Processing method of circuit board with embedded ceramic module and circuit board

Abstract

The invention provides a processing method of a circuit board of a buried ceramic module and the circuit board, and belongs to the technical field of circuit board production. The processing method of the circuit board with the embedded ceramic module comprises the following steps: manufacturing a jig according to the structure of the ceramic module, wherein the jig is provided with an open window corresponding to the ceramic module; when the ceramic module is embedded into the circuit board, the manufactured jig and the ceramic module are pressed in the circuit board; wherein in the pressing process, the ceramic module is arranged in the window of the jig. According to the processing method, when the ceramic module is embedded into the circuit board, the jig and the ceramic module are pressed together, so that the ceramic substrate of the ceramic module is prevented from being broken, the functional integrity of the ceramic module can be ensured, and the product quality is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board production, and in particular to a processing method of a circuit board with an embedded ceramic module and the circuit board. Background Art

[0002] With the vigorous development of new energy vehicles, renewable energy generation, smart grids and other fields, industries such as power supplies and electronic control modules have put forward more stringent requirements on the performance indicators and reliability of power semiconductor devices. These requirements include higher operating voltage, greater current carrying capacity, higher operating frequency, higher efficiency, higher operating temperature, stronger heat dissipation capacity and higher reliability. As a new generation of semiconductor materials, SiC, with its significant advantages such as large bandgap, large drift rate, large thermal conductivity and large breakdown field strength, provides the possibility for the development of high-voltage, high-frequency and high-temperature resistant SiC semiconductor devices. Silicon carbide power devices have achieved a significant improvement in performance, which is specifically reflected in the working characteristics of high voltage, high frequency, high power and high temperature resistance. At the same time, they have lower conduction loss and switching loss, as well as higher switching frequency, which helps to reduce the size of the module. These excellent characteristics make silicon carbide devices widely used in civil scenarios such as electric vehicle drive systems, train traction equipment, charging piles, switching power supplies, photovoltaic inverters, servo motors, high-voltage DC transmission equipment, etc., and can also improve the performance of equipment.

[0003] However, these excellent properties of silicon carbide devices can only be fully demonstrated through efficient packaging and circuit systems to achieve highly reliable connections between power and signals. In existing packaging technologies, AMB silicon nitride ceramic substrates have become an ideal choice for packaging silicon carbide devices due to their excellent thermal conductivity and stability. Packaging AMB ceramic substrates with SiC chips or power devices can significantly improve the performance of the device, thereby adapting to more application scenarios. Packaging SiC devices with AMB ceramic substrates and embedding them in PCBs can greatly reduce the volume of PCB products and increase the degree of centralization of functional modules. This technology shows great application potential in new energy vehicles, electronic control, power supplies and other fields.

[0004] However, in the existing manufacturing method of embedding the AMB silicon nitride ceramic substrate inside the PCB, the AMB silicon nitride ceramic substrate is directly embedded in the PCB during the processing stage of the PCB, which easily causes the edge of the AMB silicon nitride ceramic substrate to break, thereby affecting the overall performance of the product. This technical difficulty seriously restricts the application of the AMB ceramic substrate in the PCB.

[0005] Therefore, it is necessary to improve the existing method of embedding AMB silicon nitride ceramic substrate in PCB to overcome the defects of the prior art. Summary of the invention

[0006] In order to overcome the problems existing in the related art, one of the objects of the present invention is to provide a processing method for a circuit board with an embedded ceramic module. When embedding the ceramic module into the circuit board, the processing method uses a jig to press the ceramic module together, thereby preventing the ceramic substrate of the ceramic module from breaking, and can ensure the functional integrity of the ceramic module and ensure product quality.

[0007] A method for processing a circuit board with embedded ceramic modules, comprising:

[0008] A jig is manufactured according to the structure of the ceramic module, wherein the jig is provided with an opening window corresponding to the ceramic module;

[0009] When the ceramic module is embedded in the circuit board, the manufactured fixture and the ceramic module are pressed together in the circuit board; during the pressing process, the ceramic module is arranged in the opening of the fixture.

[0010] In a preferred technical solution of the present invention, a plurality of bosses are provided at the edge of the window opening, and during the pressing process, the bosses abut against the ceramic module.

[0011] In a preferred technical solution of the present invention, the ceramic module includes a ceramic substrate, a first metal layer is arranged on the lower surface of the ceramic substrate, and a second metal layer is arranged on the upper surface of the ceramic substrate; wherein the ceramic substrate protrudes outward from the edge of the metal layer.

