Manufacturing method of the joint

Abstract

To provide a method for manufacturing bonded parts that can shorten cycle times and increase production efficiency. [Solution] A method for manufacturing a bonded body in which a substrate containing metal or ceramics and a molded body containing a thermoplastic resin are directly joined, comprising: a rough surface forming step of forming a rough surface structure on the substrate joining surface; a preheating step of heating the substrate joining surface and the molded body joining surface; and a joining step of pressing the two heated joining surfaces together in contact with each other to join them, wherein in the preheating step, the two joining surfaces are heated in a non-contact state with each other, the molded body joining surface is heated by non-contact heating from the surface side, the substrate joining surface is heated in a range of -80°C or higher and +100°C or lower than the melting point of the thermoplastic resin, the molded body joining surface is heated in a range of above the melting point of the resin and +100°C or lower than the melting point of the resin, and in the joining step, the substrate and the molded body are joined without heating.

Description

Technical Field

[0001] The present invention relates to a method for producing a joined body in which a base material containing a metal or ceramic and a molded body containing a thermoplastic resin are directly joined.

Background Art

[0002] A method for producing a joined body by directly joining a base material containing a metal or ceramic and a molded body containing a thermoplastic resin is known. When joining the base material and the molded body, a method (thermal welding) is performed in which, with the base material and the molded body in contact with each other, a heated hot plate is brought into contact with the base material to join the base material and the molded body while heating the base material with the hot plate. In this case, the thermoplastic resin contained in the molded body is melted by the heat applied from the base material to the molded body, and the base material is joined by the melted thermoplastic resin. In this method, it is necessary to increase the heating temperature on the base material side in order to melt the thermoplastic resin. For this reason, it becomes necessary to extend the cooling time until the temperature of the base material after joining decreases, leading to a longer cycle time for manufacturing the joined body. Accordingly, when joining the base material and the molded body, a method is implemented in which preheating is performed to heat both the base material and the molded body before joining, and the base material and the molded body are joined while being heated after the preheating.

[0003] Patent Document 1 describes a method for manufacturing a metal-resin joined body, which includes a first step of exposing the surface of a synthetic resin member to a gas heated to a first temperature that is equal to or higher than the deflection temperature under load of the thermoplastic resin, and a second step of joining the surface of the synthetic resin member and the surface of a metal member. In Patent Document 1, the metal member is heated in a state where the metal member and the synthetic resin member are arranged to face each other with a gap therebetween in a gas, so that the heat of the metal member heats the gas present between the metal member and the synthetic resin member to the first temperature. In Patent Document 1, while heating the surface of the synthetic resin member and the surface of the metal member at a second temperature lower than the first temperature, one of the metal member and the synthetic resin member is pressed against the other to join the metal member and the synthetic resin member.

Prior Art Documents

[0004] [Patent Document 1] International Publication No. 2020 / 184440 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] According to the method described in Patent Document 1, preheating the molded body allows for a lower heating temperature of the base material compared to heat welding. However, in order to improve production efficiency when joining the base material and the molded body, there is a need to further shorten the cycle time.

[0006] This invention has been made in view of the above prior art, and aims to provide a method for manufacturing a bonded body that can shorten the cycle time and has high production efficiency. [Means for solving the problem]

[0007] The inventors of this invention have diligently studied methods for manufacturing such a joint and have found that it can be achieved by heating the joint surface of the molded body from the surface side by non-contact heating in the preheating step, and by heating the joint surface of the base material and the joint surface of the molded body within a predetermined temperature range, and then joining the base material and the joint without heating (without applying heat). This led to the completion of the present invention.

[0008] In other words, the gist of the present invention is as follows: (1) A method for manufacturing a joint in which a substrate containing a metal or ceramic and a molded body containing a thermoplastic resin are directly joined together, The substrate has a substrate bonding surface that is joined to the molded body, The molded body has a molded body joining surface that is joined to the substrate, A surface roughening step to form a rough surface structure on the substrate bonding surface, A preheating step for heating the substrate bonding surface and the molded body bonding surface, The invention comprises a joining step of joining the substrate and the molded body by placing the heated substrate joining surface and the molded body joining surface facing each other, and applying pressure while the substrate joining surface and the molded body joining surface are in contact, In the preheating step, the substrate bonding surface and the molded body bonding surface are heated in a non-contact state with each other. In the preheating step, the molded body joining surface is heated by non-contact heating from the surface side. In the preheating step, the substrate bonding surface is heated to a range of -80°C or higher and +100°C or lower, which is the melting point of the thermoplastic resin, and the molded body bonding surface is heated to a range of -100°C or higher and +100°C or lower, In the joining process, the substrate and the molded body are joined without heating. A method for manufacturing a jointed body, characterized by the above. (2) The method for manufacturing a bonded body according to (1), wherein in the preheating step, the heating temperature of the molded body bonding surface is higher than the heating temperature of the substrate bonding surface. (3) The method for manufacturing a bonded body according to (2), wherein in the preheating step, the heating temperature of the bonded surface of the substrate is in the range of -70°C or higher and below the melting point of the resin, and the heating temperature of the bonded surface of the molded body is in the range of -70°C or higher and above the melting point of the resin +30°C or lower. (4) The method for manufacturing a bonded body according to (1), wherein in the preheating step, the base material and the molded body are heated with the base material bonding surface and the molded body bonding surface facing each other. (5) The method for manufacturing a joined body according to (1), wherein the joining step is performed within 30 seconds after the preheating step. (6) The method for manufacturing a bonded body according to (1), wherein in the preheating step, the heating method for heating the molded body is at least one selected from the group consisting of radiant heating, convection heating, high-frequency dielectric heating, microwave heating, and laser heating. (7) The method for producing a joined body according to (1), wherein in the preheating step, a heating method for heating the base material is at least one selected from the group consisting of conduction heating, radiation heating, convection heating, high-frequency dielectric heating, microwave heating, induction heating, and laser heating. (8) The method for producing a joined body according to (1), wherein the molded body contains a filler.

