Semiconductor Ceramic Substrate Circuit Board and Its High-Precision Processing Method

Abstract

The present invention discloses a semiconductor ceramic-based circuit board and a high-precision processing method thereof, specifically including: providing a substrate, on which a low-temperature co-fired ceramic raw material layer is preset; opening through holes in the low-temperature co-fired ceramic raw material layer and filling metal paste in the through holes; performing low-temperature co-firing on the low-temperature co-fired ceramic raw material layer and the metal paste by microwave, so that the low-temperature co-fired ceramic raw material layer is sintered into a co-fired ceramic layer, and metal columns formed by the metal paste are embedded in the co-fired ceramic layer; covering the column end faces of the metal columns with nickel powder, and melting and covering the nickel powder on the metal columns by laser to form a nickel layer. By microwave heating, the inside and outside of the low-temperature co-fired ceramic raw material layer are heated synchronously, improving the position accuracy and size accuracy of the through holes. By laser cladding, the nickel powder is melted and covered on the column end faces of the metal columns to form a nickel layer, which can prevent the metal columns from separating from the through holes; the position accuracy and size accuracy of the through holes can be maintained, and the stability of the structure can be maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board processing, and in particular to a semiconductor ceramic-based circuit board and a high-precision processing method thereof. Background Art

[0002] A ceramic-based circuit board is a circuit board manufactured by combining ceramic materials with a metal conductive layer; compared with general organic resin circuit boards, ceramic-based circuit boards have advantages such as high thermal conductivity, high insulation, high mechanical strength, high temperature resistance, and chemical corrosion resistance, and are widely used in fields such as semiconductor packaging, 5G communication, LED lighting, and aerospace.

[0003] Currently, the processing methods of ceramic-based circuit boards mainly include processes such as active metal brazing, low-temperature co-fired ceramics, and high-temperature co-fired ceramics; among them, the low-temperature co-fired ceramic process has become one of the mainstream processing methods for ceramic-based circuit boards due to its advantages of low cost and good compatibility. In the traditional low-temperature co-fired ceramic process, if a conductive vertical channel needs to be formed, the following method is usually adopted: laminating a ceramic green body and a substrate, after lamination, forming a through hole by mechanical drilling or laser drilling, then performing co-firing to form a vertical channel, and then depositing or electroplating copper material into the vertical channel to make the vertical channel conductive. However, it is found in actual processing that: 1. The ceramic material will shrink and deform during the sintering process, resulting in difficulty in ensuring the dimensional accuracy of the vertical channel. Especially in application scenarios that require high-density interconnection and micro-vias, there is a risk of open circuit or short circuit; 2. The surface of the ceramic material is relatively inert, and the adhesion of the copper material is often poor, and it is easy to delaminate or peel off during subsequent electroplating or thermal cycling, and even easy to cause the copper material to fall off from the ceramic-based circuit board.

[0004] More commonly, those skilled in the art can increase the pre-sintering process to reduce ceramic shrinkage, thereby improving the accuracy, but it is easy to further widen the deformation difference between the ceramic and the copper material, thereby reducing the interfacial bonding strength and affecting the overall stability; or, use a more active metal interface layer to enhance the bonding strength, but due to factors such as its diffusion, chemical reaction, and enhanced wettability, excessive diffusion is likely to occur, and it is easy to cause a decrease in the dimensional accuracy of the vertical channel.

[0005] It can be seen that it is difficult for those skilled in the art to simultaneously improve the accuracy and structural stability of the vertical channels of ceramic-based circuit boards. Summary of the Invention

[0006] The purpose of the present invention is to provide a semiconductor ceramic-based circuit board and a high-precision processing method thereof, so as to solve the problem of difficulty in simultaneously ensuring the accuracy and structural stability of the vertical channels of the ceramic-based circuit board.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] A high-precision processing method for a semiconductor ceramic-based circuit board, comprising:

[0009] S100. Provide a substrate, on which a low-temperature co-fired ceramic raw material layer is preset;

[0010] S200. Open through holes in the low-temperature co-fired ceramic raw material layer, and fill the through holes with metal paste;

