Technologies
Die Bonding for Photonic Devices: Precision Semiconductor Attachment for High Performance Optoelectronics
Die bonding is a foundational process in the assembly of semiconductor photonic devices. Whether the application is a laser emitter, LED, photodetector, or integrated optical sensor, the quality and precision of die attach directly impact thermal management, optical alignment, and long-term reliability. At Bay Photonics, we specialize in die bonding services tailored for photonics, with a strong emphasis on flexibility, speed, and consistency—from prototyping to scalable production.
Engineered for Photonics
Photonic devices present unique die bonding challenges. They require high-precision placement accuracy, low-stress attachment, and excellent thermal conductivity. Our die bonding capabilities are built to meet these needs across a wide range of applications, including quantum photonic components and cryogenic-compatible packaging, AI-enabled optical sensors and vision system, automotive and industrial LIDAR engines, environmental, biomedical, and industrial sensing modules.
These devices are often sensitive to thermal expansion mismatch, optical misalignment, and voiding in bond layers—all of which we address through precise process control, material selection, and dedicated tooling.
Solder, Eutectic, and Epoxy Bonding
Bay Photonics offers a full suite of die attach technologies, supporting solder attach for high thermal conductivity and mechanical strength, eutectic soldering (such as AuSn) for hermetic and high-reliability applications, epoxy bonding for flexibility in die size, layout, and thermal constraints.
We understand that different photonic applications demand different bonding strategies. For example, a high-power UV LED may require a low-void eutectic bond to a heatsink for thermal performance, while a delicate InGaAs detector array might benefit from a compliant epoxy attach to reduce mechanical stress.
Our vacuum furnace capabilities ensure void-free soldering with optimal wetting and thermal uniformity—essential for high-reliability or hermetically sealed packages. All materials and processes are selected and controlled to meet the specific needs of photonics, from cryogenic compatibility in quantum devices to outgassing constraints in sealed environments.
Fully and Semi-Automated Capability
For volume manufacturing, we offer fully automated die bonding using high-precision placement systems with inline vision alignment, controlled dispense, and programmable force and temperature profiles. These systems are ideal for repeatable, high-throughput bonding of bare die, laser bars, photonic chips, or hybrid photonic assemblies. We also have a X-ray tomography system on-site for quality assurance (e.g. detecting voids).
To support early-stage development, Bay Photonics also provides semi-automatic die bonding optimized for short-turnaround prototype builds. This enables fast design iterations, parameter adjustments, and one-off or small batch production—especially important in R&D-heavy fields like quantum photonics and AI-integrated sensors.
Our team works closely with customers to tailor bonding parameters to each device and substrate, helping reduce development time and improve first-pass yield.
Built for Speed, Precision, and Scale
Die bonding is more than mechanical attachment—it’s the starting point for reliable, high-performance photonic systems. At Bay Photonics, we deliver bonding solutions that are both precise and scalable, ensuring that devices perform as designed, whether in a laboratory demo or a production-grade LIDAR module.
From precision alignment to thermal interface control, our die bonding services are built to accelerate innovation in photonics—delivering speed, quality, and flexibility every step of the way.
Wire Bonding for Photonic Devices: Precision Interconnects for Rapid Development
Wire bonding remains a critical interconnect technology for semiconductor photonic devices. It enables high-reliability, high-precision electrical connections between photonic chips—such as laser diodes, photodetectors, and optical sensors—and their packaging or circuit interfaces. At Bay Photonics, we provide specialized wire bonding services for emitter and detector-based devices as well as photonic integrated circuits (PICs), supporting rapid development and scalable production in applications ranging from quantum technologies to LIDAR, AI-enabled sensing, and industrial photonics.
Designed for Photonic Integration
Our wire bonding capabilities are optimized for the unique demands of photonics. Devices are often compact, thermally sensitive, and require precise optical alignment—conditions where wire bonding offers unmatched flexibility. We support a wide range of photonic device architectures including VCSELs, edge-emitters, photodiodes, and hybrid photonic integrated circuits (PICs).
Our experience spans the key sectors driving photonics innovation: Quantum communications and quantum sensors, automotive and UAV-based LIDAR systems, industrial process monitoring and metrology, smart vision and AI-integrated photonics
Gold and Aluminum Wire Bonding: 12–50 µm wire diameter
Bay Photonics offers fully automated ball bonding and wedge bonding using both gold and aluminium wire, the two dominant materials for high-performance and reliable photonic interconnects. Wire diameters from 12 µm to 50 µm are supported, covering fine-pitch signal connections as well as higher-current interconnects required in active optical components.
Ball bonding, typically with gold wire, provides robust electrical and thermal pathways for laser and detector applications, while wedge bonding with either gold or aluminium allows for low-profile connections and excellent bond placement accuracy—ideal for dense optical packages or planar lead frames.
We also offer ribbon bonding for applications requiring lower loop height, increased surface contact, or specialized RF or high-current performance. Ribbon bonding is particularly useful in power photonic devices or modules with limited vertical clearance.
