Senior Package Engineer

Job DescriptionJob Description

Who we are:

Persimmons is building the infrastructure that will power the next decade of AI. Founded in 2023 by veteran technologists from the worlds of semiconductors, AI systems, and software innovation, We’re on a mission to enable smarter devices, more sustainable data centers, and entirely new applications the world hasn’t imagined yet.

Why join us:

We’re growing fast and looking for bold thinkers, builders, and curious problem-solvers who want to push the limits of AI hardware and software. If you're ready to join a world-class team and play a critical role in making a global impact - we want to talk to you.

What you’ll do:

As a Senior Packaging Engineer, you will be responsible for creating and verifying Persimmons package designs that will run the smallest to largest AI models. Your primary duties and responsibilities include:

• Drive end-to-end substrate design from concept through tape-out with minimal oversight; manage OSAT partnerships for cost, schedule and DFM optimization
• Design advanced 2.5D/3D interposers for high-speed interfaces (UCIe, HBM, PCIe)
• Owner of SI/PI, stack-up definition, PDN architecture & multi-Gbps signal integrity
• Execute co-design with silicon & hardware teams: electrical modeling (Ansys Q3D, HFSS), bump pattern optimization, parasitics EMI.
• Lead DFM reviews with vendors, independently resolve design rule conflicts, deliver manufacturable solutions on schedule.

Requirements

What We Need to See:

• BS/MS in Electrical Engineering, Materials Science, or related field
• 7+ years of hands-on experience in advanced semiconductor packaging design
• Strong communication & co-design skills between silicon, package & system
• Proven track record w/ advanced substrate & interposer e.g. 2.5D/3D packaging
• Experience w/ low-loss PCB materials for high-speed applications
• Proficiency in Cadence Allegro Package Designer or similar tools
• Familiar with SI/PI tools like Ansys HFSS & SIwave
• Experience with DRC, DFM, package reliability testing and failure analysis
• Understanding of thermal management solutions for high-power packages

Benefits

• Competitive salary and benefits package
• Flexible PTO
• 401k

Please note: Our organization does not accept unsolicited candidate submissions from external recruiters or agencies. Any such submissions, regardless of form (including but not limited to email, direct messaging, or social media), shall be deemed voluntary and shall not create any express or implied obligation on the part of the organization to pay any fees, commissions, or other compensation. Direct contact of employees, officers, or board members regarding employment opportunities is strictly prohibited and will not receive a response.