[0011] S300. Perform low-temperature co-firing on the low-temperature co-fired ceramic raw material layer and the metal paste through microwave, so that the low-temperature co-fired ceramic raw material layer is sintered into a co-fired ceramic layer, and metal columns formed by the metal paste are embedded in the co-fired ceramic layer;

[0012] S400. Cover the column end faces of the metal columns with nickel powder, and melt and cover the nickel powder on the metal columns through laser to form a nickel layer;

[0013] In the step S200, the metal paste is filled in the through holes through the rings in the through holes, and the rings are removed during the sintering process, and the size of the rings is related to the sintering deformation amount of the metal columns and the sintering deformation amount of the low-temperature co-fired ceramic raw material layer.

[0014] Optionally, the step S200 specifically includes:

[0015] Step S210. Open through holes with a first diameter in the low-temperature co-fired ceramic raw material layer, and provide rings matching the through holes according to the first diameter;

[0016] Step S220. Set the rings in the first through holes, and fill the metal paste inside the rings.

[0017] Optionally, the step S300 includes:

[0018] Step S310. Set the heating temperature at 100-300 °C through a microwave heating device, and maintain the heating for 30-60 min;

[0019] Step S320. Set the heating temperature at 300-500 °C through a microwave heating device, and maintain the heating for 30-60 min;

[0020] Step S330. Set the heating temperature at 800-850 °C through a microwave heating device, and maintain the heating for 60-90 min.

[0021] Optionally, before the step S210, it further includes:

[0022] Step S201. Calculate the wall thickness t of the rings according to the sintering deformation amount of the metal columns and the sintering deformation amount of the low-temperature co-fired ceramic raw material layer at the through holes;

[0023] Step S202: Form a ring body according to the first diameter and the wall thickness t.

[0024] Optionally, in the step S201, the formula for the wall thickness t is:

[0025]

[0026] Where is the first diameter of the through hole formed in the low-temperature co-fired ceramic raw material layer, is the initial diameter of the metal column, is the shrinkage rate of the low-temperature co-fired ceramic raw material, is the shrinkage rate of the metal paste, is the thermal expansion coefficient of the metal column, is the sintering temperature difference of the metal column.

[0027] Optionally, in the step S300, the heating power P of the microwave heating device;

[0028]

[0029]

[0030] Where is the temperature rise efficiency, is the medium density of the microwave heating device, is the specific heat capacity of the medium of the microwave heating device, V is the medium volume of the microwave heating device, is the absorption efficiency of the microwave;

[0031] ω is the microwave angular frequency, is the vacuum permittivity, is the dielectric loss factor of the low-temperature co-fired ceramic raw material layer, E is the microwave electric field strength.

[0032] Optionally, the ring body is a paraffin ring and the metal paste is a silver paste.

[0033] Optionally, the step S400 includes:

[0034] Step S410: Deposit a titanium layer on the co-fired ceramic layer by evaporation coating, and the titanium layer covers the upper end surface of the metal column and the edge of the through hole;

[0035] Step S420: Lay nickel powder on the titanium layer and fuse the nickel powder on the titanium layer by a laser in a scanning mode.

[0036] Optionally, the step S410 includes:

[0037] Place the substrate in an evaporation chamber under high vacuum. Heat the titanium target through an evaporation source, and allow the titanium vapor to diffuse and deposit on the upper end face of the metal column and the edge of the through hole.

