CN115802598B

CN115802598B - Ceramic substrate and manufacturing method and application thereof

Info

Publication number: CN115802598B
Application number: CN202310047492.9A
Authority: CN
Inventors: 何锦华; 王兢; 梁超; 陈礼坤
Original assignee: Jiangsu Borui Photoelectric Co ltd; Borui Optoelectronics Taizhou Co ltd
Current assignee: Jiangsu Borui Photoelectric Co ltd; Borui Optoelectronics Taizhou Co ltd
Priority date: 2023-01-31
Filing date: 2023-01-31
Publication date: 2023-10-31
Anticipated expiration: 2043-01-31
Also published as: CN115802598A

Abstract

The invention discloses a ceramic substrate, a manufacturing method and application thereof. According to the ceramic substrate, the transition layer and the connecting layer are arranged between the copper circuit layer and the surface finishing layer, so that the effect of isolating the copper circuit layer and the surface finishing layer is achieved, migration of copper ions is effectively blocked, the problems of yellowing and blackening of the surface finishing layer in the prior art are avoided, and on the other hand, the connecting layer has a large number of crystal boundaries due to the fact that the microstructure is a compact nano columnar crystal form perpendicular to an interface, and diffusion and displacement deposition rate and deposition uniformity in silver plating in the later stage can be improved. And the bonding force between the surface finishing layer and the transition layer can be improved by the connecting layer with a specific structure, so that the ceramic substrate has better application life. The ceramic substrate provided by the invention can be applied to Light Emitting Diodes (LEDs), laser Diodes (LDs), communication, sensors or power devices as a heat dissipation packaging substrate due to good properties.

Description

Ceramic substrate and manufacturing method and application thereof

Technical Field

The invention belongs to the technical field of lighting devices, and particularly relates to a ceramic substrate, a manufacturing method and application thereof.

Background

Along with the rise and application of power devices, particularly third-generation semiconductors, the semiconductor devices gradually develop to high power, miniaturization, integration, multifunction and the like, are applied to the fields of large computers, automobile precision parts, medical equipment, LED light sources, military industry, aerospace and the like, and have higher requirements on the performance and reliability of packaging substrates.

The ceramic substrate (also called ceramic circuit board) has the characteristics of high heat conductivity, good heat resistance, low thermal expansion coefficient, high mechanical strength, good insulativity, corrosion resistance, radiation resistance and the like, and is widely applied to electronic device packaging. In the process of manufacturing a packaged circuit board, surface treatment is performed to prevent oxidation of a surface metal wiring layer, and thus a surface treatment technique is attracting attention.

The surface silver-plating finishing is an economical and practical surface treatment technology with wide application, the welding surface of the silver layer has good weldability, flatness and coplanarity, and the process cost has obvious advantages compared with nickel-plating gold and nickel-plating palladium hardware, and is widely applied. However, in a high-temperature welding process, such as a eutectic welding process, copper atoms of the underlying copper line can thermally diffuse to the surface of the silver layer along with the grain boundary of the silver layer, so that yellowing and blackening phenomena are generated, and the packaging reliability is affected. Meanwhile, due to the existence of the photosensitive film, a gap between the photosensitive film and a copper circuit is easy to generate serious 'galvanic effect' when silver is formed on the surface of the copper substrate, so that the copper circuit layer is corroded and broken.

Disclosure of Invention

In order to overcome the following two problems in the prior art:

1) The silver surface yellowing and blackening problems caused by diffusion and migration of bottom metal to the surface of the silver layer in the high-temperature welding process of the silver surface finishing layer are solved;

2) And (3) during silver-plating finishing of the ceramic substrate, the circuit is broken due to copper corrosion at the copper circuit layer and the photosensitive film caused by the 'galvanic effect'.

The invention provides a ceramic substrate with a brand new structure, which not only can effectively inhibit the high-temperature heat migration phenomenon of bottom metal and solve the problem of blackening Wen Huanghua of the surface finishing layer, but also can prevent direct chemical displacement reaction between metal ions and copper of a copper circuit layer when the surface finishing layer is formed, eliminate the 'galvanic effect' and protect copper circuits from corrosion by arranging a transition layer and a connecting layer between the copper circuit layer and the surface finishing layer.

The invention specifically provides the following technical scheme:

a ceramic substrate, comprising:

a ceramic substrate having a plurality of through holes;

the metal priming layer is discontinuously arranged on the upper surface and the lower surface of the ceramic substrate and the inner wall of the through hole;

the copper circuit layer is arranged on the surface of the metal base layer and fills the inside of the through hole;

The surface finishing layer is arranged on the copper circuit layer;

the copper circuit layer is provided with a copper layer, a surface finishing layer and a transition layer, wherein the transition layer and the connecting layer are arranged on the copper circuit layer in a lamination mode, and the microstructure of the connecting layer is a compact nano columnar crystal form perpendicular to the interface.

Further, the material of the connecting layer is any one of nickel, nickel phosphorus and nickel boron, and the thickness is not more than 1 mu m.

Further, the material of the transition layer is any one of nickel, nickel phosphorus and nickel boron, and the thickness is 0.01-15 μm.

Further, the surface finishing layer is made of silver-based material, and the thickness of the surface finishing layer is 10 nm-2000 nm.

Further, the material of the ceramic substrate is selected from any one of alumina, aluminum nitride, silicon nitride, zirconia, silicon carbide, beryllium oxide, boron nitride, lanthanum boride, or zirconia reinforced alumina (ZTA).

Further, the aperture of the through hole is in the range of 10 μm to 300 μm.

Further, the material of the metal priming layer is selected from any one or the combination of at least two of copper, chromium, manganese, titanium, nickel or tungsten, and the thickness is 0.1-3 mu m.

Further, the thickness of the copper wire layer is 10 μm to 200 μm.

Another object of the present invention is to provide a method for manufacturing the ceramic substrate, which includes the following steps:

S1, punching a ceramic substrate to obtain a plurality of through holes;

s2, forming a metal priming layer on the upper surface and the lower surface of the ceramic substrate and on the inner wall of the through hole;

s3, carrying out pattern transfer on the metal base layer to generate a circuit pattern, forming spaced photosensitive film layers on the upper surface and the lower surface of the metal base layer, and forming copper circuit layers at gaps of the photosensitive film layers and inside the through holes;

s4, forming a transition layer on the copper circuit layer;

s5, forming a connecting layer on the transition layer;

s6, forming a surface finishing layer on the connecting layer;

and S7, performing film stripping etching on the photosensitive film layer and the metal underlayer below the photosensitive film layer to expose the ceramic substrate, thereby obtaining the ceramic substrate.

Specifically, in the step S5, the transition layer is treated by any one of acid leaching, microetching and palladium activation to obtain a connection layer; or forming a connecting layer on the transition layer by adopting an electroplating process.

Generally, the acid leaching process adopts a sulfuric acid solution with the mass fraction of 1% -10%, the acid leaching temperature is 20 ℃ -50 ℃, and the acid leaching time is 5 min-20 min; the microetching process adopts a mixed solution of 5-30% sulfuric acid and 20 g/L-120 g/L sodium persulfate, wherein the microetching temperature is 20-40 ℃ and the microetching time is 0.5-5 min; the palladium activation adopts a colloid palladium activation system, which comprises metal palladium salt, sodium stannate, sodium chloride and chelating agent, wherein the concentration of palladium ions is 10 ppm-200 ppm, the concentration of sodium stannate is 0.5 g/L-5 g/L, the concentration of sodium chloride is 10 g/L-150 g/L, the chelating agent comprises ethylenediamine, ethylenediamine tetraacetic acid or sodium tartrate, the concentration of the chelating agent is 0.5 g/L-5 g/L, the activation temperature is 20 ℃ to 40 ℃, and the activation time is 1 min-10 min; the electroplating process adopts an electroplating nickel solution formed by mixing 200 g/L-400 g/L nickel sulfate, 30 g/L-80 g/L nickel chloride and 30 g/L-60 g/L boric acid, and the current density is 5 mA/cm ² ~200mA/cm ² The electroplating temperature is 60-90 ℃, and the electroplating time is 10-1800 sec.

