Joining method, joint body and plate with flow channel

Abstract

The joining method of the present invention is a joining method for joining a main body made of aluminum or an aluminum alloy and having a flow path formed therein for circulating a medium that promotes heat exchange, to a cover made of aluminum or an aluminum alloy and covering the flow path in the main body, and includes a covering step of covering the main body with the cover, and a diffusion bonding step of joining the main body and the cover by diffusion bonding under conditions of a bonding temperature of 500°C or higher and 640°C or lower and a bonding surface pressure of 0.7 MPa or higher.

Description

[Technical field]

[0001] The present invention relates to a bonding method for bonding members together by diffusion bonding, and a bonded body. [Background technology]

[0002] Components used in semiconductor manufacturing equipment include electrodes, cooling plates, heaters, shower heads, and the like, which have plates with flow channels. The plates with flow channels are made of metal or ceramic composites, and the main body, in which flow channels are formed for the movement of heating or cooling media or process gases, is covered with a cover (see, for example, Patent Document 1). In Patent Document 1, the cover and the main body are overlapped, and then the main body and the cover are joined by brazing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2009-535801 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the joining method of Patent Document 1, there are concerns that the brazing filler metal may flow into the flow path during brazing, causing roughness of the surface of the flow path, variations in the flow rate in the area where the brazing filler metal is stagnant, temperature changes due to the variations in the flow rate, and contamination with impurities due to the components of the brazing filler metal, resulting in a deterioration in quality.

[0005] The present invention has been made in consideration of the above, and aims to provide a joining method and a joined body that can reliably join a main body and a cover while suppressing quality degradation due to the joining. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the joining method of the present invention is a joining method for joining a main body made of aluminum or an aluminum alloy, in which a flow path is formed for circulating a medium that promotes heat exchange, and a cover made of aluminum or an aluminum alloy, which covers the flow path of the main body, characterized in that it includes a covering step of covering the main body with the cover, and a diffusion bonding step of bonding the main body and the cover by diffusion bonding under conditions of a bonding temperature of 500°C or higher and 640°C or lower and a bonding surface pressure of 0.7 MPa or higher.

[0007] In addition, in the joining method according to the present invention, the flatness of the joining surface of the main body and the flatness of the joining surface of the cover are each 0.2 or less.

[0008] In addition, in the joining method according to the present invention, the surface roughness of the joining surface of the main body and the joining surface of the cover are each greater than 0 and equal to or less than Ra0.4.

[0009] The joined body according to the present invention is characterized in that it comprises a main body made of aluminum or an aluminum alloy, in which a flow path is formed for circulating a medium that promotes heat exchange, and a cover made of aluminum or an aluminum alloy, which covers the flow path in the main body, and that the main body and the cover are diffusion bonded together.

[0010] In addition, the joined body according to the present invention is characterized in that, in the above-mentioned invention, the main body and the cover are made of aluminum alloy No. 6061 and have a tensile strength of 125 MPa or more. Effect of the Invention

[0011] According to the present invention, it is possible to reliably join the main body and the cover while suppressing deterioration in quality due to the joining. [Brief description of the drawings]

[0012] [Figure 1]FIG. 1 is a partial cross-sectional view showing the structure of a channel-equipped plate according to one embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a region R shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view illustrating a method for manufacturing a plate with a channel according to an embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view illustrating a method for manufacturing a plate with a channel according to an embodiment of the present invention. [Diagram 5] FIG. 5 is a diagram illustrating the configuration of a test piece used in an example of the present invention. [Figure 6A] FIG. 6A is a diagram showing an SEM image of the interface after bonding in an example of the present invention. [Figure 6B] FIG. 6B is a diagram showing an SEM image of the interface after bonding in an example of the present invention. [Figure 6C] FIG. 6C is a diagram showing an SEM image of the interface after bonding in an example of the present invention. [Figure 7A] FIG. 7A is a diagram showing an EDX observation image of the interface after bonding in an example of the present invention. [Figure 7B] FIG. 7B is a diagram showing an EDX observation image of the interface after bonding in the example of the present invention. [Figure 7C] FIG. 7C is a diagram showing an EDX observation image of the interface after bonding in an example of the present invention. [Figure 7D] FIG. 7D is a diagram showing an EDX observation image of the interface after bonding in an example of the present invention. [Figure 8] FIG. 8 shows the results of a tensile test of a test piece diffusion-bonded with a bonding surface pressure of 0.7 MPa. [Figure 9] FIG. 9 shows the results of a tensile test of a test piece diffusion-bonded with a bonding surface pressure of 0.7 MPa. [Figure 10] FIG. 10 shows the results of a tensile test of a test piece diffusion-bonded at a bonding surface pressure of 0.5 MPa. [Figure 11] FIG. 11 shows the results of a tensile test of a test piece diffusion-bonded at a bonding surface pressure of 0.5 MPa. [Figure 12] FIG. 12 is a diagram showing the results of an ultrasonic flaw detection test of the channel plate according to the example. [Figure 13] FIG. 13 is a diagram for explaining particle measurement. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiments. Also, each drawing referred to in the following description merely shows the shape, size, and positional relationship in a schematic manner to the extent that the contents of the present invention can be understood. In other words, the present invention is not limited to only the shape, size, and positional relationship exemplified in each drawing.

