Powerex Expansion & Modernization of Existing Steel City Module Assembly Facility & Construction Of a New Power Module Assembly Facility

Headquarters & manufacturing facilities are located at the former Westinghouse Power Semiconductor facility in Youngwood, PA, ~35 miles southeast of Pittsburgh. As one of the last US based vertically integrated Power Semiconductor facility, the company has a Silicon Wafer Diffusion – Class 1,000/100 Clean Room: Class 10,000 Clean Room for Module Assembly & Test & Hi-Reliability Test Center and an Integrated Power Products Assembly/Test Center. Powerex was originally the Semiconductor Division of Westinghouse Electric, established in 1956. It became Powerex in 1986. In 2012 Powerex completed the construction of a Medium Volume Automated Assembly Line to support advanced packaging for DoD and industrial applications. This was partially funded by a DOE grant. In 2024 Powerex completed construction and expansion of the phase 2 addition to Steel City Power Module Assembly and Reliability Center as needed to meet the continued rise in DoD power modules needed for our Warfighters. The DoD reliance on Powerex for mission critical military platforms to meet already established DoD roadmaps and aircraft demand provided the necessary business case to make the needed investment which is essential to economic and national security.

Powerex has participated in the F-35 since Lot 1. Through all the initial Lots Powerex has continued to improve capacity and capability ramping production to support growing production demands annually. Powerex is one of 1800 U.S. based suppliers that are critical to the annual building of the F-35 Lightning II aircraft. The F-35 impact on the US economy exceeds $49 billion. Today Powerex remains a supplier of Power Modules to the EHA application on the F-35 due to high quality and reliability.

Powerex delivered to the F-35 program in 2024 thousands of mission critical power modules to several customers who supply power box content to Lockheed Martin. Powerex currently produces IGBT & IGBT-SCR modules in dual, 6 and 7 pack configurations. The 40% floor space expansion allows Powerex to continue to meet projected F-35 aircraft builds annually by adding redundant critical capacity to each single thread tool utilized for these IGBT modules. Our content per aircraft is significant.

Lockheed Martin and the F-35 Joint Program Office delivered the 894th production F-35. With more than 900 F-35s now delivered to U.S. and international operators, the impact of the global fleet is far reaching – significantly enhancing the allied joint force. The U.S. Air Force is the largest F-35 operator with a planned purchase of 1,763 F-35A aircraft. The U.S. Marine Corps operates F-35B short takeoff/vertical landing aircraft and plans to purchase 353 F-35Bs and 67 F-35C carrier variant aircraft. Together with the Marines, the U.S. Navy is bringing 5th Generation capability to the sea with plans to procure 260 F-35C aircraft. Powerex demand has doubled over the past six years. This new higher demand resulted from increased builds of new aircraft annually. The demand will continue through 2029 and beyond as the forecasted demand for F-35s peaks at 151 builds per year. Sustaining the F-35 will require Powerex to maintain production lines for another 30 years.

Powerex began in 1999 concept development for Plastic Encapsulation to pass moisture resistance for F-35 applications. The original modules were developed & phased in after an extensive qualification that lasted nearly two decades. Parts were developed for F-35 aircraft actuators & generator systems. For many of the initial years prior to 2017 Powerex seen small revenue generated from the investment due to the limited number of aircraft delivered each year. Given our critical position as an F-35 semiconductor power module supplier it was imperative that redundancy is considered for module production. In addition, as 6th Gen capabilities are developed 5th Gen Aircraft will need to take advantage of SWaP benefits using WBG SiC power modules. Powerex has self-funded as part of this growing demand for a Test Bay and factory floor expansion in 2024 to eventually double test capacity and perform R&D to introduce WBG power modules to the F-35. Powerex has added dozens of jobs since 2022 in part due to the ramping of the F-35 production line here at Powerex.
● The ICC is the Inverter converter controller unit for the Joint Strike Fighter (2 per plane). The F-35 family includes three variants – all single-seat jets: the F-35A conventional takeoff and landing (CTOL) variant, the F-35B short takeoff/vertical landing (STOVL) variant, and the F-35C carrier variant (CV). Inverter/Converter/Controller (2) – Provides Conditioned 270-VDC Power to Flight Critical Actuation System onboard the F-35. This application requires high reliability, screened 600V IGBT power modules. The ICC is common to all three variants of the F-35. The F-35 has 28VDC, 270VDC and 115VAC electrical systems, with the 28VDC system being used to power avionics, the 270VDC system used to power high-power systems like the electro-hydrostatic actuators (which replace conventional hydraulic systems for control surfaces) and starter motors, and the 115VAC system used for powering certain weapon systems that require it.

