CIL wins "Manufacturer of the Year" at the TechWorks Gala Dinner Awards 2025

Custom Interconnect has been awarded Manufacturing Site of the Year at the TechWorks Awards 2025. The recognition reflects the scale, maturity and technical capability of BP2, the UK’s most advanced Outsourced Semiconductor Assembly and Test (OSAT) facility. It is also one of the only sites in Europe able to process devices from wafer through to power module, overmolded IC or high reliability SMT assembly.

For engineers, the significance is clear. BP2 is not simply an expanded production plant. It is a fully integrated advanced packaging ecosystem designed to close a long-standing gap in the UK semiconductor supply chain: the ability to process Si, SiC, GaN and advanced RF devices entirely onshore, at production scale, using modern automated manufacturing technology.

A Semiconductor Packaging Architecture Built for Modern Devices

BP2’s cleanroom and production flow support next-generation device architectures, including 2.5D and 3D heterogeneous integration, high current wide bandgap power modules, and high density QFN and CSP packages.

Wafer Level Capability

Custom Interconnect now provides several wafer-level processes normally carried out offshore.

Wafer bumping

Our system deposits solder spheres from 40um to 750um and supports multiple alloys including SAC305/405, SnPb – (Tin / Lead) for Defence and Space, and low temperature Bismuth (Bi) alloys for Biomedical applications.

This enables:

WLCSP formats for markets where they were previously impractical
5D interposers with dense I/O requirements
High lead-count AI processors, with examples exceeding 159k bumps per die

Wafer dicing

Our high-precision wafer dicing system is optimised for Si, SiC, GaN and compound wafers. It provides:

UV-curable tape systems for GaN and SiC
Specialist kerf geometries for brittle materials
Tight chipping control essential for high power devices
Direct integration into downstream die attach without the need for intermediate steps

These wafer-level additions allow CIL to maintain a continuous manufacturing chain similar to advanced OSAT facilities in Taiwan or Singapore, while remaining entirely UK based.

Advanced Die Attach and Interconnect for High Power and RF Devices

Silver sinter die attach / Eutectic solder / Epoxy die attach

Custom Interconnect’s capability includes:

High pressure silver sintering for SiC dies, producing extremely low thermal resistance joints
Pressureless sintering for substrates such as AMB and DBC
Automated sinter profile optimisation with in-situ monitoring
Voiding levels that meet or exceed AQG324 requirements

These processes support:

SiC MOSFETs and diodes
GaN HEMTs
High reliability LED and optical assemblies
Power devices where solder cannot meet thermal performance requirements

Wire bonding ecosystem

Custom Interconnect now operates:

Five automatic die bonders
Seven automatic wire bonders, enabling:
- Aluminium wire bonding in 25um & 32um wire, up to 1M bonds per week
- Gold wedge wire bonding for RF devices up to 122 GHz
- Gold wedge ribbon bonding for RF GaN MMIC devices
- Gold ball bonding for fine-pitch applications
- Heavy gauge Aluminium wedge bonding up to 600um wire and 2 mm ribbon
- Heavy gauge Aluminium wedge ribbon bonding for high current interconnect.

This is one of the largest wire bonding capacities in the UK. It supports:

Multi-chip module (MCM) construction
High density analogue and RF circuits
RF GaN MMIC devices
Automotive traction inverter and power conversion modules
5D multi-die power bridges
Mixed technology assemblies combining Si, SiC, GaN and MEMS

Glob-top, partial encapsulation and Film Assisted Overmold

Our epoxy dispensing platforms maintain controlled encapsulation within 25 micrometres. This enables:

Encapsulation of complex COB devices
Selective windowing for optical sensors
Partially encapsulated medical devices
Rapid prototyping on the same equipment used for production

QFN and Custom Package Overmold Capability

Our open cavity and full QFN overmold line supports:

Automotive and medical sensor packaging
High volume QFN device assembly
Custom cavity geometries for MEMS and pressure sensors
Fully integrated laser marking

High Complexity SMT Integration with Semiconductor Packaging

BP2’s scope extends beyond semiconductor packaging. Our PCBA capability includes:

Eight SMT lines, all WLCSP and 01005 capable
Single-digit voiding for power devices using vapour phase and vacuum N₂ reflow
Inline 3D AOI with full statistical process control
Three TAKAYA APT1400F flying probe testers
Dual X-ray systems, including CT, for:
- Die attach inspection
- Bond loop integrity
- BGA and QFN solder joint verification

This combination allows CIL to integrate packaged semiconductor devices into complete electronic assemblies, supporting a full vertical route from wafer through to tested PCBA.

A Technical Shift for the UK Supply Chain

UK OEMs and start-ups have historically relied on Asian OSATs for:

Wafer bumping
High pressure SiC die attach
QFN overmold
Advanced bond profiles
High reliability substrate attach

This created long lead times, iteration delays, IP concerns and high NRE for early development.

BP2 replaces these constraints with:

Shorter and more predictable development cycles
Direct co-engineering across packaging, power electronics and SMT
Local access to equipment normally found only in large overseas OSATs
Scalable production from fewer than 50 devices to more than one million per year

Many BP2 capabilities do not exist elsewhere in the UK, and several are unique in Europe within a combined semiconductor and SMT facility.