Further, in the step S4, a transition layer is formed on the copper circuit layer by using an electroless plating or electroplating process.

Generally, the process of forming the transition layer by adopting the electroless plating process comprises operations of degreasing, microetching, presoaking, activating, chemically plating the transition layer and the like, and the main steps comprise:

a) The oil removal process adopts 5-30% of sulfuric acid by mass and 1-10% of surfactant by mass, wherein the surfactant comprises, but is not limited to, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, quaternary ammonium compound and the like, the cleaning time is 1-5 min, the cleaning temperature is 30-60 ℃, and then the pure water is used for cleaning.

B) The microetching process adopts a sulfuric acid/hydrogen peroxide system, wherein the concentration of sulfuric acid is 5% -50%, the concentration of hydrogen peroxide is 10% -50%, the microetching temperature is 20 ℃ -40 ℃, and the microetching time is 0.5 min-5 min.

C) The pre-soaking process adopts sulfuric acid solution with mass fraction of 2% -20%, the pre-soaking temperature is 20 ℃ -40 ℃, and the pre-soaking time is 1 min-5 min.

D) The activation process adopts a colloid palladium activation system which comprises metal palladium salt, sodium stannate, sodium chloride and chelating agent, wherein the metal palladium salt comprises palladium chloride, palladium sulfate, tetra-ammine palladium dichloride and the like, and the palladium ion concentration is 10 ppm-200 ppm; the concentration of sodium stannate is 0.5 g/L-5 g/L; the concentration of sodium chloride is 10 g/L-150 g/L; chelating agents including but not limited to ethylenediamine, ethylenediamine tetraacetic acid, sodium tartrate, and the like, at a concentration of 0.5 g/L to 5 g/L; the activation temperature is 20-40 ℃ and the activation time is 1-10 min.

E) In the transition layer chemical plating process, (1) the plating solution of the chemical nickel-phosphorus plating transition layer comprises the following components: 5 g/L-30 g/L nickel sulfate, 5 g/L-30 g/L nickel acetate, 10 g/L-100 g/L sodium hypophosphite, 30 g/L-40 g/L sodium citrate, 0.01 g/L-0.03 g/L thiourea and 0.1% -2% EDTA, the pH of the plating solution is 6.4-7.2, and the chemical plating temperature is 60-85 ℃; the plating solution for the nickel-boron plating transition layer comprises the following components: 5. 5 g/L-30 g/L nickel sulfate, 5. 5 g/L-30 g/L nickel acetate, 20. 20 g/L-50. 50 g/L sodium citrate, 0.1% -2% EDTA, 2.5. 2.5 g/L-8 g/L sodium borohydride, 2.5. 2.5 g/L-8 g/L dimethylamine borane and 0.01. 0.01 g/L-0.03. 0.03 g/L thiourea, the pH of the plating solution is 7.2-7.8, and the plating temperature is 50-70 ℃.

In the method for manufacturing the ceramic substrate of the present invention, the punching process of the ceramic substrate, the manufacturing process of the metal priming layer, the photosensitive film layer, the copper circuit layer, the surface finishing layer, the film removing etching process, etc. may be generally performed by the following processes, but the present invention is not limited thereto, and those skilled in the art may perform other processes of the same type, and will not be described in detail herein.

Further, in the above step S6, a surface finishing layer is formed on the connection layer using a process of electroless silver plating or electro silver plating.

In general, the chemical silver plating process for forming the surface finishing layer comprises the steps of silver plating presoaking and silver plating, wherein the main steps comprise:

a) The presoaking liquid for the silver plating presoaking process comprises the following components: 1% -5% of reducing agent, 0.1% -3% of stabilizer and 1% -15% of complexing agent; wherein the reducing agent is one or more of formaldehyde, glucose, tartrate, glyoxal, sodium borohydride, triethanolamine and glycerol, the stabilizer is one or more of gelatin, iodide, inorganic metal salt, sulfur-containing compound and amino acid, and the complexing agent is one or more of ammonia water, EDTA, ethylenediamine and sodium tartrate.

B) The plating solution of the silver plating process comprises the following components: the concentration of silver ions provided by the silver source is 0.1 g/L-20 g/L, the concentration of the reducing agent is 5% -20%, the concentration of the stabilizing agent is 1% -10%, and the concentration of the complexing agent is 10% -30%; wherein the silver source can be one or more of silver nitrate, silver amine sulfonate and silver nitrite, the reducing agent is one or more of formaldehyde, glucose, tartrate, glyoxal, sodium borohydride, triethanolamine and glycerol, and the stabilizer is one or more of gelatin, iodide, inorganic metal salt, sulfur-containing compound and amino acid; the complexing agent is one or more of ammonia water, EDTA, ethylenediamine and sodium tartrate; the pH of the plating solution is 3.8-6.5, the chemical plating temperature is 35-65 ℃, the spraying pressure is 1-10 MPa, and the chemical plating time is 1-10 min.

Further, in the step S2, a metal underlayer is formed on the upper and lower surfaces of the ceramic substrate and the inner wall of the through hole by using any one or at least two of plasma chemical vapor deposition, laser chemical vapor deposition, thermal chemical vapor deposition, magnetron sputtering, ion plating deposition, electron beam evaporation or printing paste hole filling technology.

Further, in the step S3, the pattern transferring process includes photosensitive film pasting and exposure developing, wherein the film thickness of the photosensitive film pasting is 10 μm to 1000 μm; the exposure time of exposure and development is 1 s-60 s, the development temperature is 20-50 ℃, and the development time is 1-10 min.

Further, a copper circuit layer is formed at the slit of the photosensitive film layer and inside the through hole by adopting an electroplating process.

In general, the process of pattern copper circuit layer comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, and the main steps comprise:

a) The oil removal process sequentially comprises the steps of soaking in a sulfuric acid solution with the mass fraction of 5% -30% for 1 min-3 min, washing in acetone for 1 min-5 min, washing in ethanol for 1 min-5 min, and finally washing in pure water.

B) The microetching process comprises, but is not limited to, a sulfuric acid/hydrogen peroxide system, a ferric trichloride system and the like, wherein the sulfuric acid concentration in the sulfuric acid/hydrogen peroxide system is 5% -50%, the hydrogen peroxide concentration in the sulfuric acid/hydrogen peroxide system is 10% -50%, and the iron ion content in the ferric trichloride system is 5 g/L-50 g/L.

C) The microetching temperature is 20 ℃ to minus 40 ℃ and the microetching time is 0.5 min to 5 min.

D) The pickling process comprises the steps of soaking the steel plate in a sulfuric acid solution with the mass fraction of 1% -20% for 1-10 min, and then cleaning the steel plate by pure water.

E) The copper electroplating process adopts a mixed solution of 30 g/L-150 g/L copper sulfate, 50 g/L-300 g/L sulfuric acid, 0 ppm-30 ppm hydrochloric acid, 1 mL/L-30 mL/L wetting agent and 0.1 mL/L-10 mL/L brightening agent; the operation temperature is 15-45 ℃, the current density is 0.5 ASD-5 ASD, and the circulation flow is 10 m ³ /h~15m ³ /h; the anode is made of phosphor copper balls with phosphor content of 0.03% -0.06%, the diameter of the phosphor copper balls is at least 30 mm, and the cathode is made of ceramic plate for depositing metal priming layer.

In the above step S7, the film removal etching process includes two parts of photosensitive film removal and metal underlayer removal. Wherein, the film removing process is carried out by soaking for 10 min-300 min by using an organic alkali solution with the mass fraction of 5% -50%, the spraying pressure is 1 MPa-10 MPa, and the temperature is 30 ℃ -60 ℃; the etching process adopts 10% -30% of strong acid solution and 10% -30% of hydrogen peroxide solution, wherein the strong acid comprises one or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and hydrofluoric acid, the etching time is 1-5 min, the etching temperature is 25-55 ℃, and the spraying pressure is 1-10 MPa.

