WO2024021199A1

WO2024021199A1 - Laser drilling method for green ceramic sheet

Info

Publication number: WO2024021199A1
Application number: PCT/CN2022/113291
Authority: WO
Inventors: 陶克文; 田振; 罗雄科
Original assignee: 上海泽丰半导体科技有限公司
Priority date: 2022-07-29
Filing date: 2022-08-18
Publication date: 2024-02-01
Also published as: CN115156740A

Abstract

Provided in the present application is a laser drilling method for a green ceramic sheet. The laser drilling method for a green ceramic sheet comprises: arranging an attached film on a back surface of a green ceramic sheet to be drilled to obtain a first green ceramic sheet; placing the first green ceramic sheet on a target cardboard; and drilling the first green ceramic sheet to obtain a second green ceramic sheet having a target hole. In the embodiments of the present description, an auxiliary film, etc. are attached to a green ceramic tape for drilling, thereby improving the accuracy of the roundness and size for drilling the green ceramic tape, such that the quality of a drilled hole is improved, no molten slag appears on the edge of the drilled hole, and the phenomenon of burning by light and heat is avoided; and a subsequent hole filling process is not affected, the use of a high-cost ultra-fast laser or short-wavelength laser is not required, there is no need to spend a relatively long time in debugging a specific laser within a small range to perform drilling, the stability requirement for laser drilling is improved, and the applicability in laser drilling is relatively wide.

Description

A method of laser drilling of green ceramic tiles

Technical field

This application relates to the technical field of LTCC, and specifically to a method of laser drilling of green ceramic wafers.

Background technique

LTCC (Low Temperature Co-fired Ceramic, Low Temperature Co-fired Ceramic) uses laser drilling, microhole grouting, precision conductor paste printing and other processes to produce the required circuit patterns on the green ceramic tape, and combines multiple passive devices It is embedded in it for lamination, and IC and active devices are mounted on its surface, ultimately forming a LTCC passive/active integrated functional module. After the green porcelain tape is punched, the through holes between each layer of green porcelain are filled with conductor slurry to achieve interconnection between multiple layers. Therefore, the quality of the green porcelain tape punching will affect subsequent hole filling and other processes.

At present, laser drilling and mechanical punching are mainly used for drilling green porcelain tapes in LTCC technology. With the development of electronic components in the direction of miniaturization and lightweight, due to the high hardness and brittleness of ceramic materials, as the size of micropores becomes smaller and precision requirements become higher, mechanical punching processing efficiency is low and small-sized tools are easily damaged. The shortcomings are becoming more and more prominent. Although laser drilling has the characteristics of non-contact, when processing a large number of micropores and the size of the micropores is small, the laser needs to adjust different laser parameters for drilling processing of green ceramic tiles with different material parameters. On the one hand, it is impossible to adjust the laser parameters to the appropriate ones for different material parameters. On the other hand, even if the laser parameters are adjusted to the appropriate laser parameters, the drilling quality is poor, with defects such as slag on the edges of the holes and foreign matter in the holes, which seriously affects subsequent processing. Hole filling process. In some cases, even if ultrafast lasers or short-wavelength lasers are used to drill holes to avoid the above defects, such lasers have extremely high requirements for production equipment and greatly increase production costs. Moreover, even if this type of laser is used, there is still a need to adjust appropriate laser parameters for different material parameters. The adjustment time is long, resulting in a long drilling time cycle. The range of laser parameters explored is narrow, and it still cannot meet the stability requirements of laser drilling equipment. Require.

Therefore, a new laser drilling solution for green ceramic wafers is needed.

Contents of the invention

In view of this, embodiments of this specification provide a green ceramic wafer laser drilling method, which is applied to the LTCC module circuit substrate to obtain the corresponding green ceramic tape drilling process.

The embodiments of this specification provide the following technical solutions:

The embodiment of this specification provides a method for laser drilling of green porcelain wafers. The method of laser drilling of green porcelain wafers includes:

Set an attachment film on the back of the green porcelain piece to be drilled to obtain the first green porcelain piece;

Place the first green tile on the target cardboard;

Drill holes in the first green ceramic tile to obtain a second green ceramic tile with target holes.

