CN115694392A

CN115694392A - Filter, manufacturing method and electronic equipment

Info

Publication number: CN115694392A
Application number: CN202210415426.8A
Authority: CN
Inventors: 曹雪; 李月; 肖月磊; 吴艺凡; 冯昱霖; 韩基挏; 常文博; 安齐昌; 周毅; 王立会; 李必奇
Original assignee: BOE Technology Group Co Ltd; Beijing BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Beijing BOE Optoelectronics Technology Co Ltd
Priority date: 2022-04-20
Filing date: 2022-04-20
Publication date: 2023-02-03

Abstract

The disclosure provides a filter, a manufacturing method and electronic equipment, belongs to the technical field of microwaves, and can solve the problem of low inductance Q value. The present disclosure provides a filter including: the dielectric substrate comprises a first substrate and a second substrate which are oppositely arranged, wherein a dielectric cavity is arranged between the first substrate and the second substrate; the filter further comprises: the inductor comprises a first plane inductor structure arranged on the first surface of the first substrate, a second plane inductor structure arranged on the first surface of the second substrate, and a columnar inductor structure arranged in the dielectric cavity, wherein the first end part and the second end part of the columnar inductor structure are respectively and electrically connected with the first plane inductor structure and the second plane inductor structure; and the capacitor is arranged on the first surface of the first substrate and is electrically connected with the inductor.

Description

Filter, manufacturing method and electronic equipment

Technical Field

The disclosure belongs to the technical field of microwaves, and particularly relates to a filter, a manufacturing method and electronic equipment.

Background

The filtering technology can filter out the unnecessary interference signals in the signals to be processed, extract the required signals, and is an important technology in signal processing. The filter is an important component for implementing the filtering technology, and comprises an active filter and a passive filter, wherein the passive filter is also called as an LC filter, and is a filtering circuit formed by utilizing the combined design of an inductor, a capacitor and a resistor, and different filtering effects can be realized by adjusting the number of the inductor and the capacitor and the connection mode.

Disclosure of Invention

The disclosure aims to provide a filter, a manufacturing method and electronic equipment.

A first aspect of the present disclosure provides a filter, comprising: the dielectric substrate comprises a first substrate and a second substrate which are oppositely arranged, wherein a dielectric cavity is arranged between the first substrate and the second substrate; the filter further comprises:

the inductor comprises a first planar inductor structure arranged on the first surface of the first substrate, a second planar inductor structure arranged on the first surface of the second substrate, and a columnar inductor structure arranged in the dielectric cavity, wherein the second end part and the first end part of the columnar inductor structure are respectively and electrically connected with the first planar inductor structure and the second planar inductor structure;

the capacitor is arranged on the first surface of the first substrate and is electrically connected with the inductor.

The first surface of the first substrate is sequentially superposed with a first conducting layer, a dielectric layer and a second conducting layer, a first electrode plate of the capacitor is arranged on the first conducting layer, a second electrode plate of the capacitor is arranged on the second conducting layer, and a dielectric medium of the capacitor is arranged on the dielectric layer.

The first planar inductance structure is arranged on the second conducting layer;

and arranging a third conducting layer on the first surface of the second substrate, wherein the second planar inductance structure is arranged on the third conducting layer.

And covering a first protective layer on one side of the surface of the second conductive layer, which is far away from the first substrate.

And covering a second protective layer on one side of the surface of the third conductive layer, which is far away from the second substrate.

And a sealing structure is arranged at the periphery of the medium cavity between the first substrate and the second substrate, and the first substrate, the second substrate and the sealing structure enable the medium cavity to form a closed cavity.

And the sealed cavity is filled with medium gas.

Wherein the medium gas is air.

The first substrate is provided with a first inductance through hole, a second inductance through hole and a capacitance through hole which penetrate through the thickness, a first conductive column, a second conductive column and a third conductive column are respectively arranged in the first inductance through hole, the second inductance through hole and the capacitance through hole, and second end parts of the first conductive column, the second conductive column and the third conductive column are respectively and correspondingly electrically connected with a welding ball arranged on the second surface of the first substrate;

the first end of the first conductive column is electrically connected with the columnar inductance structure corresponding to the first end of the inductor, the first end of the second conductive column is electrically connected with the columnar inductance structure corresponding to the second end of the inductor, and the first end of the third conductive column is electrically connected with the first electrode plate of the capacitor;

conductive balls are arranged at the first end parts of the first conductive column, the second conductive column and the third conductive column.

The first surface of the first substrate is further provided with a first bonding pad, a second bonding pad and a third bonding pad, the first bonding pad is electrically connected with the columnar inductance structure corresponding to the first end of the inductance, the second bonding pad is electrically connected with the columnar inductance structure corresponding to the second end of the inductance, and the third bonding pad is electrically connected with the first electrode plate of the capacitance.

A second aspect of the present disclosure provides a method for manufacturing a filter, including:

manufacturing a first planar inductance structure and at least one capacitor on a first surface of a first substrate;

manufacturing a columnar inductance structure, wherein the second end part of the columnar inductance structure is electrically connected with the first plane inductance structure;

a second planar inductance structure is arranged on the first surface of the second substrate;

and carrying out box processing on the first surface of the first substrate and the first surface of the second substrate, electrically connecting the first end part of the columnar inductance structure with the second planar inductance structure to form at least one inductor, electrically connecting the inductor with the capacitor, and forming a dielectric cavity between the first substrate and the second substrate.

Wherein, the first surface of the first substrate is provided with a first plane inductance structure and at least one capacitor, and the method comprises the following steps:

sequentially manufacturing a first conducting layer, a dielectric layer and a second conducting layer on the first surface of the first substrate, wherein the first planar inductance structure is arranged on the second conducting layer; the first electrode plate of the capacitor is arranged on the first conducting layer, and the second electrode plate of the capacitor is arranged on the second conducting layer.

