WO2020009145A1

WO2020009145A1 - Method for producing high-frequency passive component

Info

Publication number: WO2020009145A1
Application number: PCT/JP2019/026447
Authority: WO
Inventors: 理額賀
Original assignee: 株式会社フジクラ
Priority date: 2018-07-06
Filing date: 2019-07-03
Publication date: 2020-01-09
Also published as: JP2020010179A

Abstract

This production method is for producing a high-frequency passive component that includes: a substrate comprising a dielectric material; and at least one of a through electrode and a side wall formed on the substrate. In the production method, a prototype having a recess that corresponds to at least one of a side wall and a through electrode is produced from glass, a mold that has a protrusion corresponding to the recess is produced from a metal using the prototype, a substrate comprising a first main surface on which a recess corresponding to the protrusion opens and a second main surface on the opposite side from the first main surface is produced from a resin using the mold, the second main surface of the substrate is polished, part of the recess forms an exposed section that is exposed on the second main surface, and a conductive layer serving as at least one of a side wall and a through electrode is formed on the recess opening on the first main surface of the substrate or on the exposed section exposed on the second main surface of the substrate.

Description

Manufacturing method of high frequency passive components

The present invention relates to a method for manufacturing a high-frequency passive component having a waveguide structure that can be used for high-frequency communication such as millimeter waves.
Priority is claimed on Japanese Patent Application No. 2018-129367, filed on July 6, 2018, the content of which is incorporated herein by reference.

In recent years, high-speed, large-capacity communication of several gigabits per second (bps) using the millimeter wave band has been proposed, and a part thereof is being realized. As a mode for realizing a small and inexpensive millimeter-wave communication module, for example, Patent Document 1 proposes a mode converter using a post-wall waveguide (Post-wall @ Waveguide).

JP 2014-158243 A

Patent Document 1 discloses a glass substrate, a quartz substrate, or the like as a substrate used for manufacturing a precise passive component. However, glass substrates, quartz substrates, and the like are difficult to process and take time, and thus have problems in manufacturing cost and mass productivity.

The present invention has been made in view of the above circumstances, and provides a method of manufacturing a high-frequency passive component capable of improving manufacturing cost and mass productivity.

In order to solve the above-described problem, one embodiment of the present invention is a method for manufacturing a high-frequency passive component including a substrate made of a dielectric, and at least one of a side wall and a through electrode formed on the substrate. Producing a prototype having a concave portion corresponding to at least one of the through electrodes from glass, using the prototype, producing a mold having a convex portion corresponding to the concave portion from metal, and using the mold, the convex portion A substrate having a first main surface in which a concave portion corresponding to the opening is provided and a second main surface opposite to the first main surface is produced from a resin, and the second main surface of the substrate is polished, A part of the concave part forms an exposed part exposed on the second main surface, and the concave part opened on the first main surface of the substrate, or the exposed part exposed on the second main surface of the substrate At least one of the side wall and the through electrode Forming a conductive layer made, to provide a method for manufacturing a high-frequency passive components.

The method for manufacturing a high-frequency passive component according to one embodiment of the present invention uses femtosecond laser-assisted etching when manufacturing the mold having the concave portion corresponding to at least one of the side wall and the through electrode from glass. You may.

In the method for manufacturing a high-frequency passive component according to one aspect of the present invention, a conductor layer is formed on the first main surface having the concave portion, and the exposed portion is formed such that a part of the concave portion is exposed on the second main surface. After that, a conductor layer may be formed on the second main surface.
In the method for manufacturing a high-frequency passive component according to one aspect of the present invention, the conductive layer may be formed on the first main surface having the concave portion before the formation of the exposed portion where a part of the concave portion is exposed on the second main surface. And a conductor layer formed on the first main surface where the recess is opened may be covered with an insulating material.

