Method for manufacturing aluminum nitride multilayer ceramic of side cavity structure

Abstract

The application discloses a manufacturing method of an aluminum nitride multilayer ceramic with a side cavity structure, and mainly comprises the following steps: laminating aluminum nitride green ceramic sheets to form a laminated body, wherein a main cavity and a side cavity are formed in the laminated body, a first filling piece is filled in the side cavity, and a second filling piece is filled in the main cavity; vacuum packaging and laminating; removing the first filling piece and the second filling piece; and finally sintering to obtain the aluminum nitride multilayer ceramic with the side cavity structure. The manufacturing method can well prevent cavity deformation, has high operability, and the product after lamination is in a good state, facilitating ceramic-metal welding in the later period.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aluminum nitride multilayer ceramic processing, and particularly relates to a manufacturing method of an aluminum nitride multilayer ceramic with a side cavity structure. BACKGROUND

[0002] Aluminum nitride ceramic has the characteristics of high thermal conductivity and small thermal expansion coefficient. The aluminum nitride multilayer ceramic has the advantages of vertical interconnection, shortened signal transmission path and high integration, and is widely used in hybrid integrated circuits, especially in ceramic housings for optical communication fields. In the application process, since the side needs to draw optical fibers or pipes, the side of the aluminum nitride multilayer ceramic needs to be opened to form a cavity, so as to realize airtight packaging. With the development of 5G and 6G communication, the demand for this type of housing is increasing every year.

[0003] At present, there are many manufacturing methods for aluminum nitride multilayer ceramics with a single cavity structure, but these methods are not suitable for the manufacturing of aluminum nitride multilayer ceramics with a side cavity structure. Since the side cavity of the aluminum nitride multilayer ceramic also needs to be welded with a metal pipe, the state of the side cavity and the flatness of the substrate surface are required to be high. If the control is not good during the lamination process of this type of ceramic substrate, problems such as cavity deformation, cracks, substrate surface bulging or collapse may occur. Although some volatile filling materials can be filled in the subsequent sintering to form a side cavity, since the degassing speed of the organic matter in the green ceramic sheet and the degassing speed of the volatile filling material are different, this still causes the product to be prone to cracking during the degassing process, which cannot meet the product demand. SUMMARY

[0004] Therefore, it is necessary to provide a manufacturing method of an aluminum nitride multilayer ceramic with a side cavity structure, which can prevent problems such as cavity deformation, cracks, substrate surface bulging or collapse, has high operability, and has a good product state after lamination, facilitating the subsequent ceramic-metal welding.

[0005] In order to achieve the above-mentioned purpose, the following technical solutions are adopted in the application:

[0006] The application provides a manufacturing method of an aluminum nitride multilayer ceramic with a side cavity structure, comprising the following steps:

[0007] Obtaining a first filling piece, a second filling piece, an anti-sticking film, a plurality of aluminum nitride green ceramic sheets and a metal cover plate;

[0008] The aluminum nitride green ceramic sheet is laminated to form a laminated body, the laminated body is formed with a main cavity and a side cavity, the first filler is filled in the side cavity, and the second filler is filled in the main cavity; a top layer of the laminated body is the metal cover plate, the metal cover plate is provided with a cavity with the same size as the main cavity, and the upper surface of the metal cover plate is flush with the upper surface of the second filler; the anti-sticking film is arranged between the metal cover plate and the aluminum nitride green ceramic sheet.

[0009] The laminated body is vacuum packaged and laminated to form a green ceramic body.

[0010] The first filler, the second filler, the anti-sticking film and the metal cover plate in the green ceramic body are removed.

[0011] The green ceramic body is sintered to obtain an aluminum nitride multilayer ceramic with a side cavity.

[0012] In a further scheme, the first filler is made of metal and has a surface treated for anti-sticking, and the second filler is made of rubber.

[0013] In a further scheme, the laminating is performed on a laminating plate, the laminating plate is provided with positioning pins, and the aluminum nitride green ceramic sheet, the second filler, the anti-sticking film and the metal cover plate are provided with positioning holes matched with the positioning pins.