Compared with the existing technology, the beneficial effects achieved by at least one of the above technical solutions adopted in the embodiments of this specification at least include:

By arranging a material that can assist in drilling the green ceramic sheet to be drilled during the drilling process (the auxiliary material is simple in design), the operation is simple, but will not affect the laser drilling process. Not only can efficient and high-precision laser drilling be achieved, hole, avoiding the occurrence of slag, burning and other phenomena at the edge of the hole after drilling, and there is no need to use high-cost ultra-fast laser or short-wavelength laser, and there is no need to spend a long time debugging a small range of specific laser for drilling, improving laser drilling hole stability requirements, and has wider applicability for laser drilling.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. Those skilled in the art can also obtain other drawings based on these drawings without exerting creative efforts.

Figure 1 is a schematic diagram of the laser drilling results of the prior art;

Figure 2 is a schematic diagram of the laser drilling results provided by the embodiment of this specification;

Figure 3 is a schematic diagram of rolling the attached film before laser drilling according to the embodiment of this specification;

Figure 4 is a schematic diagram of setting a target cardboard with initial holes provided by the embodiment of this specification;

Figure 5 is a schematic diagram of laser drilling of green ceramic wafers provided by the embodiment of this specification;

Figure 6 is a flow chart of a method for laser drilling of green ceramic wafers provided by an embodiment of this specification.

Detailed ways

The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

The following describes the implementation of the present application through specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments. This application can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, as long as there is no conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

To illustrate, the following describes various aspects of embodiments that are within the scope of the appended claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is illustrative only. Based on this application, those skilled in the art will appreciate that one aspect described herein can be implemented independently of any other aspect, and that two or more of these aspects can be combined in various ways. For example, apparatuses may be implemented and/or methods practiced using any of the numbers and aspects set forth herein. Additionally, such apparatus may be implemented and/or methods practiced using other structures and/or functionality in addition to one or more of the aspects set forth herein.

It should also be noted that the diagrams provided in the following embodiments are only schematically illustrating the basic concept of the present application. The drawings only show the components related to the present application and are not based on the number, shape and number of components during actual implementation. Dimension drawing, in actual implementation, the type, quantity and proportion of each component can be arbitrarily changed, and the component layout type may also be more complex.

Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, one skilled in the art will understand that practices may be practiced without these specific details.

LTCC green porcelain tape is an important process part of LTCC components and components. The green porcelain tape is drilled and then filled with conductor paste in the holes to achieve multi-layer interconnection. Therefore, the quality of green porcelain tape drilling will affect subsequent hole filling and other processes.

In view of this, the inventor found that as electronic components become lighter, the requirements for drilling green ceramic tapes become higher, and general mechanical drilling is inefficient and cannot meet the requirements for high-precision drilling. Laser drilling requires a specific laser to drill due to the hardness and brittleness of ceramic materials, but its production cost is extremely high. Or using laser drilling in a general light wave range requires debugging laser parameters and taking a long time to adjust. Not only cannot high-precision laser drilling be achieved, but it also causes problems such as long laser drilling cycles and low efficiency.

Based on this, the embodiment of this specification proposes a treatment plan: due to the particularity of the green porcelain sheet material in the existing technology, slag, foreign matter in the hole, etc. will easily appear at the edge of the hole after laser drilling. As shown in Figure 1 in the embodiment of the present invention, by arranging materials that can assist the drilling of green ceramic sheets to be drilled during the drilling process, but will not affect the laser drilling process, not only efficient and high-precision laser drilling can be achieved Drilling, and there is no need to use a specific laser for drilling, which means there is no need to increase the production cost, and it also avoids the occurrence of slag, burning and other phenomena at the edge of the hole after drilling.

The following describes the technical solutions provided by each embodiment of the present application with reference to the accompanying drawings.

As shown in FIG. 6 , the embodiment of this specification provides a method for laser drilling of green ceramic wafers, which may include steps S210 to S230. In step S210, an adhesion film is provided on the back of the green ceramic sheet to be drilled to obtain a first green ceramic sheet. In some embodiments, the back side of the green porcelain sheet is a polyester support film surface.

As shown in Figure 3, place the back side of the green porcelain sheet (such as the polyester support film side) upward. Starting from one side of the green porcelain sheet, use the roller on the laminating equipment to compact and adhere to the back of the green porcelain sheet. film, so that the attached film is completely attached to the back of the green porcelain tile (polyester support film surface) to obtain the first green tile. The first green ceramic piece is placed for subsequent drilling.