In the method of manufacturing a high-frequency passive component according to one aspect of the present invention, prior to forming the exposed portion in which a part of the recess is exposed to the second main surface, a sidewall and a through electrode may be formed in the recess of the substrate. Forming at least one of the conductor layers, and forming the exposed portion in which a part of the concave portion is exposed to the second main surface, forming the conductor layer formed in the concave portion on the second main surface. And may be used as at least one of the side wall and the through electrode.
In the method for manufacturing a high-frequency passive component according to one aspect of the present invention, the high-frequency passive component includes a conductor layer formed on both surfaces of the substrate and a waveguide region formed by a side wall or a through electrode connected to the conductor layer. It may have a waveguide structure configured to surround it.

The method for manufacturing a high-frequency passive component according to one aspect of the present invention includes the step of joining the substrate to a wiring substrate different from the substrate, forming a communication hole penetrating the substrate and the wiring substrate, A connection conductor may be formed in the hole to electrically connect a high-frequency passive component formed on the board to a wiring on the wiring board.

According to one embodiment of the present invention, precise processing is possible using a glass master as a master, a metal mold is produced in a desired number from the master, and at least one of a precise side wall and a through electrode is formed using the mold. The resin substrate on which is formed can be manufactured at low cost and low cost, and is excellent in mass productivity.

It is sectional drawing which shows the process of producing a type | mold from a prototype. It is sectional drawing which shows the process of producing a type | mold from a prototype. It is sectional drawing which shows the process of producing a type | mold from a prototype. It is sectional drawing which shows the process of producing a board | substrate from a type | mold. It is sectional drawing which shows the process of producing a board | substrate from a type | mold. It is sectional drawing which shows the process of producing a board | substrate from a type | mold. It is sectional drawing which shows the process of manufacturing a high frequency passive component. It is sectional drawing which shows the process of manufacturing a high frequency passive component. It is sectional drawing which shows the process of manufacturing a high frequency passive component. It is sectional drawing which shows the process of manufacturing a high frequency passive component. FIG. 4 is a cross-sectional view showing a step of joining a substrate to a wiring board. FIG. 4 is a cross-sectional view showing a step of joining a substrate to a wiring board.

Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. FIG. 1A, FIG. 1B, and FIG. 1C sequentially show steps of producing a mold from a prototype. 2A, 2B, and 2C sequentially show steps of manufacturing a substrate from a mold. FIG. 3A, FIG. 3B, FIG. 3C, and FIG. 3D sequentially show steps of manufacturing a high-frequency passive component on a substrate. 4A and 4B show a step of joining a substrate on which a high-frequency passive component is manufactured to another wiring substrate (a wiring substrate different from the substrate).

The method of manufacturing the high-frequency passive component according to the present embodiment has the following steps as schematically shown in FIGS. 1A to 3D.
A step of producing a prototype 10 from glass having a recess 11 corresponding to a side wall or a through electrode and a recess 12 corresponding to a through electrode (FIG. 1A).
A step of using the prototype 10 to fabricate a mold 20 having

projections

21 and 22 corresponding to the

recesses

11 and 12 of the prototype 10 from metal (FIGS. 1B and 1C).
Using the mold 20, the mold 20 has a first main surface 33 where the

concave portions

31 and 32 corresponding to the

convex portions

21 and 22 are open, and a second main surface 34 opposite to the first main surface 33. Step of manufacturing substrate 35 from substrate material 30 made of resin (FIGS. 2A to 2C).
A step of polishing the second main surface 34 of the substrate 35 to form an exposed portion EX in which a part of the

concave portions

31 and 32 of the substrate 35 is exposed to the second main surface 36 (FIGS. 3A to 3D).
The substrate 35 may be provided with side walls or through

electrodes

45 and 46.

Ａ As shown in FIG. 1A, the prototype 10 has a first main surface 13 in which the

concave portions

11 and 12 are open, and a second main surface 14 opposite to the first main surface 13. The

recesses

11 and 12 do not reach the second main surface 14, and the bottoms of the

recesses

11 and 12 are closed. In the present embodiment, the prototype 10 has the same shape as the substrate 35, and is used to transfer the shape of the prototype 10 to the mold 20, and further to transfer the shape of the mold 20 to the substrate material 30. That is, the prototype 10 is not a mold 20 for directly molding the substrate 35 but a master mold that is a base of the mold 20.

