阅读说明：本技术 一种电化学预处理-原位电沉积方法 (Electrochemical pretreatment-in-situ electrodeposition method ) 是由 朱增伟 沈春健 朱荻 马周 陶金 于 2019-10-14 设计创作，主要内容包括：本发明属于电化学制造技术领域,尤其涉及一种电化学预处理-原位电沉积方法。本发明将金属基体在预处理液中进行电化学预处理,得到预处理的金属基体；将所述预处理的金属基体表面保持在预处理液中的浸润状态,置入电沉积溶液中进行电沉积,得到金属-电沉积层。本发明采用表面电化学预处理-原位电沉积技术,先对基体表面进行电化学预处理,然后采用原位技术维持预处理后基体表面状态,直接进入电沉积过程进行电沉积层生长,能显著提高电沉积层与基体的结合强度,其结合强度甚至可以高于基体的抗拉强度。(The invention belongs to the technical field of electrochemical manufacturing, and particularly relates to an electrochemical pretreatment-in-situ electrodeposition method. Carrying out electrochemical pretreatment on a metal matrix in a pretreatment solution to obtain a pretreated metal matrix; and keeping the surface of the pretreated metal substrate in a soaking state in the pretreatment solution, and putting the pretreated metal substrate into an electrodeposition solution for electrodeposition to obtain a metal-electrodeposition layer. The invention adopts the surface electrochemical pretreatment-in-situ electrodeposition technology, firstly carries out the electrochemical pretreatment on the surface of the matrix, then adopts the in-situ technology to maintain the surface state of the pretreated matrix, and directly enters the electrodeposition process to carry out the growth of the electrodeposition layer, thereby obviously improving the bonding strength of the electrodeposition layer and the matrix, and the bonding strength can even be higher than the tensile strength of the matrix.)

1. An electrochemical pretreatment-in-situ electrodeposition method, comprising the steps of:

carrying out electrochemical pretreatment on a metal matrix in a pretreatment solution to obtain a pretreated metal matrix;

and keeping the surface of the pretreated metal substrate in a soaking state in the pretreatment solution, and putting the pretreated metal substrate into an electrodeposition solution for electrodeposition to obtain a metal-electrodeposition layer.

2. The method of claim 1, wherein the metal matrix is ultrasonically cleaned in a degreasing fluid prior to the electrochemical pretreatment.

3. The method of claim 1, wherein the metal matrix comprises copper, a copper alloy, nickel, a nickel alloy, or stainless steel.

4. The method of claim 1, wherein the pretreatment solution is an acidic solution, and the acidic ions of the acidic solution are any one of the acidic ions in the electrodeposition solution.

5. The method according to claim 4, wherein the pretreatment solution comprises a sulfuric acid solution or a sulfamic acid solution, the concentration of the sulfuric acid solution is 60-220 g/L, and the concentration of the sulfamic acid solution is 80-140 g/L.

6. The method according to claim 4 or 5, wherein the current density during the electrochemical pretreatment is 5-10A/cm²And the pretreatment time is 9-15 s.

7. The method of claim 1, wherein the electrodeposited layer comprises copper or nickel.

8. The method according to claim 1, wherein the electrodeposition is carried out at a current density of 1 to 4A/dm²。

Technical Field

The invention relates to the technical field of electrochemical manufacturing, in particular to an electrochemical pretreatment-in-situ electrodeposition method.

Background

In recent years, multilayer printed circuit board plating in metal-coated components in the electronics industry, multilayer printed circuit board plating in electrical components, and multilayer-structured micro parts in MEMS have been the focus of research. The multilayer structure of the part inevitably introduces critical issues of bonding force. The binding force between the electrodeposited layer and the substrate is an important parameter applicable to various parts with a structure formed by the underlayer and the electrodeposited layer in the industry, and the strength of the binding force between the substrate and the electrodeposited layer directly determines the quality of the mechanical properties of the parts.

In general, a harmful layer such as an oxide layer, a work hardening layer, or a diffusion layer is present on the surface of the substrate, and the presence of the harmful layer greatly reduces the bonding strength between the substrate and the electrodeposited layer. Researches show that the harmful layer on the surface of the substrate can be removed by a reliable substrate surface pretreatment process, and the bonding strength of the substrate and the electrodeposited layer is improved. At present, the prior substrate surface pretreatment process usually adopts a substrate degreasing and substrate etching method, and is the same as the prior substrate surface pretreatment process before electroplating, firstly, the substrate surface is subjected to electrolytic polishing to remove scratches and level the surface, then, a chemical corrosive liquid is used for corroding an oxide layer and a processing hardened layer on the substrate surface to expose a fresh metal layer, and finally, an acid solution is used for performing cathode treatment to remove residual treatment liquid and an oxide film on the substrate surface. However, these process steps were developed for surface finishing, with the following drawbacks: firstly, the surface pretreatment process is complicated, multiple steps of treatment are usually required, solutions in various treatment tanks are easy to mutually pollute, and the treatment efficiency and the service life of treatment liquid are greatly reduced; secondly, the formula of the used treatment liquid is complex, the treatment liquid contains various organic additives, and the surface of the substrate after pretreatment is easy to adsorb ions and molecules, and is difficult to remove by washing with clear water, so that the bonding strength of the electrodeposited layer and the substrate is influenced.

