WO2021196267A1

WO2021196267A1 - Fabrication process for liquid cooling heat dissipation plate

Info

Publication number: WO2021196267A1
Application number: PCT/CN2020/084392
Authority: WO
Inventors: 赵金宝; 王国伟; 樊鹏飞
Original assignee: 苏州方林科技股份有限公司
Priority date: 2020-03-31
Filing date: 2020-04-13
Publication date: 2021-10-07
Also published as: CN111326827A

Abstract

Provided is a fabrication process for a liquid-cooling heat dissipation plate that uses bonding to replace conventional welding, specifically comprising: first, processing a metal raw material to semi-finished products (1, 3) required to form the finished product of the liquid cooling heat dissipation plate, and then performing whole or partial washing and cleaning of the semi-finished products (1, 3); re-processing or selecting a metal adhesive (2), and pre-fixing the metal adhesive (2) onto the semi-finished product a (1); subsequently, assembling the semi-finished product b (3) and semi-finished products c other than the semi-finished product a (1) and the semi-finished product b (3) to the semi-finished product a (1) that has been fixed with the metal adhesive (2), and fixing all the semi-finished products in the shape of the finished product; then, keeping the temperature and the pressure constant for a certain period of time, so that the finished product of the liquid cooling heat dissipation plate is formed; lastly, performing inspection on the finished product and packaging the product that has passed the inspection, thereby completing the fabrication of the entire liquid cooling heat dissipation plate. The present process is simple, practical, and reliable, and omits the metal welding process that is in conventional fabrication processes, thus greatly reducing the difficulty in fabricating liquid cooling heat dissipation plates and improving the production efficiency.

Description

Manufacturing process of liquid-cooled radiating plate

Technical field

The invention relates to the field of new energy sources for lithium batteries, in particular to the field of production and manufacture of liquid-cooled radiating plates for lithium batteries.

Background technique

Against the background of energy constraints and environmental pollution, the Chinese government regards the development of new energy vehicles as a major measure to solve energy and environmental problems and achieve sustainable development. Automobile manufacturers also regard new energy vehicles as important to seize the commanding heights of the future automotive industry. Strategic Direction. With the development of new energy electric vehicles, breakthroughs in battery technology have become one of the important reasons that limit the large-scale listing of electric vehicles. The capacity and safety of batteries need to be broken through, and the higher the range, the higher the battery capacity is required. The greater the heating power when it is working, it brings hidden dangers to the safe use of the battery, so how to quickly take away the battery heat is particularly important. At present, battery cooling mainly has two forms: air cooling and liquid cooling, and liquid cooling has a better cooling effect. As an important part of the thermal management system of the battery pack, the liquid-cooled heat sink mainly realizes the heat dissipation of the battery pack through the flow of cooling liquid in the flow channel of the liquid-cooled plate. A reasonable flow channel design for the liquid cooling plate can effectively improve the heat dissipation function of the radiator and prolong the service life of the battery pack.

The main process of the liquid-cooled heat sink currently used in the field of power batteries is to complete the production of the liquid-cooled heat sink by connecting the metal after metal processing. Usually the main welding methods are fusion welding, pressure welding and brazing. Fusion welding is a method of heating the workpiece interface to a molten state during the welding process and completing the welding without pressure; during fusion welding, the heat source rapidly heats and melts the interface of the workpiece to be welded to form a molten pool, so the welded joint must be able to support Welding pool, and thin metal materials may melt through due to low strength and cause liquid leakage, so they are not suitable for fusion welding. Pressure welding is to make two workpieces realize interatomic bonding in a solid state under pressure, also known as solid-state welding; during pressure welding, the welding joint is under a lot of pressure, and the insufficient strength of thin metal materials is prone to deformation and even local structure. Risk of leakage due to destruction. Brazing is to use a metal material with a lower melting point than the workpiece as the solder, heat the workpiece and the solder to a temperature higher than the melting point of the solder and lower than the melting point of the workpiece, and use the liquid solder to wet the workpiece, fill the interface gap and realize it with the workpiece The mutual diffusion of atoms is a method of welding; brazing requires the use of solder to melt the workpiece and then wetting the workpiece, so there is insufficient wetting, which leads to local leakage and the risk of leakage; at the same time, the heating temperature of brazing is lower than The melting point of the workpiece, so corrosive flux will be added to improve the welding effect. The residual flux in brazing cannot be completely removed. The residual flux will reduce the strength of the welded joint and cause corrosive defects at the welded joint. There is a high risk of leakage during use.

