Process for the manufacture of millimeter wave sources of the module type
AssigneeThomson-CSF
InventorJacques Espaignol
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Abstract
A batch production process for millimeter wave sources of a module type. This module type consists of a basic metallic support, bearing a diode under the form of a semiconductor chip soldered on a projection of the support, the diode being surrounded by a dielectric substance forming a medium extending up to half a wavelength on the same support, with a metallization covering the surrounding medium and connected with the top of the chip by a metallic block. In a first embodiment, the batch process is limited to the central part of the module i.e. the semiconductor chip, the block and only a part of the dielectric medium, as well as a part of the metallic support. In a second embodiment of the process, the collective production of the entire module is achieved.
Claims8
A process for the manufacture of sources of millimeter waves, comprising at least the following stages:
- A. production of a semiconductor plate comprising a substrate and active layers constituting with the substrate a semiconductive structure;
- B. addition of a support with low thermal resistance constituted by a first metal, resistant to certain chemical agents, on the side of the active layers of the plate;
- C. grinding the substrate, followed by depositing a thin layer of the first metal and a thick layer of a second metal that can be selectively attacked by a chemical agent in the presence of the first metal;
- D. formation by photolithography of a large number of studs of the first metal penetrating the second metal up to the first layer of the first metal;
- E. selectively attacking the second metal, baring the studs, followed by etching the thin layer in the portions not protected by the studs;
- F. selectively attacking the semiconductor material, allowing a block of this material to remain underneath each stud, with the volume of a stud substantially exceeding the volume of the block;
- G. finishing of the sources, comprising the cutting out of individual elements.
Dependencies are inferred from the claim text.