[0012] In a preferred technical solution of the present invention, the jig includes a first jig, a second jig and a third jig;

[0013] During the pressing process, the first jig corresponds to the first metal layer, the second jig corresponds to the ceramic substrate, and the third jig corresponds to the second metal layer;

[0014] A first prepreg is arranged between the first jig and the second jig, and a second prepreg is arranged between the second jig and the third jig.

[0015] In a preferred technical solution of the present invention, the thickness of the first metal layer is greater than the total thickness of the first fixture and the first prepreg;

[0016] The thickness of the second metal layer is greater than the total thickness of the third fixture and the second prepreg;

[0017] The thickness of the ceramic substrate is equal to the thickness of the second fixture.

[0018] In a preferred technical solution of the present invention, the first fixture, the second fixture, and the third fixture are all provided with windows;

[0019] During the pressing process, the size of the opening window on each jig is smaller than the outer size of the corresponding ceramic module.

[0020] In a preferred technical solution of the present invention, each layer of the prepreg is provided with a window, and the size of the window on the prepreg is equal to the outer size of the ceramic module.

[0021] In a preferred technical solution of the present invention, before embedding the ceramic module into the circuit board, the method further includes:

[0022] Obtain a substrate of a circuit board, and drill alignment holes on the substrate for exposing the inner layer pattern of the circuit board;

[0023] When pressing the ceramic module and the jig onto the substrate, use the drilled alignment holes for positioning.

[0024] A second object of the present invention is to provide a circuit board, comprising a main body, wherein a ceramic module is embedded in the main body;

[0025] During the embedding of the ceramic module, the circuit board embedding ceramic module is processed using the above-mentioned processing method.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a processing method for a circuit board with an embedded ceramic module, and the processing method for a circuit board with an embedded ceramic module includes: making a jig according to the structure of the ceramic module, and the jig is provided with an opening window corresponding to the ceramic module; when the ceramic module is embedded in the circuit board, the manufactured jig and the ceramic module are pressed together in the circuit board; wherein during the pressing process, the ceramic module is arranged in the opening window of the jig. In actual production, when the ceramic module is embedded in the circuit board, the manufactured jig is first placed at a specified position of the circuit board, and then a suitable PP sheet is placed above the opening window of the jig, and the PP sheet is also provided with an opening window size that is the same as the outer size of the ceramic module. The opening window of the jig is tightly connected to the outer wall of the ceramic module to prevent the ceramic module from shifting during the pressing process. Then pressing is performed so that the ceramic module is embedded in the circuit board. This method effectively prevents the ceramic substrate of the ceramic module from breaking by pressing together the ceramic module with a specially manufactured jig. The opening window design of the fixture ensures that the ceramic module can be accurately positioned in the circuit board during the pressing process, avoiding stress concentration caused by position offset, thereby reducing the risk of ceramic substrate breakage. Since the ceramic substrate does not break, the electrical connection and heat dissipation structure inside the ceramic module remain intact, and it can stably play its role in the circuit board. The complete ceramic module also ensures the stable transmission of electrical signals, improves the performance of the circuit, and ultimately ensures the high quality of the product, enhances the competitiveness of the product in the market, and brings good economic and brand benefits to the company.

[0028] The present application also provides a circuit board, the main body of which is embedded with a ceramic module, and the ceramic module is processed using the above-mentioned processing method of a circuit board embedded with a ceramic module. The circuit board can ensure the structural integrity of the ceramic module embedded inside, so that the circuit board has higher product quality and performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Reference numerals:

[0030] 1. Ceramic module; 11. First metal layer; 12. Ceramic substrate; 13. Second metal layer; 2. First fixture; 21. Window fixture; 22. Boss; 3. Second fixture; 4. Third fixture; 5. First prepreg; 6. Second prepreg. Description of the drawings:

[0032] Figure 1 It is a flow chart of a method for processing a circuit board with embedded ceramic modules provided by an embodiment of the present invention;

[0033] Figure 2 is a schematic structural diagram of a ceramic module provided by an embodiment of the present invention;

[0034] Figure 3 is a schematic structural diagram of a first fixture provided by an embodiment of the present invention;

[0035] Figure 4 It is a schematic diagram of the structure when the ceramic module is embedded in the circuit board provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0037] Thick copper in PCB means that the thickness of copper in PCB exceeds the conventional standard. The standard PCB copper thickness is usually 1oz (35μm), while the thickness of thick copper in PCB is ≥3oz (105μm). In some special application scenarios, the copper thickness can even reach 12oz (420μm) or more. The application of thick copper technology greatly improves the load-bearing capacity and conductivity of PCB, making it an ideal choice for high-power and high-current devices.

