Micropore process for improving copper surface binding force

Abstract

The invention discloses a micropore technology for improving copper surface binding force. Micropores are formed in the copper surface of an AMB / DBC product, the specific surface area of bonding copper is increased, the anchoring effect is generated, and the binding force of EMC and the copper surface is improved. The micro-pores are concave and convex by stripping copper, so that the problem of oxide layer stripping does not exist above a certain thickness; the micropore forming method comprises sulfuric acid and hydrogen peroxide series, sodium chloride and hydrochloric acid series, permanganate and copper sulfate series, ammonia and peroxyphosphate series, plasma etching and laser copper surface micropore machining. According to the micropore technology for improving the copper surface binding force, the wet etching technology is adopted, the surface energy difference of copper crystal faces is utilized, the etching rate difference of the crystal faces with low reactivity and the crystal faces with high reactivity is maximized, and therefore the overall surface roughness change is minimized, and meanwhile the copper surface binding force is improved. And micropores with certain sizes and depths are locally formed, so that the EMC binding force is obviously improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of EMC and DBC or AMB combination, and particularly relates to a micropore process for improving copper surface bonding force. BACKGROUND

[0002] The micropore process for improving copper surface bonding force is a method for improving the bonding force of EMC and DBC or AMB, DBC refers to a substrate form product manufactured by directly bonding a copper plate with a surface forming an oxide layer to an aluminum oxide or aluminum nitride substrate at high temperature in a reducing atmosphere, and is widely used in power electronic products, AMB refers to a substrate form product manufactured by bonding a copper plate to an AlN or Si3N4 substrate using an active metal in a reducing or vacuum atmosphere, EMC is a thermosetting plastic material based on protective electronic parts and insulating epoxy resin, and provides waterproof, heat-resistant and mechanical protection during semiconductor packaging, in order to improve the bonding force of EMC and AMB / DBC copper surface, a copper surface micropore processing scheme of AMB / DBC product is given, and along with the continuous development of science and technology, the requirement for the micropore process for improving copper surface bonding force is also higher and higher.

[0003] The existing EMC and DBC or AMB combination process has certain drawbacks in use, scheme 1: in order to improve the bonding force and remove the moisture / pollution on the copper surface, plasma treatment or solvent ultrasonic cleaning is used, scheme 2: in order to improve the chemical bonding force between EMC and the copper surface, AP coating is performed, and scheme 3: in order to improve the physical bonding force between EMC and the copper surface, copper surface oxidation is performed, the above methods are one of the schemes for effectively acting on the EMC and AMB / DBC copper surface and improving the bonding force, but due to the structural problems of AMB / DBC products or the characteristics of Module process, the EMC bonding force is still reduced, and therefore, the micropore process for improving copper surface bonding force is proposed. SUMMARY

[0004] The technical problem solved by the present application is that, in view of the deficiencies in the prior art, the present application provides a micropore process for improving copper surface bonding force, which adopts a wet etching process, utilizes the surface energy difference of copper crystal faces, maximizes the etching rate difference between the crystal faces with low reactivity and the crystal faces with high reactivity, thereby minimizing the overall surface roughness change while locally forming micropores with a certain size and depth, and significantly improving the EMC bonding force, which can effectively solve the problems in the background art.

[0005] The technical scheme adopted by the present application to achieve the above object is as follows: a micropore process for improving copper surface bonding force, comprising the following operation steps: S1: wet etching forming: using wet etching process, using the surface energy difference of copper crystal surface, making the etching rate difference of the crystal surface with low reactivity and the crystal surface with high reactivity maximum, so as to minimize the overall surface roughness and locally form micropores with certain size and depth; S2: anchoring effect: forming micropores on the copper surface of AMB / DBC product, increasing the specific surface area of bonded copper, producing anchoring effect, and improving the bonding force of EMC and copper surface; S3: micropore formation: micropores are formed by the principle of forming concave-convex through copper peeling, and there is no peeling problem above a certain thickness of oxide layer; S4: micropore size: when the size of micropores is about 2-10um and the depth is about 1-3um, the overall roughness of copper surface is less affected, and the EMC bonding force can be obviously improved; S5: forming method: the micropore forming method includes sulfuric acid and hydrogen peroxide series, sodium chloride and hydrochloric acid series, permanganate and copper sulfate series, ammonia and peroxophosphate series, plasma etching and laser copper surface micropore processing.