Wherein, before performing a cartridge process on the first surface of the first substrate and the first surface of the second substrate, electrically connecting the first end of the columnar inductance structure with the second planar inductance structure, forming at least one inductance, and forming a dielectric cavity between the first substrate and the second substrate, the method comprises:

implanting a connecting ball at a first end of the columnar inductance structure;

providing a sealing structure on the first surface of the second substrate and along the periphery of the second substrate;

aligning the first surface of the first substrate and the first surface of the second substrate, and enabling the first end part of the columnar inductance structure to be opposite to the position of the second planar inductance structure;

electrically connecting the first end of the columnar inductance structure with the second planar inductance structure through a reflow soldering process to form at least one inductor; and sealingly attaching the sealing structure to the first surface of the first substrate to form a dielectric cavity between the first substrate and the second substrate.

Wherein, before the first planar inductance structure and the at least one capacitor are manufactured on the first surface of the first substrate, the method further comprises the following steps:

manufacturing a first inductance through hole, a second inductance through hole and a capacitance through hole which penetrate through the thickness of the first substrate;

and filling conductive materials in the first inductance through hole, the second inductance through hole and the capacitance through hole to obtain a first conductive column, a second conductive column and a third conductive column.

A third aspect of the present disclosure provides a radio frequency circuit, comprising:

the circuit board comprises a carrier plate, wherein a first surface of the carrier plate is provided with a conductive circuit;

a filter, a port of the filter being electrically connected to the corresponding conductive line; the filter is the filter provided by the embodiment of the disclosure;

and the port of the radio frequency element is electrically connected with the corresponding conductive circuit, and the radio frequency element is correspondingly electrically connected with the port of the filter through the conductive circuit.

The port of the filter is arranged on the second surface of the first substrate in the filter, and the filter is electrically connected with the corresponding conductive circuit on the carrier plate through the conductive balls arranged on the second surface of the first substrate.

The port of the filter is arranged on the first surface of a first substrate in the filter, and a pad arranged on the first surface of the first substrate is electrically connected with a corresponding conductive circuit on the carrier plate through a conductive lead.

A fourth aspect of the present disclosure provides an electronic device, which includes a filter, where the filter is provided in an embodiment of the present disclosure.

Drawings

Fig. 1 is a schematic structural diagram of a filter according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of a filter connected to an RF device on a package substrate according to an embodiment of the disclosure;

FIG. 3 is a schematic diagram of another filter provided by embodiments of the present disclosure;

fig. 4 is a top view of another waveguide conversion device provided by embodiments of the present disclosure;

fig. 5 is a schematic diagram of a filter connected to an rf component on a package substrate according to an embodiment of the disclosure;

fig. 6 is a flowchart of a method for manufacturing a filter according to an embodiment of the disclosure.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present disclosure, the following detailed description is given with reference to the accompanying drawings and the specific embodiments.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. Also, the use of the terms "a," "an," or "the" and similar referents do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In order to meet the requirements of various application scenarios on the integration level of the filter, a Through-thickness three-dimensional structure, such as a Through Silicon Via (TSV) or a Through Glass Via (TGV), may be disposed in the substrate (Silicon substrate or Glass substrate), thereby improving the integration level of the filter.

The integrated passive filter is manufactured by directly manufacturing components such as an inductor, a capacitor and the like on a substrate by using a thin film or thick film technology. The inductor comprises a planar inductor and an inductor in a through hole, the planar inductor is positioned on the surface of the substrate, the inductor in the through hole is positioned in the substrate (a silicon through hole or a glass through hole), the Q values (quality factors) of the planar inductor and the inductor in the through hole are related to the characteristics of the substrate, the dielectric constant and the conductivity of the substrate are high, the Q value of the inductor is inevitably reduced, the insertion loss of the passive filter is large, and the application of the passive filter in a high frequency band is limited.

The embodiment of the disclosure provides a filter, which avoids the influence of a substrate on the Q value of an inductor and reduces the insertion loss of a passive filter by changing the structure of the inductor.

Fig. 1 is a schematic structural diagram of a filter according to an embodiment of the present disclosure. As shown in fig. 1, an embodiment of the present disclosure provides a filter, including: the dielectric substrate comprises a first substrate 1 and a second substrate 2 which are oppositely arranged, and a dielectric cavity 3 is arranged between the first substrate 1 and the second substrate 2.

Note that the first substrate 1 and the second substrate 2 are also for convenience of description, and the positions of the first substrate 1 and the second substrate 2 are not limited.

In some embodiments, the first substrate 1 and the second substrate 2 include, but are not limited to, any one of a glass-based, a silicon-based, a flexible substrate, and an interlayer dielectric layer 14 including at least an organic insulating layer. Since the filter is integrated on the glass substrate, the first substrate 1 and the second substrate 2 are preferably glass-based in the embodiment of the present disclosure, because the filter has advantages of small size, light weight, high performance, low power consumption, and the like. The following description will be made by taking a glass substrate as an example.

In the embodiment of the present disclosure, the first substrate 1 includes a first surface 11 and a second surface 12, two opposite sides of the first substrate 1 of the first surface 11 and the second surface 12, and a layer structure may be fabricated on both the first surface 11 and the second surface 12. The second substrate 2 has a similar structure to the first substrate 1, with a first surface 21 and a second surface 22, on both of which first surface 21 and second surface 22 of the second substrate 2 a layer structure can be produced.

It should be noted that the first surface and the second surface are for convenience of description, and the positions of the first surface and the second surface are not limited.

The filter that this disclosed embodiment provided still includes:

the inductor comprises a first planar inductor structure 41 arranged on the first surface 11 of the first substrate 1, a second planar inductor structure 42 arranged on the first surface of the second substrate 2, and a columnar inductor structure 43 arranged in the dielectric cavity 3, wherein a first end (one end close to the second substrate) and a second end (one end close to the first substrate) of the columnar inductor structure 43 are electrically connected with the first planar inductor structure 41 and the second planar inductor structure 42 respectively.

And the capacitor is arranged on the first surface 11 of the first substrate 1 and is electrically connected with the inductor.

In the embodiment of the present disclosure, the first planar inductance structure 41 of the capacitor and the inductor are both disposed on the first surface 11 of the first substrate 1, and the first planar inductance structure 41 of the capacitor and the inductor is electrically connected.

