Senior Photonic Packaging Engineer for 2.5D/3D Interposers

CScale; Palo Alto (CA); Hybrid; USD 180,000 - 250,000; Full time

Job summary

CScale is building the interconnect for gigawatt-scale AI, focusing on integrated optical interconnect and high-speed packaging. The role centers on driving 2.5D/3D packaging development from concept to production and coordinating with OSATs and foundries to ensure reliability and manufacturability.

Ideal candidates will have hands-on experience with high-speed interposer-based packaging, cross-functional communication, and program management to meet tight schedules and complex integration

Qualifications

• Bachelor's degree in EE, Materials, or Optics
• Experience driving 2.5D/3D high-speed packaging end to end
• Strong cross-functional collaboration with design, OSATs, and vendors

Responsibilities

• Drive CScale’s package from initial concept to production
• Help establish photonic and electronic co-design process flow
• Work with OSATs to define packaging design rules and process flows
• Lead optical package development for manufacturability and reliability
• Collaborate with cross-functional teams to push the package/integration forward
• Coordinate with external foundries and OSATs on process integration

Job description

CScale is building the interconnect for gigawatt-scale AI. As AI scale-up moves toward deployments spanning thousands of accelerators and dozens of racks, the network needs to deliver high bandwidth, predictable low latency, and continuous communication. CScale is building integrated optical interconnect designed for this new scale, enabling accelerators to work together like a single, much larger computer. But at this scale, performance is only part of the challenge. Optical failures are inevitable, and the system needs to keep running. CScale is designing the interconnect for continuity.Lasers will fail. Compute shouldn’t.The ambition is simple:Build AI interconnect you can take for granted.CScale came out of stealth in September 2026 with $145 million in Series C funding, bringing total funding to $188 million.

Duties, Deliverables, and Responsibilities
● Drive CScale’s package from initial concept to production
● Help establish photonic and electronic co-design process flow
● Work with OSATs to define integration packaging design rules, process flow, and materials
● Lead optical package development to establish package manufacturability and reliability
● Collaborate with cross-functional teams including silicon photonics, IC design, layout, test and reliability to drive the package/integration forward
● Work with external foundries and OSATs on process integration and packaging for interposer

Expertise, Knowledge, and Skills
● Understanding of 2.5D and 3D packaging technologies, i.e. interposers, heterogeneous integration, high-density interconnects
● Ability to select and manage external foundries/OSATs for interposer-based packaging (must understand material selection, state of the art techniques, and advanced process flows required for advanced packaging)
● Must have strong program/project management skills (i.e. set schedule, maintain it, ensure parts arrive on time in the right place, etc.)
● Clear communication, ability to work cross-functionally and interface with design, SI/PI, testing, vendors, OSATs, etc
● Bonus: Familiarity with layout design for high-speed applications, simulation, mechanical and thermal analysis

Experience, Background, and Accomplishments
● Driven multiple 2.5D/3D high-speed packages end to end, working with all roles on the packaging team (design, layout, SI/PI, test and reliability, etc.)
● Experience driving packages with unconventional needs / uncommon processes
● Experience working with large, established OSATs and foundries on custom processes and flows
● B.Sc.+ in EE or Materials or Optics

Compensation includes a base salary of $150,000–$250,000 and equity in CScale. Final offers depend on experience, market conditions and location.