Step S220: Place the first green tile on the target cardboard. In some embodiments, the target cardboard includes hard cardboard, such as cardboard, and can be pre-punched on the corresponding position of the cardboard using a laser. In other implementations, the target cardboard is just non-adhesive white paper.

The embodiment of this specification uses the target cardboard to complete the subsequent laser drilling process of the first green porcelain piece, without the need for complicated auxiliary material design, the operation is simple, and can also improve the quality of laser drilling on the green porcelain piece and avoid the edge of the hole after drilling. There is no need to use high-cost ultrafast lasers or short-wavelength lasers to prevent slag, burning and other phenomena. There is no need to spend a long time debugging a small range of specific lasers for drilling, and the requirements for improving the stability of laser drilling have a wide range of applications. Laser drilling suitability.

Step S230: Drill holes on the first green ceramic tile to obtain a second green tile with target holes.

In conjunction with the above embodiment, as shown in FIG. 5 , after placing the first green porcelain piece on the target cardboard, a laser is used to drill holes on the first green porcelain piece to obtain a second green porcelain piece with target holes. During this process, a vacuum is maintained underneath the target cardboard. In some embodiments, the target cardboard on which the green ceramic tiles are placed is different. The laser energy during the laser drilling process is 20-25W, the number of elements is 10 times, and the scanning speed can adapt to the changes. However, the laser wavelength, laser pulse width and laser parameter range basically remain unchanged. In addition, the number of attached films and target cardboards can be adjusted adaptively according to the actual punching requirements, thereby achieving high-precision punching. See Figure 5 to set up two layers of attached films, etc. In some embodiments, the green ceramic tape suitable for LTCC laser drilling has an adhesive film itself. An additional layer of adhesive film can be added before drilling to better realize laser drilling. The laser drilling in Figure 5 can also be displayed. Hole diagram.

The embodiment of this specification uses the target cardboard to complete the subsequent laser drilling process of the first green porcelain piece, without the need for complex auxiliary material design, the operation is simple, and can also improve the quality of laser drilling on the green porcelain piece, as shown in Figure 2 Figure, avoids the occurrence of slag, burning and other phenomena at the edge of the hole after drilling. There is no need to use high-cost ultra-fast laser or short-wavelength laser, and there is no need to spend a long time debugging a small range of specific laser for drilling, improving laser drilling. The stability means that the perfect laser drilling process can be achieved by using the above-mentioned wider range of laser, without spending a long time adjusting laser parameters, etc., and has wider applicability of laser drilling.

In some embodiments, the method for laser drilling green ceramic tiles further includes: obtaining a green ceramic tile to be drilled, and the back side of the green ceramic tile to be drilled includes a polyester support film surface.

Specifically, the cast green porcelain tape is cut into a green porcelain piece of a preset size, for example, a 200*200 mm green porcelain piece, and the back of the green porcelain piece includes a polyester support film surface. Put the cut green porcelain piece into an oven, dry it at 60° C. for 30 minutes, take out the green porcelain piece from the oven and lower it to room temperature in preparation for subsequent laser drilling.

In some embodiments, disposing an adhesive film on the green porcelain sheet to be punched to obtain the first green porcelain sheet includes: rolling the green porcelain sheet to be punched so that the adhesive film adheres to the green porcelain sheet to be punched. The back side of the raw porcelain piece. Refer to Figure 3 for details. Place the back of the green porcelain tile (for example, the polyester support film side) facing up. Starting from one side of the green porcelain tile, use the roller on the laminating equipment to compact the attached film on the back of the green porcelain tile. The adhesive film is completely attached to the back of the green porcelain tile (polyester support film surface) to obtain the first green tile. The first green ceramic piece is placed for subsequent drilling.

In some implementations, the green ceramic wafer laser drilling method also includes: using a laser to punch holes in a cardboard with a preset thickness to obtain a target cardboard with initial holes. Among them, the initial hole is larger than the target hole. In other embodiments, there is no need to provide initial holes on the target cardboard, and only non-sticky and breathable white paper is required.

In some embodiments, the target cardboard thickness is 1 mm.