In the embodiment of the present disclosure, the columnar inductance structure 43 may be a columnar structure made of a metal material, for example, the metal material includes, but is not limited to, at least one of copper (Cu), aluminum (Al), molybdenum (Mo), and silver (Ag). The height of the columnar inductor structure 43 affects the inductance value. In some embodiments, the height of the columnar inductive structure 43 is 1 μm-500 μm. In order to ensure the effective electrical connection between the pillar-shaped inductor structure 43 and the second planar inductor structure 42, solder balls are implanted into the first end of the pillar-shaped inductor structure 43.

In the embodiment of the present disclosure, the inductor includes a first planar inductor structure 41, a second planar inductor structure 42, and a pillar inductor structure 43, and a first end and a second end of the pillar inductor structure 43 are electrically connected to the first planar inductor structure 41 and the second planar inductor structure 42, respectively, so as to form an inductor. Because the columnar inductance structure 43 is located in the dielectric cavity 3, the inductance Q value of the columnar inductance structure 43 is irrelevant to the characteristics (dielectric constant and conductivity) of the first substrate 1 and the second substrate 2, so that the inductance Q value of the columnar inductance structure 43 is improved, the insertion loss of the filter can be reduced, and the overall characteristic of the filter is improved.

In some embodiments, a first conductive layer 13, a dielectric layer 14 and a second conductive layer 15 are sequentially stacked on the first surface 11 of the first substrate 1, a first electrode plate 51 of a capacitor is disposed on the first conductive layer 13, a second electrode plate 52 of the capacitor is disposed on the second conductive layer 15, and a dielectric of the capacitor is disposed on the dielectric layer 14.

In some embodiments, the capacitor includes a first electrode plate 51 and a second electrode plate 52 with a dielectric disposed between the first electrode plate 51 and the second electrode plate 52. The first electrode plate 51 is disposed on the first conductive layer 13, the second electrode plate 52 of the capacitor is disposed on the second conductive layer 15, and the dielectric is disposed on the dielectric layer 14, i.e., the dielectric layer 14 is disposed between the first conductive layer 13 and the second conductive layer 15.

The material of the first conductive layer 13 and the second conductive layer 15 includes, but is not limited to, at least one of copper (Cu), aluminum (Al), molybdenum (Mo), and silver (Ag). The material of the dielectric layer 14 is an inorganic insulating material. For example: the dielectric layer 14 is an inorganic insulating layer formed of silicon nitride (SiNx), or silicon oxide (SiO) ₂ ) Inorganic insulating layer formed, or SiNx inorganic insulating layer and SiO ₂ Several stacked composite layers of inorganic insulating layers.

In some embodiments, a first conductive layer 13 is disposed on the first surface 11 of the first substrate 1, a dielectric layer 14 is disposed on the surface of the first conductive layer 13 and on the side facing away from the first substrate 1, and a second conductive layer 15 is disposed on the surface of the dielectric layer 14 and on the side facing away from the first substrate 1. The first conductive layer 13 and the second conductive layer 15 may be formed by electroplating, sputtering, or the like, and the dielectric layer 14 may be formed by chemical vapor deposition or the like.

In the embodiment of the present disclosure, the first electrode plate 51, the second electrode plate 52, and the dielectric layer 14 of the capacitor are respectively provided with the first conductive layer 13, the dielectric layer 14, and the second conductive layer 15, so that the integration level of the capacitor is improved, and the size of the filter is reduced.

In some embodiments, the first planar inductance structure 41 of the inductor is disposed on the second conductive layer 15, the third conductive layer 23 is disposed on the first surface of the second substrate 2, and the second planar inductance structure 42 is disposed on the third conductive layer 23.

In the embodiment of the present disclosure, the third conductive layer 23 is disposed on the first surface of the second substrate 2, and the third conductive layer 23 may be formed by electroplating, sputtering, or other processes.

In the embodiment of the present disclosure, the first planar inductor structure 41 of the inductor and the second electrode plate 52 of the capacitor are disposed on the second conductive layer 15, instead of being disposed on two different conductive layers, respectively, so that the structure of the filter can be simplified, and the manufacturing cost can be reduced.

In the embodiment of the present disclosure, the filter is provided with a plurality of columnar inductance structures 43, the second end of the columnar inductance structure 43 is electrically connected to the first planar inductance structure 41, and the first end of the columnar inductance structure 43 is electrically connected to the second planar inductance structure 42, that is, the plurality of first planar inductance structures 41 and the plurality of second planar inductance structures 42 may be sequentially connected in series by means of the plurality of columnar inductance structures 43, so as to obtain an inductance. The first and second ports of the inductor are each electrically connected to the second end of one of the cylindrical inductor structures 43 in the filter.

In some embodiments, the surface of the second conductive layer 15 facing away from the first substrate 1 is covered with a first protective layer 16.

In the embodiment of the present disclosure, the surface of the second conductive layer 15 facing away from the first substrate 1 is covered with the first protective layer 16, and a first opening is disposed at a position corresponding to the second end of the columnar inductive structure 43, where the second end of the columnar inductive structure 43 is electrically connected to the first planar inductive structure 41. The first protective layer 16 covers the surface of the second conductive layer 15 away from the first substrate 1, so that the second conductive layer 15 can be prevented from being oxidized due to exposure.

The material of the first protective layer 16 is an inorganic insulating material. For example: the first protective layer 16 is an inorganic insulating layer formed of silicon nitride (SiNx), or silicon oxide (SiO) ₂ ) Inorganic insulating layer formed, or SiNx inorganic insulating layer and SiO ₂ Several laminated composite layers of inorganic insulating layers.

In some embodiments, the surface of the third conductive layer 23 facing away from the second substrate 2 is covered with a second protective layer 24.

In the embodiment of the present disclosure, the surface of the third conductive layer 23 facing away from the second substrate 2 is covered with the second protection layer 24, and a second opening is disposed at a position corresponding to the second end of the pillar-shaped inductor structure 43, and the second end of the pillar-shaped inductor structure 43 is electrically connected to the second planar inductor structure 42 at the second opening. The second protective layer 24 covers the surface of the third conductive layer 23 away from the second substrate 2, so that the third conductive layer 23 can be prevented from being oxidized due to exposure.

