High-reliability ceramic circuit board and manufacturing method thereof

Abstract

The invention discloses a high-reliability ceramic circuit board and a manufacturing method thereof. The high-reliability ceramic circuit board comprises a ceramic substrate, a copper column structure, two printing copper layers and two direct electroplating copper structures. The ceramic substrate comprises a first surface and a second surface which are opposite to each other, and a through hole penetrating through the ceramic substrate. And the copper column structure is formed in the through hole of the ceramic substrate. The two printing copper layers are formed on the first surface and the second surface of the ceramic substrate respectively, and the two printing copper layers make contact with the copper column structure. And the two direct electroplating copper structures are respectively formed on the two printing copper layers. Each direct copper electroplating structure comprises a sputtering layer, a copper plating layer and a copper electroplating layer. According to the high-reliability ceramic circuit board and the manufacturing method thereof disclosed by the invention, the situation that an existing ceramic circuit board is easy to crack after being subjected to multiple temperature cycle tests can be effectively improved.

Description

Technical Field

[0001] This application relates to the field of ceramic circuit boards, and in particular to a high-reliability ceramic circuit board and its manufacturing method. Background Technology

[0002] Existing ceramic circuit boards suffer from insufficient reliability. Therefore, they are prone to cracking after repeated temperature cycling tests. Summary of the Invention

[0003] The technical problem to be solved by this application is to provide a high-reliability ceramic circuit board and its manufacturing method to address the shortcomings of the prior art, which can effectively improve the situation that existing ceramic circuit boards are prone to cracking after multiple temperature cycling tests.

[0004] To address the aforementioned technical problems, one technical solution adopted in this application is to provide a high-reliability ceramic circuit board, comprising: a ceramic substrate including a first surface and a second surface opposite to each other, and a through hole penetrating the ceramic substrate; a copper pillar structure formed in the through hole of the ceramic substrate; two printed copper layers respectively formed on the first surface and the second surface of the ceramic substrate, and the two printed copper layers contacting the copper pillar structure; and two direct electroplated copper structures respectively formed on the two printed copper layers; wherein each of the direct electroplated copper structures includes a sputtering layer, a copper plating layer, and an electroplated copper layer, the copper plating layer being located between the sputtering layer and the electroplated copper layer, and the sputtering layer being disposed adjacent to the ceramic substrate.

[0005] To address the aforementioned technical problems, another technical solution adopted in this application is to provide a high-reliability ceramic circuit board, comprising: a ceramic substrate including a first surface and a second surface opposite to each other and a through hole penetrating the ceramic substrate; a copper pillar structure formed in the through hole of the ceramic substrate; a printed copper layer formed on the first surface of the ceramic substrate and in contact with the copper pillar structure; and two direct electroplated copper structures formed on the printed copper layer and the second surface of the ceramic substrate, respectively; wherein each of the direct electroplated copper structures includes a sputtering layer, a copper plating layer and an electroplated copper layer, the copper plating layer being located between the sputtering layer and the electroplated copper layer, and the sputtering layer being disposed adjacent to the ceramic substrate.

[0006] To address the aforementioned technical problems, another technical solution adopted in this application is to provide a method for manufacturing a high-reliability ceramic circuit board, comprising: a pre-processing step of providing a ceramic substrate, the ceramic substrate including a first surface and a second surface opposite to each other and a through hole penetrating the ceramic substrate; a copper pillar structure forming step of forming a copper pillar structure in the through hole of the ceramic substrate; a printing step of forming two printed copper layers on the first surface and the second surface of the ceramic substrate by printing; and a direct electroplating step of forming two direct electroplated copper structures on the two printed copper layers by direct electroplating, each of the direct electroplated copper structures comprising a sputtering layer, a copper plating layer and an electroplated copper layer, the copper plating layer being located between the sputtering layer and the electroplated copper layer, and the sputtering layer being disposed adjacent to the ceramic substrate.

[0007] Beneficial effects of the invention

[0008] One of the beneficial effects of this application is that the high-reliability ceramic circuit board and its manufacturing method provided by this application can effectively improve the situation where existing ceramic circuit boards are prone to cracking after multiple temperature cycling tests by means of the technical solutions of "the direct electroplating copper structure formed on the printed copper layer" and "the direct electroplating copper structure including the sputtering layer, the copper plating layer and the electroplating copper layer".