Generally, the size range of the ceramic substrate can be selected according to practical needs, for example, the specification range of the ceramic substrate can be 50 mm × (50-300) mm×300 mm, and the thickness of the ceramic substrate is 0.1 mm-3.0 mm.

The ceramic substrate can be mechanically drilled or laser drilled to form a through hole, wherein the laser drilling can be specifically any one of a solid laser, a semiconductor laser, a gas laser, an infrared laser or an X-ray laser.

According to the ceramic substrate and the manufacturing method thereof, the transition layer and the connecting layer are sequentially added between the copper circuit layer and the surface finishing layer, so that on one hand, the transition layer and the connecting layer are introduced to play a role of isolating the copper circuit layer and the surface finishing layer, migration of copper ions is effectively blocked, the problems of yellowing and blackening of the surface finishing layer in the prior art are avoided, and on the other hand, the connecting layer has a large number of crystal boundaries due to the fact that a microstructure is a compact nano columnar crystal form perpendicular to an interface, and diffusion and displacement deposition rate and deposition uniformity in silver plating in the later stage can be improved.

Meanwhile, the ceramic substrate provided by the invention has the connecting layer with a specific structure, and the bonding force between the surface finishing layer and the transition layer can be improved.

The invention also aims to provide application of the ceramic substrate as a heat dissipation packaging substrate in a Light Emitting Diode (LED), a Laser Diode (LD), a communication device, a sensor or a power device.

Drawings

Fig. 1 is a schematic structural view of a ceramic substrate according to an embodiment of the present invention;

FIG. 2 is a process flow diagram of a method of fabricating a ceramic substrate according to an embodiment of the invention;

fig. 3 to 9 are schematic structural views of a manufacturing process of a ceramic substrate according to an embodiment of the present invention;

FIG. 10 is an interface TEM image of a ceramic substrate and package end chip bonding layer sintered interconnect according to embodiment 10 of the invention;

FIG. 11 is a surface element analysis chart of the ceramic substrate according to example 1 of the present invention after baking;

FIG. 12 is a surface element analysis chart of a ceramic substrate of comparative example 1 after baking according to the present invention;

fig. 13 is an acoustic emission adhesion scratch test result of the ceramic substrates according to example 10 and comparative example 2 of the present invention.

Detailed Description

As shown in fig. 1, the present invention provides a ceramic substrate comprising a ceramic substrate 11, the ceramic substrate 11 having a plurality of through holes 111. The ceramic substrate 11 has a metal primer layer 12 intermittently disposed on the upper and lower surfaces and the inner wall of the through hole 111. The metal underlayer 12 has a copper wiring layer 13 on the surface thereof and inside (filled with) the through hole 111. The copper wiring layer 13 has a transition layer 14, a connection layer 15, and a surface finishing layer 16 laminated in this order on the surface thereof.

The microstructure of the connecting layer 15 is a compact nano columnar crystal form perpendicular to the interface, and the crystal structure is a face-centered cube.

The portions of the ceramic substrate 11 not covered by the structures of the metallic primer layer 12, the copper wiring layer 13, the transition layer 14, the connection layer 15, the surface finishing layer 16, and the like are exposed.

The method for manufacturing the ceramic substrate provided by the invention is as follows, and reference is made to a process flow chart of fig. 2 and a schematic diagram of a distribution structure of fig. 3 to 9.

Step S1: punching the ceramic substrate 11 to obtain a plurality of through holes 111 on the surface thereof; as shown in fig. 3.

Step S2: a metal underlayer 12 is formed on the upper and lower surfaces of the ceramic substrate 11 and on the inner wall of the through hole 111; as shown in fig. 4.

Step S3: pattern transfer is performed on the metal underlayer 12 to generate a circuit pattern, and a photosensitive film layer 12a and a copper circuit layer 13 are formed on the upper and lower surfaces of the metal underlayer 12 at intervals, and are positioned at the gaps of the photosensitive film layer 12a and inside the through holes 111; as shown in fig. 5.

Step S4: forming a transition layer 14 on the copper wiring layer 13; as shown in fig. 6.

Step S5: forming a connection layer 15 on the transition layer 14; as shown in fig. 7.

Step S6: forming a surface finishing layer 16 on the connection layer 15; as shown in fig. 8.

Step S7: performing film stripping etching on the photosensitive film layer 12a and a part of the metal underlayer 12 positioned below the photosensitive film layer, and exposing the ceramic substrate 11 to obtain a ceramic substrate; as shown in fig. 9.

For a better understanding of the present invention, the following examples are further illustrative of the present invention and are intended to be merely illustrative of, but not limiting of, the present invention, and all similar embodiments are set forth based on the present invention and are intended to fall within the scope of protection.

Example 1

The embodiment adopts the following specific process to manufacture a ceramic substrate.

An alumina ceramic substrate with the thickness of 0.38 and mm and the size of 114 mm multiplied by 114 mm is selected, and through holes with the aperture of 10 mu m are drilled on the surface of the ceramic substrate by a carbon dioxide laser, so that a plurality of through holes are obtained.

After the drilling is finished, a titanium layer with the thickness of 0.5 mu m is deposited on the surface of the ceramic substrate and the inner wall of the through hole by a physical vacuum evaporation mode at the temperature of 600 ℃ to serve as a metal priming layer.

Then a photoresist dry film with the thickness of 30 mu m is applied to the surfaces of the metal base layers on the upper surface and the lower surface of the ceramic substrate through a film pressing machine, the exposure time is controlled to be 60 s, then 10wt% concentration sodium hydroxide developer is used for developing for 2 min at the temperature of 40 ℃, the uncured dry film is removed to form a basic circuit pattern, and pattern electroplating is carried out on the part to form a copper circuit layer.

Specifically, the pattern electroplating process comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, wherein the thickness of a copper electroplating layer is 10 mu m, and the main steps comprise:

the electroplating degreasing process sequentially adopts sulfuric acid solution with the mass fraction of 10% to soak for 3 min, acetone to wash and soak for 3 min, ethanol to wash and soak for 35 min, and finally pure water to wash;

the electroplating microetching process adopts a sulfuric acid/hydrogen peroxide system, wherein the sulfuric acid concentration is 20%, the hydrogen peroxide concentration is 10%, the microetching temperature is 40 ℃, and the microetching time is 5 min;

the pickling process adopts sulfuric acid solution with the mass fraction of 20% to soak for 2 min, and then pure water is used for cleaning.

The copper electroplating process adopts an electroplating solution with the composition of 150 g/L copper sulfate, 150 g/L sulfuric acid, 30 ppm hydrochloric acid, 30 ml/L wetting agent and 5 ml/L brightening agent; operating temperature 15℃and current density 4 ASD, circulation flow 15 m ³ /h; the anode adopts phosphor copper balls with phosphor content of 0.06%, and the diameter of the phosphor copper balls is 35 mm; the cathode is an alumina ceramic plate with a titanium layer being primed.

And the transition layer and the surface finishing layer are manufactured by adopting an electroless plating process, and the connecting layer is manufactured by adopting a palladium activation process to post-treat the transition layer.