The material of the second protective layer 24 is an inorganic insulating material. For example: the second protective layer 24 is an inorganic insulating layer formed of silicon nitride (SiNx), or silicon oxide (SiO) ₂ ) Inorganic insulating layer formed, or SiNx inorganic insulating layer and SiO ₂ Several stacked composite layers of inorganic insulating layers.

In some embodiments, a sealing structure is provided at the periphery of the dielectric cavity 3 between the first substrate 1 and the second substrate 2, and the first substrate 1, the second substrate 2 and the sealing structure form a closed cavity with the dielectric cavity 3.

In the embodiment of the present disclosure, a sealing structure, such as a sealant frame, which is circumferentially closed, is formed on the first surface of the second substrate 2, and after the first substrate 1 and the second substrate 2 are aligned to form a cassette, the sealing structure, the first substrate 1 and the second substrate 2 seal the dielectric cavity 3 into a closed cavity.

In some embodiments, the sealing structure may be formed by coating, screen printing, or the like.

In some embodiments, the sealed cavity is filled with a dielectric gas, which is selected to have a dielectric constant near 1 and a conductivity near 0, such as air. The dielectric constant of air is 1, the conductivity is close to 0, and compared with the materials of the first substrate 1 and the second substrate 2, the inductance Q value of the columnar inductance structure 43 is obviously improved, so that the overall characteristics of the filter are improved.

In the embodiment of the present disclosure, the filter may be electrically connected to other electronic devices by wire bonding, or may be electrically connected to other electronic devices by flip chip bonding.

In some embodiments, the first substrate 1 has a first inductance through hole 17, a second inductance through hole 18, and a ground through hole 19 penetrating through the thickness, a first conductive pillar 27, a second conductive pillar 28, and a third conductive pillar 29 are respectively disposed in the first inductance through hole 17, the second inductance through hole 18, and the ground through hole 19, and first end portions of the first conductive pillar 27, the second conductive pillar 28, and the third conductive pillar 29 are respectively electrically connected to the solder balls disposed on the second surface 12 of the first substrate 1.

The second end of the first conductive pillar 27 is electrically connected to the pillar inductor structure 43 corresponding to the first end of the inductor, the second end of the second conductive pillar 28 is electrically connected to the pillar inductor structure 43 corresponding to the second end of the inductor, and the second end of the third conductive pillar 29 is electrically connected to the first electrode plate 51 of the capacitor. The second ends of the first, second and third

conductive posts

27, 28, 29 are provided with conductive balls 30.

The conductive balls 30 may be solder balls, or may be made of other conductive materials.

In some embodiments, the first inductance via 17, the second inductance via 18 and the ground via 19 may not be limited to the laser modified etching manner to obtain the first inductance via 17, the second inductance via 18 and the ground via 19 on the first substrate 1. The first conductive pillars 27, the second conductive pillars 28, and the third conductive pillars 29 are obtained by an electroplating process, and before the electroplating process is performed, a seed layer may be further generated on the first inductive via 17, the second inductive via 18, and the ground via 19 by a magnetron sputtering process, and a conductive metal is plated on the seed layer. Wherein, the material of the seed layer includes but is not limited to at least one of copper (Cu), aluminum (Al), molybdenum (Mo) and silver (Ag).

Fig. 2 is a schematic diagram of an electrical connection of a filter to other electronic devices according to an embodiment of the disclosure. As shown in fig. 2, the package carrier 8 is provided with conductive traces (not shown) and pads (not shown), and the positions and the number of the pads correspond to the number of the pads of the filter and the electronic device.

The first end portions of the first conductive pillar 27, the second conductive pillar 28 and the third conductive pillar 29 of the filter are provided with conductive balls 30 corresponding to the positions of the pads on the package carrier 8, and then are electrically connected by flip chip bonding. Other electronic devices such as the first rf component 91 and the second rf component 92 may also be electrically connected to the pads on the package carrier 8 by flip-chip bonding.

In the embodiment of the present disclosure, the first conductive pillar 27, the second conductive pillar 28, and the third conductive pillar 29 are used as three ports of the filter, so that the filter is connected with other electronic devices, and the integration level of the filter and other electronic devices is improved.

In some embodiments, a first pad 81, a second pad 82 and a third pad (not shown in the figure) are further disposed on the first surface 11 of the first substrate 1, the first pad 81 is electrically connected to the columnar inductance structure 43 corresponding to the first end of the inductance through a wire disposed in the second conductive layer 41, the second pad 82 is electrically connected to the columnar inductance structure 43 corresponding to the second end of the inductance through a wire disposed in the second conductive layer 41, and the third pad is electrically connected to the first electrode plate 51 of the capacitance.

As shown in fig. 3 and 5, when the filter is electrically connected to another electronic device by wire bonding, filter pads are disposed on the first surface 11 of the first substrate 1, the filter pads are disposed around the filter, and the number of the filter pads may be arbitrarily set according to actual needs, which is not limited in this disclosure.

The filter includes a first pad 81, a second pad 82 and a third pad (not shown in the figure), the first pad 81 is electrically connected to the columnar inductance structure 43 corresponding to the first end of the inductance, the second pad 82 is electrically connected to the columnar inductance structure 43 corresponding to the second end of the inductance, and the third pad is electrically connected to the first electrode plate 51 of the capacitance.

The first pad 81, the second pad 82 and the third pad of the filter are electrically connected to the pads on the package carrier 8 correspondingly, and the first rf component 91 and the second rf component 92 are electrically connected to the pads on the package carrier 8 by flip-chip bonding and are electrically connected to the ports of the first rf component 91 and the second rf component 92 correspondingly by wires.

The embodiment of the present disclosure further provides a manufacturing method of a filter, as shown in fig. 6, the manufacturing method of the filter includes:

step S601, a first planar inductor structure 41 and at least one capacitor are fabricated on the first surface 11 of the first substrate 1.

The first substrate 1 includes, but is not limited to, any one of a glass-based substrate, a silicon-based substrate, a flexible substrate, and an interlayer dielectric layer 14 including at least an organic insulating layer.