In conclusion, the electrodeposition layer obtained by the prior substrate surface pretreatment process has limited bonding strength with the substrate, and cannot be used in occasions with higher requirements on the bonding strength.

Disclosure of Invention

The invention aims to provide an electrochemical pretreatment-in-situ electrodeposition method, and the metal surface electrodeposition layer prepared by the method has high bonding strength with a metal matrix.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides an electrochemical pretreatment-in-situ electrodeposition method, which comprises the following steps:

carrying out electrochemical pretreatment on a metal matrix in a pretreatment solution to obtain a pretreated metal matrix;

and keeping the surface of the pretreated metal substrate in a soaking state in the pretreatment solution, and putting the pretreated metal substrate into an electrodeposition solution for electrodeposition to obtain a metal-electrodeposition layer.

Preferably, before the electrochemical pretreatment, the metal matrix is subjected to ultrasonic cleaning in a degreasing liquid.

Preferably, the metal matrix comprises copper, a copper alloy, nickel, a nickel alloy or stainless steel.

Preferably, the pretreatment solution is an acidic solution, and the acid radical ions of the acidic solution are any one of acid radical ions in the electrodeposition solution.

Preferably, the pretreatment solution comprises a sulfuric acid solution or an sulfamic acid solution, the concentration of the sulfuric acid solution is 60-220 g/L, and the concentration of the sulfamic acid solution is 80-140 g/L.

Preferably, in the electrochemical pretreatment process, the current density is 5-10A/cm²And the pretreatment time is 9-15 s.

Preferably, the electrodeposited layer comprises copper or nickel.

Preferably, the electrodeposition is carried out at a current density of 1 to 4A/dm²。

The invention provides an electrochemical pretreatment-in-situ electrodeposition method, which comprises the following steps: carrying out electrochemical pretreatment on a metal matrix in a pretreatment solution to obtain a pretreated metal matrix; and keeping the surface of the pretreated metal substrate in a soaking state in the pretreatment solution, and putting the pretreated metal substrate into an electrodeposition solution for electrodeposition to obtain a metal-electrodeposition layer.

The invention adopts the surface electrochemical pretreatment-in-situ electrodeposition technology, firstly carries out the electrochemical pretreatment on the surface of the matrix, then adopts the in-situ technology to maintain the surface state of the pretreated matrix, and directly enters the electrodeposition process to carry out the growth of the electrodeposition layer, thereby obviously improving the bonding strength of the electrodeposition layer and the matrix, and the bonding strength can even be higher than the tensile strength of the matrix.

The pretreatment process is simple, the stability and the reliability of the pretreatment process can be obviously improved, the pretreatment state of the surface of the substrate is kept and the bonding strength of an electric deposition layer and the substrate is improved by emphasizing the connection process from the pretreatment of the surface of the substrate to the electrodeposition of the surface of the substrate.

Drawings

FIG. 1 is a schematic process diagram of the electrochemical pretreatment-in-situ electrodeposition method of the present invention; wherein, 1-matrix, 2-pretreatment cathode, 3-pretreatment tank, 4-pretreatment liquid film, 5-electrodeposition anode, 6-electrodeposition tank;

FIG. 2 is a micro-topography of a pure copper matrix after pretreatment according to example 1 of the present invention;

fig. 3 is a graph showing the results of the oly method bonding strength test performed on a sample prepared in example 1 of the present invention.

Detailed Description

The invention provides an electrochemical pretreatment-in-situ electrodeposition method, which comprises the following steps:

carrying out electrochemical pretreatment on a metal matrix in a pretreatment solution to obtain a pretreated metal matrix;

and keeping the surface of the pretreated metal substrate in a soaking state in the pretreatment solution, and putting the pretreated metal substrate into an electrodeposition solution for electrodeposition to obtain a metal-electrodeposition layer.

In the present invention, the required raw materials are all commercially available products well known to those skilled in the art, unless otherwise specified.

The invention carries out electrochemical pretreatment on a metal matrix in pretreatment liquid to obtain the pretreated metal matrix. Before the electrochemical pretreatment, the metal matrix is preferably subjected to ultrasonic cleaning in deoiling liquid, and the ultrasonic cleaning time is preferably 30 min-1 h; the power of the ultrasonic cleaning is not particularly limited in the present invention, and may be selected from those known to those skilled in the art. In the invention, the deoiling liquid is preferably a BH-7 type multifunctional alkaline deoiling solution, and the deoiling liquid preferably comprises 20g/L of sodium carbonate, 20g/L of trisodium phosphate and 50ml/L of BH-7 alkaline deoiling agent. The metal matrix is cleaned in the degreasing liquid, so that dirt such as grease, lubricant and the like attached to the surface of the matrix can be removed.