[0009] To gain a better understanding of the features and technical content of this application, please refer to the following detailed description and drawings. However, the drawings provided are for reference and illustration only and are not intended to limit this application. Attached Figure Description

[0010] Figure 1 This is a cross-sectional schematic diagram of a high-reliability ceramic circuit board according to one embodiment of this application.

[0011] Figure 2 The copper pillar structure of a high-reliability ceramic circuit board according to one embodiment of this application includes a ring sputtered layer, a ring-plated copper layer, and an electroplated copper pillar.

[0012] Figure 3 This is a cross-sectional view showing the printed copper layer and the direct electroplated copper structure aligned in one embodiment of the high-reliability ceramic circuit board of this application.

[0013] Figure 4 This is a cross-sectional schematic diagram showing the direct electroplated copper structure of a high-reliability ceramic circuit board according to one embodiment of this application, protruding from the printed copper layer.

[0014] Figure 5 This is a cross-sectional schematic diagram of a high-reliability ceramic circuit board according to another embodiment of this application.

[0015] Figures 6 to 9 This is a flowchart illustrating a method for manufacturing a high-reliability ceramic circuit board according to different embodiments of this application. Detailed Implementation

[0016] The following specific embodiments illustrate the implementation of the "high-reliability ceramic circuit board and its manufacturing method" disclosed in this application. Those skilled in the art can understand the advantages and effects of this application from the content disclosed in this specification. This application can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this application. Furthermore, the accompanying drawings of this application are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of this application in detail, but the disclosed content is not intended to limit the scope of protection of this application.

[0017] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used herein should, as appropriate, include any combination of one or more of the related listed items.

[0018] High reliability ceramic circuit board

[0019] Please see Figure 1 As shown, Figure 1 This is a cross-sectional schematic diagram of a high-reliability ceramic circuit board according to one embodiment of this application. One embodiment of this application provides a high-reliability ceramic circuit board 100. The high-reliability ceramic circuit board 100 includes a ceramic substrate 1, a copper pillar structure 2, two printed copper layers 3, and two directly electroplated copper structures 4. The high-reliability ceramic circuit board 100 can withstand at least 500 temperature cycle tests without cracking.

[0020] The ceramic substrate 1 includes a first surface 11 and a second surface 12 that are opposite to each other, and a through hole 13 penetrating the ceramic substrate 1. It is worth mentioning that, as long as the through hole 13 penetrates the ceramic substrate 1, this application does not limit the formation method, size, position and number of the through hole 13.

[0021] The copper pillar structure 2 is formed in the through-hole 13 of the ceramic substrate 1. In one embodiment, the copper pillar structure 2 may be formed, for example, by filling the through-hole 13 with copper paste, but this application is not limited thereto.

[0022] Please see Figure 1 and Figure 2 As shown, Figure 2 This is a cross-sectional schematic diagram of a copper pillar structure for a high-reliability ceramic circuit board according to one embodiment of the present application, comprising a ring sputtered layer, a ring-plated copper layer, and an electroplated copper pillar. In one embodiment, the copper pillar structure 2 can be formed, for example, by electroplating. More specifically, the copper pillar structure 2 is a direct electroplated copper pillar, comprising a ring sputtered layer 21 contacting the hole wall of the via 13, a ring-plated copper layer 22 located inside the sputtered layer 41, and an electroplated copper pillar 23 located inside the ring-plated copper layer 42. The direct electroplated copper pillar can be formed by a direct plating copper (DPC) process. The ring sputtered layer 21 may further comprise a ring sputtered titanium layer 211 and a ring sputtered copper layer 212, wherein the ring sputtered titanium layer 211 is in contact with the hole wall of the via 13, and the ring sputtered copper layer 212 is located inside the ring sputtered titanium layer 211 and in contact with the ring-plated copper layer 22.