In some embodiments, the first surface 11 of the first substrate 1 is plated or magnetron sputtered to obtain the first conductive layer 13, and then the first conductive layer 13 is subjected to glue coating, exposure, development, and then wet etching with copper, and after etching, the glue is removed to complete patterning of the first conductive layer 13, and the first electrode plate 51 of the capacitor and the first planar inductance structure 41 are formed on the first conductive layer 13. The first electrode plate 51 and the first planar inductive structure 41 may be electrically connected as needed.

The material of the first conductive layer 13 includes, but is not limited to, at least one of copper (Cu), aluminum (Al), molybdenum (Mo), and silver (Ag). The thickness of the first conductive layer 13 can be set as desired, for example, the thickness of the first conductive layer 13 is 5 to 10nm.

A dielectric layer 14 is made on the surface of the first conductive layer 13, which is far away from the first substrate 1, by a chemical vapor deposition process, and the dielectric layer 14 is made of an inorganic insulating material. For example: the dielectric layer 14 is an inorganic insulating layer formed of silicon nitride (SiNx), or silicon oxide (SiO) ₂ ) Inorganic insulating layer formed, or SiNx inorganic insulating layer and SiO ₂ Several laminated composite layers of inorganic insulating layers.

In the embodiment of the present disclosure, the dielectric layer 14 covers the first conductive layer 13, so as to prevent the first conductive layer 13 from being oxidized due to exposure in a subsequent process.

And obtaining a second conductive layer 15 on the side of the surface of the dielectric layer 14, which is far away from the first substrate 1, by an electroplating or magnetron sputtering method, then performing glue coating, exposure and development, then performing wet etching on copper, removing the glue after etching, completing patterning of the second conductive layer 15, and forming a second electrode plate 52 of the capacitor and a second planar inductance structure 42 of the inductor on the second conductive layer 15.

The material of the second conductive layer 15 includes, but is not limited to, at least one of copper (Cu), aluminum (Al), molybdenum (Mo), and silver (Ag). The thickness of the second conductive layer 15 can be set as desired, for example, the thickness of the second conductive layer 15 is 5 to 10nm.

In some embodiments, the method for manufacturing a filter further includes manufacturing a first protection layer 16, where the first protection layer 16 covers the second conductive layer 15 to prevent the second conductive layer 15 from being oxidized due to exposure. The material of the first protective layer 16 may be at least one of silicon nitride and silicon oxide. First protective layer 16 may also cover the exposed surface of dielectric layer 14.

Step S602, a cylindrical inductor structure 43 is fabricated, and a second end of the cylindrical inductor structure 43 is electrically connected to the first planar inductor structure 41.

A columnar inductance structure 43 is fabricated on the first surface 11 of the first substrate 1 by a plating process, and a second end portion of the columnar inductance structure 43 is connected to the first planar inductance structure 41. For example, a metal layer is obtained by electroplating on a side of the surface of the first protective layer 16 away from the first substrate 1, and then the metal layer is subjected to glue coating, exposure, development, etching, and then removing the glue after etching to obtain the columnar inductance structure 43.

In some embodiments, in order to improve the electrical connection between the pillar-shaped inductor structure 43 and the second planar inductor structure 42, a connection ball, such as a solder ball, is disposed at the first end of the pillar-shaped inductor structure 43, so as to facilitate the electrical connection between the pillar-shaped inductor structure 43 and the second planar inductor structure 42 in the subsequent box-aligning process.

In step S603, a second planar inductor structure 42 is disposed on the first surface of the second substrate 2.

The second substrate 2 includes, but is not limited to, any one of a glass-based substrate, a silicon-based substrate, a flexible substrate, and an interlayer dielectric layer 14 including at least an organic insulating layer.

In some embodiments, the third conductive layer 23 is obtained on the first surface of the second substrate 2 by electroplating or magnetron sputtering, then, by glue coating, exposure, and development, and then, by wet etching of copper, the photoresist is removed after etching, so as to complete patterning of the third conductive layer 23, and form the second planar inductor structure 42 of the inductor on the third conductive layer 23.

The material of the third conductive layer 23 includes, but is not limited to, at least one of copper (Cu), aluminum (Al), molybdenum (Mo), and silver (Ag). The thickness of the third conductive layer 23 can be set as desired, for example, the thickness of the third conductive layer 23 is 5 to 10nm.

In some embodiments, a second protection layer 24 is disposed on a side of the surface of the third conductive layer 23 facing away from the second substrate 2, and the material of the second protection layer 24 may be at least one of silicon nitride and silicon oxide. The second protective layer 24 covers the third conductive layer 23 to prevent the third conductive layer 23 from being oxidized due to exposure.

Step S604, performing a box aligning process on the first surface 11 of the first substrate 1 and the first surface of the second substrate 2, so that the first end of the columnar inductance structure 43 is electrically connected to the second planar inductance structure 42 to form at least one inductor, and the inductor is electrically connected to the capacitor; and a dielectric cavity 3 is formed between the first substrate 1 and the second substrate 2.

In some embodiments, before performing a cartridge process on the first surface 11 of the first substrate 1 and the first surface of the second substrate 2, electrically connecting the first end of the columnar inductive structure 43 with the second planar inductive structure 42, forming at least one inductor, and forming the dielectric cavity 3 between the first substrate 1 and the second substrate 2, the method includes:

implanting a connection ball at a first end of the columnar inductor structure 43; providing a sealing structure on the first surface of the second substrate 2 and along the periphery of the second substrate 2; aligning the first surface 11 of the first substrate 1 and the first surface of the second substrate 2, and making the first end of the columnar inductance structure 43 opposite to the position of the second planar inductance structure 42; electrically connecting a first end of the columnar inductance structure 43 with the second planar inductance structure 42 by a reflow soldering process to form at least one inductance; and the sealing structure is sealingly connected to the first surface 11 of the first substrate 1 to form a dielectric cavity 3 between the first substrate 1 and the second substrate 2.