Effects of the Invention

[0009] According to the method for producing a joined body of the present invention, the cycle time can be shortened, and the production efficiency can be increased.

Brief Description of the Drawings

[0010] [Figure 1] Figure 1 is a flowchart for explaining an example of the method for producing a joined body. [Figure 2] Figure 2 is a schematic cross-sectional view for explaining an example of the joined body. [Figure 3] Figure 3 is a schematic diagram for explaining an example of the preheating step. [Figure 4] Figure 4 is a schematic diagram for explaining an example of the joining step. [Figure 5] Figure 5 is a design drawing for explaining the aluminum base material used in Examples and Comparative Examples, where (a) shows a plan view and (b) shows a side view. [Figure 6] Figure 6 is a design drawing for explaining the polyphenylene sulfide (PPS) molded body used in Examples and Comparative Examples, where (a) shows a top perspective view and (b) shows a bottom perspective view.

Modes for Carrying Out the Invention

[0011] The method for producing a joined body of the present invention will be described in detail. The constituent elements of the present invention described below may be appropriately combined partially or entirely. The dimensional ratios in the drawings may differ from the actual ratios.

[0012] [1. Method for producing joined body] As shown in Figure 1, the method for producing a joined body of the present invention includes: a roughening step S1 of forming a roughened structure on the joining surface of a base material 2 to a molded body 3 (base material joining surface); a preheating step S2 of heating the base material joining surface on which the roughened structure is formed and the molded body joining surface (the joining surface of the molded body 3 to the base material 2); and a joining step S3 of bringing the heated base material joining surface and the molded body joining surface into opposition, applying pressure in a state where the base material joining surface and the molded body joining surface are in contact, and joining the base material and the molded body together. In the joining step S3, the base material and the molded body are joined without additional heating. A schematic cross-sectional view of a joined body 1 in which the base material 2 and the molded body 3 are directly joined is shown in Figure 2. Here, "direct joining" means joining in which no other layer such as an adhesive-containing layer is interposed between the base material 2 and the molded body 3. In the subsequent descriptions of the present specification, reference signs may be omitted for explanation. Hereinafter, the base material, the molded body, the joined body, the roughening step, the preheating step, and the joining step will be described in order.

[0013] [1-1. Base material] The base material contains a metal or a ceramic. There is no particular limitation as long as it is a base material containing a metal or a ceramic, and a metal base material made of a metal or a ceramic base material made of a ceramic is preferable. The type of the metal or ceramic is not limited, and can be determined based on the use of the joined body formed using the same, and various properties and physical properties such as strength, corrosion resistance, and workability required for the use. Further, as the base material, a processed material obtained by appropriately processing into a desired shape, or a combined material obtained by appropriately combining these processed materials and the like can be used. Although it also depends on the intended use, a material having a thickness (height from the joining surface) of usually about 0.3 mm to 100 mm is used.

[0014] The metals constituting the metal substrate are not limited as long as they are used and heated by the heating method described later. For example, aluminum, titanium, iron, copper, nickel, chromium, etc. can be used. The metal substrate may also be composed of an alloy of two or more metals, such as an aluminum alloy, stainless steel, titanium alloy, iron alloy (steel material), copper alloy, nickel alloy, or chromium alloy.

[0015] Furthermore, the ceramics constituting the ceramic substrate are not limited, but for example, nitride-based ceramics, oxide-based ceramics, carbide-based ceramics, etc., can be used. Specifically, examples include aluminum nitride, silicon nitride, titanium nitride, boron nitride, SiAlON, titanium carbonitride, aluminum oxide, titanium oxide, boron oxide, silicon carbide, etc., and may contain one or more of these.