[0038] A semiconductor ceramic-based circuit board, adopting the high-precision processing method of the semiconductor ceramic-based circuit board as described above, includes a substrate, and a co-fired ceramic layer is provided on the substrate, and metal columns are provided in the co-fired ceramic layer.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The semiconductor ceramic-based circuit board and its high-precision processing method provided by the present invention heat the low-temperature co-fired ceramic raw material layer synchronously inside and outside through microwave heating, so that the low-temperature co-fired ceramic raw materials are uniformly heated, reducing the non-uniform shrinkage of the ceramic matrix and improving the position accuracy and size accuracy of the through holes. The nickel powder is melted and covered on the column end face of the metal column by laser cladding to form a nickel layer. At this time, a metallurgical bond is formed between the nickel layer and the metal column, which means that the nickel layer covers outside the metal column and can prevent the metal column from separating from the through hole; and because the energy density of laser cladding is relatively high, local high-temperature treatment can be completed in a short time, avoiding the ceramic thermal expansion mismatch caused by long-term high temperature, thereby reducing the interfacial thermal stress to maintain the accuracy of the through hole. Through the above settings, the position accuracy and size accuracy of the through hole can be maintained, and the setting of the nickel layer prevents the metal column from separating and maintains the stability of the structure. Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0042] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those who are familiar with this technology to understand and read, and are not used to limit the limited conditions under which the present invention can be implemented. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship, or adjustment of the size should still fall within the scope that can be covered by the technical content disclosed in the present invention without affecting the effects that the present invention can produce and the purposes that can be achieved.

[0043] Figure 1 It is a schematic flow chart of the high-precision processing method of the semiconductor ceramic-based circuit board provided by the embodiment of the present invention. Detailed Embodiments

[0044] In order to make the object, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0045] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be intermediate components present.

[0046] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and through specific embodiments.

[0047] Embodiment 1:

[0048] The high-precision processing method of the semiconductor ceramic-based circuit board provided in this embodiment aims to solve the problem that it is difficult to achieve both the vertical channel accuracy and structural stability in the processing of traditional ceramic-based circuit boards. To solve this problem, this embodiment mainly combines the low-temperature co-fired ceramic process and microwave heating technology, and strengthens the connection stability of the metal pillars through laser cladding technology. Through the specific optimization of this high-precision processing method, the dimensional accuracy, position accuracy of the vertical channels of the semiconductor ceramic-based circuit board and the structural stability are significantly improved, ensuring the good performance of the semiconductor ceramic-based circuit board in high-density interconnection and micro-vias application scenarios.

[0049] Specifically, as Figure 1 shown, the high-precision processing method of the semiconductor ceramic-based circuit board provided in the embodiment of the present invention includes:

[0050] Step S100: Provide a substrate, on which a low-temperature co-fired ceramic raw material layer is preset;

[0051] Among them, the substrate is the base material of the semiconductor ceramic-based circuit board, which is not limited in this embodiment, including but not limited to copper plates, PCB boards, alumina ceramic substrates, aluminum nitride ceramic substrates, etc., as long as it can withstand the thermal stress during the subsequent sintering process; the low-temperature co-fired ceramic raw material includes a composite material composed of glass, ceramic powder or other inorganic powder materials, and the selected low-temperature co-fired ceramic raw material can be sintered in the temperature range of about 500°C to 900°C to form a co-fired ceramic layer;

[0052] Step S200: Open through holes in the low-temperature co-fired ceramic raw material layer, and fill the through holes with metal paste;

[0053] In the step S200, the metal paste is filled into the through holes through the rings in the through holes, and the rings are removed during the sintering process. The size of the rings is related to the sintering deformation amount of the metal columns and the sintering deformation amount of the low-temperature co-fired ceramic raw material layer; it can be understood that the size setting of the rings is matched with the above-mentioned sintering deformation amount, and can be removed during the sintering process in step S300, so the space left is suitable for the sintering deformation of the metal columns and the sintering deformation of the low-temperature co-fired ceramic raw material layer, thereby effectively balancing the deformation difference caused by the temperature difference between the ceramic and metal materials during the sintering process, reducing the interface stress, and further improving the precision;

[0054] Step S300: Perform low-temperature co-firing on the low-temperature co-fired ceramic raw material layer and the metal paste by microwave, so that the low-temperature co-fired ceramic raw material layer is sintered into a co-fired ceramic layer, and metal columns formed by the metal paste are embedded in the co-fired ceramic layer;

[0055] Step S400: Cover the column end faces of the metal columns with nickel powder, and melt and cover the nickel powder on the metal columns by laser to form a nickel layer.