● F-35 Electrical Power System provides the generation, distribution, control, and protection of electrical power on the Aircraft. Key power management functions include primary flight control power, power to numerous aircraft systems, main engine starting, emergency power control and distribution, and power for ground maintenance functions. Key system elements include a single ES/G, two ICCs, 28 VDC and 270 VDC batteries, and the additional elements required to provide the uninterruptable power sources required for the safety of flight. The EPS provides 270 VDC, 28 VDC, and 115 VAC power. There are 2 ICCs in each F-35 and there are 3 ½ bridge modules and 1 IGBT exciter per ICC for a total ship set of 8 power modules.

● Powerex also supplies high reliability planar diodes that are used in F-35 Starter Generator assemblies. These diodes see HTRB Burn In screening tests.
● There are as many as 60 Powerex components per F-35 depending on the variant.

● The Electro hydrostatic actuation (EHA) system Powerex supports with IGBT modules eliminate the need for large central hydraulic systems on the F-3. EHA systems are power-by-wire actuation systems that utilize aircraft electric power for flight control surface actuation. EHAs consist of a fixed displacement, high speed, reversible pump driven by a brushless DC electric motor. Actuator position is controlled by the pump rotation direction and actuator piston velocity is controlled by pump rotational speed. The actuator output force is a function of the electric motor output torque. EHA are dual (redundant) tandem and simplex hydraulic output and contain fail-safe features, overload protection. EHAs provide sole flight control actuation on the F-35 Fighter aircraft and rely on fully tested, 100% Burned In under load- 600V power modules from Powerex. The 2024 expansion added the needed Burn In Rack Capacity to meet production schedules.

● Powerex constructed and implemented a Module In line Test and Reliability Burn in Test system capacity upgrade to increase reliability and meet F-35 module demand.

● This proposal doubled in line Automated Test Capacity to eliminate a single thread equipment test line for risk mitigation to the F-35. This was self-funded. Shown is the 2nd in line Automated Tester in place in the expanded Test Area and the Design.

● Shown is the new Automated F-35 Burn in the Test Center. Operators today are performing the loading and unloading of the computer monitored Burn In thus allowing 24-hour operation to meet the F-35 production plan. The new area allows improved visibility and control of product movement with reduced product handling in a needed quality control climate control area to perform HTRB.

The reliability of the next generation Power Modules will be improved by the addition of the 2024 added Burn in Capacity. Burn in is a process done to electronic components prior to regular use to detect failures and ensure reliability. This is done by running a power supply through the power module at an elevated temperature continuously for many hours. All mission critical Powerex modules see hours of Burn In. The typical lifetime and failure rates of semiconductors can best be illustrated by the bath-tub curve. Many failures occur during the early stages of operational life (infant mortality). By elevating the temperatures during Burn in Testing, failure mechanisms are accelerated to eliminate early device failures in the field. Powerex expanded Burn in Capacity, eliminating the need for specialized subcontractors and thus reducing lead-time. Final device reliability will also be improved by the addition of a Thermal Impedance Tester to the reliability center to properly characterize the newly qualified power modules. This new Thermal tester goes online in February 2025. Understanding thermal performance and thermal reliability influences on semiconductor devices and packages is important during product development and across the electronics supply chain. This added test equipment will apply thermal transient test technology for thermal characterization in 4 key areas:

● How to determine package thermal metrics

● Enhancing thermal simulation accuracy with calibration

● Thermal reliability studies: failure and lifetime

● Quality assessment to identify manufacturing defects

The new fully automated production line was installed within our current class 10,000 clean room. This production line allows Powerex to modernize our module production facility and allow processes like flux-free soldering that will achieve low void rates providing higher reliability and longer life in the modules. Fully automated inspection equipment will provide accuracy and speed to ensure high quality finished modules for our customers. AI driven software is being developed at Powerex to support the inspection of F-35 modules. The F-35 aircraft builds plan to ramp to 172 aircraft per year or higher. This represents greater than a 200% increase in needed capacity that requires 0 defects. The new automation line will qualify for F-35 power modules to replace/add capacity to existing production methods, with the addition of a 2nd line.

