Summary

• CITC/TNO is working with imec and OnePlanet Research Center on a photonic laser chip module combining a tunable laser, control semiconductors and additive packaging.
• The proposed process uses screen printing to apply encapsulation materials with precisely defined openings of 100 micrometres or less for optical and sensor functions.
• A hybrid physics and AI digital twin will use packaging measurements for validation. The project targets a scalable functional demonstrator, not an operational production line or independently verified manufacturing savings.

Dutch semiconductor researchers are developing an additive packaging process for photonic chips, combining precise optical connections with screen-printed protective materials and simulation technology intended to reduce manufacturing waste.

The work forms part of the CONNECT GLD consortium, which brings together organisations working on semiconductor production equipment and manufacturing methods in the eastern Netherlands.

On 21 October, Chip Integration Technology Center (CITC) outlined its role in developing a photonic laser chip module with imec and OnePlanet Research Center, focusing on the assembly, optical alignment and encapsulation of sensitive components.

The planned result is a functional demonstrator designed with future industrial production in mind. The consortium has not announced a qualified manufacturing process, commercial production orders or independently measured reductions in material consumption.

Photonic devices require precise assembly

Photonic integrated circuits use light to perform functions that can include transmitting information, sensing physical conditions or processing optical signals.

Like electronic chips, they must be incorporated into larger systems before they can be used reliably. Packaging provides electrical connections, physical protection and interfaces with other equipment.

Optical devices introduce additional requirements because light must travel through components and connections aligned with sufficient precision.

Where a photonic circuit connects to an optical fibre, small variations in position can reduce the amount of light transferred between them.

The completed assembly must also withstand handling, changes in temperature and the operating conditions of the system in which it will be installed.

Protective materials cannot simply cover every surface without considering the optical pathways needed for the chip to function.

Some devices require openings through which light can enter or leave the package, while sensors may need controlled exposure to the surrounding environment.

Manufacturers must therefore balance protection, mechanical stability and optical performance within structures whose relevant features can be extremely small.

Those requirements can make packaging a substantial part of the development and production cost of advanced photonic components.

Even where the underlying semiconductor device performs correctly, poor alignment or defects introduced during assembly can render the finished product unsuitable for its intended application.

Screen printing offers a different encapsulation method

CITC/TNO is developing an additive fan-out packaging approach that applies encapsulation materials through screen printing.

Screen printing deposits material in selected areas using a patterned process, allowing protective structures to be created with controlled openings.

The consortium is targeting windows of 100 micrometres or less, equivalent to one tenth of a millimetre, for light transmission and sensor interactions.

Those openings must be positioned accurately alongside optical fibres, electrical connections and the components they are intended to protect.

The proposed process also incorporates high-precision fibre alignment and robust electrical interconnections.

By placing encapsulation material where it is required, an additive method could reduce waste compared with approaches that deposit larger quantities before removing unwanted material.

CITC says the technique may also reduce manufacturing costs and support densely packed sensor arrays.

These remain development objectives. The organisation has not published completed manufacturing trials demonstrating a particular percentage reduction in material use or cost.

The environmental benefit of an additive process also depends on factors beyond the amount of encapsulation material deposited.

Energy consumption, equipment requirements, processing temperatures, material formulations and the proportion of finished devices that pass quality testing can all affect the resources needed per usable component.

A method that reduces waste during one processing step may not reduce total manufacturing expenditure if it requires additional testing or produces inconsistent results.

The consortium will therefore need to establish whether the proposed approach provides reliable component performance alongside any resource savings.

A tunable laser provides a practical test

The project involves developing a module based on a tunable external cavity laser integrated with a photonic circuit.

A tunable laser can operate across a specified range of wavelengths, making it useful in applications that require optical signals with adjustable characteristics.

External cavity designs use an optical arrangement to help determine the laser’s operating behaviour, although the exact implementation depends on the components involved.

The planned module combines the laser, photonic integrated circuit, control semiconductors and protective packaging into one functioning assembly.

That combination provides a demanding practical test because optical, electronic and mechanical components must operate together rather than being assessed individually.

The packaging must maintain suitable alignment and electrical connections while allowing the optical pathways needed for the device’s functions.

A successful demonstrator would show that the components can be assembled into a functioning system using the proposed methods.

However, demonstrating one working module is different from proving that thousands can be manufactured consistently at an acceptable cost.

Industrial qualification would require further evidence covering yields, reliability, variation between production batches and the ability to test completed devices efficiently.

Manufacturers would also need assurance that the packaged components remain stable throughout their intended operating lives.

Digital modelling uses production measurements

Alongside the physical packaging work, imec and OnePlanet Research Center are developing a digital twin intended to support more sustainable semiconductor assembly.

The project combines physics-based simulations with predictions generated from experimental data, allowing engineers to investigate relationships between process conditions and packaging outcomes.

CITC/TNO will supply measurements collected during its packaging work for use in training and evaluating the model.

Physics-based simulation can represent known material and mechanical behaviour, while data-driven methods may identify relationships that are difficult to calculate directly.

Combining the two approaches could help researchers explore process changes without repeating every possible variation through physical experiments.

The usefulness of the resulting digital twin will depend on the quality and range of information used during development.

A model trained on measurements from a narrow set of conditions may perform poorly when a material, equipment setting or component geometry changes substantially.

The consortium plans to validate the model using new test data that was not included in training.

That approach can provide stronger evidence of predictive capability than testing a model solely against information it has already encountered.

However, successful validation against a selected dataset would not automatically demonstrate reliable operation under every condition encountered in industrial production.

Further testing would be required as the process moves towards manufacturing, particularly where equipment or material suppliers differ from those used during development.

Regional research targets industrial capability

CONNECT GLD brings together semiconductor research organisations and industrial partners in Gelderland, seeking to develop production machinery and processes that consume fewer resources.

The programme is connected with the region’s wider semiconductor and advanced manufacturing ecosystem, which includes specialist organisations developing components, machinery and integration technologies.

Photonic packaging is an important part of that ecosystem because usable products depend on more than the performance of individual chips.

Reliable assembly methods help determine whether a promising photonic technology can progress from laboratory devices into equipment manufactured consistently for commercial use.

Companies developing optical sensors, communications components and related products may require packaging processes that accommodate different device structures without excessive redesign.

An adaptable additive process could become useful where several product types share similar protection and connection requirements.

However, industrial adoption would depend on the cost of the necessary equipment, the reliability of completed assemblies and compatibility with existing production arrangements.

The consortium’s wider sustainability objective must also be supported by measurements covering complete processes rather than assumptions based on the use of a particular manufacturing technique.

For CITC/TNO, the immediate work involves building the proposed photonic module, refining the screen printing process and supplying measurements for the digital twin.

Those activities should produce evidence about whether the method can deliver suitable optical performance and manufacturing consistency.

The 21 October development establishes the organisation’s technical contribution to an existing regional programme. Its next milestones concern a functional demonstrator, validated simulation results and evidence that the packaging approach could be scaled for industrial production.