[0056] Specifically, in the high-precision processing method of the semiconductor ceramic-based circuit board in this embodiment, the low-temperature co-fired ceramic raw material layer is heated synchronously inside and outside by microwave heating, so that the low-temperature co-fired ceramic raw material is evenly heated, reducing the non-uniform shrinkage of the ceramic matrix and improving the position accuracy and size accuracy of the through holes. The nickel powder is melted and covered on the column end faces of the metal columns by laser cladding to form a nickel layer. At this time, the nickel layer forms a metallurgical bond with the metal columns, which means that the nickel layer covers outside the metal columns and can prevent the metal columns from separating from the through holes; and because the energy density of laser cladding is relatively high, local high-temperature treatment can be completed in a short time, avoiding the mismatch of ceramic thermal expansion caused by long-term high temperature, thereby reducing the interface thermal stress to maintain the accuracy of the through holes. Through the above settings, the position accuracy and size accuracy of the through holes can be maintained, and the setting of the nickel layer prevents the metal columns from separating and maintains the stability of the structure.

[0057] Further, step S200 specifically includes:

[0058] Step S210: Open a through-hole with a first diameter on the low-temperature co-fired ceramic raw material layer, and provide an annular body that matches the through-hole according to the first diameter;

[0059] Step S220: Set the annular body in the first through-hole, and fill the inside of the annular body with metal paste.

[0060] Among them, the through-hole is opened by laser drilling or mechanical drilling; the annular body is a structure that matches the through-hole, and its function is to support the filling of the metal paste and effectively control the shape of the metal column during the sintering process; the forming method of the annular body can adopt die forming or 3D printing technology, and materials that are easy to process and can remain stable during the sintering process are selected, such as paraffin rings, gypsum rings, etc., so that they can be removed during the sintering process to ensure the filling effect of the annular body on the metal paste, so as to ensure the bonding stability between the formed metal column and the co-fired ceramic layer, thereby ensuring the stability and accuracy of the metal column.

[0061] As a preferred embodiment, the annular body is a paraffin ring and the metal paste is silver paste.

[0062] More specifically, step S300 includes:

[0063] Step S310: Set the heating temperature at 100-300 °C through a microwave heating device and maintain the heating for 30-60 min;

[0064] Step S320: Set the heating temperature at 300-500 °C through a microwave heating device and maintain the heating for 30-60 min;

[0065] Step S330: Set the heating temperature at 800-850 °C through a microwave heating device and maintain the heating for 60-90 min.

[0066] Referring to step S310, in the initial stage of sintering, the organic matter in the silver paste volatilizes, and at this time the silver paste shrinks. Similarly, slight bonding occurs between the particles of the low-temperature co-fired ceramic raw material, and the overall change is small; and, at this temperature, the paraffin ring gradually melts and volatilizes to initially form a silver column in the through-hole. At this time, there is a gap between the silver column and the through-hole, and this gap matches the thickness of the paraffin ring;

[0067] Referring to step S320, in the middle stage of sintering, sintering begins on the surface of the silver particles in the silver paste, and preliminary connections are formed between the silver particles through diffusion; at this time, the wettability of silver increases and it begins to contact the ceramic particles. At the same time, as the glass phase softens, the ceramic particles are rearranged and densified, resulting in a large proportion of shrinkage;

[0068] Referring to step S330, in the later stage of sintering, silver particles grow grains through stronger diffusion and complete the densification process. The density of the silver pillars increases, and the connection between silver particles becomes closer. At this time, the low-temperature co-fired ceramic layer of the semiconductor ceramic-based circuit board also undergoes a sintering process, and the ceramic layer gradually densifies and forms an interfacial bond with the silver pillars; the high wettability of silver enables it to effectively bond with the ceramic surface, forming a strong metal-ceramic bonding interface. At this stage, the metal particles in the silver paste are completely sintered to form high-density silver pillars, and the metal-ceramic interfacial bond is stable, providing the required conductivity and mechanical strength.

[0069] Further, before step S210, it further includes:

[0070] Step S201: Calculate the wall thickness t of the ring body according to the sintering deformation amount of the metal pillar and the sintering deformation amount of the low-temperature co-fired ceramic raw material layer at the through hole.