誘電 Glass is an example of a dielectric material constituting the prototype 10. Examples of the glass include multi-component glass, quartz glass (silica glass), and silicate glass. As a material similar to glass, inorganic materials such as sapphire, synthetic quartz, natural quartz, and semiconductors can be used. The dielectric substrate constituting the prototype 10 may be, for example, a wafer-shaped large-area substrate. 1A to 1C, the

concave portions

11 and 12 of the prototype 10 are displayed downward, but the prototype 10 may be arranged in a direction different from the downward direction.

方法 As a method of forming the

concave portions

11 and 12 in the prototype 10, a punching machine such as a drill, a laser, an etching and the like can be mentioned. For example, there is a method in which a material such as glass is locally modified by laser condensing irradiation, and a portion having high solubility due to the modification is selectively removed by wet etching. For example, femtosecond laser-assisted etching enables processing with high positional accuracy and high processing accuracy. The femtosecond laser-assisted etching referred to here means that, first, an ultrashort pulse laser having a pulse width of 10 ps or less is condensed and scanned to form a modified portion including a crack or a structurally modified portion along the condensed portion. Next, a processing method in which the modified portion is selectively etched by etching to provide the

concave portions

11 and 12 and the like. Not only can micropores having a high aspect ratio (ratio of depth to diameter) be formed, but also recesses of any shape including a tapered shape, a stepped shape, and the like can be processed. The tapered shape may have a smaller diameter or shape from the first main surface of the material to the second main surface or inside, or conversely, may have a larger diameter or shape.

(1) As shown in FIG. 1B, a metal is adhered to the

concave portions

11 and 12 and the first main surface 13 of the prototype 10 by electroforming or plating using a metal such as Ni, for example, to form the mold 20. The

protrusions

21 and 22 are made of metal deposited on the

recesses

11 and 12 of the prototype 10, and the base 23 is made of metal deposited on the first main surface 13 of the prototype 10. By peeling the master 10 and the mold 20, as shown in FIG. 1C, the mold 20 in which the

protrusions

21 and 22 project on one surface of the base 23 is obtained. Since the material constituting the prototype 10 is excellent in durability, the process of manufacturing the mold 20 from the prototype 10 using the same prototype 10 can be repeated a plurality of times.

2) As shown in FIG. 2A, a substrate material 30 made of resin is prepared, and as shown in FIG. 2B, the substrate material 30 is overlaid on the

projections

21 and 22 of the mold 20. Substrate material 30 may be a flat film, sheet, or the like. Preferred resins for the substrate material 30 include cycloolefin copolymer (COC), fluororesin, liquid crystal polymer (LCP) and the like. 2A to 2C, the

protrusions

21 and 22 of the mold 20 are displayed upward, but the mold 20 may be arranged in a different direction from the upward.

When the resin constituting the substrate material 30 is a thermoplastic resin, the resin is softened by heating, the shape of the mold 20 is transferred to the substrate material 30 by the hot embossing method, and the concave portions having the shapes corresponding to the

convex portions

21 and 22 are formed. 31, 32 can be formed. When the substrate material 30 is a curable resin such as a thermosetting resin or a photo-curable resin, the substrate material 30 is applied to the mold 20 in an uncured state having fluidity such as a liquid, and is superimposed on the mold 20. By curing the resin as it is, the

concave portions

31 and 32 having shapes corresponding to the

convex portions

21 and 22 can be formed.

By peeling off the mold 20 and the substrate material 30, as shown in FIG. 2C, a substrate 35 having the

concave portions

31 and 32 formed in the first main surface 33 in contact with the base 23 of the mold 20 is obtained. The first main surface 33 is a surface where the

concave portions

31 and 32 are opened. The second main surface 34 is a surface opposite to the first main surface 33. The

recesses

31 and 32 do not reach the second main surface 34, and the bottoms of the

recesses

31 and 32 are closed. Since the material constituting the mold 20 is excellent in durability, the step of forming the substrate 35 having the

concave portions

31 and 32 using the same mold 20 can be repeated a plurality of times.