[0023] The two printed copper layers 3 are respectively formed on the first surface 11 and the second surface 12 of the ceramic substrate 1, and the two printed copper layers 3 are in contact with the copper pillar structure 2. Circuit patterns can be formed on the surface of each printed copper layer 3 away from the ceramic substrate 1. It is worth noting that each printed copper layer 3 is formed by printing, and other copper layers formed by other methods are not suitable for comparison with the printed copper layers 3 in this application. Preferably, the thickness of each printed copper layer 3 can be less than 15 micrometers. In other words, in the high-reliability ceramic circuit board 100, the overall copper thickness is mainly increased by the two direct electroplated copper structures 4, rather than by the two printed copper layers 3.

[0024] The two direct electroplated copper structures 4 are respectively formed on the two printed copper layers 3. Each direct electroplated copper structure 4 includes a sputtering layer 41, a copper plating layer 42 and an electroplated copper layer 43, wherein the copper plating layer 42 is located between the sputtering layer 41 and the electroplated copper layer 43, and the sputtering layer 41 is disposed adjacent to the ceramic substrate 1.

[0025] In each of the direct electroplated copper structures 4, the sputtered layer 41 may include a sputtered titanium layer 411 and a sputtered copper layer 412. The sputtered titanium layer 411 is disposed adjacent to the ceramic substrate 1, and the sputtered copper layer 412 is in contact with the copper plating layer 42.

[0026] In each of the aforementioned direct electroplated copper structures 4, the thickness of the electroplated copper layer 43 can be between 20 micrometers and 800 micrometers. Preferably, the thickness of the electroplated copper layer 43 can be between 50 micrometers and 250 micrometers. More preferably, the thickness of the electroplated copper layer 43 can be between 100 micrometers and 200 micrometers.

[0027] like Figure 1 As shown, in one embodiment, at least one of the direct electroplated copper structures 4 partially covers only one of the corresponding printed copper layers 3, and the surface of the printed copper layer 3 away from the ceramic substrate 1 is partially exposed from the direct electroplated copper structure 4. More specifically, the direct electroplated copper structure 4 may cover the central region of the printed copper layer 3, such that the surrounding area of ​​the printed copper layer 3 around the central region is exposed from the direct electroplated copper structure 4. In other words, in this embodiment, the horizontal dimension of each of the direct electroplated copper structures 4 may be smaller than the horizontal dimension of the corresponding printed copper layer 3, but this application is not limited thereto. Furthermore, another direct electroplated copper structure 4 may only partially cover another printed copper layer 3, but this application is not limited thereto.

[0028] Please see Figure 3 As shown, Figure 3 This is a cross-sectional schematic diagram showing the printed copper layer and the direct electroplated copper structure aligned with each other in one embodiment of the high-reliability ceramic circuit board of this application. In one embodiment, at least one side edge of the direct electroplated copper structure 4 is aligned with the side edge of a corresponding printed copper layer 3, and the side edge of another direct electroplated copper structure 4 may be aligned with the side edge of another printed copper layer 3, but this application is not limited thereto. Specifically, the direct electroplated copper structure 4 may have four side edges, and the four side edges of the direct electroplated copper structure 4 may be aligned with the four side edges of the printed copper layer 3.

[0029] Please see Figure 4 As shown, Figure 4 This is a cross-sectional schematic diagram showing a direct copper plating structure protruding from a printed copper layer in one embodiment of the high-reliability ceramic circuit board of this application. In one embodiment, at least one of the direct copper plating structures 4 covers the side edge of a corresponding printed copper layer 3 and the surface of the printed copper layer 3 away from the ceramic substrate 1, so that the side edge of the printed copper layer 3 and the surface of the printed copper layer 3 away from the ceramic substrate 1 are not exposed from the direct copper plating structure 4.

[0030] More specifically, in the direct electroplated copper structure 4, the side edges of the sputtered layer 41, the side edges of the copper plating layer 42, and the side edges of the electroplated copper layer 43 extend toward the ceramic substrate 1 in the longitudinal direction, thereby making the direct electroplated copper structure 4 present a multi-layer stack in the horizontal direction. Furthermore, another direct electroplated copper structure 4 may cover the side edge of another printed copper layer 3 and the surface of the printed copper layer 3 away from the ceramic substrate 1, but this application is not limited to this.

