CN-121983769-A - Preparation method of micro-coaxial transmission structure and micro-coaxial transmission structure

CN121983769ACN 121983769 ACN121983769 ACN 121983769ACN-121983769-A

Abstract

The method is characterized in that the structure of an outer conductor is divided into three parts, namely an outer conductor side wall, an outer conductor bottom and an outer conductor top, which are formed independently, and then the manufacturing modes of bonding connection are respectively carried out, so that the micro-coaxial transmission structure can be integrally constructed and released; meanwhile, as the structures of the parts of the outer conductor are formed on different wafers and finally released, the release Kong Laiqu except photoresist is not required to be reserved on the structures of the parts of the outer conductor, so that the problems of pollutant introduction and device performance reduction are avoided.

Inventors

LI HANG
LIU JIANKUN
LU YUAN
DING YAN
GUO PENGFEI

Assignees

北京赛微电子股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260202

Claims (10)

1. A method of making a micro-coaxial transmission structure, comprising: Providing a first wafer, and forming an outer conductor side wall, a support body and an inner conductor on one side of the first wafer, wherein the support body is connected with the outer conductor side wall, and the inner conductor is positioned on one side of the support body; providing a second wafer, and forming an outer conductor bottom on one side of the second wafer; Providing a third wafer, and forming an outer conductor top on one side of the third wafer; Bonding the second wafer and the first wafer to enable the bottom of the outer conductor to be connected with the side wall of the outer conductor in a bonding mode so as to form a bonding sheet; Processing the bonding sheet to expose one side of the outer conductor side wall away from the outer conductor bottom; bonding the third wafer and the bonding sheet to enable the top of the outer conductor and one side of the side wall of the outer conductor far away from the bottom of the outer conductor to be in bonding connection; and separating the micro coaxial transmission structure from the second wafer and the third wafer.
2. The method of claim 1, wherein providing a first wafer and forming an outer conductor sidewall, a support, and an inner conductor on one side of the first wafer comprises: Providing a first wafer; two first grooves and a second groove are formed on one side of the first wafer, the second groove is positioned between the two first grooves, and the depth of the first groove is larger than that of the second groove; forming a first sub-portion in the first groove and forming an inner conductor in the second groove; Forming a support body over the first sub-portion and the inner conductor; And forming a second sub-part on the first sub-part, and enabling the second sub-part to wrap the edge of the support body, wherein the second sub-part and the first sub-part form an outer conductor side wall.
3. The method of manufacturing a micro coaxial transmission structure according to claim 2, wherein forming two first grooves and one second groove on one side of the first wafer comprises: Forming a first oxide layer on one side of the first wafer, and processing the first oxide layer to form two first openings and one second opening, wherein the first openings and the second openings penetrate through the first oxide layer along the thickness direction of the first oxide layer, and the second openings are positioned between the two first openings; Forming photoresist on one side of the first oxide layer, which is away from the first wafer, and processing the photoresist to enable the photoresist to expose the first opening and cover the second opening; Etching the position, corresponding to the first opening, of the first wafer to form a first groove on the position, corresponding to the first opening, of the first wafer; removing the photoresist; Etching positions of the first wafer corresponding to the first opening and the second opening to form a second groove on the first wafer corresponding to the second opening, and enabling the depth of the first groove to be larger than that of the second groove; and oxidizing the first wafer to form a second oxide layer on the side surfaces and the bottom surfaces of the first groove and the second groove.
4. The method of manufacturing a micro coaxial transmission structure according to claim 3, wherein the processing the bonding pad to expose a side of the outer conductor sidewall away from the outer conductor bottom comprises: Thinning one side of the first wafer, which is away from the second wafer; Etching the first wafer to expose the first oxide layer and the second oxide layer; And removing the first oxide layer and the second oxide layer.
5. The method of manufacturing a micro coaxial transmission structure according to claim 2, wherein forming a second sub-portion on the first sub-portion further comprises: And forming a first protection part on one side of the first wafer, and enabling the first protection part to be positioned on two opposite sides of the two second sub-parts.
6. The method of manufacturing a micro coaxial transmission structure according to claim 5, wherein forming the outer conductor bottom on one side of the second wafer further comprises: and forming a second protection part on one side of the second wafer, and enabling the second protection part to be positioned on two opposite sides of the bottom of the outer conductor.
7. The method of manufacturing a micro coaxial transmission structure according to claim 6, wherein bonding the second wafer to the first wafer, and bonding the bottom of the outer conductor to the sidewall of the outer conductor comprises: The side of the bottom of the outer conductor in the second wafer faces to the side of the side wall of the outer conductor in the first wafer, the bottom of the outer conductor is opposite to the side wall of the outer conductor, and the second protection part is opposite to the first protection part; and the bottom of the outer conductor is connected with the side wall of the outer conductor in a bonding way, and the second protection part is connected with the first protection part in a bonding way.
8. The method of manufacturing a micro coaxial transmission structure according to claim 1, wherein an adhesion layer is provided between the bottom of the outer conductor and the second wafer and between the top of the outer conductor and the third wafer, respectively, and the separating the micro coaxial transmission structure from the second wafer and the third wafer comprises: And removing the adhesion layer to separate the bottom of the outer conductor from the second wafer and separate the top of the outer conductor from the third wafer.
9. The method for manufacturing a micro coaxial transmission structure according to any one of claims 1 to 8, wherein the bottom of the outer conductor and the side wall of the outer conductor are bonded by an electroplating bonding process, and/or, And the top of the outer conductor and the side wall of the outer conductor are bonded and connected by adopting an electroplating bonding process.
10. A micro-coaxial transmission structure, characterized in that it is manufactured by the manufacturing method of the micro-coaxial transmission structure according to any one of claims 1 to 9, and the micro-coaxial transmission structure comprises: The outer conductor comprises an outer conductor top, an outer conductor bottom and two outer conductor side walls connected between the outer conductor top and the outer conductor bottom, and the outer conductor top, the outer conductor bottom and the outer conductor side walls are enclosed to form an inner cavity; The support body is positioned in the inner cavity and connected with the side wall of the outer conductor; an inner conductor positioned in the inner cavity, the inner conductor positioned at one side of the support body; The front projection of the top of the outer conductor, the bottom of the outer conductor and the side wall of the outer conductor on the inner conductor respectively cover the corresponding surfaces of the inner conductor.