As shown in FIG. 3A, the first conductor layers 41, 42, and 43 are provided on each of the concave portion 31, the concave portion 32, and the first main surface 33 with respect to the substrate 35 having the

concave portions

31 and 32 opened on the first main surface 33. Is formed. Specifically, among these conductor layers, the first conductor layer 41 is formed on the inner wall of the recess 31, the first conductor layer 42 is formed on the inner wall of the recess 32, and the first conductor layer 43 is formed on the first wall. It is formed on the main surface 33. In this structure, the first conductor layers 41, 42, 43 are formed so as to conform to the respective surface shapes (inner wall, bottom wall, surface) of the concave portion 31, the concave portion 32, and the first main surface 33. The first conductor layers 41 and formed on the inner walls of the

recesses

31 and 32 are not exposed on the second main surface of the substrate. The first conductor layer 42 forms a blind via. The first conductor layer 41 forms a blind via when the concave portion 31 has a hole shape. The first conductor layer 41 forms a continuous side wall 45 when the concave portion 31 has a continuous groove shape along the waveguide structure 48 shown in FIG. 3D. The range in which the groove-shaped concave portion 31 or the side wall 45 is continuous is not particularly limited as long as it is at least a part in the longitudinal direction or the width direction of the waveguide structure 48, and may be over the entire circumference of the waveguide structure 48.

As a method of forming a conductor layer such as the first conductor layers 41, 42, and 43, one or two or more of a sputtering method, a vapor deposition method, an electroless plating method, an electrolytic plating method, and a method of applying a conductor paste are used. Method. Two or more kinds of conductor materials or film forming methods may be used in combination, and two or more kinds of conductors may be laminated to form a conductor layer. When a conductor layer is formed on an insulator, a seed layer is formed with a smaller thickness than the target by sputtering, vapor deposition, or electroless plating, and then the conductor is laminated to the target thickness by electrolytic plating. You may. On the surfaces of the first conductor layers 41, 42, and 43 (the outer surface opposite to the surface in contact with the substrate 35), an oxidation preventing layer such as NiAu or NiPdAu may be provided to prevent oxidation. Further, patterning or the like may be appropriately performed so that the first conductive layer 43 has a shape such as a wiring and a pad.

(3) As shown in FIG. 3B, the first main surface 33 of the substrate 35 having the first conductor layer 43 formed on the first main surface 33 is covered with an insulating material 44. The insulating material 44 may be filled in the

recesses

31 and 32. Examples of the insulating material 44 include a resin. Thereby, as described later, when the second main surface 34 of the substrate 35 is polished, the first conductive layer formed on each of the inner wall of the concave portion 31, the inner wall of the concave portion 32, and the surface of the first main surface 33 is formed. 41, 42 and 43 can be protected. When the first conductor layer 41 serves as a side wall, the second main surface 34 of the substrate 35 is polished, and when the

concave portions

31 and 32 are exposed on the second main surface 36 of the substrate 35, the insulating material 44 is bonded to the bonding material. Alternatively, it functions as an adhesive and can prevent the waveguide structure 48 from separating from the substrate 35.

As shown in FIG. 3C, by polishing the second main surface 34 of the substrate 35, a part of the

recesses

31 and 32 is exposed to a new second main surface 36 (polishing processing surface, surface obtained by polishing). The exposed portion EX is formed. In addition, the first conductor layers 41 and 42 formed in the

concave portions

31 and 32 are exposed on the new second main surface 36 to become the side walls or the through electrodes 45 and the through electrodes 46 (exposed electrodes). The shapes of the side wall or through electrode 45 and the through electrode 46 are based on the shapes of the precisely formed recesses 31 and 32 according to the shapes of the

recesses

11 and 12 of the prototype 10, respectively. Thereby, highly accurate side walls and through holes can be formed in the substrate 35 made of resin.

Ｄ As shown in FIG. 3D, a second conductor layer 47 is formed on the second main surface 36 of the substrate 35. The method of forming the second conductor layer 47 may be the same as the method of forming the first conductor layers 41, 42, and 43, as described above. Further, as described above, an oxidation preventing layer may be provided on the surface of the second conductor layer 47 (the outer surface opposite to the surface in contact with the substrate 35), and the second conductor layer 47 may be appropriately patterned. Good. The second conductor layer 47 formed on the second main surface 36 may be the same as or different from the first conductor layer 43 formed on the first main surface 33 with respect to the layer configuration, patterning, and the like. .