[0014] In a further scheme, the thickness of the metal cover plate is between 200 and 400 microns.

[0015] In a further scheme, the outer size of the second filler is 0.10-0.15mm smaller than the single-side size of the main cavity.

[0016] In a further scheme, the length direction L of the first filler has the same size as the side cavity, and the width direction W and the thickness direction H of the first filler are 0.05mm-0.10mm smaller than the width and height of the side cavity, respectively.

[0017] In a further scheme, the laminated forming is performed by hot isostatic pressing, the preheating temperature of the hot isostatic pressing is 40-65℃, the isostatic pressing pressure is 6MPa-14MPa, and the pressure holding time is 300-500s.

[0018] In a further scheme, when the first filler is removed, the first filler is preheated at 60-70℃ for 15-20min and then taken out.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] The manufacturing method provided by the application places the first filling piece in the side cavity and the second filling piece in the main cavity during the lamination process, and the filling pieces can prevent the cavity from deforming, thereby obtaining the side cavity aluminum nitride ceramic. The manufacturing method has high operability, and the laminated product is in good condition, facilitating the subsequent ceramic-metal welding. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 FIG. 1 is a flowchart of a manufacturing method of a side cavity structure aluminum nitride multilayer ceramic according to a preferred embodiment of the application;

[0022] Figure 2 FIG. 2 is a sectional view of a side cavity according to an embodiment of the application;

[0023] Figure 3 FIG. 3 is a sectional view of the placement of filling pieces in the manufacturing process of a side cavity structure aluminum nitride multilayer ceramic according to an embodiment of the application.

[0024] In the figure: 10-first filling piece, 20-second filling piece, 30-anti-adhesion film, 40-metal cover plate. DETAILED DESCRIPTION

[0025] The embodiments of the application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the application, and cannot be understood as limiting the application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs. The terms used in the specification of the application herein are only for the purpose of describing the specific embodiments and are not intended to limit the application.

[0027] A manufacturing method of a side cavity structure aluminum nitride multilayer ceramic is disclosed in a preferred embodiment of the application, and the specific process is shown in FIG. 1, mainly including the following steps: Figure 1

[0028] S100, respectively obtaining a first filling piece, a second filling piece, an anti-adhesion film, a plurality of aluminum nitride green ceramic pieces, and a metal cover plate.

[0029] ​According to the embodiment of the present application, the first filling piece is used to fill the side cavity, and the second filling piece is used to fill the main cavity, wherein the first filling piece is made of metal material and its surface is treated by anti-sticking, wherein the metal material includes but is not limited to stainless steel, aluminum alloy and the like; the anti-sticking treatment can be Teflon treatment on the surface of the metal material, of course, other conventional anti-sticking treatments in the art can also be used in the present application; the second filling piece is made of rubber material, and specific examples can include but are not limited to silicone, AB glue and the like, so as to realize non-sticking metallization and prevent the product from being invalid due to the sticking of the printed metallized conductor band during lamination. The anti-sticking film and the metal cover plate can be made of conventional materials in the art, preferably, the thickness of the metal cover plate is 200-400 μm, which will not be specifically described herein. In addition, the aluminum nitride green ceramic sheet described herein refers to a treated green ceramic sheet, specifically, the aluminum nitride green ceramic sheet is pretreated (such as cleaning), punched, filled, printed, and then opened according to the needs of the product. Since the treatment of the green ceramic sheet is a conventional means in the art, it will not be specifically described here. Further, the outer dimensions of the first filling piece and the second filling piece are made according to the layout design of the product, so here will not be specifically limited.

[0030] S200, laminating step.