In some embodiments, before the first planar inductance structure 41 and the at least one capacitor are fabricated on the first surface 11 of the first substrate 1, the method further includes:

manufacturing a first inductance through hole 17, a second inductance through hole 18 and a grounding through hole 19 which penetrate through the thickness of the first substrate 1; conductive material is filled in the first inductance via 17, the second inductance via 18, and the ground via 19, so that a first conductive pillar 27, a second conductive pillar 28, and a third conductive pillar 29 are obtained.

In some embodiments, the first inductance via 17, the second inductance via 18 and the ground via 19 may be formed on the first substrate 1 by wet etching, dry etching or laser drilling. When the first substrate 1 is a glass substrate, a laser may be used to strike the surface of the first substrate 1 with a laser beam incident perpendicularly, so as to obtain the first inductance via 17, the second inductance via 18, and the ground via 19 on the first substrate 1. Specifically, when the laser beam interacts with the first substrate 1, atoms in the first substrate 1 are ionized and projected out of the glass surface due to the high energy of laser photons, and the holes drilled are gradually deepened with time until the whole first substrate 1 is drilled, i.e., a plurality of through holes are formed. The laser wavelength can be 532nm, 355nm, 266nm, 248nm, 197nm, 1-100fs, 1-100ps, 1-100ns, continuous laser, pulse laser, etc.

And forming a seed layer on the inner walls of the first inductance through hole 17, the second inductance through hole 18 and the grounding through hole 19 by adopting a magnetron sputtering mode. The material of the seed layer includes, but is not limited to, at least one of copper (Cu), aluminum (Al), molybdenum (Mo), and silver (Ag). In the following description, the material of the seed layer is copper as an example.

In some embodiments, in order to increase the adhesion of the seed layer to the first substrate 1, an auxiliary metal film may be formed in the holes by means including, but not limited to, magnetron sputtering before forming the deposition seed layer. The material of the auxiliary metal thin film includes, but is not limited to, at least one of nickel (Ni), molybdenum (Mo) alloy, and titanium (Ti) alloy.

After seed layers are formed in the first inductance through hole 17, the second inductance through hole 18 and the ground through hole 19, copper is filled in the first inductance through hole 17, the second inductance through hole 18 and the ground through hole 19 by using a method of Cu electroplating or Cu core solder ball filling. For example, the first substrate 1 is placed on a carrier of an electroplating machine, a bonding pad (pad) is pressed, the substrate is placed in a hole filling electroplating bath (a special hole filling electrolyte is used in the bath), current is applied, the electroplating solution keeps flowing continuously and rapidly on the surface of the substrate, cations in the electroplating solution on the inner walls of the first inductance through hole 17, the second inductance through hole 18 and the grounding through hole 19 obtain electrons to be deposited on the inner walls, and through the special hole filling electrolyte with special proportion, metal copper can be deposited at high speed (deposition speed is 0.5-3 um/min) mainly in the first inductance through hole 17, the second inductance through hole 18 and the grounding through hole 19, and the upper surface and the lower surface of the first substrate 1 are flat areas, and the deposition speed of the metal copper on the two surfaces is extremely small (0.005-0.05 um/min). As time increases, the metal copper on the inner walls of the first inductance via 17, the second inductance via 18 and the ground via 19 gradually grows to be thick, and even the first inductance via 17, the second inductance via 18 and the ground via 19 can be completely filled or partially filled, that is, the corresponding first conductive pillar 27, the second conductive pillar 28 and the third conductive pillar 29 are formed.

In some embodiments, the filled metal copper only fills the sidewall of the first inductor via 17, the second inductor via 18, and the ground via 19, and the thickness of the metal copper on the inner sidewall of the first inductor via 17, the second inductor via 18, and the ground via 19 is greater than the skin depth, so as to reduce the process time and the manufacturing cost.

In some embodiments, after the first substrate 1 and the second substrate 2 are aligned to form a box, the filter is heated to cure the sealant sufficiently, so that the dielectric cavity 3 is formed into a closed cavity, and a good sealing effect is obtained.

In order to better understand the filter and the manufacturing method provided by the present disclosure, the following description will be made in detail by taking the manufacturing of the filter as an example.

The manufacturing method of the filter comprises the following steps:

step S701 is to obtain a first substrate 1, fabricate the first inductor via 17, the second inductor via 18, and the ground via 19 on the first substrate 1, and fill copper in the first inductor via 17, the second inductor via 18, and the ground via 19 to obtain the first conductive pillar 27, the second conductive pillar 28, and the third conductive pillar 29.

The first inductance through hole 17, the second inductance through hole 18 and the grounding through hole 19 penetrating through the thickness of the first substrate 1 are obtained on the first substrate 1 through a laser modification etching process, then a seed layer is obtained on the side walls of the first inductance through hole 17, the second inductance through hole 18 and the grounding through hole 19 through a magnetron sputtering process, then the first inductance through hole 17, the second inductance through hole 18 and the grounding through hole 19 are filled through an electroplating process, and a first conductive column 27, a second conductive column 28 and a third conductive column 29 are obtained.

In step S702, a first conductive layer 13 is formed on the first surface 11 of the first substrate 1, and a first electrode plate 51 of a capacitor is formed on the first conductive layer 13.

A copper layer is manufactured on the first surface 11 of the first substrate 1 through an electroplating or magnetron sputtering process, then glue coating, exposure and development are performed, etching is performed, glue is removed after etching is completed, patterning of the first conductive layer 13 is completed, and a first electrode plate 51 of a capacitor and a first planar inductance structure 41 of an inductor are formed in the first conductive layer 13.

In step S703, a dielectric layer is formed.

A dielectric layer is produced by means of a chemical vapour deposition process on the side of the surface of the first electrically conductive layer 13 facing away from the first substrate 1. The dielectric layer may act as a dielectric for the capacitor.

In some embodiments, dielectric layer 14 covers not only first conductive layer 13, but also the first substantially exposed portion.

In step S704, a second conductive layer 15 is formed.

A second conductive layer 15 is formed on the surface of the dielectric layer facing away from the first substrate 1, and a second electrode plate 52 of the capacitor and a first planar inductor structure 41 of the inductor are formed in the second conductive layer 15.

