Laser structuring of 3D interconnected circuits

Microcertec S.A.S is one of the very few manufacturers offering this unique expertise.
Laser ablation technology helps the engineer to develop circuit carriers which cannot be manufactured with usual microelectronics processes based on photolithography and chemical etching. This kind of product results from combining the technologies of ceramics precision-grinding and laser ablation of metal thin-film coatings. We call this concept "three-dimensional interconnected circuit or CI3D”. Our technology together with plastic 3D interconnection devices (3DMID) are aimed at mechatronics applications.

Laser structuring is based on using a laser beam - without prior masking - to etch directly a metallized layer deposited on a ceramic carrier. This is called laser micromachining - or laser ablation as metal is ablated away (vaporized). To do so, the speed of ablation is extremely high because of the very short laser pulses in the range of a few nanoseconds. As a result the etching is very selective : material ablation is restricted to the spot size in width and to a fraction of a micrometer in depth. Also, the very high-rate laser shot repetition allows the beam to be moved across several millimeters per second with a scanner - oscillating mirrors. The metal layer ablation is operated in several sequences of repeated beam runs with a width accuracy of a few microns and a limited thermal impact on the ceramic carrier.

Laser structuring is based on using a laser beam - without prior masking - to etch directly a metallized layer deposited on a ceramic carrier. This is called laser micromachining - or laser ablation as metal is ablated away (vaporized). To do so, the speed of ablation is extremely high because of the very short laser pulses in the range of a few nanoseconds. As a result the etching is very selective : material ablation is restricted to the spot size in width and to a fraction of a micrometer in depth. Also, the very high-rate laser shot repetition allows the beam to be moved across several millimeters per second with a scanner - oscillating mirrors. The metal layer ablation is operated in several sequences of repeated beam runs with a width accuracy of a few microns and a limited thermal impact on the ceramic carrier.

This technology is robust and reliable as a result of the straightforward process, the microelectronics quality of the metallization and the use of ceramics – alumina or aluminium nitride – which offer dimensional stability and good electrical insulation. The process is particularly suited for fast prototyping of microelectronics circuits in view of low-cost tooling and flexible design changes only requiring programming work. The concept offers a great freedom of design to position the microelectronics components in relation to each other in space and associate mechanical and electronics functions in a monolithic way. The production quantities depend on the design of the part but can account for up to a few thousand items per month.

The reasons for using this kind of circuit are proven by the functional performances and/or the reliability of the electronics module. The robustness and precision of ceramic CI3D’s fully justify their use in severe environment applications in aerospace, military, scientific and medical industries. In general these CI3D’s allow the final user to integrate microelectronics chips – Mems, calculators, CCD’s, LED’s.. – in order to achieve sensing functions.