[0031] According to the layout design of the product, the aluminum nitride green ceramic sheet is laminated to form a laminated body, and the laminated body is formed with a main cavity and a side cavity. According to the embodiment of the present application, the specific process is as follows: the aluminum nitride green ceramic sheet is subjected to frame removal treatment, and is placed on a laminating plate in order, when the number of layers of the side cavity is reached, the first filling piece is placed at the corresponding side cavity position; then the corresponding aluminum nitride green ceramic sheet is sequentially laminated upward, after the placement of the aluminum nitride green ceramic sheet is completed, the anti-sticking film is placed, and finally the metal cover plate is placed on the top layer, specifically, the anti-sticking film is arranged between the metal cover plate and the aluminum nitride green ceramic sheet; wherein the opening position of the metal cover plate corresponds to the main cavity, after the metal cover plate is fixed, the second filling piece is placed, and the upper surface of the metal cover plate is flush with the upper surface of the second filling piece.

[0032] Further, in the embodiment of the present application, the laminating step is carried out on the laminating plate which is conventionally used in the art, specifically, the laminating plate is provided with positioning pins, and the aluminum nitride green ceramic sheet, the anti-sticking film, the metal cover plate and the second filling piece are provided with positioning holes, the positioning holes cooperate with the positioning pins to form an integral whole, preferably, the positioning position of each layer of green ceramic sheet and the mark can be made according to the positioning position of the laminating plate.

[0033] Further, in the embodiment of the present application, the size of the first filling piece filled in the side cavity must be well matched with the size of the side cavity in tolerance, preventing the collapse of the side cavity during lamination, while requiring the surface of the first filling piece to be smooth and easy to remove after lamination. Specifically, the length direction L of the first filling piece is the same size as the side cavity, and the width direction W and the thickness direction H of the first filling piece are 0.05-0.10mm smaller than the width and height of the side cavity, respectively. The second filling piece is 0.10-0.15mm smaller than the single side size of the main cavity, preventing the deformation of the filling piece extruding the cavity during lamination.

[0034] S300, lamination process.

[0035] Specifically, the laminated body obtained after lamination is vacuum packaged and then laminated, because the aluminum nitride porcelain body is easily hydrolyzed by water, which leads to the scrap of the material. According to the embodiment of the present application, the specific process is as follows: the laminated body is placed in a sealed bag for vacuum packaging, and in order to prevent the sealed bag from being damaged, two layers of sealed bags are preferably used for two times of sealing; it can be understood that the lamination molding process can use the conventional process in the art, and in the embodiment of the present application, hot isostatic pressing lamination molding is used, wherein the temperature, pressure, etc. of isostatic pressing can be adjusted according to the actual situation, and in some specific embodiments of the present application, the preheating temperature is 40-65℃, the isostatic pressing pressure is 6-14MPa, and the pressure holding time is 300-500s.

[0036] S400, obtaining a porcelain body.

[0037] Specifically, after lamination, the first filling piece, the second filling piece, the metal cover plate and the release film are removed to obtain a porcelain body with a side cavity structure. According to the embodiment of the present application, the filling pieces are taken out in reverse order according to the order in which they are placed, i.e. the second filling piece is taken out first, and then the metal cover plate, the release film and the first filling piece are taken out. In addition, it should be noted that when the first filling piece is taken out, it needs to be preheated on a 60-70℃ heating table for 15-20min before being taken out, which is to prevent cracks from occurring in the side cavity, and the edge of the side cavity taken out after preheating is complete.

[0038] S500, sintering to obtain an aluminum nitride multilayer ceramic.

[0039] Specifically, the green porcelain body with the side cavity structure is sintered to obtain the aluminum nitride multilayer ceramic. In the embodiment of the present application, the green porcelain body with the side cavity structure is cut, the cut green porcelain body is degreased, sintered, and sliced, and finally the aluminum nitride multilayer ceramic with the side cavity structure is obtained. It can be understood that cutting, degreasing, sintering, slicing and the like are all conventional processes in the art. For example, when cutting, the cutting line can be printed with a metallized pattern at the corresponding position of the green porcelain body for cutting alignment. Here, it will not be described one by one.

[0040] The aluminum nitride multilayer ceramic with the side cavity structure prepared by the preparation method in the embodiment has no problems such as collapse, deformation, and cracking of the side cavity, and the laminated product is in good condition, facilitating the later welding of ceramic-metal; and the preparation method has the advantage of high operability.