Refer to Figure 4. As shown in Figure 4, a 1mm thick cardboard is placed on a semi-hollow laser drilling work platform. The laser drilling equipment is used to process the cardboard on the cardboard according to the drilling requirements and punching positions of the green porcelain sheets. Micropores with the size of the original drawing, for example micropores with a diameter slightly larger than 20 microns, can obtain the target cardboard with initial holes. In the subsequent laser drilling process, by setting the target cardboard with the initial hole under the first green ceramic piece, the efficiency of drilling is improved, the accuracy and accuracy of drilling are improved, and slag is avoided at the edge of the hole after drilling. , burning and other phenomena, there is no need to use high-cost ultra-fast lasers or short-wavelength lasers, and there is no need to spend a long time debugging a small range of specific lasers for drilling. To improve the stability of laser drilling, use the above-mentioned wider range of lasers, There is no need to spend a long time adjusting laser parameters to achieve a perfect laser drilling process, which has a wide range of laser drilling applicability.

In some embodiments, drilling a hole on the first green porcelain piece to obtain a second green porcelain piece with a target hole includes: according to the position of the initial hole, the adhesion film of the first green porcelain piece fits the said The target cardboard places the first green tile on the target cardboard, uses laser drilling according to the position of the initial hole, and obtains the second green tile with the target hole from the first green tile.

Combined with Figure 5, after obtaining the target cardboard with the initial hole, according to the position of the initial hole, fit the adherent film of the first green porcelain piece to the target cardboard and place the first green porcelain piece on it, that is, the first green porcelain piece. Place the piece face up on the target cardboard. Extract a vacuum inside the laser drilling platform, that is, the bottom of the target cardboard is in a vacuum state. Then, according to the position of the initial hole, laser drilling is used. Specifically, the laser wavelength is 355nm and the laser pulse width is less than 350 picoseconds. The laser is used to drill the green ceramic sheet. The parameter range is laser frequency 600-800kHz and laser energy 20-22W element times. 10 times; scanning speed 500-800; jump speed 6000. Finally, the second green ceramic chip with the target hole is obtained from the first green ceramic chip.

In some embodiments, after obtaining the second green porcelain piece with the target hole, the method further includes: irradiating the second green porcelain piece with UV (Ultra-Violet Ray, ultraviolet lamp) light, so that the second green porcelain piece on the The attached film loses its viscosity, and the attached film is removed to obtain the target green ceramic tile.

Combined with the above embodiment, after obtaining the second green porcelain piece with the target hole, it is necessary to irradiate the second green porcelain piece with a UV lamp to make the adhesive film on it lose its stickiness, and then tear off the failed adhesion film to obtain Target green tiles.

In some embodiments, after obtaining the first green ceramic tile, it is directly placed on non-sticky and breathable white paper for laser drilling, thereby obtaining a target green ceramic tile with target holes. That is, the second green tile is the target green tile. The method of obtaining the green ceramic sheet to be drilled in this process is the same as that of the above embodiment, and will not be described again here. Specifically, during the drilling process, place the green porcelain piece with the adhesive film face up on the laser drilling workbench equipped with the non-sticky breathable cardboard, and vacuum the inside of the platform to make the back side of the green porcelain piece It is a negative pressure state. The specific laser parameters are laser wavelength 355nm, laser pulse width less than 350 picoseconds, laser drilling of green ceramic wafers, parameter range: laser frequency 600-800kHz, laser energy 23-25W element times 10 times; scanning speed 400-600; Jump speed 6000. After drilling, turn off the vacuum adsorption, take out the green porcelain piece with the target hole, and complete the processing of the target green porcelain piece.

Therefore, in some embodiments, the laser wavelength of the drilling laser is 355 nm, the laser pulse width is less than 350 picoseconds, and the laser frequency is 600-800 kHz to drill the green ceramic wafer. As described in detail above, no further details will be given here.

The embodiments of this specification provide a material that can assist the drilling of the green ceramic sheet to be drilled during the drilling process (the auxiliary material is simple in design), and the operation is simple, but will not affect the laser drilling process. Not only can it achieve high efficiency and high Precision laser drilling avoids slag, burning and other phenomena at the edge of the hole after drilling, and there is no need to use high-cost ultra-fast lasers or short-wavelength lasers, and there is no need to spend a long time debugging a small range of specific lasers for drilling. , to improve the requirements of laser drilling stability and have wider applicability of laser drilling.