[0071] Step S202: Form the ring body according to the first diameter and the wall thickness t.

[0072] It can be understood that in step S201, first, it is necessary to calculate the wall thickness of the ring body according to the sintering deformation amount of the metal pillar and the sintering deformation amount of the low-temperature co-fired ceramic raw material layer at the through hole. The deformations of the metal pillar and the ceramic matrix during the sintering process have different properties. In particular, the shrinkage rate of the ceramic material during sintering is different from the thermal expansion coefficient of the metal pillar, which will lead to a stress difference between the metal pillar and the ceramic matrix after sintering. By considering these factors, an appropriate wall thickness t of the ring body can be calculated to ensure that the metal pillar can maintain a stable structure during the sintering process, and at the same time prevent the metal pillar from shifting or falling off due to excessive thermal stress or uneven deformation. That is to say, by calculating the wall thickness t, the ring body can be formed according to this parameter. The ring body can be made of paraffin material, which has good formability and a low sintering temperature, and can be completely removed after sintering without affecting the final structure, and can provide support when the metal paste fills the through hole, ensure the correct filling of the metal paste, and prevent the paste from flowing or shifting during the sintering process.

[0073] As a specific implementation manner, in step S201, the formula for the wall thickness t is:

[0074]

[0075] Wherein, is the first diameter of the through hole opened on the low-temperature co-fired ceramic raw material layer, is the initial diameter of the metal pillar, is the shrinkage rate of the low-temperature co-fired ceramic raw material, is the shrinkage rate of the metal paste, is the thermal expansion coefficient of the metal pillar, is the sintering temperature difference of the metal column. It should be noted that the shrinkage rate of the low-temperature co-fired ceramic raw material is determined by the properties of the purchased low-temperature co-fired ceramic raw material, can be determined through the parameters provided by the purchasing manufacturer, and can also be measured through testing; the shrinkage rate of the metal paste is related to the organic matter and solvent of the metal paste, and can also be determined through the parameters provided by the purchasing manufacturer and measured through testing; The thermal expansion coefficient of the metal column is related to the physical properties of silver and can be obtained by looking up the table; the sintering temperature difference of the metal column refers to the difference between the temperature after the metal column is formed and the temperature at the end of sintering; through the above settings, the deformation of the metal column and the ceramic substrate during sintering can be calculated, the wall thickness of the ring body can be better controlled, the stability of the metal column during sintering can be ensured, and the displacement or shedding of the metal column caused by inappropriate wall thickness of the ring body can be avoided. And due to the supporting effect of the ring body, the metal paste can be evenly distributed in the through hole, avoiding the loss or deviation of the metal paste during sintering, thereby improving the size accuracy and position accuracy of the through hole, effectively balancing the deformation difference caused by the temperature difference between the ceramic and metal materials during sintering, reducing the interfacial stress, and enhancing the structural stability of the circuit board.

[0076] As a specific implementation manner, in step S300, the heating power P of the microwave heating device;

[0077]

[0078]

[0079] Among them, is the temperature rise efficiency, is the medium density of the microwave heating device, is the specific heat capacity of the medium of the microwave heating device, V is the medium volume of the microwave heating device, is the absorption efficiency of the microwave; ω is the microwave angular frequency, is the vacuum permittivity, is the dielectric loss factor of the low-temperature co-fired ceramic raw material layer, and E is the microwave electric field strength.

[0080] It should be noted that first, according to the vacuum permittivity , the dielectric loss factor of the low-temperature co-fired ceramic raw material layer, the microwave angular frequency ω, the microwave electric field strength E, and the specific heat capacity of the medium , the temperature rise efficiency is deduced; among them, the vacuum permittivity are all values that can be directly looked up, and the dielectric loss factor It can be determined by the parameters provided by the purchasing manufacturer, or can also be measured through testing; the microwave angular frequency ω and the microwave electric field strength E are preset values of the microwave heating device, which are related to the used microwave heating device and are not limited in this embodiment. The microwave electric field strength E can be selected as 3×104 V / m, and the microwave angular frequency ω can be selected as 2.45 GHz; the medium density , the specific heat capacity of the medium and the medium volume V refer to the density, specific heat capacity and volume of the low-temperature co-fired ceramic raw material layer, which can also be determined by the parameters provided by the purchasing manufacturer or can be measured through testing.