[0016] [1-2. Molded product] The molded article is formed from a resin composition containing a thermoplastic resin. While not limited, it is preferable that the resin constituting the molded article be a thermoplastic resin. The thermoplastic resin included in the molded article can be appropriately selected from known thermoplastic resins depending on the application. Examples include polyamide resins (aliphatic polyamides such as PA6 and PA66, aromatic polyamides), copolymers containing styrene units such as polystyrene, ABS resin, and AS resin, copolymers containing polyethylene and ethylene units, copolymers containing polypropylene and propylene units, other polyolefins, polyvinyl chloride, polyvinylidene chloride, polycarbonate resins, acrylic resins, methacrylic resins, polyester resins, polyacetal resins, and polyphenylene sulfide resins. One or more of these thermoplastic resins can be used. Among these, polyamide resins and polyphenylene sulfide (PPS) resins are preferred because they have high fluidity during resin molding and easily penetrate the rough surface structure formed on the substrate, as described later.

[0017] Here, the molded body joining surface is the region of the molded body where the base material and the molded body are to be joined. It may be just a part of one surface of the molded body, the entire surface, or parts or all of both surfaces. Depending on the application, the joining surface should be formed in the necessary parts. Furthermore, there are no limitations on the shape, size, or arrangement of the joining surface.

[0018] Furthermore, the molded body may contain fillers. That is, the thermoplastic resin (thermoplastic resin composition) before molding the molded body may contain fillers. By including fillers in the thermoplastic resin and its molded body, the physical properties of the molded body, such as its mechanical strength, can be improved. The fillers are not limited and can be any known type. For example, fillers can be in the form of elongated fibrous or needle-like structures; particulate; or flake-like structures. Examples include glass fibers, carbon fibers, and natural fiber fillers. Preferably, the filler is a fibrous filler made of glass fibers (glass fiber). In the preheating step described later, the molded body may be heated, and a desired filler may be included to generate heat according to the heating method.

[0019] As in the method of the present invention, performing a preheating step described later, in which the substrate bonding surface and the molded body bonding surface are each heated within a predetermined temperature range, is particularly preferable when the molded body contains filler. That is, in the bonding step after the preheating step, when the substrate and the molded body are brought into contact and pressurized, the melting of the thermoplastic resin proceeds from the surface of the molded body bonding surface in the depth direction. In a configuration in which the molded body contains filler, if the molded body is brought into contact with a heated substrate without preheating the molded body bonding surface, and the molded body is heated while bonding, the resin on the surface portion in contact with the substrate melts first, and then the filler moves later, resulting in the filler being concentrated on the molded body bonding surface. At this time, in the part where the filler is concentrated, the strength of the resin on the molded body bonding surface decreases, and the strength of the joint between the substrate and the molded body decreases. In contrast, according to the method of the present invention, the molded body bonding surface can be heated to a certain extent in the depth direction in advance by performing preheating. When the bonding surface of the substrate and the bonding surface of the molded body are brought into contact and pressurized in this state during the bonding process, the resin and filler move simultaneously at the bonding surface of the molded body. This reduces the concentration of the filler at the bonding surface of the molded body, thereby suppressing the decrease in strength at the joint between the substrate and the molded body.

[0020] [1-3.Zygote] The bonded body is formed with the thermoplastic resin embedded in the rough surface structure of the bonding surface on the substrate surface, and the substrate and the molded body are integrally bonded via the bonding surface. The bonded body may be formed using one substrate and one molded body each, or multiple sets of either or both may be used, or even multiple sets of either set or both may be arbitrarily laminated, and the configuration can be appropriately determined according to the application.

[0021] For example, the joined body may be formed by joining a base material and a molded body in a stacked or continuous arrangement. Alternatively, the joined body may be formed by joining a base material, a molded body, and another base material in a stacked or continuous arrangement in that order. Alternatively, the joined body may be formed by joining a molded body, a base material, and another molded body in a stacked or continuous arrangement in that order.

[0022] When the joint joins two or more substrates via a molded body, it may include a molded body formed from a thermoplastic resin sandwiched between the substrates. Alternatively, the substrates may be joined via the adhesive, using an adhesive containing a thermoplastic resin as the molded body.

[0023] [1-4. Surface Roughening Process] In the surface roughening process, a rough surface structure is formed on the substrate bonding surface, which is the bonding surface between the substrate and the molded body. Here, the substrate bonding surface is the area of ​​the substrate where the bonding between the substrate and the molded body is planned, and it may be just a part of one surface of the substrate, the entire surface, or parts or all of both surfaces, etc. Depending on the application, the bonding surface can be formed only in the necessary parts. Furthermore, there are no limitations on the shape, size, arrangement, etc. of the bonding surface. The same applies when the substrate is a composite material, etc.

[0024] Furthermore, a rough surface structure refers to a surface structure in which the surface of the substrate has multiple irregularities, making it rougher than a smooth surface. By forming a rough surface structure with multiple irregularities on the surface of the substrate, when joining it to a molded body, the molten thermoplastic resin contained in the molded body fills into the rough surface structure, resulting in an anchoring effect. This makes it easier to improve the quality of the joint, such as the joint strength and airtightness of the joined body.