[0031] As mentioned above, the configuration of the direct electroplated copper structure 4 and the printed copper layer 3 on the first surface 11 may be the same as or different from the configuration of the direct electroplated copper structure 4 and the printed copper layer 3 on the second surface 12.

[0032] Please see Figure 5 As shown, Figure 5 This is a cross-sectional schematic diagram of a high-reliability ceramic circuit board according to another embodiment of this application. This embodiment provides a high-reliability ceramic circuit board 100, which is substantially the same as the high-reliability ceramic circuit board 100 of the previous embodiment, with the differences described below.

[0033] In this embodiment, the high-reliability ceramic circuit board 100 includes one printed copper layer 3, and two direct electroplated copper structures 4 are respectively formed on the printed copper layer 3 and the second surface 12 of the ceramic substrate 1. Alternatively, the second surface 12 may not have the printed copper layer 3 formed thereon, and the direct electroplated copper structure 4 may be directly formed on the ceramic substrate 1 and directly contact the copper pillar structure 2. In this embodiment, the printed copper layer 3 is formed on the first surface 11, and the first surface 11 is the lower surface of the ceramic substrate 1 (e.g., ...). Figure 5 (as shown), but this application is not limited thereto. For example, in other embodiments not illustrated in this application, the first surface 11 and the second surface 12 may be the upper surface and the lower surface of the ceramic substrate 1, respectively, the printed copper layer 3 is formed on the first surface 11 (that is, the printed copper layer 3 is formed on the upper surface of the ceramic substrate 1), and the lower surface of the ceramic substrate 1 (i.e., the second surface 12) may not have the printed copper layer 3 formed thereon.

[0034] Manufacturing method of high reliability ceramic circuit board

[0035] Please see Figures 6 to 9 As shown, Figures 6 to 9This is a flowchart illustrating a method for manufacturing a high-reliability ceramic circuit board according to different embodiments of this application. This application also provides a method for manufacturing a high-reliability ceramic circuit board. The aforementioned high-reliability ceramic circuit board 100 can be manufactured using the method described above, but this application is not limited thereto.

[0036] like Figure 6 As shown, the manufacturing method of the high-reliability ceramic circuit board may include a pre-processing step S110, a copper pillar structure forming step S120, a printing step S130, and a direct electroplating step S140. Of course, the manufacturing method of the high-reliability ceramic circuit board may include other steps as needed, but this application does not impose any limitations thereon.

[0037] In the preceding step S110, a ceramic substrate 1 is provided, the ceramic substrate 1 including a first surface 11 and a second surface 12 opposite to each other and a through hole 13 penetrating the ceramic substrate.

[0038] In the copper pillar structure forming step S120, a copper pillar structure 2 is formed in the through hole 13 of the ceramic substrate 1.

[0039] like Figure 7 As shown, in one embodiment, the copper pillar structure forming step S120 includes a copper filling step S121, in which copper paste is filled into the through hole 13 to form the copper pillar structure 2.

[0040] like Figure 8 As shown, in one embodiment, the copper pillar structure forming step S120 includes a through-hole sputtering step S122, a through-hole copper plating step S123, and a through-hole electroplating step S124. In the through-hole sputtering step S122, a ring-shaped sputtered layer 21 is formed in the through-hole by sputtering. In the through-hole copper plating step S123, a ring-shaped copper plating layer 22 is formed inside the ring-shaped sputtered layer 21 by copper plating. In the through-hole electroplating step S124, an electroplated copper pillar 23 is formed inside the ring-shaped copper plating layer 22. The copper pillar structure 2 is a direct electroplated copper pillar and includes the ring-shaped sputtered layer 21, the ring-shaped copper plating layer 22, and the electroplated copper pillar 23. Furthermore, the ring sputtered coating 21 may further include a ring sputtered titanium layer 211 and a ring sputtered copper layer 212. The ring sputtered titanium layer 211 is in contact with the hole wall of the through hole 13, and the ring sputtered copper layer 212 is located inside the ring sputtered titanium layer 211 and in contact with the ring sputtered copper layer 22.

[0041] In the printing step S130, two printed copper layers 3 are formed on the first surface 11 and the second surface 12 of the ceramic substrate 1 by printing. The thickness of the printed copper layer 3 is less than 15 micrometers.