A copper layer is manufactured on the first surface 11 of the first substrate 1 through an electroplating or magnetron sputtering process, then glue coating, exposure and development are performed, etching is performed, after etching is completed, glue is removed, patterning of the second conductive layer 15 is completed, and a first electrode plate 51 of a capacitor and a first planar inductance structure 41 of an inductor are formed in the second conductive layer 15.

In step S705, the first protective layer 16 is fabricated.

And manufacturing a first protective layer 16 on the exposed surfaces of the second conductive layer 15 and the dielectric layer 14 by a chemical vapor deposition process, wherein the first protective layer 16 is made of an inorganic insulating material. For example: the first protective layer 16 is an inorganic insulating layer formed of silicon nitride (SiNx), or silicon oxide (SiO) ₂ ) Inorganic insulating layer formed, or SiNx inorganic insulating layer and SiO ₂ Several stacked composite layers of inorganic insulating layers.

In step S706, the columnar inductor structure 43 is fabricated.

The columnar inductance structure 43 is manufactured by an electroplating process, and a first end of the columnar inductance structure 43 is electrically connected with the first planar inductance structure 41 in the second conductive layer 15.

In order to ensure the electrical connection between the pillar-shaped inductor structure 43 and the second planar inductor structure 42, solder balls are implanted into the first end of the pillar-shaped inductor structure 43.

In step S705, the first protection layer 16 covers the exposed portions of the second conductive layer 15 and the dielectric layer 14, but a window is opened at a position corresponding to the pillar-shaped inductor structure 43 for electrically connecting the second end of the pillar-shaped inductor structure 43 with the first planar inductor structure 41.

In step S707, the conductive balls 30 are implanted on the first conductive pillars 27, the second conductive pillars 28, and the third conductive pillars 29 on the second surface 12 of the first substrate 1.

In some embodiments, the first conductive post 27, the second conductive post 28, and the third conductive post 29 may respectively serve as an input terminal, an output terminal, and a ground terminal of the filter.

In step S708, a third conductive layer 23 is formed on the second substrate 2.

A copper layer is manufactured on the second substrate 2 through an electroplating or magnetron sputtering process, then the second substrate is subjected to glue coating, exposure and development, then etching is performed, glue is removed after the etching is finished, the patterning of the third conductive layer 23 is finished, and an inductive second planar inductive structure 42 is formed in the third conductive layer 23.

In step S709, a second passivation layer 24 is formed on the surface of the third conductive layer 23 facing away from the second substrate 2.

And manufacturing a second protective layer 24 on the third conductive layer 23 and the exposed part of the first surface of the second substrate 2 by a chemical vapor deposition process, wherein the material of the second protective layer 24 is an inorganic insulating material. For example: the second protective layer 24 is an inorganic insulating layer formed of silicon nitride (SiNx), or silicon oxide (SiO) ₂ ) Inorganic insulating layer formed, or SiNx inorganic insulating layer and SiO ₂ Several laminated composite layers of inorganic insulating layers.

In step S710, a closed sealing structure is provided on the first surface and the periphery of the second substrate 2.

The sealing structure is manufactured by using a sealant on the first surface of the second substrate 2 and in the edge region of the second substrate 2 through processes such as coating, screen printing, and the like. The sealing structure can seal the medium space to a closed space when the first substrate 1 and the second substrate 2 are aligned with each other in height.

In step S711, the first substrate 1 and the second substrate 2 are subjected to the pair-cassette process.

In step S711, the first surface 11 of the first substrate 1 and the first surface of the second substrate 2 are opposed to each other, and the first end portion of the columnar inductance structure 43 is electrically connected to the second planar inductance structure 42, so as to form at least one inductor, and at the same time, the dielectric cavity 3 is formed between the first substrate 1 and the second substrate 2.

In step S711, after the first end of the columnar inductor structure 43 is electrically connected to the second planar inductor structure 42 by reflow soldering, the sealant is cured by raising the temperature, so that the dielectric cavity 3 becomes a sealed cavity.

It should be noted that steps S701 to S707 and steps S708 to S710 may be performed simultaneously, or steps S708 to S710 may be performed first, and then steps S701 to S707 are performed.

In the filter manufacturing method provided by the embodiment of the present disclosure, the inductor includes a first planar inductor structure 41, a second planar inductor structure 42, and a columnar inductor structure 43, and a first end and a second end of the columnar inductor structure 43 are electrically connected to the first planar inductor structure 41 and the second planar inductor structure 42, respectively, so as to form the inductor. Because the columnar inductance structure 43 is located in the dielectric cavity 3, the inductance Q value of the columnar inductance structure 43 is irrelevant to the characteristics (dielectric constant and conductivity) of the first substrate 1 and the second substrate 2, so that the inductance Q value of the columnar inductance structure 43 is improved, the insertion loss of the filter can be reduced, and the overall characteristic of the filter is improved.

As shown in fig. 2, an rf circuit according to an embodiment of the present disclosure further includes a carrier 8, and a first surface of the carrier 8 is disposed with a conductive trace (not shown).

A filter 10, the port of the filter 10 is electrically connected with the corresponding conductive circuit; the filter is the filter that this disclosed embodiment provided.

The carrier plate 8 may be a circuit board or other structural members with carrying and electrical connection functions. The shape, size and material of the carrier plate 8 are not limited in the embodiment of the present disclosure.

In some embodiments, the rf elements include a first rf element 91 and a second rf element 92, wherein the first rf element 91 and the second rf element 92 may be the same rf element or different rf elements. The radio frequency component comprises a radio frequency port for input and output of signals. The number of rf ports is determined according to the function of the rf element, and is not limited in the embodiments of the present disclosure.

In some embodiments, the ports of the filter 10 are disposed on the second surface of the first substrate 1, and the filter 10 is electrically connected to the corresponding conductive traces on the carrier board 8 through the conductive balls 30 disposed on the second surface of the first substrate 1. For example, the filter 10 and the carrier plate 8 are flip-chip bonded such that the conductive balls 30 are electrically connected to corresponding conductive traces on the carrier plate 8.