[0038] However, as the copper thickness increases, the difficulty of PCB production also increases greatly. In the process of making thick copper PCBs, processes such as graphic production and lamination production are facing new challenges. Especially in the lamination process, due to the increase in copper thickness, the traditional method of using only semi-pregs to fill glue can no longer meet the requirements. When the copper thickness is greater than 8oz, using too much semi-preg for lamination can easily cause the semi-preg to slip, resulting in problems such as insufficient local filling and filling voids. In addition, the glass fibers between the semi-pregs are easily bent during the lamination process and enter between the lines, increasing the risk of short circuits during later use.

[0039] Based on this, the present application provides a method for processing a circuit board with an embedded ceramic module.

[0040] Example

[0041] like Figure 1 As shown, the present embodiment provides a method for processing a circuit board with embedded ceramic modules, comprising:

[0042] S100, manufacturing a jig according to the structure of the ceramic module, wherein the jig is provided with an opening corresponding to the ceramic module;

[0043] S200, when embedding the ceramic module into the circuit board, pressing the manufactured fixture and the ceramic module into the circuit board; during the pressing process, the ceramic module is arranged in the opening of the fixture.

[0044] In the corresponding process of circuit board processing, when it comes to the stage of embedding the ceramic module into the circuit board, the operation is as follows: the manufactured jig is accurately placed on the pre-planned position of the circuit board, and the high-precision positioning equipment is used to ensure that the position deviation of the jig is within ±0.1mm. Next, a PP sheet is placed above the opening window of the jig. The opening size of the PP sheet is the same as the outer size of the ceramic module, and the tolerance is controlled within ±0.1mm. Subsequently, the ceramic module is placed in the opening window of the jig. At this time, the ceramic module and the jig are tightly fitted, and the opening window of the jig clamps the edge of the ceramic module to prevent any displacement in subsequent operations. After that, a PP sheet of the same specification is placed above the ceramic module again, and a matching upper jig is placed to ensure that the structures of each layer are closely aligned. Finally, the entire assembly is sent to a professional hot pressing equipment for pressing operation. The pressing temperature is set to 200℃, the pressure is 400psi, and the pressing time is 90 minutes. During the pressing process, the pressure and temperature changes are monitored in real time to ensure the stability of the process parameters.

[0045] The above-mentioned method for processing a circuit board with an embedded ceramic module effectively prevents the ceramic substrate 12 of the ceramic module from breaking by using a specially made jig to press together with the ceramic module. The window design of the jig ensures that the ceramic module can be accurately positioned in the circuit board during the pressing process, avoiding stress concentration caused by position offset, thereby reducing the risk of the ceramic substrate 12 breaking. Since the ceramic substrate 12 is not broken, the electrical connection and heat dissipation structure inside the ceramic module are kept intact, and can stably play its role in the circuit board. The complete ceramic module also ensures the stable transmission of electrical signals, improves the performance of the circuit, and ultimately ensures the high quality of the product, enhances the competitiveness of the product in the market, and brings good economic and brand benefits to the enterprise.

[0046] More preferably, the edge of the window opening is provided with a plurality of bosses 22, and during the pressing process, the bosses 22 abut against the ceramic module. The bosses 22 on the edge of the jig further enhance the fixing effect on the ceramic module, so that it remains stable during the pressing process and does not slide even under high pressure and temperature, thereby ensuring the quality of the product.

[0047] Example 2

[0048] This embodiment is improved on the basis of embodiment 1.

[0049] like Figure 1-Figure 4 As shown, in this embodiment, a method for embedding an AMB silicon nitride module into a PCB board is provided.

[0050] Specifically, the ceramic module 1 includes a ceramic substrate 12, a first metal layer 11 is disposed on the lower surface of the ceramic substrate 12, and a second metal layer 13 is disposed on the upper surface of the ceramic substrate 12; wherein the ceramic substrate 12 protrudes outward from the edge of the metal layer. The ceramic substrate 12 is Si3N4, and the first metal layer 11 and the second metal layer 13 are both copper layers.

