Semiconductor Package Glass Substrate Metallic Seal High Temperature
Solution Overview
Problem
Conventional optical detector packages face limitations due to temperature constraints of over molding compounds and adhesives, which can lead to bond wire failure and increased diffraction, making them unsuitable for high-temperature applications and precision measurements.
Innovation Solution
The use of a glass substrate with metal plating and a metallic seal structure replaces bond wires and low-temperature adhesives, allowing for higher temperature resistance and a thinner profile, reducing diffraction by eliminating polymeric materials and creating a hermetic seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an over molding compound is used to cover the integrated circuit, then the package is inexpensive and easy to manufacture, but the package has a temperature limitation of about 105°C and may shear bond wires at high temperatures
Solution Approach 1:
The patent changes the material parameter from polymeric overmold compound to glass, which fundamentally alters the temperature resistance parameter. Glass can withstand temperatures up to 400°C or higher, compared to the 105°C limit of conventional molding compounds, while maintaining manufacturability through established glass sealing and bonding processes
Solution Approach 2:
The patent employs composite material structures including glass substrates with metal seal rings, metallic bonding materials, and hermetic seal structures. These composite materials provide both high temperature resistance and structural integrity, resolving the contradiction between ease of manufacture and temperature resistance
2Temperature
If a glass lid is placed over the integrated circuit with headroom to clear bond wires, then the package can withstand higher temperatures, but the space between the integrated circuit and glass lid causes noticeable diffraction
Solution Approach 1:
The patent extracts and eliminates the bond wires from the package structure by implementing direct bonding between the integrated circuit and glass substrate. This removal of bond wires eliminates the source of diffraction while maintaining the temperature resistance benefits of the glass construction
Solution Approach 2:
The patent transitions from a three-dimensional structure with bond wires extending vertically to a planar direct-bond structure. This dimensional change eliminates the vertical space requirement and associated diffraction issues while maintaining thermal performance
3Device complexity
If a conventional adhesive is used to bond the glass lid to the PCB, then the assembly is simple, but the adhesive has a temperature limitation of about 125°C and suffers loss of integrity at higher temperatures
Solution Approach 1:
The patent replaces the chemical bonding mechanism of conventional adhesives with metallic diffusion bonding and hermetic sealing mechanisms. This substitution eliminates the 125°C adhesive limitation while maintaining assembly simplicity through established metal-to-glass bonding processes
Solution Approach 2:
The patent changes the bonding material parameter from organic adhesive to inorganic metallic bonding materials, which fundamentally alters the temperature resistance parameter from 125°C to above 400°C, while maintaining bonding functionality
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
This solution enables chip packages to withstand higher temperatures (up to 400°C) while maintaining structural integrity and reducing diffraction, enhancing precision and reliability in various applications.
Implementation Method 1
a metallic seal structure bonding a side of the glass substrate having the conductive traces with the side of the semiconductor device facing the glass substrate
Implementation Method 2
a glass substrate configured to pass light from an outside environment to a surface of the semiconductor device
Implementation Method 3
a semiconductor device having an optical detector exposed on a side facing the glass substrate
Data Source
AI summary
An optical detector device including: a glass substrate having conductive traces plated thereon; a semiconductor device having an optical detector exposed on a side facing the glass substrate, the semiconductor device further including a plurality of bond pads electrically coupled to a first subset of the conductive traces; a metallic seal structure bonding a side of the glass substrate having the conductive traces with the side of the semiconductor device facing the glass substrate; and a plurality of conductive structures outside of a perimeter of the semiconductor device, the plurality of conductive structures being electrically coupled to a second subset of the conductive traces.