Semi-Automated Prototyping for Fast Turnaround
To support fast-paced development cycles, we maintain semi-automatic wire bonding capability ideal for short-run builds, evaluation units, and early prototypes. This is especially valuable for emerging applications in quantum technology and AI-enhanced sensors, where design changes and rapid iteration are common.
Our experienced process engineers work directly with clients to fine-tune bond programs, adapt to new die or substrate designs, and ensure high yield from the very first lot.
Quality, Reliability, and Process Control
We combine automation and engineering oversight to ensure consistent, high-reliability interconnects. Our systems provide fine control of bonding parameters—force, ultrasonic energy, time, and loop profile—with built-in monitoring and in-process inspection. We offer standard bond integrity tests (pull, shear) and support qualification for high-reliability and hermetic applications.
All processes are developed with scalability in mind: prototypes built in semi-automatic mode can transition seamlessly to high-volume automated production.
Enabling Scalable Photonic Innovation
At Bay Photonics, we’re committed to helping our customers turn cutting-edge photonics into real-world products. Our wire bonding services support everything from early R&D through to production scale, combining material flexibility (gold and aluminium), dimensional precision (12–50 µm wires and ribbon), and engineering collaboration to meet the demands of next-generation photonic systems.
Whether you’re building a quantum sensor, a LIDAR engine, or a custom optical module, our wire bonding capabilities ensure speed, precision, and reliability—every step of the way.
Optical Alignment & Attach for Photonics: Precision Coupling for Next-Generation Optoelectronic Systems
Accurate optical alignment and attachment is essential to unlocking the full performance of photonic devices. Whether coupling light into or out of edge-emitting lasers, photodetectors, or photonic integrated circuits (PICs), the quality of optical alignment & attach defines key parameters such as insertion loss, signal stability, and system efficiency. At Bay Photonics, we provide precision optical alignment & attach services tailored for high-performance photonic applications—from early prototypes to production-grade subassemblies.
Sub-Micron Alignment for Advanced Photonic Devices
Our optical assembly capability is built around a fleet of sub-micron precision alignment workstations designed specifically for semiconductor photonics. These systems enable active and passive alignment of optical elements, supporting micro-optic alignment (e.g. lenses, isolators, filters), single fibre and fibre array alignment, edge-emitter and PIC alignment
Our solutions address the demands of photonic packaging across a wide application space, including, quantum photonics and cold-compatible optical packaging, AI-driven optical computing and vision systems, automotive and industrial LIDAR, environmental and biomedical sensing
These sectors depend on repeatable, high-precision optical coupling to meet power budgets, spectral alignment, and signal integrity requirements—especially where compact footprints or ruggedized packaging are required.
Fibre Attach: Edge Emitters and PICs
We specialize in fibre and fibre-array alignment and attach, accommodating a wide range of photonic device architectures:
Direct butt-coupling of single fibres or arrays to edge-emitting lasers and detectors, using index-matching adhesive for low-loss, high-stability joins
Free-space coupling from edge emitters into lensed fibres, combining precision alignment with reduced mechanical stress on facets
Grating coupler alignment for coupling into silicon photonic PICs, with sub-micron accuracy and angular control to optimize insertion efficiency
Our alignment processes combine precision motion stages with active alignment feedback (where applicable) to optimize optical throughput prior to fixative cure or bonding.
Adhesive and Fixation Expertise
We offer a range of optical attach methods—including UV-curable adhesives, index-matching epoxies, and low-outgassing options for sealed or vacuum environments. These are selected based on coupling geometry, optical power, thermal conditions, and reflow compatibility. Our process development team works closely with customers to select materials and process parameters that maintain alignment accuracy through cure and environmental stress.
Built for Rapid Development and Scaling
As with all our photonics services, we support both high-precision prototyping and scalable production. Our semi-automatic workstations enable fast turnarounds during early-stage development, particularly valuable in R&D-heavy fields such as quantum photonics and AI-integrated sensors, where rapid iteration and novel geometries are common. We offer automated and guided processes for repeatable coupling and fixative dispense, ensuring alignment integrity and high throughput while maintaining process flexibility for evolving designs.
Partnering for Photonic Innovation
At Bay Photonics, we recognize that successful optical alignment is not just about precision—it’s about repeatability, environmental stability, and time-to-product. Our alignment and attach services are designed to help customers shorten development cycles and de-risk scale-up.
Whether you’re coupling into a single-mode fibre, aligning to a grating coupler, or building a multi-channel optical engine, our optical alignment capabilities ensure your device is optimally connected—ready for real-world performance.
Hermetic Packaging: Sealing Reliability In, and the World Out
At the heart of any high-reliability photonic system lies the humble but heroic hermetic package—a miniaturized fortress, designed to protect delicate semiconductor devices from the ravages of moisture, oxygen, and mechanical stress. The story of hermetic packaging is one of precision engineering and materials science, but also of cultural continuity—an artisanal knowledge base passed through generations of engineers, from the telco boom to the quantum age.
What Is Hermetic Packaging?