Description

Preparation method of micro-coaxial transmission structure and micro-coaxial transmission structure Technical Field The application belongs to the technical field of micro-electro-mechanical systems, and particularly relates to a preparation method of a micro-coaxial transmission structure and the micro-coaxial transmission structure. Background In the field of micro-electromechanical systems, the fabrication of micro-coaxial transmission structures has long relied on traditional building block electroplating processes. The process needs to coat an ultra-thick photoresist layer on a substrate, and forms a three-dimensional 'fence' structure by photoetching to serve as a temporary electroplating mould. In the area enclosed by the enclosure wall, copper materials are stacked and heightened step by step through multiple times of electroplating, baking and solidification are needed after each time of electroplating to maintain the shape of the photoresist, the repeated circulation of the process results in long process period and huge resource consumption, and more importantly, after the metal structure is integrally formed, the photoresist wrapped inside is difficult to thoroughly clean. Since the photoresist is completely enclosed inside the copper layer, conventional solvents cannot penetrate effectively, and residues are prone to signal interference or structural failure. In order to accelerate photoresist release, a large number of release holes are needed to be additionally arranged in the micro coaxial transmission structure in the prior art, but the holes not only damage the physical continuity of the outer conductor, but also provide an intrusion path for external pollutants, and weaken the electromagnetic shielding capability at the same time, so that the high-frequency transmission performance is reduced and the reliability of the device is reduced. Disclosure of Invention In order to solve the technical problems, the application provides a preparation method of a micro-coaxial transmission structure and the micro-coaxial transmission structure, which can improve the preparation efficiency and enhance the structural integrity and electromagnetic shielding performance of the micro-coaxial transmission structure. The technical scheme adopted for realizing the purpose of the application is as follows: The embodiment of the application provides a preparation method of a micro coaxial transmission structure, which comprises the following steps: Providing a first wafer, and forming an outer conductor side wall, a support body and an inner conductor on one side of the first wafer, wherein the support body is connected with the outer conductor side wall, and the inner conductor is positioned on one side of the support body; providing a second wafer, and forming an outer conductor bottom on one side of the second wafer; Providing a third wafer, and forming an outer conductor top on one side of the third wafer; Bonding the second wafer and the first wafer to enable the bottom of the outer conductor to be connected with the side wall of the outer conductor in a bonding mode so as to form a bonding sheet; Processing the bonding sheet to expose one side of the outer conductor side wall away from the outer conductor bottom; bonding the third wafer and the bonding sheet to enable the top of the outer conductor and one side of the side wall of the outer conductor far away from the bottom of the outer conductor to be in bonding connection; and separating the micro coaxial transmission structure from the second wafer and the third wafer. In some embodiments, the providing a first wafer and forming an outer conductor sidewall, a support, and an inner conductor on one side of the first wafer includes: Providing a first wafer; two first grooves and a second groove are formed on one side of the first wafer, the second groove is positioned between the two first grooves, and the depth of the first groove is larger than that of the second groove; forming a first sub-portion in the first groove and forming an inner conductor in the second groove; Forming a support body over the first sub-portion and the inner conductor; And forming a second sub-part on the first sub-part, and enabling the second sub-part to wrap the edge of the support body, wherein the second sub-part and the first sub-part form an outer conductor side wall. In some embodiments, the forming two first grooves and one second groove on one side of the first wafer includes: Forming a first oxide layer on one side of the first wafer, and processing the first oxide layer to form two first openings and one second opening, wherein the first openings and the second openings penetrate through the first oxide layer along the thickness direction of the first oxide layer, and the second openings are positioned between the two first openings; Forming photoresist on one side of the first oxide layer, which is away from the first wafer, and processing the photoresist to ena