermediary blocks stray light from reaching the sensor while allowing both components to remain in close proximity, thus preventing light interference without increasing device size.
2Device complexity
If multiple sensors are integrated on the same chip for compact design, then device complexity is reduced, but optical isolation between sensors becomes difficult
Solution Approach 1:
The sensor chip is divided into multiple isolated sensor regions, each surrounded by opaque dams or opaque structures. This segmentation allows multiple sensors to coexist on the same chip while maintaining optical isolation between them, preventing cross-talk and interference.
Solution Approach 2:
Different regions of the sensor chip are assigned different optical characteristics through the use of opaque dams and selective transparent encapsulation. Each sensor region has localized optical properties that ensure it only receives light from its corresponding emitter, achieving optical isolation while maintaining integration.
3Illumination intensity
If transparent encapsulation material is used for optical clarity, then light transmission is improved, but optical isolation between regions is compromised
Solution Approach 1:
The encapsulation structure uses different material properties in different regions: transparent encapsulation material is used where light transmission is needed (over sensors and emitters), while opaque encapsulation material or opaque dams are used in regions where light blocking is required (between emitter and sensor regions). This local differentiation of optical properties achieves both light transmission and optical isolation.
Solution Approach 2:
The encapsulation system combines transparent and opaque materials in a composite structure. The transparent portions allow necessary light transmission to sensors, while the opaque portions prevent light interference between regions, achieving both functions through material composition.
4Object-affected harmful factors
If opaque dam is made thick for complete light blocking, then optical isolation is improved, but manufacturing precision requirements increase
Solution Approach 1:
Instead of relying solely on increasing dam thickness in one dimension, the solution uses the planar dimension to extend opaque dams beyond the active optical regions. This dimensional approach allows thinner dams to achieve complete light blocking by covering larger areas, reducing manufacturing precision requirements for thickness control.
Solution Approach 2:
The opaque dam structure is designed with extended coverage areas that preliminary block light paths before they can reach unintended sensors. This preliminary blocking action reduces the required thickness of the dam material, as the extended planar coverage compensates for reduced thickness, lowering manufacturing precision requirements.
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 enhances optical isolation and performance by preventing light interference, improving adhesion, and facilitating precise construction, leading to efficient and accurate optical device manufacturing with improved spectral control and isolation between emitter and sensor components.
Implementation Method 1
an opaque dam disposed on the front surface of the optical sensor chip and at least a portion of the front face of the substrate... the opaque encapsulation material extends between the first transparent encapsulation block and the second transparent encapsulation block and abuts the opaque dam
Implementation Method 2
a first transparent encapsulation block encapsulating the optical emitter chip and the reference optical sensor... a second transparent encapsulation block encapsulating the main optical sensor
Implementation Method 3
using different viscosities of epoxy materials for encapsulation and coating to prevent light interference and enhance adhesion
Data Source
AI summary
Disclosed are optical devices and methods of manufacturing optical devices. An optical device can include a substrate; an optical emitter chip affixed to the front surface of the substrate; and an optical sensor chip affixed to the front surface of the substrate. The optical sensor chip can include a main sensor and a reference sensor. The optical device can include an opaque dam separating the main optical sensor and the reference sensor. The optical device can include a first transparent encapsulation block encapsulating the optical emitter chip and the reference optical sensor and a second transparent encapsulation block encapsulating the main optical sensor. The optical device can include an opaque encapsulation material encapsulating the first transparent encapsulation block and the second transparent encapsulation block with a first opening above the main optical sensor and a second opening above the optical emitter chip.