In the post Moore era of explosive growth in computing power demand, high-speed data transmission has become a key bottleneck restricting system performance. The traditional electrical interconnection technology of copper interconnection is facing physical limitations, while photon integration technology, with its absolute advantages of high bandwidth, low latency, and anti-interference, has become the core path to solve this problem. However, how to efficiently and reliably connect micro scale photonic chips with the external world has always been a huge challenge faced by the industry. The photon wire bonding printing system, as an optical interconnect packaging technology, is opening up new possibilities for high-speed optical communication, artificial intelligence computing, sensing and other fields with its flexibility, high precision and automation potential.

1、 Technical bottleneck: the "last mile" problem of traditional optical interconnection

The biggest cost and technical challenge in the packaging of photonic integrated chips (PIC) comes from the docking of optical fibers with nano optical waveguides on the chip. Traditional methods face enormous difficulties:

1. Alignment accuracy requirements: The mode field diameter of single-mode fiber is only about 10 microns, and the alignment tolerance with chip waveguide needs to be sub micron level, making assembly extremely difficult.

2. Complex process and high cost: relying on precision mechanical adjustment, active alignment and bonding, time-consuming and laborious, difficult to scale, packaging cost can account for more than 80% of the total device cost.

3. Poor flexibility: Once solidified, the connection path is fixed and cannot adapt to the interconnection of ports at different positions and heights on the chip, resulting in low design freedom.

2、 Core principle: Printing free-form optical waveguides with light

The core idea of the photon wire bonding printing system is amazing: it is like a 3D printer, directly "printing" any shape of optical waveguide connecting two optical ports in three-dimensional space with "ink".

Its workflow is a precision dance that integrates multiple technologies:

1. Precise positioning: The high-resolution vision system first images and precisely locates the optical waveguide end face and target fiber end face on the chip, establishing a three-dimensional coordinate model.

2. Femtosecond laser direct writing: The system controls a beam of ultrafast femtosecond laser focus, accurately focusing inside a special photosensitive polymer ("ink"). The material undergoes two-photon absorption at the laser focal point, resulting in local polymerization and solidification, while the area outside the focal point remains liquid.

3. Three dimensional "painting": According to the preset program path, the laser focus moves in three-dimensional space and scans any curved trajectory connecting the two ends. The material passing through is solidified, forming a solid, low loss optical waveguide buried in the liquid polymer.

4. Post processing and protection: After printing is completed, wash away the uncured liquid resin, leaving behind the structurally intact photon leads. It is usually covered with a protective layer to form a stable embedded optical interconnect structure.

3、 Composition and technical advantages of photon wire bonding printing system

A complete PWB system is the culmination of multiple cutting-edge technologies:

-Ultrafast laser system: Provides high peak power femtosecond laser required to initiate two-photon polymerization.

-High precision 3D motion platform: achieving nanometer level resolution laser focus positioning and scanning.

-Multi perspective visual positioning system: used for initial high-precision alignment and process monitoring.

-Material System: Low loss, high transparency photoresist developed specifically for optical interconnects.

-Intelligent control software: a core brain that integrates visual recognition, path planning, and process control.

The revolutionary advantages it brings include:

1. Design freedom: It can print any 3D curve and easily achieve low loss interconnection between ports in different planes and angles, overcoming the limitations of traditional planar optical path design.

2. Alignment tolerance: The printed waveguide can be made wider at both ends than the chip waveguide, like a "funnel", effectively reducing the precision requirements for docking, from sub micron to several microns.

3. Automation and Scalability: The entire process is controlled by computer programs and is highly likely to develop into high-speed, fully automated packaging solutions, significantly reducing packaging costs and cycles.

4. Excellent performance: The printed waveguide loss can be as low as 0.05 dB/mm or less, and the performance is close to that of traditional prepared optical waveguides.

4、 Application prospects: ushering in a new era of photon integration

1. High speed optical communication: Provide efficient and low-cost chip level optical interconnect solutions for advanced packaging forms such as CPO/OBO (co packaged/onboard optical) within data centers.

2. Artificial intelligence and high-performance computing: In complex multi chip systems such as AI accelerators and optical computing chips, high-density and low latency inter chip optical interconnection can be achieved.

3. Quantum information processing: Used to connect different functional units on quantum chips, its requirements for low loss and flexible wiring are highly compatible with PWB technology.

4. Advanced sensing and medical equipment: In integrated photon sensors, flexible connections between light sources, detectors, and sensing units are made to create more compact and high-performance sensing modules.

The photon wire bonding printing system is more like a "micro sculptor" creating at the micrometer scale. It uses a beam of light as a cutting edge and intelligence as a blueprint to freely weave the path of light in three-dimensional space. This technology not only solves the core pain point of photonic integrated packaging, but also opens up unlimited imagination space for the design and innovation of photonic devices. It is quietly driving a packaging revolution from "electrical interconnection" to "optical interconnection", laying a "highway of light" leading to the future for the construction of next-generation computing infrastructure.