[0014] FIG. 1 is a partial cross-sectional view showing the structure of a plate with flow channels according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an enlarged region R shown in FIG. 1. The plate with flow channels 1 shown in FIG. 1 includes a disk-shaped main body 10 and a cover 20 covering one surface (here, the upper surface) of the main body 10. The plate with flow channels 1 is a bonded body in which the main body 10 and the cover 20 are bonded by diffusion bonding. The plate with flow channels 1 is attached to, for example, a semiconductor device and functions as a cooling device for the semiconductor device. In addition, the plate with flow channels 1 may be used as a heater for heating the device to which it is attached, as a heater plate for circulating gas through the flow channels described later, or as a shower head for spraying process gas in a thin film forming device.

[0015] The main body 10 is in the shape of a disk and made of aluminum or an aluminum alloy. The main body 10 has flow paths (for example, flow paths 11-13 shown in FIG. 1) formed therein, which allow a medium to flow to promote heat exchange. The main body 10 has an open surface of the flow path joined to the cover 20 by diffusion bonding. The flow paths 11-13 are separated by a wall 14 or a wall 15. The flow paths 11-13 may be connected to each other to form a single flow path, or at least some of the flow paths may form independent flow paths. The medium is, for example, a liquid such as water, or a gas.

[0016] The cover 20 is a disk-shaped member made of aluminum or an aluminum alloy and covers the surface of the main body 10 on which the flow passage is formed. An example of the aluminum alloy is aluminum alloy No. 6061 (A6061). The main body 10 and the cover 20 are joined by diffusion bonding, which will be described later.

[0017] In the plate 1 with flow channels, a medium is introduced from a medium inlet (not shown) and circulated through the flow channels, and the medium is discharged from a medium outlet (not shown). In the plate 1 with flow channels, heat transferred from a heat source is released to the outside via the main body 10 and the cover 20, or the medium that has absorbed the heat transferred from the heat source is discharged from the flow channels.

[0018] Next, a method for producing the plate with a flow channel 1 will be described. Figures 3 and 4 are cross-sectional views illustrating a method for producing a plate with a flow channel according to one embodiment of the present invention.

[0019] First, the main body 10 in which the above-mentioned flow paths (e.g., flow paths 11 to 13) are formed, and the cover 20 are prepared (see FIG. 3). Then, the cover 20 is placed on the main body 10 (covering step). At this time, the openings of the flow paths in the main body 10 are covered by the cover 20. The plate 1 with flow paths has a disk shape of, for example, φ150 mm or more.

[0020] Next, the main body 10 and the cover base material 200 are bonded by diffusion bonding (see FIG. 4: diffusion bonding step). In diffusion bonding, pressure is applied to the members that are in close contact with each other at a temperature condition below the melting point of the members, and the members are bonded by utilizing the diffusion of atoms that occurs between the bonding surfaces. At this time, a load is applied to the members that causes as little plastic deformation as possible.

[0021] The conditions for diffusion bonding of members made of aluminum or an aluminum alloy are a bonding temperature of 500° C. or higher and 640° C. or lower, and a bonding surface pressure of 0.7 MPa or higher. The joining temperature varies depending on the type of aluminum alloy, but is set to a temperature lower than the melting point of the members, for example. The joining surface pressure varies depending on the type of members, but is preferably 3 MPa or less. As for the precision of the joining surfaces of the respective members, the flatness is preferably 0.2 or less, and the surface roughness of the joining surfaces is preferably greater than 0 and less than Ra0.4, and more preferably less than Ra0.1.