[0025] The process for forming the rough surface structure is not limited, and known methods such as irradiation with a continuous-wave laser, irradiation with a pulsed-wave laser, etching, blasting, and cutting can be used. Here, as an example of a method for forming a rough surface structure and the degree of that rough surface structure, for example, the laser irradiation treatment and laser treatment conditions described in Japanese Patent Application Publication No. 2023-59622, as well as the aperture diameter (D), depth (L), and aspect ratio (L / D) of the macro-relief portion formed thereby, can be used as reference for a method for forming a rough surface structure on a metal substrate. Furthermore, known methods such as irradiation with a continuous-wave laser, irradiation with a pulsed-wave laser, blasting, and cutting can be used to form a rough surface structure on a ceramic substrate.

[0026] [1-5. Preheating Process] In the preheating step, the substrate bonding surface, which has a rough surface structure formed on its surface, and the molded body bonding surface are heated within a predetermined temperature range, prior to the bonding step described later, while the substrate and the molded body are in a non-contact state with each other. The non-contact state between the substrate and the molded body means that they are separated and physically apart without contact. In the preheating step, the substrate and the molded body are heated in this state. Furthermore, in this invention, the molded body bonding surface is heated by non-contact heating from the surface side.

[0027] An example of the preheating process is shown in Figure 3. Specifically, as shown in Figure 3, the molded body 20 is restrained using a restraining jig 60 and set in a predetermined position, while the molded body heating jig 30 is heated without contact with the molded body joining surface 21. Note that in Figure 3, the specific restraining means for restraining the molded body 20 with the restraining jig 60 are omitted from the illustration. This restraining mechanism can be realized, for example, by a clamping mechanism that fixes the molded body 20. The restraining jig 60 may have a base that makes it movable. Meanwhile, while setting the base material 10 in a predetermined position, the base material heating jig 40 is heated on the base material joining surface 11 by contact heating and / or non-contact heating. Figure 3 shows the state in which the base material joining surface 11 is heated by contact heating. At this time, a base material installation jig 50 for installing the base material 10 can be provided on the surface 12 of the base material 10 opposite to the base material joining surface 11. In the preheating process, the base material 10 may be heated from the side 12 opposite to the base material joining surface 11 using the base material mounting jig 50. The base material mounting jig 50 can also be used to restrain the base material 10, to keep the base material 10 warm, or to apply pressure during joining. The base material mounting jig 50 may have a base or the like to make it movable. Furthermore, as long as the type, performance, shape, size, etc. of jigs such as the molded body heating jig 30, the base material heating jig 40, the base material installation jig 50, and the restraining jig 60 are not impaired, they may be selected and used as appropriate.

[0028] <Heating the joint surface of the molded body> Heating of the molded joint surface is performed by non-contact heating. While there are no limitations as long as the heating temperature of the molded joint surface described later can be achieved, non-contact heating may be either direct heating or indirect heating. Examples of direct heating include high-frequency dielectric heating, microwave heating, resistance heating, induction heating, etc. Examples of indirect heating include radiant heating (radiation heating) which heats by irradiating with infrared rays emitted from an infrared heater or heated hot plate, convection heating which heats a medium such as air between the substrate and the molded body and heats the substrate joint surface through that medium, high-frequency dielectric heating using a high-frequency electric field, microwave heating by irradiating with microwaves, and laser heating by irradiating with laser light.

[0029] By employing non-contact heating, the risk of molten thermoplastic resin adhering to and contaminating the heating jig can be reduced. Furthermore, non-contact heating makes it easier to mask a portion of the joining surface from heat, thus facilitating partial heating of the joining surface. Moreover, by applying non-contact heating to the joining surface of the molded body, it is possible to melt the thermoplastic resin near the joining surface that contributes to bonding with the substrate, compared to heating the entire molded body. In this case, heating of thermoplastic resin other than the joining surface of the molded body can be suppressed, thereby suppressing deformation of the molded body during bonding. Therefore, given that applying non-contact heating to the joining surface of the molded body is relatively easy, it is preferable to select at least one from the group consisting of radiant heating, convection heating, and laser heating.

[0030] The heating temperature of the molded joint surface shall be within the range of the resin melting point temperature (the melting point temperature of the thermoplastic resin contained in the molded body) and the resin melting point temperature plus 100°C (+100°C). In other words, the heating temperature of the molded joint surface shall be within the range of the resin melting point temperature or higher.