[0041] The present application will be described below through specific embodiments. It should be noted that the specific embodiments below are for illustrative purposes only and do not limit the scope of the present application in any way. In addition, unless otherwise specified, the methods without specifically described conditions or steps are conventional methods, and the reagents and materials used can be obtained from commercial channels.

[0042] Example 1

[0043] In the embodiment, a preparation method of an aluminum nitride multilayer ceramic with a side cavity structure is disclosed, and the specific steps are as follows:

[0044] S1. Design and manufacture corresponding first filler 10, second filler 20, release film 30, and metal cover plate 40 according to the product layout; wherein the first filler 10 is made of stainless steel and the surface is treated with Teflon release treatment; the second filler 20 is made of silica gel; and the length direction L dimension of the first filler 10 is the same as the size of the side cavity, and the width W and thickness H dimensions are 0.05 mm smaller than the width and height dimensions of the side cavity, as shown in FIG. 1. Figure 2 The outer dimensions of the second filler 20 are 0.10-0.15 mm smaller than the single side dimension of the main cavity.

[0045] S2. Perform pretreatment, punching, hole filling, printing, and cavity punching processes on the aluminum nitride green porcelain sheet, and simultaneously use the product cavity punching program to punch the cavities of the release film 30 and the metal cover plate 40, wherein the cavity opening size of the release film 30 is the same as the surface cavity size of the product, and the thickness of the metal cover plate 40 is 200 μm, and the cavity opening size is the same as the size of the main cavity of the aluminum nitride multilayer ceramic.

[0046] S3. Perform frame removal processing on the green porcelain sheet in step S2, and place it on the lamination plate according to the product design sequence to obtain a laminated body, as shown in FIG. 2. Figure 3The first filler 10 is placed in the corresponding side cavity position when the number of layers is placed to the side opening cavity; after the first filler 10 is placed, the corresponding green ceramic sheet is placed in turn upwards, the release film 30 is placed after the green ceramic sheet is placed, and finally the metal cover plate 40 is placed. The opening cavity position of the metal cover plate 40 corresponds to the opening cavity position of the substrate one by one, and after the position of the metal cover plate 40 is fixed, the second filler 20 is placed.

[0047] S4, the laminated body after lamination is placed in a sealed bag for vacuum packaging. In order to prevent the sealed bag from being damaged, two seals are required, and two layers of sealed bags are required.

[0048] S5, the laminated body after vacuum packaging is placed in a laminator for isostatic pressing forming. The preheating temperature of isostatic pressing forming is 50 DEG C, the isostatic pressing pressure is 10 MPa, and the pressure holding time is 400 s.

[0049] S6, after the lamination is finished, the laminated green ceramic body in the sealed bag is taken out; and after cooling, the second filler 20 is taken out first, and then the metal cover plate 40, the release film 30 and the first filler 10 are taken out. It is worth noting that when the first filler 10 is taken out, it needs to be taken out on a 65 DEG C heating table, and the preheating time is 17 min.

[0050] S7, the laminated green ceramic body is cut according to the required size, and the cutting line is printed on the corresponding position of the green ceramic body to cut the alignment. The cut green ceramic body is subjected to glue removal, sintering and abrasive wheel slicing process to obtain an aluminum nitride multilayer ceramic.

[0051] Example 2

[0052] In this embodiment, a manufacturing method of an aluminum nitride multilayer ceramic with a side cavity structure is disclosed, and the specific steps are as follows:

[0053] S1, according to the product layout design, the corresponding first filler 10, second filler 20, release film 30 and metal cover plate 40 are manufactured; wherein the first filler 10 is made of aluminum alloy and the surface is treated with Teflon release film; the second filler 20 is made of AB glue; and the length direction L size of the first filler 10 is the same as the size of the side cavity, and the width W and thickness H size are 0.08 mm smaller than the width and height size of the side cavity, as shown in Figure 2 The outer size of the second filler 20 is 0.12 mm smaller than the single side size of the main cavity.