[0042] like Figure 9 As shown, after the printing step S130 and before the direct electroplating step S140, the manufacturing method of the high-reliability ceramic circuit board further includes a circuit pattern forming step S131, in which a circuit pattern is formed on the surface of each of the printed copper layers 3 away from the ceramic substrate 1 by exposure and development.

[0043] It is worth noting that the typical Direct Bonded Copper (DBC) process involves covering a ceramic substrate with a copper foil layer and then etching circuit patterns onto the ceramic substrate using exposure, development, and etching methods. However, the circuit patterns formed by the direct copper bonding process are relatively imprecise. In contrast, in the high-reliability ceramic circuit board manufacturing method of this embodiment, a relatively precise circuit pattern is formed through the circuit pattern forming step S131 prior to the direct electroplating step S140. Furthermore, after the direct electroplating step, the high-reliability ceramic circuit board manufacturing method may not include other circuit forming steps, but this application is not limited to this.

[0044] In the direct electroplating step S140, two direct electroplated copper structures 4 are formed on the two printed copper layers 3 by direct electroplating. Each direct electroplated copper structure 4 includes a sputtered layer 41, a copper oxide layer 42, and an electroplated copper layer 43. The copper oxide layer 42 is located between the sputtered layer 41 and the electroplated copper layer 43, and the sputtered layer 41 is disposed adjacent to the ceramic substrate 1. In each direct electroplated copper structure 4, the sputtered layer 41 includes a sputtered titanium layer 411 and a sputtered copper layer 412. The sputtered titanium layer 411 is disposed adjacent to the ceramic substrate 1, and the sputtered copper layer 412 contacts the copper oxide layer 42.

[0045] Beneficial effects of the embodiments of this application

[0046] One of the beneficial effects of this application is that the high-reliability ceramic circuit board and its manufacturing method provided by this application can effectively improve the situation where existing ceramic circuit boards are prone to cracking after multiple temperature cycling tests by means of the technical solutions of "the direct electroplating copper structure formed on the printed copper layer" and "the direct electroplating copper structure including the sputtering layer, the copper plating layer and the electroplating copper layer".

[0047] Furthermore, after the printing step and before the direct electroplating step, the manufacturing method of the high-reliability ceramic circuit board may further include a circuit pattern forming step, in which circuit patterns are formed on the surface of each of the printed copper layers away from the ceramic substrate by exposure and development. Accordingly, the high-reliability ceramic circuit board can have a circuit pattern with high precision.

[0048] The content disclosed above is only a preferred and feasible embodiment of this application, and is not intended to limit the scope of the patent application. Therefore, all equivalent technical changes made using the content of this application specification and drawings are included in the scope of the patent application.

Claims

1. A high-reliability ceramic circuit board, characterized in that, The high-reliability ceramic circuit board includes: A ceramic substrate includes a first surface and a second surface opposite to each other, and a through hole penetrating the ceramic substrate; A copper pillar structure is formed in the through hole of the ceramic substrate; Two printed copper layers are formed on the first surface and the second surface of the ceramic substrate, respectively, and the two printed copper layers are in contact with the copper pillar structure; and Two direct electroplated copper structures are formed on two of the printed copper layers, respectively; wherein each of the direct electroplated copper structures includes a sputtering layer, a copper plating layer and an electroplated copper layer, the copper plating layer is located between the sputtering layer and the electroplated copper layer, and the sputtering layer is disposed adjacent to the ceramic substrate.

2. The high-reliability ceramic circuit board according to claim 1, characterized in that, The copper pillar structure is a direct electroplated copper pillar, which includes an annular sputtered layer in contact with the hole wall of the through hole, an annular copper plating layer located inside the sputtered layer, and an electroplated copper pillar located inside the copper plating layer.

3. The high-reliability ceramic circuit board according to claim 1, characterized in that, The thickness of each of the printed copper layers is less than 15 micrometers.

4. The high-reliability ceramic circuit board according to claim 1, characterized in that, In each of the aforementioned direct electroplated copper structures, the sputtered layer includes a sputtered titanium layer and a sputtered copper layer, wherein the sputtered titanium layer is disposed adjacent to the ceramic substrate, and the sputtered copper layer is in contact with the copper plating layer.