In the present invention, the metal matrix preferably includes copper, a copper alloy, nickel, a nickel alloy, or stainless steel. In the invention, the pretreatment solution is preferably an acidic solution, and the acid radical ions of the acidic solution are preferably any one of acid radical ions in the electrodeposition solution; the pretreatment solution more preferably comprises a sulfuric acid solution or an sulfamic acid solution, and the concentration of the sulfuric acid solution is preferably 60-220 g/L, and more preferably 170-200 g/L; the concentration of the sulfamic acid solution is preferably 80-140 g/L, and more preferably 100-140 g/L.

In the invention, in the electrochemical pretreatment process, the current density is preferably 5-10A/cm²More preferably 6 to 8A/cm²The pretreatment time is preferably 9-15 s, and more preferably 8-12 s; the flow rate of the pretreatment liquid is preferably 1-2 m/s, and more preferably 1.5 m/s. In the present invention, the method of using the pretreatment liquid is preferably to brush the surface of the substrate with the pretreatment liquid at a fixed flow rate. The invention controls the pretreatment time and matches with the current density, and can completely remove the oxide layer and the processing hardened layer on the surface of the workpiece to expose fresh metal. The invention controls the flow rate of the pretreatment liquid, can quickly drive away oxygen bubbles and pretreatment products possibly generated on the surface of the substrate, and timely updates the treatment liquid on the surface of the substrate.

In the present invention, for a substrate having a complicated shape and a large area, a scanning electrochemical pretreatment of the substrate surface may be performed by using a nozzle having a cathode attached thereto.

In the electrochemical pretreatment process, the electrochemical pretreatment is carried out by adopting a simple acidic solution, the components of the electrochemical pretreatment are similar to those of the electrodeposition solution, the removal, surface polishing and surface activation of an oxide layer and a processing hardened layer on the surface of the matrix can be completed by one step of the electrochemical pretreatment, and the activated and clean matrix surface is obtained, so that the foundation is laid for improving the bonding strength of the matrix and the electrodeposition layer.

The device used in the pretreatment process is not specially limited, and the parameter requirements of the technical scheme can be met.

After the pretreated metal matrix is obtained, the surface of the pretreated metal matrix is kept in a soaking state in pretreatment solution, and the pretreated metal matrix is placed in electrodeposition solution for electrodeposition to obtain a metal-electrodeposition layer.

In the invention, after the pretreatment is finished, a pretreatment liquid film playing a role of wetting is generated on the surface of the substrate, the surface of the pretreated metal substrate is kept in a wetting state, specifically, the wetting state of the pretreatment liquid on the surface of the metal substrate is kept, namely, the substrate is wetted by using a liquid film, the activated ultra-clean surface state of the pretreated substrate is maintained, and the substrate directly enters an electrodeposition solution to carry out in-situ growth of a metal layer, namely, an electrodeposition process.

In the invention, a small amount of pretreatment liquid brought in the process of keeping the surface of the metal substrate in a wet state does not influence the electrodeposition process of the surface of the substrate and the bonding performance of the substrate and an electrodeposition layer.

In the invention, when the electrodeposition is carried out, the current density of the electrodeposition is preferably 1-4A/dm²More preferably 2 to 3A/dm². In the present invention, the electrodeposition layer preferably comprises copper or nickel; when the electrodeposition layer is copper, the electrodeposition solution used for electrodeposition is copper sulfate solution, the concentration of the copper sulfate solution is 60g/L, and the pretreatment solution is sulfuric acid solution; the current density of the electrodeposition is preferably 1A/dm²The invention does not apply to the time of the electrodepositionThere are specific limitations to the process chosen, as is well known to those skilled in the art.

When the electrodeposition layer is nickel, the electrodeposition solution used for electrodeposition is a mixed solution of nickel sulfamate, nickel chloride and boric acid, the concentration of the nickel sulfamate in the mixed solution is 400g/L, the concentration of the nickel chloride is 15g/L, and the concentration of the boric acid is 30 g/L; the pretreatment solution is preferably a nickel sulfamate solution; the current density of the electrodeposition is preferably 4A/dm²The electrodeposition time is not particularly limited in the present invention, and a process known to those skilled in the art may be selected.

The electrodeposition apparatus of the present invention is not particularly limited, and an apparatus known to those skilled in the art may be selected to satisfy the above parameter conditions. In an embodiment of the invention, the electrodeposition is carried out in an electrodeposition cell; the electrodeposition anode used in the electrodeposition process is preferably adjusted according to the electrodeposition layer, and in an embodiment of the present invention, the electrodeposition anode preferably includes a pure nickel anode or a phosphor copper anode.

FIG. 1 is a schematic process diagram of the electrochemical pretreatment-in-situ electrodeposition method of the present invention, in which 1-substrate, 2-pretreatment cathode (stainless steel), 3-pretreatment tank, 4-pretreatment liquid film, 5-electrodeposition anode, 6-electrodeposition tank; as shown in the figure, in the pretreatment tank, the metal matrix is subjected to electrochemical pretreatment by adopting pretreatment liquid; after pretreatment, generating a pretreatment liquid film on the surface of the substrate, then directly feeding the obtained substrate into an electrodeposition tank, and simultaneously connecting a loop to carry out deposition growth of a metal layer.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.