In some embodiments, as shown in fig. 1 and 2, the ports of the filter 10 include a first port, a second port and a third port, wherein the first port corresponds to the first conductive pillar 27, i.e., the first conductive pillar 27 serves as the first port of the filter 10, the second port corresponds to the second conductive pillar 28, i.e., the second conductive pillar 28 serves as the second port of the filter 10, and the third port corresponds to the third conductive pillar 29, i.e., the third conductive pillar 29 serves as the third port of the filter 10.

In some embodiments, the port of the filter 10 is disposed on the first surface of the first substrate 1 in the filter 10, and the pad disposed on the first surface of the first substrate 1 is electrically connected to the corresponding conductive trace on the carrier via a conductive lead.

As shown in fig. 3 and 5, the first surface of the first substrate 1 in the filter 10 is provided with first pads 81 and second pads 82, and the first pads 81 and second pads 82 are provided outside the dielectric cavity 3. The first pad 81 and the second pad 82 correspond to two ports of the filter 10, the first pad 81 is electrically connected to a conductive trace on the carrier board 8 by a first lead, and the second pad 82 is electrically connected to the conductive trace on the carrier board 8 by a second lead.

In the radio frequency circuit provided by the embodiment of the disclosure, the filter electrically connects the first planar inductance structure and the second planar inductance structure by using the columnar inductance structure, and the columnar inductance structure is located in the dielectric cavity, so that the inductance Q value of the columnar inductance structure is unrelated to the characteristics of the first substrate and the second substrate, and the inductance Q value of the columnar inductance structure can be improved, thereby reducing the insertion loss of the filter and further improving the overall characteristics of the radio frequency circuit.

The embodiment of the disclosure also provides an electronic device, which includes a filter, and the filter is the filter provided by the embodiment of the disclosure.

The electronic device can be a mobile phone, a tablet computer, an electronic watch, a sports bracelet, a notebook computer and the like. The implementation principle and the technical effect of the electronic device can refer to the above discussion of the implementation principle and the technical effect of the filter, and are not described herein again.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.

It is to be understood that the above embodiments are merely exemplary embodiments that are employed to illustrate the principles of the present disclosure, and that the present disclosure is not limited thereto. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the disclosure, and these are to be considered as the scope of the disclosure.

Claims

1. A filter, comprising: the dielectric substrate comprises a first substrate and a second substrate which are oppositely arranged, wherein a dielectric cavity is arranged between the first substrate and the second substrate; the filter further comprises:

2. The filter of claim 1, wherein a first conductive layer, a dielectric layer, and a second conductive layer are sequentially stacked on the first surface of the first substrate, the first electrode plate of the capacitor is disposed on the first conductive layer, the second electrode plate of the capacitor is disposed on the second conductive layer, and the dielectric of the capacitor is disposed on the dielectric layer.

3. The filter of claim 2, wherein the first planar inductive structure is disposed on the second conductive layer;

4. A filter according to claim 3, wherein a first protective layer is covered on a side of the surface of the second conductive layer facing away from the first substrate.

5. A filter according to claim 3, wherein a second protective layer is applied to the surface of the third conductive layer facing away from the second substrate.

6. The filter according to any of claims 1-5, wherein a sealing structure is provided at the periphery of the dielectric cavity between the first substrate and the second substrate, the first substrate, the second substrate and the sealing structure forming a closed cavity for the dielectric cavity.

7. The filter of claim 6, wherein the sealed cavity is filled with a dielectric gas.

8. The filter of claim 7, wherein the dielectric gas is air.

9. The filter of claim 1, wherein the first substrate has a first inductance via, a second inductance via, and a capacitance via penetrating through the thickness, and a first conductive pillar, a second conductive pillar, and a third conductive pillar are respectively disposed in the first inductance via, the second inductance via, and the capacitance via, and second ends of the first conductive pillar, the second conductive pillar, and the third conductive pillar are respectively electrically connected to a solder ball disposed on the second surface of the first substrate;

and the second end parts of the first conductive column, the second conductive column and the third conductive column are provided with conductive balls.

10. The filter of claim 1, wherein a first bonding pad, a second bonding pad and a third bonding pad are further disposed on the first surface of the first substrate, the first bonding pad is electrically connected to the columnar inductor structure corresponding to the first end of the inductor, the second bonding pad is electrically connected to the columnar inductor structure corresponding to the second end of the inductor, and the third bonding pad is electrically connected to the first electrode plate of the capacitor.

11. A method of making a filter, comprising:

and carrying out box processing on the first surface of the first substrate and the first surface of the second substrate, so that the first end part of the columnar inductance structure is electrically connected with the second planar inductance structure to form at least one inductor, the inductor is electrically connected with the capacitor, and a dielectric cavity is formed between the first substrate and the second substrate.

12. The method of claim 11, wherein the fabricating a first planar inductive structure and at least one capacitor on a first surface of a first substrate comprises:

13. The method of claim 12, wherein the performing a cartridge process on the first surface of the first substrate and the first surface of the second substrate to electrically connect the first end of the columnar inductive structure with the second planar inductive structure to form at least one inductor, and prior to forming a dielectric cavity between the first substrate and the second substrate, comprises:

implanting a connection ball at a first end of the columnar inductance structure;

arranging a sealing structure on the first surface of the second substrate and along the periphery of the second substrate;

14. The method of claim 12, wherein prior to fabricating the first planar inductive structure and the at least one capacitor on the first surface of the first substrate, further comprising:

15. A radio frequency circuit, comprising:

a filter, a port of the filter being electrically connected to the corresponding conductive line; the filter is the filter of any one of claims 1-10;

16. The radio frequency circuit of claim 15, wherein the port of the filter is disposed on the second surface of the first substrate of the filter, and the filter is electrically connected to a corresponding conductive trace on the carrier board via a conductive ball disposed on the second surface of the first substrate.

17. The radio frequency circuit of claim 15, wherein the port of the filter is disposed on a first surface of a first substrate of the filter, and the pad disposed on the first surface of the first substrate is electrically connected to a corresponding conductive trace on the carrier via a conductive trace.

18. An electronic device comprising a filter according to any one of claims 1-10.