[0031] The heating temperature of the molded body joining surface is preferably the resin melting point temperature + 5°C or higher, more preferably the resin melting point temperature + 10°C or higher, and even more preferably the resin melting point temperature + 20°C or higher. By setting the heating temperature of the molded body joining surface to be above the lower limit of the above, when the substrate and the molded body are joined in the joining process, the heat from the substrate melts, and the molten resin (thermoplastic resin contained in the molded body) can be filled into the rough surface structure of the substrate. Furthermore, since it becomes unnecessary to excessively heat the substrate joining surface as described later, the heating temperature on the lower limit side of the substrate joining surface can be suppressed, shortening the cooling time of the substrate after joining and making it easier to reduce the cycle time of manufacturing the joined body. On the other hand, the heating temperature of the molded body joining surface is preferably the resin melting point temperature + 80°C or lower, more preferably the resin melting point temperature + 60°C or lower, even more preferably the resin melting point temperature + 40°C or lower, and even more preferably the resin melting point temperature + 30°C or lower. By setting the heating temperature of the molded body joining surface to be below the upper limit of the above, it is possible to avoid the molded body becoming excessively hot, and it is possible to avoid deformation of parts of the molded body other than the joining part. Furthermore, there are the following advantages. Specifically, when heating from the joint surface side of the molded body, the melting area (fusible surface) increases in the depth direction from the surface. If the heating temperature of the joint surface of the molded body is too high, melting beyond the desired welding allowance will occur when joining the base material and the molded body. Here, there is little problem if the joint surface of the base material and the joint surface of the molded body are in surface contact. However, for example, if the joint surface of the base material is almost flat, but the molded body has a recess and the joint surface is frame-shaped surrounding the recess, and the goal is to join these base material joint surfaces and molded body joint surfaces to form a container or the like with a cavity inside, then if the melting of the joint surface of the molded body becomes large, dimensional differences will become a problem. In this case, one can consider reducing the pressure load on the base material joint surface in order to reduce the melting of the joint surface of the molded body, but if the load is insufficient, voids may form in the joint and leakage may occur. From this viewpoint as well, the heating temperature of the joint surface of the molded body should be kept below the aforementioned upper limit.

[0032] In this invention, the resin melting point temperature is measured as follows: The temperature of the peak top of the endothermic peak observed when measuring the thermoplastic resin contained in the molded article using differential scanning calorimetry (DSC) with a heating condition of 5°C / min is used. Furthermore, if multiple endothermic peaks are observed in the DSC measurement, the heat of fusion is first calculated from each endothermic peak, and the ratio of the resin components is calculated from the ratio of these heats of fusion. Next, the intermediate melting point of the multiple components is calculated from the ratio. By using the resin melting point temperature obtained in this way, it becomes possible to use it not only as a reference for determining the heating temperature of the molded article bonding surface as described above, but also in cases where, for example, the details of the resin are unknown, multiple resins are mixed, or components other than resin (e.g., fillers) are mixed. Furthermore, by using an intermediate melting point among multiple components, when a molded body heated above the resin melting point temperature in the preheating process is brought into contact with the substrate in the joining process, at least one of the multiple components that is in a molten state can be filled into the rough surface structure, making joining easier.

[0033] Furthermore, there is no limit to the time required to heat the joint surface of the molded body (non-contact heating time), but it is generally preferable to be 1 minute or less, more preferably 40 seconds or less, even more preferably 30 seconds or less, even more preferably 20 seconds or less, and particularly preferably 10 seconds or less. If the heating time is within this range, it becomes easier to reduce the cycle time of joint manufacturing. The heating time refers to the time of non-contact heating, excluding operations before and after heating (heating operations, movement time of equipment, workpieces, jigs, etc.).

[0034] The heating temperature of the molded joint surface refers to the surface temperature of the heated molded joint surface. There are no restrictions on the method of measuring the heating temperature of the molded joint surface, and known methods can be used, but from the viewpoint of accurately and instantaneously detecting the temperature, thermocouples or radiation thermometers can be used.

[0035] <Heating the bonding surface of the substrate> Heating of the substrate bonding surface is performed by contact heating and / or non-contact heating. Heating of the substrate bonding surface may be direct heating or indirect heating. Heating of the substrate bonding surface is not limited as long as the heating temperature of the substrate bonding surface described later can be achieved, and can be appropriately selected depending on the type of substrate, heating method, and the jig used for heating. For example, contact heating (conduction heating) by contact with a heated hot plate is used. Other examples include radiant heating, which heats by irradiating with infrared rays emitted from an infrared heater or heated hot plate; convection heating, which heats a medium such as air between the substrate and the molded body and heats the substrate bonding surface through that medium; high-frequency dielectric heating using a high-frequency electric field; microwave heating by irradiation with microwaves; induction heating, which heats by electromagnetic induction generated by passing an alternating current; and laser heating by irradiation with laser light. When heating of the substrate bonding surface is performed by indirect heating using a heated substrate heating jig, the heating of the substrate heating jig may be performed by direct heating or indirect heating. The heating, shape, and material of the base material heating jig can be the same as those described for the molded body heating jig in the section on heating the joint surface of the molded body.

[0036] The heating temperature of the substrate bonding surface shall be within the range of -80°C or higher and +100°C or lower of the melting point of the thermoplastic resin contained in the molded body. In other words, the heating temperature of the substrate bonding surface shall be within the range of a temperature below the melting point of the resin as the lower limit and a temperature 100°C higher than the melting point of the resin as the upper limit.