In summary, the welding method is a relatively mature connection method in the industry. However, reliable welding joints have strict requirements on the structure of the base metal and joint parts. And due to the characteristics of the welding process itself, some of the thickness is relatively thin, the structure is more complex, and there are special Liquid-cooled heat sinks with functional requirements are difficult to achieve directly through metal welding, and only part of the heat dissipation performance can be sacrificed to meet process requirements. Commonly used welding methods have difficulty in recombination between thin materials, easy to deform, or leakage due to missing welding or destruction of thin materials.

Summary of the invention

The technical problem to be solved by the present invention is to provide a manufacturing process of a liquid-cooled heat sink to solve the problem of unsatisfactory heat dissipation effect caused by the limitation of the existing process and the connection joints of the flow channel structure of the liquid-cooled heat sink in the prior art The performance of the part is reduced and the problem of susceptibility to corrosion.

In order to achieve the above technical effects, the technical solutions adopted by the present invention are:

A manufacturing process of a liquid-cooled heat sink is characterized in that it includes the following process steps:

S1. Material forming: processing metal raw materials into semi-finished products required to form a finished liquid-cooled heat sink through extrusion, casting, stamping, machining, bending, laser, and wire cutting processes, and the semi-finished products include at least supporting bonding The semi-finished product a of glue and the semi-finished product b used for bonding and connecting to the semi-finished product a;

S2 Cleaning: Fully or partial cleaning and cleaning of all semi-finished products;

S3. Adhesive glue pre-fixation: Pre-fix the metal adhesive glue on the semi-finished product a according to the bonding shape between the semi-finished product a and the other semi-finished products;

S4. Semi-finished product assembly: Assemble the remaining semi-finished products except for the semi-finished product a to the semi-finished product a that has been fixed or positioned with the metal bonding glue, and fix all the semi-finished products to form a combined body of the finished product shape;

S5. Curing and bonding: Put the combined body into a device with controllable temperature and pressure. By controlling the temperature and pressure of the device, and keeping the temperature and pressure for a certain period of time, a finished liquid-cooled heat sink is formed;

S6. Inspection: Take the finished product out of the equipment and tooling, and conduct appearance inspection and performance inspection on the finished product;

S7. Packing: Pack the qualified products.

Further, in the pre-fixing of the adhesive glue in step S3, the metal adhesive glue is an organic material glue, resin or other organic material, which is fixed or positioned on the semi-finished product a by means of die cutting, transfer printing, and glue dispensing. .

Furthermore, in the pre-fixing of the adhesive glue in step S3, the metal adhesive glue has a sheet-like structure and only contains one layer of material. Bond strength and tightness.

Further, in the pre-fixing of the adhesive glue in the step S3, the metal adhesive glue may be a sheet-like structure composed of two or more layers of materials with different properties, and the metal adhesive glue is attached to the metal. The layer is the bonding layer of the metal-philic modified material, so as to ensure the bonding strength and tightness of the bonding glue and the metal material; in order to ensure the strength, high temperature resistance and tightness of the metal bonding glue, other layers can be used Functional layers such as a reinforced structure layer, a high melting point material layer, and a high density material layer are added as needed.

Further, in the pre-fixing of the adhesive glue in step S3, the metal adhesive glue is a liquid glue, and the glue is a liquid under normal temperature and pressure and certain storage conditions. The main components of the liquid adhesive are metal-philic modified materials or basic materials added with metal-philic modified materials. The secondary components may or may not contain additives and fillers that improve the corresponding performance of the metal adhesive, such as to improve For the strength, durability and tightness of the adhesive, reinforcing materials, anti-aging additives and high-density materials can be added to the glue.

Further, in the pre-fixing of the adhesive glue in the step S3, when the metal adhesive glue is a solid material adhesive glue with a sheet structure, the pre-fixing of the adhesive glue is based on the mutual relationship between the semi-finished product a and the remaining semi-finished products. The bonding shape is processed with the metal bonding glue that matches the bonding shape, and then the metal bonding glue is pre-fixed on the semi-finished product a.

Further, in the step S2 cleaning, the cleaning and cleaning are one or more of cleaning and cleaning using an aqueous solvent, an organic solvent, a supercritical fluid, a plasma or a laser process.