[0081] It can be understood that through the microwave heating method, synchronous heating inside and outside the low-temperature co-fired ceramic raw material layer can be achieved, ensuring that the ceramic material and the metal paste can be evenly heated during the sintering process, thereby improving the accuracy and stability of the through holes. Microwave heating can not only accelerate the sintering process, but also reduce the thermal stress caused by the temperature difference between the ceramic substrate and the metal column, ensuring the structural stability of the circuit board. The above settings further optimize the entire heating process by precisely regulating the parameters of the microwave heating device, improve the dimensional accuracy and performance of the product, provide a reference for the parameter setting before formal production, and more accurately provide a reference for the setting direction of those skilled in the art.

[0082] Based on the above embodiments, step S400 includes:

[0083] Step S410, depositing a titanium layer on the co-fired ceramic layer by evaporation coating, and the titanium layer covers the upper end surface of the metal column and the edge of the through hole;

[0084] Step S420, laying nickel powder on the titanium layer, and cladding the nickel powder on the titanium layer by a laser in a scanning mode. Among them, the nickel powder can be electrostatically sprayed, mechanically coated or manually spread. The laser includes but is not limited to a fiber laser and a CO2 laser. The laser power should be maintained between 100-500 watts, and the scanning speed is controlled between 5-15 mm / s to ensure that the nickel layer adheres to the titanium layer evenly and firmly.

[0085] More specifically, the step S410 includes:

[0086] Placing the substrate in a high-vacuum evaporation chamber, heating the titanium target by an evaporation source, and allowing the titanium vapor to be deposited on the upper end surface of the metal column and the edge of the through hole by diffusion.

[0087] Among them, the substrate is placed in an evaporation chamber with high vacuum. The titanium target is heated by an evaporation source, and the titanium target evaporates into titanium vapor at high temperature. Through diffusion, it is deposited on the upper end surface of the metal column and the edge of the through hole. The titanium vapor is evenly deposited on the surface of the metal column through the diffusion effect of the high-vacuum environment to form a uniform titanium layer. The deposition time of the titanium layer is 10 - 30 minutes, and the deposition temperature is about 200 - 300 °C. After the deposition of the titanium layer, nickel powder is laid on the titanium layer, and then the nickel powder is melted by laser scanning cladding technology to form a uniform nickel layer. The cladding process of the nickel layer ensures that the nickel powder can evenly cover the surface of the titanium layer, and finally a nickel layer with a thickness of 10 - 50 μm is formed. The overall thickness is small, which can protect the silver column from oxidation and improve the stability of the structure. The nickel layer plays an important role in enhancing the electrical conductivity and adhesion of the metal column, preventing the separation of the metal column from the ceramic-based circuit board. In addition, through the above evaporation coating and laser cladding technologies, the present invention effectively solves the interface problem between the metal column and the ceramic-based circuit board. The double protection of the titanium layer and the nickel layer not only improves the bonding strength between the metal column and the ceramic-based circuit board, but also enhances the electrical conductivity and mechanical stability of the metal column, significantly improving the reliability and performance of the ceramic-based circuit board, especially the stability in high-frequency and high-temperature working environments.

[0088] Embodiment 2;

[0089] This embodiment also provides a semiconductor ceramic-based circuit board, adopting the high-precision processing method of the semiconductor ceramic-based circuit board in Embodiment 1, including a substrate, a co-fired ceramic layer is provided on the substrate, and metal columns are provided in the co-fired ceramic layer. At the same time, a titanium layer and a nickel layer can be provided on the metal columns.