The tests performed in this modernized area are capable of inducing semiconductor device and packaging related failures. The objective of these harsh tests is to determine whether failures occur in an accelerated manner compared to normal use conditions for a representative sample size. Passing all appropriate reliability tests (no failures) for a representative sample size Qualifies the package for Industrial Applications. For the F-35 program 100% of the packaged devices undergo these tests. During HTRB, multiple devices from multiple modules are connected in parallel to each power supply. As many as 3 power supplies are utilized per module design, Powerex records power supply readings. During HTRB, if a leakage of certain power supply is observed to drift, the technician will isolate the devices connected in parallel to determine which one has increased leakage. Per the MIL-STD, Powerex utilizes post HTRB measurements as pass-fail criteria. Powerex 100% tests F-35 modules using specific customer requirements to assure long term reliability per MIL STD 883-1.

The expansion needed permitted Powerex to perform a portion of the DPA (Destructive Physical Analysis) previously completed by long lead-time subcontractors. The electrical testing and Environmental testing developed at Powerex allows for the product to resume production after a sub-contractor experienced long lead-time delays.

The Planar-design diode used on the F-35 & bipolar transistor wafers processed in the Powerex wafer fab are diced out of wafers and then feed the Power Module Assembly Fab, where they are assembled into modules with various standard & custom power electronics circuit configurations. This Class 10,000 facility, originally constructed at 10,000 sq. ft. was expanded to 14,000 square feet. inside our existing building. The new area is in full production status.

To reduce cost and reliability a single station solder die attach, and busbar vacuum oven will be replaced with automated Ultrasonic Terminal Welding. This will reduce several minutes per module from today’s processing times. X Ray equipment will be modernized to improve throughput, reducing costs.

Technology Refresh - The F-35 Electrostatic Hydrostatic Actuation System (EHAS) was originally designed during the SDD phase of the F-35 development program. The EHAS has six (6) electronic Units (EU) and has not seen a redesign in more than 20 years. A redesign would incorporate significant electronic technology advancements from commercial aviation industry, and drive improvement in affordability, reliability, quality performance and more commonality across all three variants of the F-35. Without eventual redesign there are risks of parts availability to support the aircraft due to diminishing manufacturing resources (DMS) and obsolescence that would result in higher program costs and decreasing reliability from outdated technology. Powerex has addressed these issues with life time buy DMS Chip Actions and has collaborated with the customers to discuss WBG Wideband Gap SiC solutions.

For Chip temperatures to operate above 200C Powerex will employ the latest technology in the manufacturing line, identified as a 2nd Automated line. These Technology improvements to the production of Power Modules will result in elevated temperature compatible power modules. Alternate substrate material Silicon Nitride will be qualified to replace Aluminum Nitride, providing higher thermal conductivity, and improved thermal cycling for longer lifetime. Encapsulation changes from silicone gel to higher temperature epoxies and gels including solid lid technology will be employed in the next gen power modules. Interconnect technology presently utilizes Aluminum wire bond to Aluminum metallization of the Silicon die. The Technology refresh will eliminate some of these wire bonds, the weak link in the reliability of a power module with low inductance interconnects, including Power Over Lay, DTS copper foils, and copper wire bonding and ultrasonic bonded copper terminals. Low yield packaging issues where wire bonding to insert molded copper terminals that are nickel plated and subsequently oxidized will be improved with Copper interconnect technology.

In Summary the 2nd module line will have the following major critical enhancements:

a. A 2nd Source line redundancy with tooling for critical Power Module Key components

b. First article testing and inspection for 2nd Line Qualification for F-35 Modules

c.MVL Process changes include new Auto Gel dispense, Qualify LBB & PCB outsourcing /automate fixturing & AOI incoming inspection/cleaning of all components

d. Adding Auto F-35 Burn in Capacity & Test fixtures Area

e. Qualification of 5th Gen to 7th Gen Chips, Leaded to ROHS & DMS LTB acquisition

f. A 2nd Automated fluxless Line Area Prep/Installation & qualification to allow ramping to 172 aircraft per year including 2nd Red Wolf/X Ray/Ag Sinter/in line Copper Wirebonder/US welder for Power Terminals/AOI & automated assemblies

g. Tech Refresh for Nex Gen F-35 where possible to (SIC) for improved performance & critical weight reduction includes

h. Powerex has considerable experience in developing new, innovative power semiconductor modules and integrated power subsystems. Development activities in recent years have concentrated on new power semiconductor devices such as silicon carbide for power conversion applications requiring high voltage, high frequency and high temperature operation.

Powerex has over 20 years of experience developing and producing high reliability modules for industrial, military, and aircraft applications. Our experience in developing low cost, high reliability devices will mean rapid product introduction. Powerex is pleased to announce the opening of the Steel City expansion, - wheels Up!