As a method of forming a patterned conductor layer using a patterned resist, for example, the following two methods can be mentioned.
(1) A method in which a conductor layer is formed after a patterned resist is formed, the conductor layer laminated on the resist is removed together with the resist, and the conductor layer is left in a region where there is no resist (lift-off).
(2) After forming a patterned resist on the entire surface of the conductor layer, the material layer in a region not covered with the resist is removed by etching or the like, and if necessary, unnecessary resist is removed. Method.
The etching method can be appropriately selected from various types such as dry etching and wet etching.

The side wall or the through electrode 45 and the through electrode 46 formed on the substrate 35 may constitute a passive component (passive device) such as a waveguide, a filter, a diplexer, a directional coupler, and a distributor. For example, when the dielectric constituting the substrate 35 has a region surrounded by the first conductor layer 43, the second conductor layer 47, and the side wall 45, a waveguide structure 48 similar to a waveguide may be constituted. it can. This waveguide structure can be used, for example, as a high-frequency device through which a high-frequency signal (electromagnetic wave) such as a millimeter wave is propagated. Although the frequency is not particularly limited, for example, 30 to 300 GHz, 60 to 80 GHz and the like can be mentioned.

ポスト As a waveguide structure composed of a conductor layer and a through electrode, for example, a post wall waveguide can be mentioned. For example, a wide wall grounded by connecting to a ground potential may be provided on both main surfaces of the substrate constituting the post wall waveguide. The through electrodes can constitute a wall surrounding the waveguide structure by arranging a large number of through electrodes, for example. Examples of the wall portion formed of the through electrode include a narrow wall facing the width direction of the waveguide structure, a short wall provided at an end in the longitudinal direction, and other side walls. The shape of the through-electrode forming the wall is not limited to the cylindrical shape as shown in FIGS. 3A to 3D, but may be a cylindrical shape or the like. In addition, the arrangement of the through electrodes can be variously configured in accordance with the function of the passive component, and the like. A portion in which the through electrodes are arranged at equal intervals, a portion in which the intervals between the through electrodes are uneven, and A portion that is not arranged over a section may be provided.

貫通 The through electrode 46 provided inside the waveguide structure 48 may constitute a mode conversion mechanism. The mode conversion mechanism is connected to a wiring layer (not shown) provided outside the waveguide structure 48, and inputs an electric signal from the wiring layer to the waveguide structure, or inputs a signal from the waveguide structure to the wiring layer. To output electrical signals.

As shown in FIG. 3D, in the case of the substrate 35 having passive components such as the waveguide structure 48, when the substrate 35 has a plurality of passive components mounted thereon, a singulation process of cutting the substrate for each passive component is performed. May have. As a device for cutting a substrate, a known processing device using a blade dicer, a laser, or the like can be given.

FIGS. 4A and 4B show an example of a process of joining the passive component 40 in which the waveguide structure 48 is formed on the substrate 35 to the wiring substrate 50. The wiring board 50 has a wiring layer 52 on at least one surface of an insulating base material 51. In the case of FIG. 4A, the second conductor layer 47 of the passive component 40 is overlaid on the side facing the wiring board 50. The wiring layer 52 on the side facing the passive component 40 is provided with an insulating layer 53 for protecting the wiring layer 52 and the like. Thus, a structure in which the insulating layer 53 is interposed between the second conductor layer 47 and the wiring layer 52 is obtained. The joining method between the passive component 40 and the wiring board 50 is not particularly limited, and examples thereof include an adhesive, soldering, and a mechanical structure such as fitting or engaging.

When the passive component 40 is electrically connected to the wiring board 50, for example, as shown in FIG. 4B, after forming a communication hole 55 penetrating the passive component 40 and the wiring board 50, by electroless plating or the like, The connection conductor 54 may be formed in the communication hole 55. Thus, the waveguide structure 48 formed on the substrate 35 and the wiring layer 52 of the wiring substrate 50 can be electrically connected. The connection conductor 54 and the communication hole 55 may penetrate the second conductor layer 47 and may be arranged between the side walls 45 or on the insulating material 44 inside the through electrode 45. A device for forming the communication hole 55 is not particularly limited, and examples thereof include a drilling machine such as a drill, a laser, and the like.

