ProtoPCBA's for a quantum computer

PCBAProtoLabLearnings

For the intended quantum computer, DeltaProto B.V. produces a number of remarkable ProtoPCBA's.

The PCBA's will ultimately be used at a temperature of 20 milliKelvin (2-thousandths above absolute zero). To achieve optimal heat distribution, the bare PCB (110 x 52 mm) features more than 16,000 vias.

For DeltaProto B.V. the challenge is to solder all components without the protective function of solder mask, while preventing solder tin from spreading across the ENIG surface. It's surprising to see how quickly that normally happens without the protection of solder mask.

By applying a tiny solder mask made of kapton per PCBA, we manage to prevent 'flow-through'. (See photo.) After this, TUDelft places a connector on the 'clean' ENIG surface and the board disappears into the computer, where optimal heat transfer is pursued.

In the meantime, we have the process reasonably under control and we deliver about 20 ProtoPCBA's this way.

Quite a nice example of finding solutions in less familiar application areas by simply trying, right?

HappyEngineering