[0006] As a preferred technical solution of the present application, in the sulfuric acid and hydrogen peroxide series of S5 step, the following operation steps are specifically included: A1: add sulfuric acid, the amount of sulfuric acid added is 50-150mL / L; A2: add hydrogen peroxide, the amount of hydrogen peroxide added is 50-150mL / L; A3: add stabilizer, the stabilizer uses chelating agent, and one of EDTA and organic acid is added, wherein EDTA is ethylenediaminetetraacetic acid, which is one of organic compounds; A4: control the reaction temperature, and control the temperature at 25-40℃; A5: control the reaction time, and control the time at 1-5 minutes.

[0007] As a preferred technical solution of the present application, in the sodium chloride and hydrochloric acid series of S5 step, the following operation steps are specifically included: B1: add sodium chloride, the amount of sodium chloride added is 100-300g / L; B2: add hydrochloric acid, the amount of hydrochloric acid added is 20-100mL / L; B3: control the reaction temperature, and control the temperature at 30-50℃; B4: control the reaction time, and control the time at 2-10 minutes.

[0008] As a preferred technical solution of the present application, in the permanganate and copper sulfate series of S5 step, the following operation steps are specifically included: C1: adding potassium permanganate, the amount of potassium permanganate added is 5-25 g / L; C2: adding copper sulfate, the amount of copper sulfate added is 10-50 g / L; C3: controlling the reaction temperature, the temperature is controlled at 50-80℃; C4: controlling the reaction time, the time is controlled at 2-10 minutes.

[0009] As a preferred technical solution of the present application, the S5 step of ammonia and peroxophosphate series specifically includes the following operation steps: D1: adding ammonia water solution, the amount of ammonia water solution added is 50-150 mL / L; D2: adding peroxysulfate, the amount of peroxysulfate added is 50-150 g / L; D3: controlling the reaction temperature, the temperature is controlled at 40-60℃; D4: controlling the reaction time, the time is controlled at 2-10 minutes.

[0010] As a preferred technical solution of the present application, the S3 step, the surface porosity of the microporous product is 24.81%, the surface porosity of the copper surface oxidation product is 13.17%, and the surface porosity of the general product is 0.32%.

[0011] As a preferred technical solution of the present application, in the S2 step, when the DBC product is combined with the EMC, the process is copper preparation, copper pre-oxidation, DBC bonding, pre-cleaning and polishing, exposure, DES circuit, chemical plating, micropore process, laser cutting, final inspection, wherein the DBC bonding includes AlN pre-oxidation treatment and Al2O3 substrate.

[0012] As a preferred technical solution of the present application, in the S2 step, when the AMB product is combined with the EMC, the process is copper preparation, AMB solder printing, AMB soldering, pre-cleaning and polishing, exposure, DES circuit, chemical plating, micropore process, laser cutting, final inspection, wherein the AMB soldering includes AlN substrate and Si3N4 substrate, and solder etching is added in the DES circuit.

[0013] Beneficial effects: compared with the prior art, the application provides a micropore process for improving the bonding force of a copper surface, which has the following beneficial effects: the micropore process for improving the bonding force of a copper surface adopts a wet etching process, utilizes the surface energy difference of a copper crystal surface, maximizes the etching rate difference between a crystal surface with low reactivity and a crystal surface with high reactivity, minimizes the overall surface roughness change, and locally forms micropores with a certain size and depth, so that the overall roughness of the copper surface is less affected, the EMC bonding force can be obviously improved, the micropores are formed on the copper surface of the AMB / DBC product, thereby increasing the specific surface area of the bonded copper, producing an anchoring effect, and improving the bonding force of the EMC and the copper surface, the entire micropore process for improving the bonding force of the copper surface has simple structure, convenient operation, and better use effect compared with the traditional mode. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is an overall flow structure schematic diagram of the micropore process for improving the bonding force of the copper surface.

[0015] Figure 2 It is a micropore schematic diagram of the AMB / DBC copper surface in the micropore process for improving the bonding force of the copper surface.

[0016] Figure 3 It is a specific surface area comparison schematic diagram of general products, micropore products and copper surface oxidation products in the micropore process for improving the bonding force of the copper surface.

[0017] Figure 4 It is a cross-sectional schematic diagram of general products, micropore products and copper surface oxidation products in the micropore process for improving the bonding force of the copper surface.

[0018] Figure 5 It is a structure schematic diagram of the bonding force comparison of general products, micropore products and copper surface oxidation products in the micropore process for improving the bonding force of the copper surface.

[0019] Figure 6 It is a micropore effectiveness verification area ratio schematic diagram in the micropore process for improving the bonding force of the copper surface.