[0037] The heating temperature of the substrate bonding surface is preferably 70°C or higher than the resin melting point, more preferably 40°C or higher than the resin melting point, and even more preferably 20°C or higher. By setting the heating temperature of the substrate bonding surface to be above the lower limit of the above, the thermoplastic resin contained in the molded body heated at the aforementioned temperature is melted when the heat from the substrate is applied to the molded body during the bonding process, and the molten resin (thermoplastic resin contained in the molded body) fills the rough surface structure of the substrate, making it easier to improve bonding quality such as bonding strength and airtightness, even without heating during the bonding process. On the other hand, the heating temperature of the substrate bonding surface is preferably 70°C or lower than the resin melting point, more preferably 50°C or lower than the resin melting point, even more preferably 30°C or lower than the resin melting point, even more preferably 10°C or lower than the resin melting point, and most preferably below the resin melting point. By keeping the heating temperature of the substrate bonding surface below the above upper limit, it is possible to avoid the substrate becoming excessively hot, and when the substrate and molded body are bonded during the bonding process, it is possible to avoid deformation of parts of the molded body other than the bonding surface due to the heat of the substrate.

[0038] Furthermore, there is no limit to the time required for heating the substrate bonding surface (contact heating and / or non-contact heating time), but it is generally preferable to be 1 minute or less, more preferably 50 seconds or less, even more preferably 40 seconds or less, and even more preferably 30 seconds or less. If the heating time is within this range, it becomes easier to reduce the cycle time of manufacturing the bonded body. The heating time refers to the time spent heating by contact and / or non-contact, excluding operations before and after heating (heating operations, movement time of equipment, workpieces, jigs, etc.). In this case, the timing of the end of heating the substrate bonding surface may differ from the timing of the end of heating the molded body bonding surface, but from the viewpoint of controlling the temperatures of the molded body bonding surface and the substrate bonding surface to facilitate bonding at the desired temperature, it is preferable that the time difference between the end of heating of the two surfaces be as small as possible, and it is more preferable that the end of heating of both surfaces be simultaneous. Furthermore, in order to reduce the cycle time of manufacturing the bonded body, the timing of the start of heating of the substrate bonding surface may differ from the timing of the start of heating of the molded body bonding surface as described above, but it is preferable that the time difference between the start of heating of the two is as small as possible, and it is more preferable that the start of heating of both be simultaneous.

[0039] The heating temperature of the substrate bonding surface refers to the surface temperature of the heated substrate bonding surface. The same method as for measuring the heating temperature of the molded body bonding surface can be used.

[0040] In the preheating step, it is preferable that the preheating temperature of the molded body joining surface is higher than the preheating temperature of the substrate joining surface. By doing so, the higher temperature of the molded body during preheating makes it easier to join the molded body to the substrate even when the substrate temperature is low, thus shortening the cooling time of the substrate and reducing the cycle time. Furthermore, while the preheating temperature of the molded body joining surface is higher than that of the substrate joining surface, it is even more preferable to heat both the preheating temperature of the substrate joining surface and the preheating temperature of the molded body joining surface within the aforementioned preferred preheating temperature ranges. Even more preferable is to set the preheating temperature of the molded body joining surface higher than that of the substrate joining surface, while the heating temperature of the substrate joining surface is in the range of -70°C or higher and below the resin melting point, and the heating temperature of the molded body joining surface is in the range of above the resin melting point and +30°C or lower. By doing so, in particular, the upper limit of the heating temperature of the substrate joining surface can be suppressed, shortening the cooling time of the substrate and reducing the cycle time of the joint manufacturing.

[0041] Furthermore, in the preheating step, it is preferable to heat the substrate and the molded body with the substrate joining surface and the molded body joining surface facing each other. By heating the joining surfaces in a positional relationship facing each other in the preheating step, the joining surfaces that were facing each other can be brought closer together in the next joining step to join them. In addition, it is easier to align the substrate and the molded body for joining after the preheating step, which leads to a reduction in cycle time.

[0042] [1-6.Joining process] In the joining process, the heated substrate joining surface and the molded body joining surface are brought into contact and pressurized to join the substrate and the molded body. At this time, the resin on the molded body joining surface melts due to the heat from the substrate, and the molten resin fills the rough surface structure of the substrate. As a result, a joined body is obtained in which the substrate and the molded body are joined via their respective joining surfaces.

[0043] The joining process is preferably carried out promptly after the preheating process. By performing the joining process promptly after the preheating process, the substrate and molded body, which were heated to a predetermined temperature range during the preheating process, can be joined before their temperatures drop. For example, it is preferable that the joining process be carried out within 30 seconds after the preheating process.