The chemical plating process comprises degreasing, microetching, presoaking, activating, chemically plating the transition layer, post-treating the transition layer to obtain a connecting layer, chemically plating silver, presoaking and plating silver, and comprises the following main process steps:

The degreasing process sequentially adopts 10% sulfuric acid and 5% sodium dodecyl sulfate with mass fraction for 5 min, the cleaning temperature is 50 ℃, and then pure water is used for cleaning;

the microetching process adopts a sulfuric acid/hydrogen peroxide system, wherein the concentration of sulfuric acid is 30 percent, and the concentration of hydrogen peroxide is 20 percent; the microetching temperature is 40 ℃ and the microetching time is 5 min;

the pre-soaking process adopts a sulfuric acid solution with the mass fraction of 10 percent, the pre-soaking temperature is 30 ℃, and the pre-soaking time is 5 min;

the activation process adopts a colloid palladium activation system, the metal palladium salt is palladium chloride, and the palladium ion concentration is 200ppm; the concentration of sodium stannate is 2 g/L; the concentration of sodium chloride is 50 g/L, and the chelating agent is ethylenediamine with the concentration of 1 g/L; the activation temperature is 20 ℃ and the activation time is 1 min;

the transition layer chemical plating type is chemical nickel-phosphorus plating with the thickness of 3.1 mu m; the plating solution comprises the following components: 50 g/L nickel sulfate, 1% EDTA, 20 g/L sodium hypophosphite and 0.01 g/L thiourea, wherein the pH of the plating solution is 4.5, and the chemical plating temperature is 80 ℃;

the post-treatment process is palladium activation, wherein a colloid palladium activation system is adopted for palladium activation, the metal palladium salt is palladium chloride, the concentration of palladium ions is 100 ppm, the concentration of sodium stannate is 1.0g/L, the concentration of sodium chloride is 30 g/L, and the chelating agent is ethylenediamine tetraacetic acid with the concentration of 3 g/L; the activation temperature is 30 ℃, the activation time is 5 min, a nano columnar crystal layer with the thickness of 0.1 mu m is formed after post treatment, and a nickel-phosphorus layer with the thickness of 3 mu m is reserved as a transition layer;

The presoaking liquid for the silver plating presoaking process comprises the following components: 1% of triethanolamine, 1% of inorganic metal salt and 3% of ethylenediamine, wherein the pre-soaking time is 2 min, and the pre-soaking temperature is 30 ℃;

the plating solution of the silver plating process comprises the following components: 5 g/L silver amine sulfonate, 10% triethanolamine, 3% inorganic metal salt, 20% ethylenediamine; the pH of the plating solution is 5.7, the silver plating temperature is 40 ℃, the spraying pressure is 5 MPa, the chemical plating time is 2 min, and the silver plating thickness is 200 nm;

the film removing etching process comprises photosensitive film removal and metal priming layer removal, wherein the film removing process is carried out by soaking for 100 min by using 30% organic alkali solution with the spraying pressure of 10 MPa and the temperature of 60 ℃; the etching process adopts 30% sulfuric acid solution and 10% hydrogen peroxide solution, the etching time is 5 min, the etching temperature is 25 ℃, and the spraying pressure is 10 MPa.

Example 2

An aluminum nitride ceramic substrate with the thickness of 0.5 mm and the size of 114 mm ×114 mm is selected, and a plurality of through holes are obtained by drilling through holes with the aperture of 25 μm on the surface of the ceramic substrate through a carbon dioxide laser.

After the drilling is finished, a chromium layer with the thickness of 0.1 mu m is deposited on the surface of the ceramic substrate and the inner wall of the through hole by a magnetron sputtering mode at the temperature of 300 ℃ to serve as a metal priming layer.

Then a photosensitive dry film with the thickness of 30 mu m is applied to the surfaces of the metal base layers on the upper surface and the lower surface of the ceramic substrate through a film pressing machine, the exposure time is controlled to be 60 s, then 10wt% concentration sodium hydroxide developer is used for developing for 2 min at the temperature of 40 ℃, the uncured dry film is removed to form a basic circuit pattern, and pattern plating is carried out on the part to form a copper circuit layer.

Specifically, the pattern electroplating process comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, wherein the thickness of a copper electroplating layer is 25 mu m, and the main steps comprise:

the electroplating microetching process adopts a sulfuric acid/hydrogen peroxide system, wherein the concentration of the sulfuric acid is 20 percent, and the concentration of the hydrogen peroxide is 10 percent; the microetching temperature is 40 ℃ and the microetching time is 5 min;

The copper electroplating process adopts an electroplating solution with the composition of 180 g/L copper sulfate, 160 g/L sulfuric acid, 30 ppm hydrochloric acid, 30 ml/L wetting agent and 5 ml/L brightening agent; operating temperature 15℃and current density 4 ASD, circulation flow 15 m ³ /h; the anode adopts phosphor copper balls with phosphor content of 0.06%, and the diameter of the phosphor copper balls is 35 mm; the cathode is an aluminum nitride ceramic plate with a chromium layer being primed.

And subsequently adopting an electroless plating process to manufacture the transition layer and the surface finishing layer, and adopting an acid leaching process to post-treat the transition layer to manufacture the connecting layer.

The transition layer plating type is nickel plating boron, and the thickness is 0.63 mu m; the plating solution comprises the following components: 5. 5 g/L nickel sulfate, 10 g/L nickel acetate, 20 g/L sodium citrate, 1% EDTA, 2.5 g/L sodium borohydride, 2.5 g/L dimethylamine borane and 0.01 g/L thiourea, wherein the pH of the plating solution is 7.5, and the chemical plating temperature is 60 ℃;

the process of the connecting layer is acid leaching, wherein the acid leaching process adopts sulfuric acid solution with the mass fraction of 10%, the acid leaching temperature is 50 ℃, the acid leaching time is 5 min, a nano columnar crystal layer with the thickness of 0.13 mu m is formed after acid leaching, and a nickel boron layer with the thickness of 0.5 mu m is reserved as a transition layer;

the plating solution of the silver plating process comprises the following components: 5 g/L silver amine sulfonate, 10% triethanolamine, 3% inorganic metal salt, 20% ethylenediamine; the pH of the plating solution is 5.7, the silver plating temperature is 40 ℃, the spraying pressure is 5 MPa, the chemical plating time is 2 min, and the silver plating thickness is 300 nm;

Example 3

A silicon nitride ceramic substrate with the thickness of 0.25 and mm and the size of 190 mm multiplied by 140 mm is selected, and through holes with the aperture of 50 mu m are drilled on the surface of the ceramic substrate by a carbon dioxide laser, so that a plurality of through holes are obtained.

After the drilling is finished, a copper-titanium layer with the thickness of 1.3 mu m is deposited on the surface of the ceramic substrate and the inner wall of the through hole by a plasma chemical vapor deposition mode at the temperature of 50 ℃ to serve as a metal priming layer.

Then a photosensitive dry film with the thickness of 75 mu m is applied to the surfaces of the metal base layers on the upper surface and the lower surface of the ceramic substrate through a film pressing machine, the exposure time is controlled to be 60 s, then 10wt% concentration sodium hydroxide developer is used for developing for 2 min at the temperature of 40 ℃, the uncured dry film is removed to form a basic circuit pattern, and pattern plating is carried out on the part to form a copper circuit layer.

Specifically, the pattern electroplating process comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, wherein the thickness of a copper electroplating layer is 55 mu m, and the main steps comprise:

The copper electroplating process adopts an electroplating solution with the composition of 180 g/L copper sulfate, 160 g/L sulfuric acid, 30 ppm hydrochloric acid, 30 ml/L wetting agent and 5 ml/L brightening agent; operating temperature 15℃and current density 4 ASD, circulation flow 15 m ³ /h; the anode adopts phosphor copper balls with phosphor content of 0.06%, and the diameter of the phosphor copper balls is 35 mm; the cathode is a silicon nitride ceramic plate with a copper titanium layer which is primed.

And manufacturing the transition layer and the surface finishing layer by adopting an electroless plating process, and manufacturing the connecting layer on the transition layer by adopting an electroplating process.