[0051] In this embodiment, the jig includes a first jig 2, a second jig 3 and a third jig 4;

[0052] During the pressing process, the first jig 2 corresponds to the first metal layer 11, the second jig 3 corresponds to the ceramic substrate 12, and the third jig 4 corresponds to the second metal layer 13;

[0053] A first prepreg 5 is disposed between the first jig 2 and the second jig 3 , and a second prepreg 6 is disposed between the second jig 3 and the third jig 4 .

[0054] The preparation process of this method is as follows:

[0055] The thickness of the ceramic substrate 12 is 0.32 mm, the thickness of the first metal layer 11 on the lower surface is 0.8 mm, the thickness of the second metal layer 13 on the upper surface is 0.8 mm, and the ceramic substrate 12 protrudes 4 mm outward from the edge of the metal layer. Based on these parameters, a jig is made.

[0056] The thickness of the first fixture 2 is designed to be 0.55mm, and the outer dimensions of its window opening are 50μm smaller than the actual dimensions of the corresponding part of the first metal layer 11, and a boss 22 with a height of 0.1mm and a cross-sectional length of 3mm is made at the edge contact part, and the spacing between two adjacent bosses is 3mm. The thickness of the second fixture 3 is the same as the thickness of the ceramic substrate 12, both of which are 0.32mm, and the size of the window opening of the second fixture 3 is 50μm smaller than the actual size of the ceramic substrate 12. The thickness of the third fixture 4 is 0.65mm, and the outer dimensions of the window opening of the second fixture 3 are 50μm smaller than the corresponding size of the second metal layer 13. Multiple bosses 22 are also set on the edge of the window opening of the second fixture 3.

[0057] When the PCB board is processed to the embedded AMB silicon nitride module link, the operation process is as follows: first, the first fixture 2 is accurately placed at the specified position of the PCB board, and the positioning accuracy is ensured within the range of ± 0.05mm by using high-precision positioning tooling. Then, a first semi-cured sheet 5 with a thickness of 0.2mm is placed above the first fixture 2, and its window size is consistent with the profile of the first metal layer 11 of the AMB silicon nitride module. Subsequently, the AMB silicon nitride module is carefully placed so that the lower surface of the ceramic substrate 12 is in close contact with the first fixture 2, and the boss 22 effectively limits the movement of the AMB silicon nitride module. Afterwards, a second fixture 3 is placed above the AMB silicon nitride module, and then a second semi-cured sheet 6 with a thickness of 0.1mm is placed, and its window size is adapted to the profile of the second metal layer 13. Finally, the third fixture 4 is placed, and the entire assembly is sent to an advanced vacuum hot pressing device for pressing operation. During the pressing process, the heating rate was controlled at 2°C / min, from room temperature to 80°C, and kept at 180°C for 90 minutes. The pressure was maintained at 350psi. High-precision pressure and temperature sensors were used for monitoring and feedback control throughout the pressing process to ensure process stability.

[0058] This method uses a specially designed multi-layer fixture structure to accurately match the dimensions of each part of the AMB silicon nitride module, and sets a boss 22 at the contact edge of the fixture and the module to effectively disperse the pressure during the pressing process and avoid stress concentration on the edge of the ceramic substrate 12.

[0059] More preferably, the thickness of the first metal layer 11 is greater than the total thickness of the first fixture 2 and the first prepreg 5;

[0060] The thickness of the second metal layer 13 is greater than the total thickness of the third fixture 4 and the second prepreg 6;

[0061] The thickness of the ceramic substrate 12 is equal to the thickness of the second fixture 3 .

[0062] The present application strictly stipulates the relationship between the jig and the thickness of the prepreg to ensure that the metal layer has enough space to buffer the pressure during pressing, so as to avoid the stress being directly transmitted to the edge of the ceramic substrate 12.

[0063] In this embodiment, the first fixture 2, the second fixture 3, and the third fixture 4 are all provided with windows;

[0064] During the pressing process, the size of the opening window on each fixture is smaller than the outer size of the corresponding ceramic module.

[0065] Specifically, the size of the openings on each jig is 50 μm smaller than the outer dimensions of the corresponding ceramic module 1. This size design ensures that the jig can effectively define the position of the ceramic module, thereby ensuring that the ceramic module will not be lost during the pressing process, and the openings of the second jig 3 can define the edge position of the ceramic, so that the ceramic substrate 12 is not easily broken.

[0066] More preferably, each layer of the prepreg is provided with a window, and the size of the window on the prepreg is equal to the outer size of the ceramic module.