Hermetic packaging refers to the method of sealing semiconductor devices—like lasers, modulators, and photodetectors—inside airtight enclosures that prevent ingress of moisture and contaminants over decades. This is essential for long-term reliability, especially in demanding environments such as telecom networks, space, defence, and now, quantum technologies, where even trace moisture or thermal drift can cause catastrophic failure or degraded performance.
There are several classic formats for these packages:
TO Cans (Transistor Outline packages): These are metal can enclosures with a glass-to-metal seal for electrical feedthroughs and an optional lens or window for optical access. Widely used for laser diodes and photodiodes, especially in telecoms.
Gold Boxes: These rectangular or custom-shaped metal enclosures (often Kovar, plated in gold) house more complex photonic assemblies. These provide better thermal and mechanical stability and can be precisely tailored to specific geometries.
These packages are not just metal boxes—they’re precision-fabricated environments. Getting the lid on is where the true alchemy happens.
Sealing the Deal: Resistive Welding and Projection Welding
To make a package hermetic, the lid must be sealed with the body in a way that ensures molecular-tight closure. Bay Photonics uses two main techniques for this:
Resistive Welding (Seam Sealing): In this process, a lid is pressed onto the package flange and a controlled electrical current is passed through electrodes to generate heat via electrical resistance. The materials fuse in a continuous seam—a delicate balance of pressure, heat, and time that ensures a strong, reliable weld without damaging the sensitive components inside.
Projection Welding: This involves tiny raised points (or “projections”) on one of the surfaces being welded. When current is applied, these projections heat and collapse, forming multiple localized welds at once. It’s a precise and repeatable method, ideal for small packages and tight thermal budgets.
Both methods require fixtures and tooling as unique as the devices they seal, and they’re operated by engineers with years of hands-on experience—a skillset that Bay Photonics has meticulously preserved and passed on since its founding.
TO Cans for Photonic Devices: A Proven Platform for Hermeticity and Thermal Control
Transistor Outline (TO) packages—commonly known as TO cans—have long served as a trusted packaging solution in the semiconductor industry. Originally developed in the 1950s for transistors and simple integrated circuits, TO cans have evolved into a versatile and reliable platform for photonic devices, particularly emitters (lasers, LEDs) and detectors (photodiodes, avalanche photodiodes). At Bay Photonics, TO-packaging capability supports the rigorous demands of optical communication, sensing, and quantum technologies through precision assembly and thermal management expertise.
Proven Heritage in Photonics
TO cans offer a compact, cylindrically symmetric package design that is ideal for aligning optical components. Their radial layout simplifies coupling to optical fibers or free-space optics, making them a natural choice for devices such as laser diodes, VCSELs, PIN and APD photodiodes, and integrated photonic subassemblies. The package body—typically fabricated from Kovar or other matched expansion alloys—is sealed with a glass-to-metal or ceramic-to-metal feedthrough, ensuring both mechanical robustness and electrical isolation.
Over the years, TO cans have remained a mainstay in datacom and telecom transceivers, LIDAR modules, medical diagnostics, and industrial sensing, where reliability, thermal control, and compact form factors are paramount.
Hermetic Sealing for Long-Term Reliability
One of the primary advantages of TO cans is their ability to achieve true hermeticity. Unlike molded plastic packages, hermetically sealed TO cans protect sensitive photonic devices from moisture ingress, outgassing, and particulate contamination over extended service lifetimes. This makes them indispensable for high-reliability applications such as aerospace, automotive lidar, and quantum photonics, where long-term optical and electrical stability is critical.
With hermetic sealing via our projection welding workstation, plus gross and fine-leak testing to MIL-STD-883 or equivalent industry standards, we provide rapid manufacturing design cycles. We offer custom lid options including flat & angled windows, UV, visible and IR wavelengths enabling efficient optical access while maintaining environmental integrity.
Integrated Thermal Control: TECs and Thermistors
Temperature plays a critical role in the performance of photonic devices. Laser diodes, for instance, are highly sensitive to temperature variations, which can shift emission wavelengths and reduce efficiency or lifespan and Single Photon Avalanche Photodiodes (SPADs) and infra-red detectors require cooling to provide low noise operation To address this, our TO packages integrate active thermal management elements: a thermoelectric cooler (TEC) and a thermistor.
The TEC enables precise thermal regulation, pumping heat away from the die and dissipating it through an external heatsink. The thermistor provides real-time temperature feedback to a control loop, ensuring stable operation across a wide range of ambient conditions. These elements are mounted directly onto the package header and bonded to the die, allowing for tight thermal coupling and fast response.
Our assembly capabilities include automated die placement, resistive welding, and thermal interface optimization to achieve high cooling efficiency and long-term stability.
Customization and Integration
At Bay Photonics, we work closely with customers to tailor TO-based solutions for specialized applications. Whether it’s miniature (e.g.TO59, TO46) precisely temperature controlled VCSELs for quantum photonics, or larger (e.g. TO8) devices with multi-stack TECs for low temperature operation, or meeting stringent aerospace-grade reliability standards, our vertically integrated services—from design for assembly to final test—help accelerate product development while reducing risk.
As photonics continues to reshape communications, sensing, and computing, TO cans remain a foundational building block—offering a blend of legacy reliability and modern performance.