[0054] S2, the aluminum nitride green sheet is pretreated, punched, filled, printed, and the cavity is punched, and the cavity of the product is punched out at the same time. The cavity size of the release film 30 is the same as the product surface cavity size, and the thickness of the metal cover plate 40 is 300μm, and the cavity size is the same as the size of the aluminum nitride multilayer ceramic main cavity.

[0055] S3, the green sheet in step S2 is removed from the frame, and is placed on the lamination plate according to the product design sequence to obtain a laminated body; when the number of layers is placed on the side cavity, the first filler 10 is placed in the corresponding side cavity position; after the first filler 10 is placed, the corresponding green sheet is placed in turn; after the green sheet is placed, the release film 30 is placed, and finally the metal cover plate 40 is placed. The cavity position of the metal cover plate 40 corresponds to the cavity position of the substrate one by one, and the second filler 20 is placed after the position of the metal cover plate 40 is fixed.

[0056] S4, the laminated body after lamination is placed in a sealed bag for vacuum packaging. In order to prevent the sealed bag from being damaged, it needs to be sealed twice, and two layers of sealed bags are needed.

[0057] S5, the vacuum packaged laminated body is placed in a laminator for isostatic pressing. The preheating temperature of isostatic pressing is 40℃, the isostatic pressing pressure is 6MPa, and the pressure holding time is 300s.

[0058] S6, after the lamination is finished, the laminated green ceramic blank in the sealed bag is taken out; and after cooling, the second filler 20 is taken out first, and then the metal cover plate 40, the release film 30 and the first filler 10 are taken out. It is worth noting that when the first filler 10 is taken out, it needs to be taken out on a 60℃ heating table, and the preheating time is 15min.

[0059] S7, the laminated green ceramic blank is cut according to the required size, and the cutting line is printed on the corresponding position of the green ceramic blank to cut the alignment; the cut green ceramic blank is treated by glue removal, sintering and grinding, and the aluminum nitride multilayer ceramic is obtained.

[0060] Example 3

[0061] The embodiment discloses a kind of aluminum nitride multilayer ceramic of side cavity structure, and its specific steps are as follows:

[0062] S1, according to the product layout design to make the corresponding first filler 10, second filler 20, anti-sticking film 30 and metal cover plate 40; wherein the first filler 10 is stainless steel material and the surface is treated with Teflon anti-sticking; the second filler 20 is AB glue material; and the length direction L size of the first filler 10 is the same as the side cavity size, and the width W and thickness H size are 0.10mm smaller than the width and height size of the side cavity, as shown in Figure 2 The outer size of the second filler 20 is 0.15mm smaller than the single side size of the main cavity.

[0063] S2, the aluminum nitride green sheet is pretreated, punched, filled, printed, and the cavity is punched, and the cavity of the anti-sticking film 30 and the metal cover plate 40 is punched out using the product cavity program, wherein the cavity size of the anti-sticking film 30 is the same as the product surface cavity size, and the thickness of the metal cover plate 40 is 400μm, and the cavity size is the same as the size of the aluminum nitride multilayer ceramic main cavity.

[0064] S3, the green sheet in step S2 is removed from the frame, and is placed on the laminated plate according to the product design sequence to obtain a laminated body; when the number of layers is placed to the side cavity, the first filler 10 is placed at the corresponding side cavity position; after the first filler 10 is placed, the corresponding green sheet is placed in turn; after the green sheet is placed, the anti-sticking film 30 is placed, and finally the metal cover plate 40 is placed, the cavity position of the metal cover plate 40 corresponds to the substrate cavity position one by one, and after the position of the metal cover plate 40 is fixed, the second filler 20 is placed.

[0065] S4, the laminated body after lamination is placed in a sealed bag for vacuum packaging, to prevent the sealed bag from being damaged, two seals are required, and two layers of sealed bags are required.

