Semiconductor Assembly Services

Flexible, Subcontract Microelectronic Assembly Solutions

Reltronix offers specialised, high-precision semiconductor assembly services directly from our UK-based facility. Whether you require a full turnkey packaging solution or wish to subcontract specific process steps, such as die attach, wire bonding, die bumping or chip-on-board assembly, our engineering team delivers strict quality control, full traceability, and fast turnaround times.

We work with customer-supplied components, substrates, and packages, providing modular assembly services tailored to your exact project specifications and volume requirements.

Why work with Reltronix for Subcontract Assembly?

UK-Based Facility
Complete in-house processing ensures data security, clear communication, and strict quality assurance.

Flexible Process Modules
Access individual process capabilities or combine multiple services into a bespoke manufacturing flow.

Hi-Rel Focus
Expertise in handling sensitive, high-reliability devices for demanding industries (Aerospace, Defence, Automotive, Medical, and Industrial).

Process & Material Flexibility
Qualified to handle a wide range of industry-standard epoxies, pre-forms, wire types, and substrates.

Our Core Assembly Capabilities

Precision Die Attach Services

Our automated and semi-automated die attach solutions accommodate a broad range of die sizes, aspect ratios, and material combinations:

Epoxy Die Attach
Automated dispensing of qualified conductive and non-conductive epoxies with precise bond-line thickness control.

Eutectic Die Attach
High-thermal-performance bonding both with and without gold-tin (AuSn) or custom pre-forms.

Heat Spreader & Substrate Attach
Specialist mounting onto high-thermal-conductivity materials such as Molybdenum (Moly) tabs and specialised carriers.

Precision Die Wire Bonding Services

Interconnect solutions engineered for high-frequency, power, and high-density applications:

Gold (Au) Ball Bonding
Fine-pitch, high-speed interconnects for complex die configurations.

Gold (Au) Wedge Bonding: Deep-access bonding ideal for specialised ceramic and metal packages.

Aluminium (Al) Wedge Bonding: Ambient-temperature bonding suitable for temperature-sensitive devices and power electronics.

Ribbon Bonding: Low-inductance, high-frequency interconnections designed for RF, microwave, and high-power applications.

Stud Bumping & Flip Chip Assembly

Gold Stud Bumping: Precision bump placement on individual die or wafers to enable flip-chip interconnections without complex wafer-level redistribution layers (RDL).

Flip Chip Attach: High-density, short-interconnect mounting to reduce signal inductance and optimise thermal transfer.

Chip-on-Board (COB) Assembly & Encapsulation

Direct COB Wire Bonding: Direct die placement and interconnection onto PCB, ceramic, or customer-provided substrates.

Glob-Top & Dam-and-Fill Encapsulation: Precisely dispense protective dam-and-fill or glob-top materials to shield delicate die and wire bonds from environmental and mechanical damage.

Turnkey vs. Modular Sub-Contract Workflows

Whether you need a partner to manage the entire assembly process or help to relieve a capacity constraint in your manufacturing line, Reltronix can assist with:

Full Sub-Contract Turnkey
Send us your die and substrate/package requirements, and we can manage die attach, wire bonding, encapsulation/sealing, and post-assembly test.

Process-Specific Sub-Contracting
Utilise single services (e.g., Wire Bonding only, or Stud Bumping only) on your pre-processed assemblies.

(Note: Reltronix focuses purely on packaging, assembly, and testing. We do not manufacture hybrid circuits or substrates such as LTCC, thin film, or thick film, but we are fully equipped to assemble onto customer-supplied substrates).

Call us on 01603 859640 to discuss your custom semiconductor assembly requirements or drop us a message.