Further, in the curing and bonding in step S5, the temperature of the equipment is controlled to be 50 to 200° C., the pressure is controlled to be 0 to 10 MPa, and the heat preservation and pressure retention time is 1 min to 120 min.

Compared with the prior art, the beneficial effects of the present invention are:

1. The process of the present invention can realize the production of a liquid-cooled heat sink with a relatively complex structure and special functional requirements, and the implementation process is simple, practical, and highly reliable.

2. Compared with the traditional welding process (the temperature is higher than or close to the melting point of the base material), the process of the present invention has a lower operating temperature and will not reduce the performance of the base material; it avoids the metal welding process in the traditional manufacturing process and greatly simplifies The liquid-cooled heat sink is difficult to manufacture, and the production efficiency is improved.

3. The materials used in the process of the present invention do not contain materials that are corrosive to the base material, so there will be no corrosive flux residues as in traditional brazing.

4. The process of the present invention improves the design concept of the existing liquid-cooled radiator plate structure, and makes the design of the liquid-cooled radiator plate structure more flexible. The optimal liquid-cooled radiator plate runner structure can be designed according to specific requirements to realize the liquid-cooled radiator plate. The heat dissipation effect is optimized.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, it can be implemented in accordance with the content of the specification, and in order to make the above and other objectives, features and advantages of the present invention more obvious and understandable. The following describes the present invention in further detail with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments.

Description of the drawings

FIG. 1 is an exploded view of the structure of a liquid-cooled heat dissipation plate according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a tooling structure equipped with a finished shape according to an embodiment of the present invention.

3 is a partial schematic diagram of the pre-fixing of the adhesive glue during the liquid glue according to the embodiment of the present invention.

Fig. 4 is a partial structural diagram of the semi-finished product assembling with liquid glue in the embodiment of the present invention.

FIG. 5 is a partial schematic diagram of the pre-fixing of the adhesive glue when the single-layer solid glue is used in the embodiment of the present invention.

Fig. 6 is a schematic diagram of a partial structure of the semi-finished product assembling in a single-layer solid glue according to an embodiment of the present invention.

Fig. 7 is a partial schematic diagram of the pre-fixing of the adhesive glue when the multi-layer solid glue is used in the embodiment of the present invention.

FIG. 8 is a schematic diagram of a partial structure of the semi-finished product assembling in the multi-layer solid glue according to the embodiment of the present invention.

The labels in the figure and the names of their corresponding parts are:

1. Semi-finished product a; 2. Metal bonding glue; 21. Adhesive layer;

22. Functional layer; 3. Semi-finished product b; 4. Tooling;

5. Combination.

Detailed ways

As shown in Figure 1 and Figure 2, a liquid-cooled heat sink manufacturing process includes the following process steps:

S1. Material forming: processing metal raw materials into semi-finished products required to form a finished liquid-cooled heat sink through extrusion, casting, stamping, machining, bending, laser, and wire cutting processes, and the semi-finished products include at least supporting bonding The semi-finished product a1 of glue and the semi-finished product b3 for bonding and connecting to the semi-finished product a1.

S2 Cleaning: Use one or more of the methods of water-based solvent, organic solvent, supercritical fluid, plasma or laser technology to clean and clean all semi-finished products in whole or in part.

S3. Adhesive glue pre-fixing: According to the bonding shape between the semi-finished product a1 and the other semi-finished products, the metal adhesive glue 2 is pre-fixed on the semi-finished product a1 by means of the tooling 4. Among them, the metal bonding glue 2 can be liquid glue or sheet-like organic material glue, resin or other organic material solid glue, which is fixed or positioned on the semi-finished product a1 by die cutting, transfer printing, glue dispensing and other processes. . When the metal bonding glue is a solid glue, the bonding glue is pre-fixed by processing the metal bonding glue that matches the bonding shape according to the bonding shape between the semi-finished product a and the other semi-finished products, and then pre-fixing the metal bonding glue On the semi-finished product a.