[0066] S5, the vacuum packaged laminated body is placed in a laminator for isostatic pressing, the preheating temperature of isostatic pressing is 65℃, the isostatic pressing pressure is 14MPa, and the pressure holding time is 500s.

[0067] S6, after the lamination is finished, the laminated green ceramic blank is taken out of the sealed bag; and after cooling, the second filler 20 is taken out first, and then the metal cover plate 40, the anti-sticking film 30 and the first filler 10 are taken out; it is worth noting that when the first filler 10 is taken out, it needs to be taken out on a 70℃ heating table, and the preheating time is 20min.

[0068] S7, the laminated green ceramic blank is cut according to the required size, and the cutting line is printed on the corresponding position of the green ceramic blank to serve as a cutting alignment; the cut green ceramic blank is treated by glue removal, sintering and abrasive wheel slicing process to obtain an aluminum nitride multilayer ceramic.

[0069] The aluminum nitride multilayer ceramic with the side cavity structure prepared in the above examples has no deformation, crack, substrate surface bulging or collapse problem, and the product state is good, meeting the product demand.

[0070] The technical features of the above embodiments can be combined arbitrarily, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not contradict, they should be considered as the scope of the description.

[0071] The above embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. A method of fabricating a side cavity structure aluminum nitride multilayer ceramic, characterized by, The method comprises the following steps: obtaining a first filler, a second filler, an anti-adhesion film, a plurality of aluminum nitride green ceramic sheets and a metal cover plate; stacking the aluminum nitride green ceramic sheets to form a laminated body, the laminated body being provided with a main cavity and a side cavity, the first filler being filled in the side cavity and the second filler being filled in the main cavity; the top layer of the laminated body is the metal cover plate, the metal cover plate being provided with a cavity with the same size as the main cavity, the upper surface of the metal cover plate being flush with the upper surface of the second filler; the anti-adhesion film is arranged between the metal cover plate and the aluminum nitride green ceramic sheets; vacuum packaging and laminating the laminated body to obtain a green ceramic body; removing the first filler, the second filler, the anti-adhesion film and the metal cover plate from the green ceramic body; sintering the green ceramic body to obtain an aluminum nitride multilayer ceramic with a side cavity; the first filler is made of metal and has an anti-adhesion surface treatment; The length direction of the first filling piece L The width direction of the side surface cavity W The thickness direction of the side surface cavity H The width and thickness of the side surface cavity are respectively 0.05mm-0.10mm smaller than the width and height of the side surface cavity. when the first filler is removed, the first filler is preheated at 60-70°C for 15-20 min and then taken out.

2. The method of claim 1, wherein the aluminum nitride multilayer ceramic is formed by a process comprising: forming a green sheet by mixing and kneading aluminum nitride powder, a binder, and a solvent; and drying the green sheet. the second filler is made of rubber.

3. The method of claim 1, wherein the aluminum nitride multilayer ceramic is formed by a side cavity structure. The stacking is performed on a stacking plate, the stacking plate being provided with positioning pins, the aluminum nitride green ceramic sheets, the second filler, the anti-adhesion film and the metal cover plate being provided with positioning holes, the positioning holes being matched with the positioning pins.

4. The method of claim 1, wherein the aluminum nitride multilayer ceramic is formed by a side cavity structure. The thickness of the metal cover plate is 200-400 μm.

5. The method of claim 1, wherein the aluminum nitride multilayer ceramic is formed by a side cavity structure. The outer size of the second filler is 0.10-0.15 mm smaller than the single-side size of the main cavity.

6. The method of claim 1, wherein the aluminum nitride multilayer ceramic is formed by a side cavity structure. The laminating is performed by hot isostatic pressing, the preheating temperature of the hot isostatic pressing being 40-65°C, the isostatic pressing pressure being 6 MPa-14 MPa, and the pressure maintaining time being 300-500 s.

7. An aluminum nitride multilayer ceramic of a side cavity structure, characterized by, The aluminum nitride multilayer ceramic with a side cavity is prepared by the method according to any one of claims 1-6.

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