[0020] Figure 7 It is an EMC thrust comparison schematic diagram in the micropore effectiveness verification in the micropore process for improving the bonding force of the copper surface.

[0021] Figure 8 It is an EMC thrust actual measurement schematic diagram in the micropore effectiveness verification in the micropore process for improving the bonding force of the copper surface. DETAILED DESCRIPTION

[0022] The technical solutions of the present application will be clearly and completely described below in combination with the drawings and specific embodiments, but those skilled in the art will understand that the following described embodiments are part of the embodiments of the present application, not all the embodiments, and are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. The specific conditions are not specified in the embodiments, which are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, which are conventional products that can be purchased on the market.

[0023] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0024] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] As shown in Figures 1-8 A micropore process for improving the bonding force of copper surface includes the following operation steps: S1: wet etching forming: using wet etching process, taking advantage of the surface energy difference of copper crystal surface, making the etching rate difference of the crystal surface with low reactivity and the crystal surface with high reactivity maximized, so as to minimize the overall surface roughness while locally forming micropores with certain size and depth; S2: anchoring effect: forming micropores on the copper surface of AMB / DBC product, increasing the specific surface area of bonded copper, producing anchoring effect, and improving the bonding force of EMC and copper surface; S3: micropore forming: micropores are formed by the principle of forming concave-convex through copper peeling, and there is no peeling problem of oxidation layer above a certain thickness; S4: Micro-pore forming size: when the size of the micro-pore is about 2-10 um and the depth is about 1-3 um, the overall roughness of the copper surface has less influence, and the EMC binding force can be obviously improved; S5: forming method: the micro-pore forming method includes sulfuric acid and hydrogen peroxide series, sodium chloride and hydrochloric acid series, permanganate and copper sulfate series, ammonia and peroxophosphate series, plasma etching and laser copper surface micro-pore processing.

[0026] Further, in the sulfuric acid and hydrogen peroxide series of S5 step, the following operation steps are specifically included: A1: add sulfuric acid, the amount of sulfuric acid added is 50-150 mL / L; A2: add hydrogen peroxide, the amount of hydrogen peroxide added is 50-150 mL / L; A3: add stabilizer, the stabilizer uses a chelating agent, and one of EDTA and organic acid is added, wherein EDTA is ethylenediaminetetraacetic acid, which is one of organic compounds; A4: control the reaction temperature, and control the temperature at 25-40℃; A5: control the reaction time, and control the time at 1-5 minutes.

[0027] Further, in the sodium chloride and hydrochloric acid series of S5 step, the following operation steps are specifically included: B1: add sodium chloride, the amount of sodium chloride added is 100-300 g / L; B2: add hydrochloric acid, the amount of hydrochloric acid added is 20-100 mL / L; B3: control the reaction temperature, and control the temperature at 30-50℃; B4: control the reaction time, and control the time at 2-10 minutes.

[0028] Further, in the permanganate and copper sulfate series of S5 step, the following operation steps are specifically included: C1: add potassium permanganate, the amount of potassium permanganate added is 5-25 g / L; C2: add copper sulfate, the amount of copper sulfate added is 10-50 g / L; C3: control the reaction temperature, and control the temperature at 50-80℃; C4: control the reaction time, and control the time at 2-10 minutes.

[0029] Further, in the ammonia and peroxophosphate series of S5 step, the following operation steps are specifically included: D1: add ammonia solution, the amount of ammonia solution added is 50-150 mL / L; D2: add peroxysulfate, the amount of peroxysulfate added is 50-150 g / L; D3: control the reaction temperature, and the temperature is controlled at 40-60℃; D4: control the reaction time, and the time is controlled at 2-10 minutes.

[0030] Further, the surface porosity of the microporous product in S3 is 24.81%, the surface porosity of the copper surface oxidation product is 13.17%, and the surface porosity of the general product is 0.32%.

[0031] Further, in the combination of the DBC product and the EMC in S2, the process is copper preparation, copper pre-oxidation, DBC bonding, pre-cleaning and polishing, exposure, DES circuit, chemical plating, microporous process, laser cutting, and final inspection, wherein the DBC bonding includes AlN pre-oxidation treatment and Al2O3 substrate.