S4. Semi-finished product assembly: If the semi-finished products made into the finished liquid-cooled heat sink are only semi-finished products a1 and semi-finished products b3, then the semi-finished product b3 is assembled to the semi-finished product a1 that has been fixed with the metal adhesive through tooling 4, and the semi-finished product is assembled through tooling 4. a1 and semi-finished product b3 are fixed to form a combination of the finished shape; if the semi-finished product made into a finished liquid-cooled heat sink has other semi-finished products c between semi-finished a and semi-finished products b, then semi-finished b and semi-finished products a and semi-finished b The other semi-finished products c are all assembled to the semi-finished product a that has been fixed with the metal adhesive glue, and the tooling 4 (in this embodiment, the tooling can be used to position and assemble the product, and then press to form, it can be understood All semi-finished products are fixed to the upper and lower structure or other structural forms with an inner cavity matching the shape of the product to form a combined body 5 in the shape of the finished product.

As shown in FIG. 3 and FIG. 4, the metal bonding glue can be a liquid glue, and the glue is liquid under normal temperature and pressure and certain storage conditions. The main component of the liquid glue can be a metal-philic modified material or a matrix material that can be added with a metal-philic modified material. In order to improve the strength of the adhesive, reinforcing materials can be added to the glue; in order to improve the durability of the adhesive, anti-aging additives can be added to the glue; in order to improve the sealability of the adhesive, high density can be increased Materials, etc. When pre-fixing the adhesive glue and assembling the semi-finished product, the metal adhesive glue 2 is pre-fixed to the semi-finished product a1, and then the semi-finished product b3 is assembled to the semi-finished product a1 to which the metal adhesive has been fixed to form a combined body 5 in the shape of the finished product. .

As shown in Figure 5-8, the metal adhesive has a sheet-like structure, which can be a single-layer sheet material, and this material can be a metal-philic modified material to ensure the bonding strength of the adhesive and the metal material. It can also contain two or more layers of materials with different properties; the bonding layer 21 where the metal bonding glue and the metal semi-finished product are bonded is a metal-philic modified material, so as to ensure the bonding of the bonding glue and the metal material Bonding strength and sealing; other functional layers 22 can be a reinforced structural layer added to ensure the strength of the adhesive, a high-melting point material layer added to improve the high-temperature resistance of the adhesive, and to reduce gas penetration One or more of the high-density material layers that increase the rate. When the adhesive glue is pre-fixed and the semi-finished product is assembled, the metal adhesive 2 is pre-fixed to the semi-finished product a1, and then the semi-finished product b3 is assembled to the already fixed metal The semi-finished product a1 of the adhesive glue is bonded to form a combined body 5 in a finished shape.

The aforementioned liquid glue can be selected from a polymer binder or an inorganic binder material depending on the application conditions and process requirements. Preferred polymer binders include epoxy resins, phenolic resins, polyamide resins, amino resins, unsaturated polyesters, alkyd resins, polyacrylic acid and its derivatives, silicones and other thermosetting resins. Such thermosetting resins can be A single component can also be a multi-component composition, which can be softened and flowed at the initial stage. After heating to a certain temperature or adding a curing agent to cure, a chemical reaction occurs and cross-linking is cured. The aforementioned polymer binder can also be a thermoplastic polymer resin, such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyoxymethylene, polycarbonate, polyamide, acrylic plastics, polyolefins and their copolymers. , Polysulfone, polyphenylene ether, chlorinated polyether and other thermoplastics; the resin molecular chains in this type of thermoplastics are all linear or branched, and there is no chemical bond between the molecular chains. It softens and flows when heated, and changes when cooled. The hard process is physical change. The aforementioned inorganic binders include silicates, phosphates, oxides, sulfates, and borates. One or more of them can be mixed according to actual conditions. At the same time, considering the brittleness of inorganic binder materials, the overall performance of the bonding layer can be improved by mixing organic and inorganic materials.

S5. Curing and bonding: Put the tooling 4 equipped with the combined body into the equipment with controllable temperature and pressure, and by controlling the temperature and pressure of the equipment, and keeping the temperature and pressure for a certain period of time, all the semi-finished products are bonded into a whole to form the liquid cooling of the finished product. Radiating plate. Among them, the equipment temperature is controlled at 50-200°C, the pressure is controlled at 0-10MPa, and the heat preservation and pressure holding time can be customized according to different products, preferably 1min～120min.

S7. Packing: Pack the qualified products.