[0044] An example of the joining process is shown in Figure 4. Specifically, as shown in Figure 4, the molded body heating jig 30 and the base material heating jig 40 used in the preheating process are moved, for example, away from the molded body joining surface 21 and the base material joining surface 11, respectively, so that the joining surfaces are not heated (unheated). Next, the molded body 20 and the base material 10 are positioned with their respective joining surfaces facing each other, and are moved closer together, so that the base material joining surface 11 and the molded body joining surface 21 are in contact and pressure is applied to join the base material 10 and the molded body 20. At this time, for example, the base material setting jig 50 and the restraining jig 60 may be used as needed, or they may be moved and removed. However, the base material setting jig 50 and the restraining jig 60 must be kept in a state where they are not heated (unheated) during the joining process. In Figure 4, when the molded body 20 and the base material 10 are brought into contact, the base material mounting jig 50 and the restraining jig 60 are not heated.

[0045] In other words, in this invention, the substrate and the molded body are joined without heating. Here, "non-heating" joining means that the substrate and molded body are not directly or indirectly heated. In the preheating process, the substrate and molded body are heated directly and / or indirectly, whereas in the joining process, the substrate and molded body are joined without direct or indirect heating. For example, in this joining process, not only are no operations performed to intentionally (forcibly) heat the substrate joining surface, the molded body joining surface, or any parts other than those joining surfaces, but operations are also performed not to intentionally (forcibly) heat other jigs (e.g., pressure jigs) that are in contact with the substrate and molded body. In the present invention, since the substrate and molded body are joined non-heatingly in the joining process, the temperature of the substrate after joining (immediately after joining) can be suppressed because there is no heating during joining, thus shortening the cooling time until the temperature of the substrate decreases and making it easier to reduce the cycle time.

[0046] The method of applying pressure during joining is not limited, but for example, a pressure jig may be used. For example, one method is to press with a press device from one or both sides while the base material joining surface and the molded body joining surface are in contact. The pressure applied is not limited, and should be sufficient to ensure a secure bond without deformation or damage to the base material or molded body, but for example, preferably 0.1 MPa or more and 20 MPa or less, more preferably 0.2 MPa or more and 10 MPa or less, and even more preferably 0.3 MPa or more and 20 MPa or less. There are no restrictions on the time for applying pressure during joining, but for example, it can be between 1 and 300 seconds, and preferably between 30 and 90 seconds.

[0047] Furthermore, after applying pressure while the substrate and molded body are joined, the pressure is released. At this time, the substrate and molded body may be cooled while under pressure or while the pressure is released. In particular, in order to reduce the time it takes for the temperature of the substrate to decrease, it is preferable to start cooling the substrate while under pressure before releasing the pressure. Cooling methods include natural cooling while maintaining the substrate and molded body in an unheated state, or forced cooling. For example, cooling methods such as forced air cooling or contact with a cooled metal jig can be used.

[0048] [2. Effects] As described above, in the present invention, the substrate bonding surface is heated to a temperature range from above -80°C above the resin melting point to above +100°C above the resin melting point, with a lower limit of a temperature below the resin melting point and an upper limit of a temperature 100°C above the resin melting point. In addition, the molded body bonding surface is heated to a temperature range above the resin melting point to above the resin melting point and above +100°C above the resin melting point. In the present invention, when preheating is performed using a non-contact method in which the molded body heating jig and the molded body joining surface do not come into contact, there is no risk of molten molded body adhering to the jig performing the preheating and contaminating the jig. Therefore, in the present invention, in the joining process, the molded body is pressurized while in contact with the base material, allowing the molten thermoplastic resin to be filled into the rough surface structure of the base material, and preventing deformation of parts of the molded body other than the joining area due to excessive heat is avoided. In this manner, the upper and lower temperature limits of the molded body during preheating are set.

[0049] On the other hand, the thermoplastic resin contained in the molded body, which is preheated at the aforementioned temperature, is melted by applying heat from the substrate when pressure is applied while the substrate and the molded body are in contact. The molten resin fills the rough surface structure of the substrate, so that the substrate and the molded body are joined even without heating during joining. The lower limit temperature of the substrate is set in this manner. In addition, the upper limit temperature of the substrate is set to prevent deformation of parts of the molded body other than the joining area during the joining process due to the substrate becoming excessively hot.

[0050] Therefore, according to the present invention, the substrate and the molded body are joined while preventing contamination of the jig by non-contact preheating, and because no heating is performed during joining, it is easier to suppress the temperature of the substrate after joining (immediately after joining) when a predetermined time has elapsed since the start of joining, thereby shortening the cooling time until the temperature of the substrate decreases and making it easier to reduce the cycle time.

[0051] In this process, when joining a molded body and a base material by applying pressure while they are in contact, the temperature of the base material needs to have decreased to the point where the resin of the molded body has solidified by the time the pressure is released after a predetermined period of time has elapsed since the start of joining. In conventional heat welding, a hot plate is used as a base material mounting jig to hold the base material, and the base material and the molded body are joined while the base material is heated by the hot plate, requiring the base material to be heated to a relatively high temperature by the hot plate. In this case, the temperature of the hot plate in contact with the base material needs to have decreased to the point where the resin of the molded body has solidified by the time the pressure is released. Therefore, both the time required to raise the temperature of the hot plate, which had decreased in the previous cycle, and the time required to lower the temperature of the heated base material and hot plate become long, resulting in a long cycle time required for manufacturing the joined body.