In summary, the embodiments of the green ceramic wafer laser drilling method are as follows:

Example A

Step a. Cut the cast green porcelain tape into 200*200mm green porcelain pieces.

Step b. Put the cut green porcelain pieces into the oven and dry them at 60°C for 30 minutes.

Step c. Take out the green porcelain tiles from the oven. After cooling to room temperature, compact the attached film with a roller so that it completely adheres to the back of the green porcelain tiles (polyester support film surface) and put it aside for use.

Step d. Place the 1mm thick cardboard on the semi-hollow laser drilling work platform, and use the laser drilling equipment to process micro holes slightly larger than the size of the original drawing.

Step e. Place the green porcelain piece with the adhesive film face up on the laser drilling worktable equipped with cardboard, and vacuum the inside of the platform so that the back side of the green porcelain is in a negative pressure state.

Step f. Use a laser wavelength of 355nm and a laser pulse width of less than 350 picoseconds to drill the green ceramic wafer. The parameter range is laser frequency 600-800kHz, laser energy 20-22W, element count 10 times; scanning speed 500-800; jump RPM 6000.

Step g. Turn off the vacuum adsorption, use UV light to make the attached film lose its stickiness, tear off the attached film, and complete the processing.

Example B

The steps a-c are the same as above

In step d, place non-sticky and breathable white paper directly under the green porcelain tape.

Step e, use a laser with a wavelength of 355nm and a laser pulse width of less than 350 picoseconds to drill the green ceramic sheet. The parameter range is laser frequency 600-800kHz, laser energy 23-25W, element times 10 times; scanning speed 400-600; jump RPM 6000.

Step f: Turn off the vacuum adsorption, take out the raw porcelain pieces, and complete the processing.

Each embodiment in this specification is described in a progressive manner. The same and similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the product embodiments described later, since they correspond to the methods, the description is relatively simple. For relevant details, please refer to the partial description of the system embodiments.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application. All are covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A method for laser drilling of green porcelain wafers, characterized in that the method of laser drilling of green porcelain wafers includes:

Set an attachment film on the back of the green porcelain piece to be drilled to obtain the first green porcelain piece;

Place the first green tile on the target cardboard;

Drill holes in the first green ceramic tile to obtain a second green ceramic tile with target holes.
The method for laser drilling of green porcelain wafers according to claim 1, characterized in that the method of laser drilling of green porcelain wafers further includes:

Obtain the green porcelain sheet to be punched; the back of the green porcelain sheet to be punched includes a polyester support film surface.
The laser drilling method of green ceramic tiles according to claim 2, characterized in that, setting an adhesion film on the green ceramic tile to be drilled to obtain the first green ceramic tile includes:

By rolling the green porcelain sheet to be punched, the adhesive film is attached to the back of the green porcelain sheet to be punched.
The method for laser drilling of green porcelain wafers according to claim 1, characterized in that the method of laser drilling of green porcelain wafers further includes:

Use a laser to punch holes in a cardboard with a preset thickness to obtain a target cardboard with initial holes.
The method for laser drilling green ceramic wafers according to claim 4, wherein the initial hole is larger than the target hole.
The method for laser drilling of green ceramic tiles according to claim 1, characterized in that there is no initial hole on the target cardboard.
The laser drilling method of green ceramic tiles according to claim 4, characterized in that drilling holes on the first green ceramic tile to obtain a second green ceramic tile with target holes includes:

The adhesive film of the first green tile is attached to the target cardboard, and the first green tile is placed on the target cardboard,

According to the position of the initial hole, laser drilling is used to obtain the second green ceramic chip with the target hole from the first green ceramic chip.
The laser drilling method of green ceramic tiles according to claim 7, characterized in that after obtaining the second green ceramic tile with target holes, it further includes:

The second green porcelain piece is irradiated with UV light to cause the attached film on it to lose its viscosity, and the attached film is removed to obtain the target green porcelain piece.
The method for laser drilling green ceramic wafers according to any one of claims 1 to 8, characterized in that the laser wavelength of the drilling laser is 355nm, and the laser pulse width is less than 350 picoseconds. The laser drills the green ceramic wafers, The laser frequency is 600-800kHz.
The method for laser drilling green ceramic tiles according to claim 9, wherein the thickness of the target cardboard is 1 mm.