The chemical plating process comprises degreasing, microetching, presoaking, activating, chemically plating a transition layer, electroplating to obtain a connecting layer, chemically plating silver, presoaking and plating silver, and mainly comprises the following process steps:

the transition layer chemical plating type is chemical nickel-phosphorus plating with thickness of 0.22 μm; the plating solution comprises the following components: 50 g/L nickel sulfate, 1% EDTA, 20 g/L sodium hypophosphite and 0.01 g/L thiourea, wherein the pH of the plating solution is 4.5, and the chemical plating temperature is 80 ℃;

the connecting layer is made of electroplated nano nickel, the process adopts an electroplated nickel solution formed by mixing 400g/L nickel sulfate, 80 g/L nickel chloride and 60 g/L boric acid, and the current density is 200mA/cm ² Forming a nano columnar crystal layer with the thickness of 0.25 mu m, wherein the electroplating temperature is 90 ℃ and the electroplating time is 480 sec;

the plating solution of the silver plating process comprises the following components: 5 g/L silver amine sulfonate, 10% triethanolamine, 3% inorganic metal salt, 20% ethylenediamine; the pH value of the plating solution is 5.7, the silver plating temperature is 40 ℃, the spraying pressure is 5 MPa, and the silver plating thickness is 600 nm;

Example 4

A silicon carbide ceramic substrate with the thickness of 0.5 mm and the size of 120 mm multiplied by 120 mm is selected, and through holes with the aperture of 80 mu m are drilled on the surface of the ceramic substrate by a carbon dioxide laser, so that a plurality of through holes are obtained.

After the drilling is finished, a manganese layer with the thickness of 1.5 mu m is deposited on the surface of the ceramic substrate and the inner wall of the through hole by an electron beam evaporation mode at the temperature of 25 ℃ to serve as a metal priming layer.

Specifically, the pattern electroplating process comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, wherein the thickness of a copper electroplating layer is 60 mu m, and the main steps comprise:

The copper electroplating process adopts an electroplating solution with the composition of 180 g/L copper sulfate, 160 g/L sulfuric acid, 30 ppm hydrochloric acid, 30 ml/L wetting agent and 5 ml/L brightening agent; operating temperature 15℃and current density 4 ASD, circulation flow 15 m ³ /h; the anode adopts phosphor copper balls with phosphor content of 0.06%, and the diameter of the phosphor copper balls is 35 mm; the cathode is a silicon carbide ceramic plate with a manganese layer for priming.

the transition layer plating type is nickel plating boron, and the thickness is 1.20 mu m; the plating solution comprises the following components: 5. 5 g/L nickel sulfate, 10 g/L nickel acetate, 20 g/L sodium citrate, 1% EDTA, 2.5 g/L sodium borohydride, 2.5 g/L dimethylamine borane and 0.01 g/L thiourea, wherein the pH of the plating solution is 7.5, and the chemical plating temperature is 60 ℃;

the connecting layer is prepared by electroplating nano nickel, the process adopts an electroplating nickel solution prepared by mixing 300g/L nickel sulfate, 70 g/L nickel chloride and 50 g/L boric acid, and the current density is 150mA/cm ² Forming a nano columnar crystal layer with the thickness of 0.36 mu m, wherein the electroplating temperature is 80 ℃ and the electroplating time is 600 sec;

the plating solution of the silver plating process comprises the following components: 5 g/L silver amine sulfonate, 10% triethanolamine, 3% inorganic metal salt, 20% ethylenediamine; the pH value of the plating solution is 5.7, the silver plating temperature is 40 ℃, the spraying pressure is 5 MPa, and the silver plating thickness is 2000 nm;

Example 5

Selecting a boron nitride ceramic substrate with the thickness of 0.1 mm and the size of 120 mm multiplied by 120 mm, and drilling through holes with the aperture of 100 mu m on the surface of the ceramic substrate by a carbon dioxide laser to obtain a plurality of through holes.

After the drilling is finished, a nickel-copper-manganese layer with the thickness of 2.2 mu m is deposited on the surface of the ceramic substrate and the inner wall of the through hole by a magnetron sputtering mode at the temperature of 500 ℃ to serve as a metal priming layer.

Then a photosensitive dry film with the thickness of 100 mu m is applied to the surfaces of the metal base layers on the upper surface and the lower surface of the ceramic substrate through a film pressing machine, the exposure time is controlled to be 60 s, then 10wt% concentration sodium hydroxide developer is used for developing for 2 min at the temperature of 40 ℃, the uncured dry film is removed to form a basic circuit pattern, and pattern plating is carried out on the part to form a copper circuit layer.

Specifically, the pattern electroplating process comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, wherein the thickness of a copper electroplating layer is 80 mu m, and the main steps comprise:

The copper electroplating process adopts an electroplating solution with the composition of 180 g/L copper sulfate, 160 g/L sulfuric acid, 30 ppm hydrochloric acid, 30 ml/L wetting agent and 5 ml/L brightening agent; operating temperature 15℃and current density 4 ASD, circulation flow 15 m ³ /h; the anode adopts phosphor copper balls with phosphor content of 0.06%, and the diameter of the phosphor copper balls is 35 mm; the cathode is a boron nitride ceramic plate with a nickel-copper-manganese layer as a bottom.

The transition layer plating type is nickel plating boron, and the thickness is 3.5 mu m; the plating solution comprises the following components: 5. 5 g/L nickel sulfate, 10 g/L nickel acetate, 20 g/L sodium citrate, 1% EDTA, 2.5 g/L sodium borohydride, 2.5 g/L dimethylamine borane and 0.01 g/L thiourea, wherein the pH of the plating solution is 7.5, and the chemical plating temperature is 60 ℃;

the connecting layer is made of nickel nano-plating solution prepared by mixing nickel sulfate with concentration of 350g/L, nickel chloride with concentration of 70 g/L and boric acid with concentration of 50g/L, and the current density is 200mA/cm ² Forming a nano columnar crystal layer with the thickness of 0.52 mu m, wherein the electroplating temperature is 70 ℃ and the electroplating time is 600 sec;

the plating solution of the silver plating process comprises the following components: 5 g/L silver amine sulfonate, 10% triethanolamine, 3% inorganic metal salt, 20% ethylenediamine; the pH value of the plating solution is 5.7, the silver plating temperature is 40 ℃, the spraying pressure is 5 MPa, and the silver plating thickness is 1000 nm;

Example 6

Selecting a lanthanum boride ceramic substrate with the thickness of 0.3 mm and the size of 50 mm multiplied by 50 mm, and drilling holes with the aperture of 150 mu m on the surface of the ceramic substrate by a carbon dioxide laser to obtain a plurality of through holes.

And after the drilling is finished, depositing a titanium tungsten layer with the thickness of 3 mu m on the surface of the ceramic substrate and the inner wall of the through hole by a printing slurry and hole filling slurry mode to serve as a metal priming layer.

Then a photosensitive dry film with the thickness of 150 mu m is applied to the surfaces of the metal base layers on the upper surface and the lower surface of the ceramic substrate through a film pressing machine, the exposure time is controlled to be 60 s, then 10wt% concentration sodium hydroxide developer is used for developing for 5 min at the temperature of 40 ℃, the uncured dry film is removed to form a basic circuit pattern, and pattern plating is carried out on the part to form a copper circuit layer.

Specifically, the pattern electroplating process comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, wherein the thickness of a copper electroplating layer is 120 mu m, and the main steps comprise:

The copper electroplating process adopts an electroplating solution with the composition of 180 g/L copper sulfate, 160 g/L sulfuric acid, 30 ppm hydrochloric acid, 30 ml/L wetting agent and 5 ml/L brightening agent; operating temperature 15℃and current density 4 ASD, circulation flow 15 m ³ /h; the anode adopts phosphor copper balls with phosphor content of 0.06%, and the diameter of the phosphor copper balls is 35 mm; yin type vaginaLanthanum boride ceramic plates primed with titanium tungsten layers.

And subsequently adopting an electroless plating process to manufacture the transition layer and the surface finishing layer, and adopting a microetching process to post-treat the transition layer to manufacture the connecting layer.