[0022] In the above-described embodiment, the main body 10 and the cover 20 are joined by diffusion bonding. By using diffusion bonding, the main body and the cover can be reliably joined while suppressing deterioration in quality due to the joining. In the present embodiment, deterioration in quality caused by the brazing filler metal flowing into the flow path during brazing, roughening of the surface of the flow path, variations in the flow rate in the portion where the brazing filler metal is retained, temperature changes due to the variations in the flow rate, and impurity contamination due to the brazing material components, as in the conventional case, can be suppressed, and the components can be reliably joined.

[0023] In this manner, the present invention may include various embodiments not described here, and various design modifications may be made without departing from the technical idea specified by the scope of the claims. EXAMPLES

[0024] Hereinafter, examples of the bonding method and bonded body according to the present invention will be described, although the present invention is not limited to these examples.

[0025] (Evaluation of the bonded surface of the test piece) The test piece used for the test as a joint was one in which two members of the same shape were joined. FIG. 5 is a diagram for explaining the configuration of the test piece used in the examples of the present invention. The test piece used was one in which members 300 were diffusion-joined. Members 300 were made of 6061 aluminum alloy (A6061). Members 300 had a substantially cylindrical joint 301 having a joint surface, and a gripping portion 302 that was connected to the side opposite to the joint surface of joint 301 and was gripped during testing. Grip portion 302 had a screw thread formed on the side.

[0026] In this example, six test pieces were produced by diffusion bonding at a bonding temperature of 550°C and a bonding surface pressure of 0.7 MPa, and six test pieces were produced by bonding at a bonding surface pressure of 0.5 MPa using the above-mentioned member 300. Figures 6A to 6C are diagrams showing SEM images of the interface after bonding in an example of the present invention. Figure 6B is an enlarged view of the center of Figure 6A. Figure 6C is an enlarged view of the center of Figure 6B. As shown in Figures 6A to 6C, it can be seen that bonding is performed without defects at the bonding interface.

[0027] 7A to 7D are diagrams showing EDX observation images of the interface after bonding in an example of the present invention. FIG. 7A shows a reflection image at the interface after bonding. FIG. 7B shows an image of aluminum (Al) distribution at the interface after bonding. FIG. 7C shows an image of magnesium (Mg) distribution at the interface after bonding. FIG. 7D shows an image of silicon (Si) distribution at the interface after bonding. In FIG. 7B to 7D, the lighter the color, the more of that component is contained.

[0028] As shown in FIG. 7B, it can be seen that aluminum, which is the main component of member 300, is widely distributed. 7C and 7D, it can be seen that magnesium and silicon are precipitated at the bonding interface. Here, magnesium and silicon reduce the aluminum oxide film to become oxide. This reaction changes the amorphous oxide film at the bonding interface into crystalline oxide particles, which is thought to contribute to the bonding of the members 300.

[0029] (Tensile test of test piece) Further, tensile tests were carried out on these test pieces. The test pieces bonded at a bonding pressure of 0.7 MPa were numbered No. 1 to No. 6, and the test pieces bonded at a bonding pressure of 0.5 MPa were numbered No. 11 to No. 16. The tensile test results are shown in Figs. 8 to 11.

[0030] 8 is a diagram showing the results of a tensile test on test pieces that were diffusion bonded with a bonding surface pressure of 0.7 MPa. All of test pieces No. 1 to No. 6 have a tensile strength exceeding 125 MPa. Here, the tensile strength of 6061 aluminum alloy (A6061) is 125 MPa. From this, it can be said that all of test pieces No. 1 to No. 6 have a tensile strength greater than the tensile strength of 6061 aluminum alloy (A6061), which is the main component of member 300.

[0031] 9 is a diagram showing the results of a tensile test of test pieces diffusion-bonded at a bonding surface pressure of 0.7 MPa. It can be seen that in all of test pieces No. 1 to No. 6, fracture occurred not at the bonding interface but in one of the members.