5. The high-reliability ceramic circuit board according to claim 1, characterized in that, In each of the aforementioned direct electroplated copper structures, the thickness of the electroplated copper layer is between 20 micrometers and 800 micrometers.

6. The high-reliability ceramic circuit board according to claim 1, characterized in that, At least one of the direct electroplated copper structures has its side edge flush with the side edge of the corresponding printed copper layer.

7. The high-reliability ceramic circuit board according to claim 1, characterized in that, At least one of the direct electroplated copper structures partially covers only one of the corresponding printed copper layers, and the surface of the printed copper layer away from the ceramic substrate is partially exposed from the direct electroplated copper structure.

8. The high-reliability ceramic circuit board according to claim 1, characterized in that, At least one of the direct electroplated copper structures covers the side edge of one of the corresponding printed copper layers and the surface of the printed copper layer away from the ceramic substrate.

9. A high-reliability ceramic circuit board, characterized in that, The high-reliability ceramic circuit board includes: A ceramic substrate includes a first surface and a second surface opposite to each other, and a through hole penetrating the ceramic substrate; A copper pillar structure is formed in the through hole of the ceramic substrate; A printed copper layer is formed on the first surface of the ceramic substrate and contacts the copper pillar structure; and Two direct electroplated copper structures are formed on the printed copper layer and the second surface of the ceramic substrate, respectively; wherein each of the direct electroplated copper structures includes a sputtering layer, a copper plating layer and an electroplated copper layer, the copper plating layer is located between the sputtering layer and the electroplated copper layer, and the sputtering layer is disposed adjacent to the ceramic substrate.

10. A method for manufacturing a high-reliability ceramic circuit board, characterized in that, The manufacturing method of the high-reliability ceramic circuit board includes: A preliminary step includes providing a ceramic substrate, the ceramic substrate comprising a first surface and a second surface opposite to each other and a through hole through the ceramic substrate; A copper pillar structure forming step involves forming a copper pillar structure in the through hole of the ceramic substrate; A printing step involves forming two printed copper layers on the first and second surfaces of the ceramic substrate using a printing method; and A direct electroplating step involves forming two direct electroplated copper structures on two printed copper layers using a direct electroplating method. Each direct electroplated copper structure includes a sputtering layer, a copper plating layer, and an electroplated copper layer. The copper plating layer is located between the sputtering layer and the electroplated copper layer, and the sputtering layer is disposed adjacent to the ceramic substrate.

11. The method for manufacturing a high-reliability ceramic circuit board according to claim 10, characterized in that, The copper pillar structure forming step includes a copper filling step, in which copper paste is filled into the through hole to form the copper pillar structure.

12. The method for manufacturing a high-reliability ceramic circuit board according to claim 10, characterized in that, The copper pillar structure formation steps include a through-hole sputtering step, a through-hole copper plating step, and a through-hole electroplating step; wherein, in the through-hole sputtering step, a ring sputtering layer is formed in the through-hole by sputtering; in the through-hole copper plating step, a ring copper plating layer is formed inside the ring sputtering layer by copper plating; and in the through-hole electroplating step, an electroplated copper pillar is formed inside the ring copper plating layer; wherein, the copper pillar structure is a direct electroplated copper pillar and includes the ring sputtering layer, the ring copper plating layer, and the electroplated copper pillar.

13. The method for manufacturing a high-reliability ceramic circuit board according to claim 10, characterized in that, The thickness of the printed copper layer is less than 15 micrometers.

14. The method for manufacturing a high-reliability ceramic circuit board according to claim 10, characterized in that, After the printing step and before the direct electroplating step, the method for manufacturing the high-reliability ceramic circuit board further includes a circuit patterning step, in which circuit patterns are formed on the surface of each of the printed copper layers away from the ceramic substrate by exposure and development.

15. The method for manufacturing a high-reliability ceramic circuit board according to claim 10, characterized in that, In each of the aforementioned direct electroplated copper structures, the sputtered layer comprises a sputtered titanium layer and a sputtered copper layer, wherein the sputtered titanium layer is disposed adjacent to the ceramic substrate. Furthermore, the sputtered copper layer is in contact with the copper plating layer.

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