[0032] Further, in the combination of the AMB product and the EMC in S2, the process is copper preparation, AMB solder printing, AMB soldering, pre-cleaning and polishing, exposure, DES circuit, chemical plating, microporous process, laser cutting, and final inspection, wherein the AMB soldering includes AlN substrate and Si3N4 substrate, and solder etching is added in the DES circuit. Embodiment

[0033] When the sulfuric acid and hydrogen peroxide solution method is used: Sulfuric acid is added, and the amount of sulfuric acid added is 80 mL / L; Hydrogen peroxide is added, and the amount of hydrogen peroxide added is 80 mL / L; A stabilizer is added, and the stabilizer uses a chelating agent, and one of EDTA and an organic acid is added, wherein EDTA is ethylenediaminetetraacetic acid, which is one of organic compounds; The reaction temperature is controlled, and the temperature is controlled at 30℃; The reaction time is controlled, and the time is controlled at 3 minutes. Embodiment

[0034] When the sodium chloride and hydrochloric acid solution method is used: Sodium chloride is added, and the amount of sodium chloride added is 200 g / L; Hydrochloric acid is added, and the amount of hydrochloric acid added is 60 mL / L; The reaction temperature is controlled, and the temperature is controlled at 40℃; The reaction time is controlled, and the time is controlled at 6 minutes. Embodiment

[0035] When the potassium permanganate and copper sulfate solution method is used: Potassium permanganate is added, and the amount of potassium permanganate added is 15 g / L; Copper sulfate is added, and the amount of copper sulfate added is 30 g / L; The reaction temperature is controlled at 65°C. The reaction time is controlled at 6 minutes. Examples

[0036] When using the ammonia and peroxophosphate solution method: The ammonia solution is added, and the amount of ammonia solution added is 100 mL / L; The peroxysulfate is added, and the amount of peroxysulfate added is 100 g / L; The reaction temperature is controlled at 50°C. The reaction time is controlled at 6 minutes.

[0037] As shown in Figure 3 , the general product surface has about 0.32% surface pores, the copper surface oxidized product surface has about 13.17% surface pores, and the surface pores of the microporous product are about 24.81%, so the specific surface area (BET) is relatively large. That is, the wide specific surface area means high wettability with EMC and high bonding force.

[0038] As shown in Figure 4 , when confirming the copper surface cross-sectional image of the microporous treatment, the general product A has almost no surface concave-convex, and the copper surface oxidized product C has a surface concave-convex, but the width is below 2um and the depth is 0.5um, which has a smaller concave-convex. On the contrary, the microporous product B forms a micropore on the surface, which has a width of more than 5um and a depth of more than 1um, so relatively speaking, when bonding with EMC, a large anchoring effect can be seen.

[0039] As shown in Figure 5 , by comparing the EMC bonding force of different products, it can be seen that the EMC bonding force of the AMB / DBC product using micropores is higher than that of the general product and the copper surface oxidized product.

[0040] Working principle: using wet etching process, taking advantage of the surface energy difference of copper crystal surface, making the etching rate difference between the low reactivity crystal surface and the high reactivity crystal surface maximized, so as to minimize the overall surface roughness while locally forming micropores with certain size and depth; form micropores on the copper surface of AMB / DBC product, increase the specific surface area of bonded copper, produce anchoring effect, and improve the bonding force of EMC and copper surface; micropores do not have peeling problem above a certain thickness by the principle of peeling copper to form concave-convex; when the size of micropore is about 2~10um and the depth is about 1~3um, the overall roughness of copper surface is less affected, and the EMC bonding force can be significantly improved; the micropore forming method includes sulfuric acid and hydrogen peroxide series, sodium chloride and hydrochloric acid series, permanganate and copper sulfate series, ammonia and peroxophosphate series, plasma etching and laser copper surface micropore processing.

[0041] It has to be noted that, in the present document, the terms "first" and "second", etc. merely serve the purpose of distinguishing between two entities or operations, without necessarily requiring or implying any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "containing", or any other transitional term, do not exclude other elements or steps, but merely serve as specifications of the presence of the stated elements or steps. The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Strictly speaking, the term "comprising" does not exclude the presence of elements or steps other than those listed in a process, method, article, or apparatus that includes the enclosed elements or steps. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The meaning of "in" and "determining" in this context includes a direct measurement or an indirect measurement of the stated element, step, operation, input or output. Unless otherwise indicated, the use of "or" in the present document is the inclusive, and not the exclusive use, i.e. "and / or". The use of "and" in the present document is both the conjunctive and disjunctive, i.e. "and / or". The use of "comprise", "comprises" or "comprising" in the present document does not exclude the presence of elements other than those listed in the process, method, article, or apparatus that includes the enclosed elements or steps. The use of "including" in the present document does not exclude the presence of elements other than those listed in the process, method, article, or apparatus that includes the enclosed elements or steps.

