VCSEL Laser Emission Module With Integrated Drive Chips
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Solution Overview
Problem
The assembly size of laser emission circuits in laser rangefinders is large due to the use of discrete electronic components, hindering miniaturization, and traditional VCSEL packaging methods face challenges in achieving dense spacing and efficient manufacturing.
Innovation Solution
A laser emission module with integrated anode and cathode drive chips on a substrate, using a laser array with common anode and cathode connections, and packaged using Ball Grid Array, Land Grid Array, or Quad Flat No-leads technologies, along with an airtight structure for VCSELs and drive modules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If discrete electronic components are used for the emission drive circuit, then the circuit can be assembled on a circuit board, but the assembly size becomes large, hindering miniaturization
Solution Approach 1:
The patent merges the emission drive circuit and VCSEL array into a single integrated chip structure. The drive circuit is directly formed on the same substrate as the VCSEL array, eliminating the need for separate discrete components and circuit boards. This integration dramatically reduces the overall assembly size while maintaining manufacturing feasibility through standardized chip fabrication processes.
Solution Approach 2:
The patent transitions from a two-dimensional circuit board layout to a three-dimensional integrated chip structure. By stacking the drive circuit and VCSEL array in vertical layers on the same substrate, the design utilizes the third dimension to achieve high-density integration, reducing the footprint area while preserving all necessary electrical connections and functionality.
2Ease of manufacture
If traditional COB packaging process is used for VCSEL, then the VCSEL can be assembled on PCB, but dense spacing of about 50um is difficult to achieve and excessive wire bonding reduces manufacturing efficiency
Solution Approach 1:
The patent extracts the wire bonding step from the traditional COB packaging process. Instead of using wire bonds to connect bonding pads, the design employs direct metal traces formed on the substrate during semiconductor fabrication. This eliminates the need for precise wire bonding and allows for much smaller spacing between connection points, achieving the desired 50um dense spacing.
Solution Approach 2:
The patent uses photolithography and other semiconductor fabrication techniques to create precise metal interconnect patterns that copy the required electrical connection layout directly onto the substrate. This copying process achieves sub-50um precision consistently, far exceeding what is achievable with manual or automated wire bonding methods.
3Ease of manufacture
If traditional COB packaging with wire bonding is used, then VCSEL can be connected to PCB, but excessive wire bonding reduces overall manufacturing efficiency
Solution Approach 1:
The patent replaces the mechanical wire bonding process with a photolithography-based metal trace formation process. The electrical connections are created by depositing and patterning metal layers during standard semiconductor manufacturing, eliminating the need for mechanical wire bonding operations. This substitution dramatically increases manufacturing throughput and efficiency.
Solution Approach 2:
The patent changes the manufacturing parameters from those suitable for wire bonding (larger pitch, manual/automated bonding head positioning) to those suitable for photolithography (sub-50um feature sizes, batch processing). This parameter change enables much higher density connections to be formed simultaneously across entire chip surfaces, vastly improving manufacturing efficiency.
4Reliability
If VCSEL is scrapped in traditional packaging, then the entire product's PCB must be scrapped, but integrated chip design can reduce waste
Solution Approach 1:
The patent segments the laser emission system into a separate integrated VCSEL chip that can be independently manufactured and tested. If a defect is found, only the small VCSEL chip needs to be replaced rather than scrapping an entire large PCB assembly. This segmentation isolates the failure risk to a minimal component, reducing material waste and improving yield.
Solution Approach 2:
The patent performs preliminary testing and characterization of the VCSEL array on the integrated chip before final product assembly. Any defective chips are identified and rejected at this early stage, preventing defective units from reaching final assembly. This preliminary action ensures that only good chips are installed, reducing the need for field replacements and associated waste.
Data Source
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AI summary
Embodiment of this application discloses a laser emission module and a laser ranging device. The laser emission module includes an emission substrate, a light emitting chip, at least one anode drive chip, and at least one cathode drive chip. The light emitting chip is assembled on a first surface of the emission substrate, internally integrated with a laser array, which includes m*n lasers. In the laser array, the anodes of the lasers located in the same row are electrically connected and lead out a common anode end, and the cathodes of the lasers located in the same column are electrically connected and lead out a common cathode end. The anode drive chip is assembled on the emission substrate, internally integrated with m anode drive circuits; the m anode drive circuits are respectively electrically connected with m common anode ends. The cathode drive chip is assembled on the emission substrate, internally integrated with n cathode drive circuits; the n cathode drive circuits are electrically connected with n common cathode ends respectively. Embodiment of this application can reduce the size of the laser emission module.