Although the present invention has been described based on the preferred embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention. Modifications include addition, substitution, omission, and other changes of the components in each embodiment.

方法 The method of providing the through electrode in the through hole is not limited to the method of forming the conductor layer in the concave portion before polishing the second main surface of the substrate as in the above-described embodiment. For example, after the second main surface of the substrate is polished to form a through hole in the substrate, the conductor layer may be formed in the through hole.

In the high-frequency passive component according to the above-described embodiment, a plurality of components may be configured on the same substrate. Other components configured on the substrate are not limited to high frequency passive components, and may include other passive components, active components, and the like. By modularizing the components, a high-frequency module can be configured. The high-frequency module of the present embodiment is, for example, a module including the above-described high-frequency passive component. Various components necessary for the function can be incorporated in the module.

Reference numerals 10: prototype, 11, 12: prototype recess, 20: mold, 21, 22, ... projection, 30: substrate material, 31, 32: recess, 35: substrate, 40: passive component, 41, 42, 43 ... A first conductor layer, 44 an insulating material, 45 a side wall or through electrode, 46 a through electrode, 47 a second conductor layer, 48 a waveguide structure, 50 a wiring board, 52 a wiring layer, 54 a connection conductor , 55 ... communication holes.

Claims

A method for manufacturing a high-frequency passive component having a substrate made of a dielectric material and at least one of a side wall and a through electrode formed on the substrate,
Producing a prototype having a concave portion corresponding to at least one of the side wall and the through electrode from glass,
Using the prototype, a mold having a convex portion corresponding to the concave portion is made of metal,
Using the mold, a substrate having a first main surface in which a concave portion corresponding to the convex portion is opened and a second main surface opposite to the first main surface is produced from a resin,
Polishing the second main surface of the substrate to form an exposed portion in which a part of the concave portion is exposed on the second main surface;
Forming a conductor layer to be at least one of a side wall and a through electrode on the concave portion opened on the first main surface of the substrate, or on the exposed portion exposed on the second main surface of the substrate;
Manufacturing method of high frequency passive components.
2. The method for manufacturing a high-frequency passive component according to claim 1, wherein when the mold having the concave portion corresponding to at least one of the side wall and the through electrode is manufactured from glass, femtosecond laser-assisted etching is used.
Forming a conductor layer on the first main surface having the concave portion;
After forming the exposed portion where a part of the concave portion is exposed on the second main surface, a conductor layer is formed on the second main surface.
The method for manufacturing a high-frequency passive component according to claim 1.
Prior to the formation of the exposed portion where a part of the concave portion is exposed on the second main surface,
Forming a conductor layer on the first main surface having the concave portion;
Covering the conductor layer formed on the first main surface where the concave portion opens with an insulating material;
The method for manufacturing a high-frequency passive component according to claim 1.
Prior to the formation of the exposed portion where a part of the concave portion is exposed on the second main surface, a conductive layer to be at least one of a side wall and a through electrode is formed in the concave portion of the substrate,
When forming the exposed portion in which a part of the concave portion is exposed on the second main surface, the conductive layer formed on the concave portion is exposed on the second main surface, and the side wall and the through electrode are formed. The method for manufacturing a high-frequency passive component according to any one of claims 1 to 4, wherein the method is at least one.
2. The high-frequency passive component according to claim 1, having a waveguide structure configured to surround a conductor layer formed on both surfaces of the substrate and a waveguide region by a sidewall or a through electrode connected to the conductor layer. 3. A method for manufacturing the high-frequency passive component according to claim 5.
Bonding the substrate on a wiring substrate different from the substrate,
Forming a communication hole penetrating the substrate and the wiring substrate,
Forming a connection conductor in the communication hole, and electrically connecting a high-frequency passive component formed on the substrate and the wiring of the wiring substrate,
A method for manufacturing a high-frequency passive component according to any one of claims 3 to 6.