[0090] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A high-precision processing method for a semiconductor ceramic-based circuit board, characterized in that, Including: Step S100: Provide a substrate, on which a low-temperature co-fired ceramic raw material layer is preset; Step S200: Open a through hole with a first diameter in the low-temperature co-fired ceramic raw material layer, and fill the through hole with a metal paste; Step S300: Perform low-temperature co-firing on the low-temperature co-fired ceramic raw material layer and the metal paste through microwave, so that the low-temperature co-fired ceramic raw material layer is sintered into a co-fired ceramic layer, and metal columns formed by the metal paste are embedded in the co-fired ceramic layer; Step S400: Cover the column end face of the metal column with nickel powder, and melt and cover the nickel powder on the metal column through laser to form a nickel layer; In the step S200, the metal paste is filled in the through hole through a ring body in the through hole, and the ring body is removed during the sintering process. The size of the ring body is related to the sintering deformation amount of the metal column and the sintering deformation amount of the low-temperature co-fired ceramic raw material layer; The step S200 specifically includes: Step S201: Calculate the wall thickness t of the ring body according to the sintering deformation amount of the metal column and the sintering deformation amount of the low-temperature co-fired ceramic raw material layer at the through hole; Step S210: Open a through hole with a first diameter in the low-temperature co-fired ceramic raw material layer, and provide a ring body matching the through hole according to the first diameter; wherein, the ring body is formed according to the first diameter and the wall thickness t; Step S220: Set the ring body in the first through hole, and fill the metal paste inside the ring body.

2. The high-precision processing method of a semiconductor ceramic-based circuit board according to claim 1, wherein The step S300 includes: Step S310: Set the heating temperature at 100-300 °C through a microwave heating device, and maintain the heating for 30-60 min; Step S320: Set the heating temperature at 300-500 °C through a microwave heating device, and maintain the heating for 30-60 min; Step S330: Set the heating temperature at 800-850 °C through a microwave heating device, and maintain the heating for 60-90 min.

3. A high-precision processing method for a semiconductor ceramic-based circuit board according to claim 2, characterized in that, In the step S201, the formula for the wall thickness t is: Wherein, is the first diameter of the through hole formed in the low temperature co-fired ceramic raw material layer, is the initial diameter of the metal column, is the shrinkage rate of the low temperature co-fired ceramic raw material, is the shrinkage rate of the metal paste, is the thermal expansion coefficient of the metal column, is the sintering temperature difference of the metal column.

4. A high-precision processing method for a semiconductor ceramic-based circuit board according to claim 2, characterized in that, In the step S300, the heating power P of the microwave heating device; Among them, is the temperature rise efficiency, is the medium density of the microwave heating device, is the specific heat capacity of the medium of the microwave heating device, V is the medium volume of the microwave heating device, is the absorption efficiency of microwaves; ω is the microwave angular frequency, is the vacuum permittivity, is the dielectric loss factor of the low-temperature co-fired ceramic raw material layer, and E is the microwave electric field strength.

5. A high-precision processing method for a semiconductor ceramic-based circuit board according to any one of claims 1-4, characterized in that, The ring body is a paraffin ring, and the metal paste is a silver paste.

6. The high-precision processing method of a semiconductor ceramic-based circuit board according to claim 1, characterized in that, The step S400 includes: Step S410: Deposit a titanium layer on the co-fired ceramic layer through evaporation coating, and the titanium layer covers the upper end face of the metal column and the edge of the through hole; Step S420: Lay nickel powder on the titanium layer, and melt and coat the nickel powder on the titanium layer through a laser in a scanning mode.

7. A high-precision processing method for a semiconductor ceramic-based circuit board according to claim 6, characterized in that, The step S410 includes: Place the substrate in an evaporation chamber with high vacuum, heat the titanium target through an evaporation source, and make the titanium vapor deposit on the upper end face of the metal column and the edge of the through hole through diffusion.

8. A semiconductor ceramic-based circuit board, characterized in that, Adopt the high-precision processing method of the semiconductor ceramic-based circuit board as described in any one of claims 1-7, including a substrate, and a co-fired ceramic layer is provided on the substrate, and metal columns are provided in the co-fired ceramic layer.

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