[0067] Furthermore, before embedding the ceramic module 1 into the circuit board, the method further includes:

[0068] Obtain a substrate of a circuit board, and drill alignment holes on the substrate for exposing the inner layer pattern of the circuit board;

[0069] When pressing the ceramic module and the jig onto the substrate, use the drilled alignment holes for positioning.

[0070] By utilizing the alignment holes used for inner layer pattern exposure as positioning holes for pressing the ceramic module, the step of opening holes can be saved and the alignment accuracy can be ensured, so that the ceramic module can be accurately pressed in the preset position, thereby ensuring the quality of the product.

[0071] Example 3

[0072] like Figure 1-Figure 4 As shown, this embodiment provides a circuit board, including a main body, and a ceramic module is embedded in the main body;

[0073] During the process of embedding the ceramic module in the circuit board, the circuit board is processed using the above-mentioned processing method for embedding the ceramic module in the circuit board.

[0074] The present application also provides a circuit board, the main body of which is embedded with a ceramic module, and the ceramic module is processed using the above-mentioned processing method of a circuit board embedded with a ceramic module. The circuit board can ensure the structural integrity of the ceramic module embedded inside, so that the circuit board has higher product quality and performance.

[0075] During the production process of the circuit board, a special fixture can be used to accurately control the position of the ceramic module in the circuit board, avoiding the inaccurate positioning problem in traditional methods, thereby improving the overall performance of the circuit board.

[0076] The use of the fixture provides additional support for the ceramic module, reduces the risk of ceramic module movement or damage caused by external forces during the embedding process, and enhances the stability of the circuit board. Moreover, this method is suitable for ceramic modules of various shapes and sizes, as well as different types of circuit boards, and has wide applicability and flexibility.

[0077] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for processing a circuit board with embedded ceramic modules, characterized in that: include: A jig is manufactured according to the structure of the ceramic module, wherein the jig is provided with an opening window corresponding to the ceramic module; When embedding the ceramic module into the circuit board, the manufactured jig and the ceramic module are pressed into the circuit board; During the pressing process, the ceramic module is arranged in the opening window of the fixture.

2. The method for processing a circuit board with embedded ceramic modules according to claim 1, characterized in that: A plurality of bosses are arranged at the edge of the window opening, and during the pressing process, the bosses abut against the ceramic module.

3. The method for processing a circuit board with embedded ceramic modules according to claim 1, characterized in that: The ceramic module comprises a ceramic substrate, a first metal layer is disposed on the lower surface of the ceramic substrate, and a second metal layer is disposed on the upper surface of the ceramic substrate; wherein the ceramic substrate protrudes outward from the edge of the metal layer.

4. The method for processing a circuit board with embedded ceramic modules according to claim 3, characterized in that: The fixture includes a first fixture, a second fixture and a third fixture; During the pressing process, the first jig corresponds to the first metal layer, the second jig corresponds to the ceramic substrate, and the third jig corresponds to the second metal layer; A first prepreg is arranged between the first jig and the second jig, and a second prepreg is arranged between the second jig and the third jig.

5. The method for processing a circuit board with embedded ceramic modules according to claim 4, characterized in that: The thickness of the first metal layer is greater than the total thickness of the first fixture and the first prepreg; The thickness of the second metal layer is greater than the total thickness of the third fixture and the second prepreg; The thickness of the ceramic substrate is equal to the thickness of the second fixture.

6. The method for processing a circuit board with embedded ceramic modules according to claim 4, characterized in that: The first fixture, the second fixture, and the third fixture are all provided with windows; During the pressing process, the size of the opening window on each fixture is smaller than the outer size of the corresponding ceramic module.

7. The method for processing a circuit board with embedded ceramic modules according to claim 6, characterized in that: Each layer of the prepreg is provided with an opening, and the opening of the prepreg is equal to the outer size of the ceramic module.

8. The method for processing a circuit board with embedded ceramic modules according to claim 1, characterized in that: Before embedding the ceramic module into the circuit board, the method further comprises: Obtain a substrate of a circuit board, and drill alignment holes on the substrate for exposing the inner layer pattern of the circuit board; When pressing the ceramic module and the jig onto the substrate, use the drilled alignment holes for positioning.

9. A circuit board, comprising a main body, wherein a ceramic module is embedded in the main body; characterized in that: During the process of embedding the ceramic module, the circuit board embedded with the ceramic module is processed using the processing method of any one of claims 1 to 8.

Images