[0032] 10 is a diagram showing the results of a tensile test of test pieces diffusion-bonded at a bonding surface pressure of 0.5 MPa. Among test pieces No. 11 to No. 16, the tensile strength of test piece No. 13 is below 125 MPa. This indicates that test pieces No. 11 to No. 16 may have tensile strengths that are lower in some parts than the tensile strength of aluminum alloy No. 6061 (A6061), which is the main component of member 300.

[0033] 11 is a diagram showing the results of a tensile test of test pieces diffusion-bonded at a bonding surface pressure of 0.5 MPa. It can be seen that some of test pieces No. 11 to No. 16 (test pieces No. 13 and No. 16) had fractures at the bonding interface.

[0034] (Ultrasonic flaw detection test for plates with flow channels) Fig. 12 shows the results of an ultrasonic inspection test of the plate with a channel according to the embodiment. Fig. 12 shows the plate with a channel bonded with a bonding surface pressure of 0.7 MPa. As can be seen from Fig. 12, there are no defects such as damage in the channel formed in the circular plate member.

[0035] (Particle measurement on a plate with a channel) Further, the above-mentioned plate 1 with a flow channel was produced, and a particle measurement was performed using this plate 1 with a flow channel as a test piece. As a comparison object, a test piece joined by brazing was produced, and a particle measurement was performed. FIG. 13 is a diagram for explaining the particle measurement. In this example, each test piece (test piece 100) was attached to a jig 101, and particles collected through the jig 101 were measured by a measuring device 102. The particle measurement was performed three times for each test piece. Since the amount of particles was large at the beginning, in the first measurement, nitrogen was flowed into the flow path for several minutes several times to stabilize the particles before measuring the particles. In the particle measurement, isopropyl alcohol (IPA) was first introduced into the flow path and blown with nitrogen for 45 seconds. Nitrogen was then introduced for one minute, and the number of particles (cumulative number) according to the particle size was counted. In this example, the number of particles with a particle size of 0.3 μm or less and the number of particles with a particle size of more than 0.3 μm and 0.5 μm or less were counted.

[0036] The results of particle measurement using test pieces bonded by diffusion bonding were as follows: Particle Size 0.5μm or less 0.3μm or less 1st time 88 15 2nd time 39 13 3rd time 15 2 In contrast, the results of particle measurement on test pieces joined by brazing were as follows: Particle Size 0.3μm or less 0.5μm or less 1st time 483 168 2nd time 238 84 3rd time 189 87 In addition, when particles were measured using only the jig, the count number was zero for all sizes. From the above-mentioned measurement results, it can be said that the flow channels of the flow channel plates joined by diffusion bonding have fewer particles than the flow channels of the flow channel plates joined by brazing. [Industrial Applicability]

[0037] As described above, the joining method and joined body according to the present invention are suitable for reliably joining a main body and a cover while suppressing deterioration in quality due to the joining. [Explanation of symbols]

[0038] 1 Plate with channel 10 Main body 11~13 Flow path 14, 15 Wall section 20 Cover

Claims

1. A method for joining a main body made of aluminum or an aluminum alloy and having a flow path for circulating a medium, to a cover made of aluminum or an aluminum alloy and covering the flow path of the main body, comprising: The flatness of the joint surfaces of the main body and the cover is 0.2 or less, a covering step of covering the main body with the cover; a diffusion bonding step of bonding the main body and the cover by diffusion bonding under conditions of a bonding temperature of 500° C. or more and 640° C. or less and a bonding surface pressure of 0.7 MPa or more and 3 MPa or less; A bonding method comprising the steps of:

2. The surface roughness of the joint surface of the main body and the joint surface of the cover are each greater than 0 and equal to or less than Ra 0.

4. The bonding method according to claim 1 .

3. A main body portion made of aluminum or an aluminum alloy and having a flow path through which a medium flows; a cover made of aluminum or an aluminum alloy and covering the flow path of the main body; Equipped with The flatness of the joint surfaces of the main body and the cover is 0.2 or less, The body and the cover are diffusion bonded together. A conjugate characterized in that

4. The body and the cover are made of 6061 aluminum alloy, Tensile strength is 125 MPa or more 4. The bonded body according to claim 3.

5. A main body portion made of aluminum or an aluminum alloy, the main body portion having a flow path for circulating a medium; a cover made of aluminum or an aluminum alloy and covering the flow path of the main body; Equipped with The flatness of the joint surfaces of the main body and the cover is 0.2 or less, The body and the cover are diffusion bonded together. A plate with a channel.

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