The chemical plating process comprises degreasing, microetching, presoaking, activating, chemically plating a transition layer, post-treating to obtain a connecting layer, chemically plating silver, presoaking and plating silver, and mainly comprises the following process steps:

the microetching process adopts a sulfuric acid/hydrogen peroxide system, wherein the concentration of sulfuric acid is 30%, the concentration of hydrogen peroxide is 20%, the microetching temperature is 40 ℃, and the microetching time is 5 min;

the transition layer plating type is nickel plating boron, and the thickness is 9.32 mu m; the plating solution comprises the following components: 5. 5 g/L nickel sulfate, 10 g/L nickel acetate, 20 g/L sodium citrate, 1% EDTA, 2.5 g/L sodium borohydride, 2.5 g/L dimethylamine borane and 0.01 g/L thiourea, wherein the pH of the plating solution is 7.5, and the chemical plating temperature is 60 ℃;

the process of the connecting layer is microetching, a mixed solution of sulfuric acid with mass fraction of 20% and sodium persulfate with mass fraction of 50 g/L is adopted, the microetching temperature is 40 ℃, the microetching time is 5 min, a nano columnar crystal layer with thickness of 0.82 mu m is formed, and a nickel boron layer with thickness of 8.5 mu m is reserved as a transition layer;

the plating solution of the silver plating process comprises the following components: 5 g/L silver amine sulfonate, 10% triethanolamine, 3% inorganic metal salt, 20% ethylenediamine; the pH value of the plating solution is 5.7, the silver plating temperature is 40 ℃, the spraying pressure is 5 MPa, and the silver plating thickness is 100 nm;

Example 7

And selecting a beryllium oxide ceramic substrate with the thickness of 0.3 mm and the size of 120 mm multiplied by 120 mm, and drilling holes with the aperture of 300 mu m on the surface of the ceramic substrate by a carbon dioxide laser to obtain a plurality of through holes.

And after the drilling is finished, a nickel layer with the thickness of 2.5 mu m is deposited on the surface of the ceramic substrate and the inner wall of the through hole by an ion plating deposition mode to serve as a metal priming layer.

Then a photosensitive dry film with the thickness of 200 mu m is applied to the surfaces of the metal base layers on the upper surface and the lower surface of the ceramic substrate through a film pressing machine, the exposure time is controlled to be 60 s, then 10wt% concentration sodium hydroxide developer is used for developing for 5 min at the temperature of 40 ℃, the uncured dry film is removed to form a basic circuit pattern, and pattern plating is carried out on the part to form a copper circuit layer.

Specifically, the pattern electroplating process comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, wherein the thickness of a copper electroplating layer is 180 mu m, and the main steps comprise:

the electroplating microetching process adopts a sulfuric acid/hydrogen peroxide system, wherein the sulfuric acid concentration is 20%, the hydrogen peroxide concentration is 10%, the microetching temperature is 40 ℃, and the microetching time is 6 min;

The copper electroplating process adopts an electroplating solution with the composition of 180 g/L copper sulfate, 160 g/L sulfuric acid, 30 ppm hydrochloric acid, 30 ml/L wetting agent and 5 ml/L brightening agent; operating temperature 15℃and current density 4 ASD, circulation flow 15 m ³ /h; the anode adopts phosphor copper balls with phosphor content of 0.06%, and the diameter of the phosphor copper balls is 35 mm; the cathode is a beryllium oxide ceramic plate with a nickel layer for priming.

The microetching process adopts a sulfuric acid/hydrogen peroxide system, wherein the concentration of sulfuric acid is 30%, the concentration of hydrogen peroxide is 20%, the microetching temperature is 50 ℃, and the microetching time is 5 min;

the transition layer plating type is nickel plating boron, and the thickness is 10.9 mu m; the plating solution comprises the following components: 5. 5 g/L nickel sulfate, 10 g/L nickel acetate, 20 g/L sodium citrate, 1% EDTA, 2.5 g/L sodium borohydride, 2.5 g/L dimethylamine borane and 0.01 g/L thiourea, wherein the pH of the plating solution is 7.5, and the chemical plating temperature is 60 ℃;

the process of the connecting layer is microetching, a mixed solution of 10% sulfuric acid and 40 g/L sodium persulfate is adopted, the microetching temperature is 50 ℃, the microetching time is 4 min, a nano columnar crystal layer with the thickness of 0.9 mu m is formed, and a nickel boron layer with the thickness of 10 mu m is reserved as a transition layer;

The plating solution of the silver plating process comprises the following components: 5 g/L silver amine sulfonate, 10% triethanolamine, 3% inorganic metal salt, 20% ethylenediamine; the pH value of the plating solution is 5.7, the silver plating temperature is 40 ℃, the spraying pressure is 5 MPa, and the silver plating thickness is 1200 nm;

Example 8

A ZTA ceramic substrate with the thickness of 0.2 mm and the size of 120 mm multiplied by 120 mm is selected, and a plurality of through holes are obtained by drilling 300 mu m-aperture through holes on the surface of the ceramic substrate through a carbon dioxide laser.

After the drilling is finished, a tungsten layer with the thickness of 1.3 mu m is deposited on the surface of the ceramic substrate and the inner wall of the through hole by a laser chemical vapor deposition mode to serve as a metal priming layer.

Then a photosensitive dry film with the thickness of 200 mu m is applied to the surfaces of the metal base layers on the upper surface and the lower surface of the ceramic substrate through a film pressing machine, the exposure time is controlled to be 70 s, then 10wt% concentration sodium hydroxide developer is used for developing for 7 min at the temperature of 40 ℃, the uncured dry film is removed to form a basic circuit pattern, and pattern plating is carried out on the part to form a copper circuit layer.

Specifically, the pattern electroplating process comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, wherein the thickness of a copper electroplating layer is 200 mu m, and the main steps comprise:

The process of the transition layer, the connecting layer and the finishing layer comprises degreasing, microetching, electroplating the transition layer, electroplating the connecting layer, chemical silver plating presoaking and silver plating, and the main process steps comprise:

The microetching process adopts a sulfuric acid/hydrogen peroxide system, wherein the sulfuric acid concentration is 30%, the hydrogen peroxide concentration is 20%, the microetching temperature is 50 ℃, and the microetching time is 5 min;

the transition layer is electroplated with nickel solution of nickel sulfate 350g/L, nickel chloride 70 g/L and boric acid 50g/L, and the current density is 50mA/cm ² The plating temperature was 80℃and the plating time was 1200sec, forming a nickel layer with a thickness of 6.65. Mu.m;

the connecting layer is made of nickel nano-plating solution prepared by mixing nickel sulfate with concentration of 350g/L, nickel chloride with concentration of 80 g/L and boric acid with concentration of 30 g/L, and the current density is 180mA/cm ² Forming a nano columnar crystal layer with the thickness of 0.95 mu m, wherein the electroplating temperature is 80 ℃ and the electroplating time is 800 sec;

the plating solution of the silver plating process comprises the following components: 5 g/L silver amine sulfonate, 10% triethanolamine, 3% inorganic metal salt, 20% ethylenediamine; the pH value of the plating solution is 5.7, the silver plating temperature is 40 ℃, the spraying pressure is 5 MPa, and the silver plating thickness is 500 nm;

Example 9

A zirconia ceramic substrate with the thickness of 0.2 mm and the size of 120 mm multiplied by 120 mm is selected, and a plurality of through holes are obtained by drilling through holes with the aperture of 160 mu m on the surface of the ceramic substrate through a carbon dioxide laser.

And after the drilling is finished, depositing a nickel-copper layer with the thickness of 1.8 mu m on the surface of the ceramic substrate and the inner wall of the through hole by a plasma chemical vapor deposition mode to serve as a metal priming layer.