[0042] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the following claims.

Claims

1. A microporous process for improving the adhesion of copper to a surface, characterized by: The method comprises the following steps: S1: wet etching forming: using the wet etching process, the surface energy difference of copper crystal surface is used to maximize the etching rate difference between the low reactivity crystal surface and the high reactivity crystal surface, so as to minimize the overall surface roughness and locally form micro-holes with a certain size and depth; S2: anchoring effect: the micro-holes formed on the copper surface of the AMB / DBC product increase the specific surface area of the bonded copper, produce the anchoring effect, and improve the bonding force between the EMC and the copper surface; S3: micro-hole forming: the micro-holes are formed by the principle of forming concave-convex through copper peeling, and there is no peeling problem of the oxidation layer above a certain thickness; S4: micro-hole forming size: when the size of the micro-holes is about 2-10 um and the depth is about 1-3 um, the overall roughness of the copper surface is less affected, and the EMC bonding force can be obviously improved; S5: forming method: the micro-hole forming method includes sulfuric acid and hydrogen peroxide series, sodium chloride and hydrochloric acid series, permanganate and copper sulfate series, ammonia and peroxophosphate series, plasma etching and laser copper surface micro-hole processing.

2. The micro-void process for improving the adhesion of copper to a surface according to claim 1, wherein: The S5 step of the sulfuric acid and hydrogen peroxide series specifically comprises the following steps: A1: add sulfuric acid, the amount of sulfuric acid added is 50-150 mL / L; A2: add hydrogen peroxide, the amount of hydrogen peroxide added is 50-150 mL / L; A3: add stabilizer, the stabilizer uses a chelating agent, and one of EDTA and organic acid is added, wherein EDTA is ethylenediaminetetraacetic acid, which is one of organic compounds; A4: control the reaction temperature, and control the temperature at 25-40℃; A5: control the reaction time, and control the time at 1-5 minutes.

3. The micro-void process for improving the adhesion of copper to a surface according to claim 1, wherein: The S5 step of the sodium chloride and hydrochloric acid series specifically comprises the following steps: B1: add sodium chloride, the amount of sodium chloride added is 100-300 g / L; B2: add hydrochloric acid, the amount of hydrochloric acid added is 20-100 mL / L; B3: control the reaction temperature, and control the temperature at 30-50℃; B4: control the reaction time, and control the time at 2-10 minutes.

4. The micro-void process for improving the adhesion of copper to a surface according to claim 1, wherein: The S5 step of the permanganate and copper sulfate series specifically comprises the following steps: C1: add potassium permanganate, the amount of potassium permanganate added is 5-25 g / L; C2: add copper sulfate, the amount of copper sulfate added is 10-50 g / L; C3: control the reaction temperature, and control the temperature at 50-80℃; C4: control the reaction time, and control the time at 2-10 minutes.

5. The micro-void process for improving the adhesion of copper according to claim 1, wherein: The S5 step of the ammonia and peroxophosphate series specifically comprises the following steps: D1: add ammonia solution, the amount of ammonia solution added is 50-150 mL / L; D2: add peroxysulfate, the amount of peroxysulfate added is 50-150 g / L; D3: control the reaction temperature, and control the temperature at 40-60℃; D4: control the reaction time, and control the time at 2-10 minutes.

6. The micro-void process for improving the adhesion of copper to a surface according to claim 1, wherein: In the S3 step, the surface porosity of the micro-hole product is 24.81%, the surface porosity of the copper surface oxidation product is 13.17%, and the surface porosity of the general product is 0.32%.

7. The micro-void process for improving the adhesion of copper to a surface according to claim 1, wherein: The process in the S2 step when the DBC product is combined with the EMC is copper preparation, copper pre-oxidation, DBC bonding, pre-cleaning polishing, exposure, DES circuit, chemical plating, micro-hole process, laser cutting, final inspection, wherein the DBC bonding includes AlN pre-oxidation treatment and Al2O3 substrate.

8. The micro-void process for improving the adhesion of copper to a surface according to claim 1, wherein: The process in the S2 step when the AMB product is combined with the EMC is copper preparation, AMB solder printing, AMB soldering, pre-cleaning polishing, exposure, DES circuit, chemical plating, micro-hole process, laser cutting, final inspection, wherein the AMB soldering includes AlN substrate and Si3N4 substrate, and solder etching is added in the DES circuit.

Images