Compared with the existing process and technology, the process of the present invention can realize the production of liquid-cooled heat sinks with a more complex structure and special functional requirements. The implementation process is simple and the reliability is higher. Compared with the traditional welding process (temperature exceeding or close to The melting point of the base material), the process of the present invention has a lower operating temperature and will not reduce the performance of the base material; in addition, the materials used in the process of the present invention do not contain materials that are corrosive to the base material, so it will not produce as traditional The presence of corrosive flux residues in brazing; the process of the present invention also improves the design process of the liquid-cooled radiating plate structure, so that the liquid-cooled radiating plate structure design flexibility is high, and the optimal liquid-cooled radiating plate flow can be designed according to specific needs The channel structure realizes the optimization of the heat dissipation effect of the liquid-cooled heat sink. For example, by installing spoiler ribs or spoiler columns on the inner wall of the liquid-cooled plate flow channel or at the same time, the turbulence degree of the flow field is increased, the Reynolds number is increased, and the convective heat transfer is increased. The coefficient ultimately enhances the cooling capacity of the liquid cooling plate, improves the heat dissipation effect of the liquid cooling plate, extends the service life of the battery pack, and ensures the safety of batteries and new energy vehicles. Moreover, the liquid-cooled heat sink can be in a flexible state, and can vary in size and/or structural characteristics within a certain allowable range of deformation. The flow channel characteristics of the liquid-cooled radiator can also be customized, through the design of three-dimensional flow channels, etc., to ensure the uniformity and velocity distribution of the liquid in the entire flow field, reduce the overall pressure drop of the flow field, and reduce the work of the drive system (pump) Consumption, improve overall efficiency.

The present invention is not limited to the above-mentioned specific embodiments. For those of ordinary skill in the art, starting from the above-mentioned concept and without creative work, all the changes made fall within the protection scope of the present invention.

Claims

A manufacturing process of a liquid-cooled heat sink is characterized in that it includes the following process steps:

S1. Material forming: processing metal raw materials into semi-finished products required to form a finished liquid-cooled heat sink through extrusion, casting, stamping, machining, bending, laser, and wire cutting processes, and the semi-finished products include at least supporting bonding The semi-finished product a of glue and the semi-finished product b used for bonding and connecting to the semi-finished product a;

S2 Cleaning: Fully or partial cleaning and cleaning of all semi-finished products;

S3. Adhesive glue pre-fixation: Pre-fix the metal adhesive glue on the semi-finished product a according to the bonding shape between the semi-finished product a and the other semi-finished products;

S4. Semi-finished product assembly: Assemble the remaining semi-finished products except for the semi-finished product a to the semi-finished product a that has been pre-fixed with the metal bonding glue, and fix all the semi-finished products to form a combined body of the finished product shape;

S5. Curing and bonding: Put the combined body into a device with controllable temperature and pressure. By controlling the temperature and pressure of the device, and keeping the temperature and pressure for a certain period of time, a finished liquid-cooled heat sink is formed;

S6. Inspection: Take the finished product out of the equipment and tooling, and conduct appearance inspection and performance inspection on the finished product;

S7. Packing: Pack the qualified products.
The manufacturing process of a liquid-cooled heat sink according to claim 1, wherein in the pre-fixing of the adhesive glue in step S3, the metal adhesive glue is an organic material glue or resin, which is die-cutting, transfer printing , The dispensing process is fixed or positioned on the semi-finished product a.
The manufacturing process of a liquid-cooled heat sink according to claim 2, characterized in that, in the pre-fixing of the adhesive glue in the step S3, the metal adhesive glue is a single-layer sheet structure adhesive glue.
The manufacturing process of a liquid-cooled heat sink according to claim 2, characterized in that, in the pre-fixing of the adhesive glue in the step S3, the metal adhesive glue is a two-layer or more than two-layer sheet structure bonding glue.
The manufacturing process of a liquid-cooled heat sink according to claim 2, wherein, in the pre-fixing of the adhesive glue in the step S3, the metal adhesive glue is a liquid glue.
The manufacturing process of a liquid-cooled heat sink according to any one of claims 3 or 4, wherein the step S3 adhesive pre-fixing is first processed according to the bonding shape between the semi-finished product a and the remaining semi-finished products The metal bonding glue that matches the shape of the fit, and then the metal bonding glue is pre-fixed on the semi-finished product a.
The manufacturing process of a liquid-cooled heat sink according to claim 1, wherein in the step S2 cleaning, the cleaning and cleaning are cleaning and cleaning using water-based solvents, organic solvents, supercritical fluids, plasma or laser processes. One or more of them.