Specifically, the pattern electroplating process comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, wherein the thickness of a copper electroplating layer is 160 mu m, and the main steps comprise:

The copper electroplating process adopts an electroplating solution with the composition of 180 g/L copper sulfate, 160 g/L sulfuric acid, 30 ppm hydrochloric acid, 30 ml/L wetting agent and 5 ml/L brightening agent; operating temperature 15℃and current density 4 ASD, circulation flow 15 m ³ /h; the anode adopts phosphor copper balls with phosphor content of 0.06%, and the diameter of the phosphor copper balls is 35 mm; the cathode is a zirconia ceramic plate with a nickel-copper layer bottom.

the activation process adopts a colloid palladium activation system, the metal palladium salt is palladium chloride, and the palladium ion concentration is 200ppm; the concentration of sodium stannate is 2 g/L; the concentration of sodium chloride is 50g/L, and the chelating agent is ethylenediamine with the concentration of 1 g/L; the activation temperature is 20 ℃ and the activation time is 1 min;

the transition layer chemical plating type is chemical nickel plating boron, and the thickness is 10 mu m; the plating solution comprises the following components: 5. 5 g/L nickel sulfate, 10 g/L nickel acetate, 20 g/L sodium citrate, 1% EDTA, 2.5 g/L sodium borohydride, 2.5 g/L dimethylamine borane and 0.01 g/L thiourea, wherein the pH of the plating solution is 7.5, and the chemical plating temperature is 60 ℃;

the connecting layer is made of nickel nano-plating solution prepared by mixing nickel sulfate with concentration of 350g/L, nickel chloride with concentration of 80 g/L and boric acid with concentration of 30 g/L, and the current density is 180mA/cm ² The plating temperature was 80℃and the plating time was 750sec,forming a nano columnar crystal layer with the thickness of 0.99 mu m;

the plating solution of the silver plating process comprises the following components: silver amine sulfonate has a concentration of 5 g/L, triethanolamine has a concentration of 10%, inorganic metal salt has a concentration of 3%, and ethylenediamine has a concentration of 20%; the pH value of the plating solution is 5.7, the silver plating temperature is 40 ℃, the spraying pressure is 5 MPa, and the silver plating thickness is 400 nm;

Example 10

An aluminum nitride ceramic substrate with the thickness of 0.38 and mm and the size of 120 mm multiplied by 120 mm is selected, and a plurality of through holes are obtained by drilling through holes with the aperture of 65 mu m on the surface of the ceramic substrate through a carbon dioxide laser.

And after the drilling is finished, a copper layer with the thickness of 2.9 mu m is deposited on the surface of the ceramic substrate and the inner wall of the through hole by a thermal chemical vapor deposition mode to serve as a metal priming layer.

Then a photosensitive dry film with the thickness of 75 mu m is applied to the surfaces of the metal base layers on the upper surface and the lower surface of the ceramic substrate through a film pressing machine, the exposure time is controlled to be 60 s, then 10wt% concentration sodium hydroxide developer is used for developing for 1 min at the temperature of 40 ℃, the uncured dry film is removed to form a basic circuit pattern, and pattern plating is carried out on the part to form a copper circuit layer.

Specifically, the pattern electroplating process comprises the processes of degreasing, microetching, pickling, copper electroplating and the like, wherein the thickness of a copper electroplating layer is 75 mu m, and the main steps comprise:

The copper electroplating process adopts an electroplating solution with the composition of 180 g/L copper sulfate, 160 g/L sulfuric acid, 30 ppm hydrochloric acid, 30 ml/L wetting agent and 5 ml/L brightening agent; operating temperature 15℃and current density 4 ASD, circulation flow 15 m ³ /h; the anode adopts phosphor copper balls with phosphor content of 0.06%, and the diameter of the phosphor copper balls is 35 mm; the cathode is an aluminum nitride ceramic plate with a copper layer being primed.

The chemical plating process comprises degreasing, microetching, presoaking, activating, chemically plating a transition layer, obtaining a connecting layer by an electroplating process, chemically plating silver, presoaking and plating silver, and mainly comprises the following process steps:

the transition layer chemical plating type is chemical nickel-phosphorus plating with the thickness of 8 mu m; the plating solution comprises the following components: 50g/L nickel sulfate, 1% EDTA, 20 g/L sodium hypophosphite and 0.01 g/L thiourea, wherein the pH of the plating solution is 4.5, and the chemical plating temperature is 80 ℃;

the connecting layer is made of nickel nano-plating solution prepared by mixing nickel sulfate with concentration of 350g/L, nickel chloride with concentration of 80 g/L and boric acid with concentration of 30 g/L, and the current density is 180mA/cm ² Forming a nano columnar crystal layer with the thickness of 0.3 mu m, wherein the electroplating temperature is 80 ℃ and the electroplating time is 240 sec;

the plating solution of the silver plating process comprises the following components: 5 g/L silver amine sulfonate, 10% triethanolamine, 3% inorganic metal salt, 20% ethylenediamine; the pH value of the plating solution is 5.7, the silver plating temperature is 40 ℃, the spraying pressure is 5 MPa, and the silver plating thickness is 550 nm;

Table 1 below shows the dimensions and material selection of each structural layer in examples 1 to 10.

Table 1 the size and material selection of the ceramic substrates in examples 1-10

TEM testing was performed at the interface of the sintered interconnect with the package-side die bonding layer when the ceramic substrate provided in example 10 above was applied, as shown in FIG. 10. As can be seen from fig. 10, the silver-based material surface finishing layer of the ceramic substrate has been sintered together with the package-end chip bonding layer (i.e., the nano-sintered silver layer), and the two mutually diffused to form a continuous microstructure (i.e., the nano-silver portion on the left side in the view of fig. 10), while the middle portion connected with the silver-based material surface finishing layer, i.e., the connecting layer in the ceramic substrate, has a dense interface with the silver layer on the left side, and has no holes and faults, so that a good bond is formed. Also, as can be seen from fig. 10, the thickness of the connection layer (i.e., the width of the structural layer in this view) is about 300 nm, which is a dense nano-columnar crystal form perpendicular to the interface at the microscopic level, the nano-columnar crystal spans the entire connection layer region, and the width of the nano-columnar crystal is about tens of nanometers.

In order to verify the beneficial effects of the ceramic substrate with the transition layer and the connection layer provided by the invention, the following comparative experiments were performed.

Comparative example 1

This comparative example is the same as example 1 and will not be described in detail herein, and only the differences from example 1 will be described. In this comparative example, the ceramic substrate provided was free of transition and tie layers, i.e., the surface finish in the ceramic substrate was formed directly over the copper wiring layer. Correspondingly, the relevant treatment process for obtaining the connecting layer by the chemical plating transition layer and the post-treatment transition layer in the embodiment 1 is also absent in the manufacturing process. The remainder was as described in reference to example 1, a first comparative ceramic substrate was obtained.

Comparative example 2

This comparative example is the same as example 10 and will not be described in detail herein, and only the differences from example 10 will be described. In this comparative example, the ceramic substrate provided was free of a connection layer, i.e., the surface finishing layer in the ceramic substrate was formed directly on top of the transition layer. Accordingly, the related treatment process for post-treating the transition layer to obtain the connection layer in example 10 was also lacking during its fabrication. A second comparative ceramic substrate was obtained as described in the rest of the reference example 10.

Ageing tests were performed on the two ceramic substrates provided in example 1 and comparative example 1, respectively, and the ageing resistance of the two ceramic substrates was compared and observed under the same environment. The aging condition was high temperature baking at 200 ℃ for 3 h, and then the surface condition of the silver-based surface finish layer was observed and EDX elemental analysis was performed on the surface, and the results are shown in fig. 11 and 12, respectively.

As can be seen by comparing fig. 3 and fig. 4, when the first comparative ceramic substrate with the common silver oxide finish is baked, the phenomena of yellowing and blackening of the silver layer begin to occur step by step in 20min, and when the first comparative ceramic substrate is baked to 3 h, the surface is completely discolored, and the copper content of the surface reaches 21.4% after EDX analysis; in contrast, after baking the silver-plated finished ceramic substrate with the transition layer and the connecting layer for 3 h, no abnormal change is seen on the surface, and no copper element is detected on the surface of the silver layer by EDX analysis, which indicates that the transition layer and the connecting layer of the ceramic substrate provided by the invention effectively inhibit the high-temperature migration and diffusion phenomenon of copper atoms in the copper circuit layer during high-temperature baking.

The acoustic emission adhesion scratch test was performed on the two ceramic substrates provided in example 10 and comparative example 2, respectively. The test equipment is WS-2005 type coating adhesion automatic scratch instrument (Kaihua, orchikuwa); the test conditions were: the loading range is 0-50N, the scratch speed is 5 mm/min, the loading speed is 50N/min, and the scratch length is 5 mm. The test results of both are shown in fig. 13.

The acoustic emission adhesive force scratch test is used for evaluating the binding force of the film layer, linear scratches are drawn on the surface of the coating layer at a constant speed through the diamond pressure head, the linear scratches are increased from 0 to a certain vertical load at a constant speed in the process, and the film layer binding force is judged by monitoring the corresponding load of a sound signal generated by the breaking of the coating layer in the process. As can be seen from fig. 13, the film combination of the connection layer provided in the ceramic substrate of example 10 showed peeling of the film layer under a load of 24.1N, and the film combination of the connection layer lacking in the second comparative ceramic substrate of comparative example 2 showed peeling of the film layer at 13.1N, and the film combination with the connection layer showed better bonding force of the surface finishing layer than the film combination lacking the connection layer. The result reveals that the existence of the connecting layer with the microstructure in the compact nano columnar crystal form perpendicular to the interface in the ceramic substrate provided by the invention has a remarkable effect on improving the binding force of the whole film system.

The ceramic substrate provided by the invention can be applied to Light Emitting Diodes (LEDs), laser Diodes (LDs), communication, sensors or power devices as a heat dissipation packaging substrate due to good properties.

Claims

1. A ceramic substrate, comprising:

A ceramic substrate having a plurality of through holes;

the surface finishing layer is arranged on the copper circuit layer;

the copper circuit layer is arranged on the surface of the surface finishing layer, and is provided with a transition layer and a connecting layer which are arranged on the copper circuit layer in a lamination way, wherein the microstructure of the connecting layer is a compact nano columnar crystal form perpendicular to an interface;

the connecting layer is obtained by carrying out any one of acid leaching, microetching and palladium activation on the transition layer, or is formed on the transition layer by adopting an electroplating process;

the acid leaching process adopts a sulfuric acid solution with the mass fraction of 1% -10%, the acid leaching temperature is 20 ℃ -50 ℃, and the acid leaching time is 5 min-20 min; the microetching process adopts a mixed solution of 5-30% sulfuric acid and 20 g/L-120 g/L sodium persulfate, wherein the microetching temperature is 20-40 ℃ and the microetching time is 0.5-5 min; the palladium activation adopts a colloid palladium activation system, which comprises metal palladium salt, sodium stannate, sodium chloride and chelating agent, wherein the concentration of palladium ions is 10 ppm-200 ppm, the concentration of sodium stannate is 0.5 g/L-5 g/L, the concentration of sodium chloride is 10 g/L-150 g/L, the chelating agent is selected from ethylenediamine, ethylenediamine tetraacetic acid or sodium tartrate, the concentration of the chelating agent is 0.5 g/L-5 g/L, the activation temperature is 20 ℃ to 40 ℃, and the activation time is 1 min-10 min; the electroplating process adopts an electroplating nickel solution formed by mixing 200 g/L-400 g/L nickel sulfate, 30 g/L-80 g/L nickel chloride and 30 g/L-60 g/L boric acid, and the current density is 5 mA/cm ² ~200 mA/cm ² The electroplating temperature is 60-90 ℃, and the electroplating time is 10-1800 sec.

2. The ceramic substrate according to claim 1, wherein the material of the connection layer is any one of nickel, nickel phosphorus, nickel boron, and the thickness is not more than 1 μm.

3. The ceramic substrate according to claim 1 or 2, wherein the material of the transition layer is any one of nickel, nickel phosphorus and nickel boron, and the thickness is 0.01 μm to 15 μm.

4. The ceramic substrate according to claim 3, wherein the surface finishing layer is made of silver-based material and has a thickness of 10 nm to 2000 nm.

5. A ceramic substrate according to claim 3, wherein the material of the ceramic substrate is selected from any one of alumina, aluminum nitride, silicon nitride, zirconia, silicon carbide, beryllium oxide, boron nitride, lanthanum boride or zirconia reinforced alumina; and/or the aperture range of the through hole is 10-300 mu m.

6. The ceramic substrate according to claim 3, wherein the metal underlayer is made of any one or a combination of at least two of copper, chromium, manganese, titanium, nickel, and tungsten, and has a thickness of 0.1 μm to 3 μm; and/or the thickness of the copper circuit layer is 10-200 mu m.

7. The method for manufacturing a ceramic substrate according to any one of claims 1 to 6, comprising the steps of:

s1, punching a ceramic substrate to obtain a plurality of through holes;

s2, manufacturing metal priming layers on the upper surface and the lower surface of the ceramic substrate and on the inner wall of the through hole;

s4, forming a transition layer on the copper circuit layer;

s5, forming a connecting layer on the transition layer;

s6, forming a surface finishing layer on the connecting layer;

and S7, performing film stripping etching on the photosensitive film layer and the metal underlayer below the photosensitive film layer, and exposing the ceramic substrate to obtain the ceramic substrate.

8. The method according to claim 7, wherein in the step S5, the connection layer is obtained by performing any one of acid leaching, microetching, and palladium activation on the transition layer, or the connection layer is formed on the transition layer by using an electroplating process.

9. The manufacturing method of claim 8, wherein the acid leaching process adopts a sulfuric acid solution with the mass fraction of 1% -10%, the acid leaching temperature is 20 ℃ -50 ℃, and the acid leaching time is 5 min-20 min; the microetching process adopts a mixed solution of 5-30% sulfuric acid and 20 g/L-120 g/L sodium persulfate, wherein the microetching temperature is 20-40 ℃ and the microetching time is 0.5-5 min; the palladium activation adopts a colloid palladium activation system, which comprises metal palladium salt, sodium stannate, sodium chloride and chelating agent, wherein the concentration of palladium ions is 10 ppm-200 ppm, the concentration of sodium stannate is 0.5 g/L-5 g/L, the concentration of sodium chloride is 10 g/L-150 g/L, the chelating agent is selected from ethylenediamine, ethylenediamine tetraacetic acid or sodium tartrate, the concentration of the chelating agent is 0.5 g/L-5 g/L, the activation temperature is 20 ℃ to 40 ℃, and the activation time is 1 min-10 min; the electroplating process adopts an electroplating nickel solution formed by mixing 200 g/L-400 g/L nickel sulfate, 30 g/L-80 g/L nickel chloride and 30 g/L-60 g/L boric acid, and the current density is 5 mA/cm ² ~200 mA/cm ² The electroplating temperature is 60-90 ℃, and the electroplating time is 10-1800 sec.

10. The method according to any one of claims 7 to 9, wherein in the step S4, the transition layer is formed on the copper circuit layer by electroless plating or electroplating.

11. The method according to claim 10, wherein in the step S6, the surface finishing layer is formed on the connection layer by using a chemical silver plating or an electro-silver plating process;

in the step S2, any one or at least two of a plasma chemical vapor deposition, a laser chemical vapor deposition, a thermal chemical vapor deposition, a magnetron sputtering, an ion plating deposition, an electron beam evaporation or a printing slurry pore-filling technology is adopted to manufacture and form the metal priming layer on the upper and lower surfaces of the ceramic substrate and the inner wall of the through hole;

in the step S3, the pattern transferring process comprises photosensitive film pasting and exposure development, wherein the film thickness of the photosensitive film pasting is 10-1000 mu m; the exposure time of exposure and development is 1 s-60 s, the development temperature is 20-50 ℃, and the development time is 1-10 min; and manufacturing the copper circuit layer at the gap of the photosensitive film layer and inside the through hole by adopting an electroplating process.

12. The ceramic substrate according to any one of claims 1 to 6 is used as a heat dissipation package substrate in a light emitting diode LED, a laser diode LD, a sensor or a power device.