[0052] In contrast, in the present invention, the molded body and the substrate are heated in a preheating step, and the heating temperatures of the molded body joining surface and the substrate joining surface are set within the above-mentioned range, with no heating during joining. As a result, according to the present invention, joining can be performed with a relatively low heating temperature of the substrate joining surface, and the time required to raise the temperature of the substrate heating jig and substrate mounting jig before joining, and the time required to lower the temperature of the substrate and substrate mounting jig during joining are shortened, thereby shortening the cycle time required for manufacturing the joined body.

[0053] Furthermore, by performing non-contact preheating on the joint surface of the molded body, it is possible to melt the thermoplastic resin near the joint surface that contributes to bonding with the substrate, compared to heating the entire molded body. At this time, heating of the thermoplastic resin other than the joint surface of the molded body can be suppressed, thereby suppressing deformation of the molded body during bonding. [Examples]

[0054] Preferred embodiments of the present invention will be specifically described below based on examples and comparative examples, but the present invention shall not be construed as being limited thereto.

[0055] [Example 1] [1. Manufacturing of the joint] <Surface roughening process (laser treatment method)> As the substrate, an A6063T5 aluminum substrate 110, as shown in Figure 5, was used. The aluminum substrate 110 is a roughly rectangular plate material with dimensions of 75 mm in length, 150 mm in width, and 2 mm in thickness when viewed from above. One side of the aluminum substrate 110 becomes the joining surface 111, and the other side becomes the opposite side 112. Laser light was irradiated concentrically at an irradiation interval of 0.09 mm in a range of 3 mm inward from the outermost edge of the substrate. The laser irradiation device used was a Keyence laser marker MDF-5200. The specifications of the device are a pulsed fiber laser, wavelength 1090 nm, maximum output 50 W, and beam diameter 60 μm. The laser conditions were output 42.5 W (85%), irradiation interval 90 μm, scanning speed 340 mm / s, and frequency 60 kHz.

[0056] As shown in Figures 6(a) and 6(b), the resin molded body 120 used in this embodiment has a cavity 121 inside, an upper surface portion 122 that covers the cavity 121, side wall portions 123 that descend from the upper surface portion 122 and surround the cavity 121, and an opening 124 formed by the ends of the side wall portions 123, through which the cavity 121 opens to the outside. When viewed from above, the side wall portion 123 is approximately rectangular in shape, measuring 76 mm in length, 151 mm in width, and with a wall thickness (width) of 3 mm. The side wall portion 123 has cylindrical pipe portions 126 (126a, 126b) on two opposing sides. The pipe portions 126 (126a, 126b) penetrate the side wall portion 123 and connect the cavity 121 inside the resin molded body 120 to the outside. The pipe section 126 (126a, 126b) has a diameter of approximately 20 mm. An open end face 125 with a width of 3 mm is provided at the lower end surface of the opening 124 of the side wall section 123. The open end face 125 serves as the joining surface for the resin molded body. The resin molded body 120 was manufactured by injection molding of PPS manufactured by DIC Corporation.

[0057] <Preheating process, joining process> In this embodiment, a hot plate welding device manufactured by Kobayashi Kogyo Co., Ltd. (no model number) was used for the pre-processing and joining processes. This hot plate welding device has an upper base and a lower base (not shown) that are positioned opposite each other and can move vertically to change the distance between them. Using the reference numerals shown in Figures 3-4 to describe the arrangement, a base material installation jig 50 is fixed to the lower base. A restraining jig 60 for restraining the molded body 20 is fixed to the upper base. By moving the upper base, with the molded body 20 restrained below by the restraining jig 60, and the lower base, with the base material 10 placed on the base material installation jig 50, closer to each other, the molded body 20 and the base material 10 can be brought into contact and joined. Furthermore, this hot plate welding device has a molded body heating jig 30 that can move horizontally to change the position in which the molded body 20, which is restrained on the upper base via the restraining jig 60, approaches the molded body joining surface 21 without contacting it, and a position in which it moves away from it. Furthermore, this hot plate welding apparatus has a base material heating jig 40 that can move horizontally to change the position in which it contacts and separates from the joining surface 11 of the base material 10, which is installed on the lower base via a base material installation jig 50. The molded body heating jig 30, the base material heating jig 40, and the base material installation jig 50 are in the shape of thick aluminum plates and have built-in electric heaters, and can be heated to a desired set temperature by conductive heating from the electric heaters. In this embodiment, the hot plate welding apparatus can heat the molded body 20 by non-contact radiant heating by the molded body heating jig 30. In this embodiment, the hot plate welding apparatus can heat the base material 10 by heat transfer heating by the base material heating jig 40 and the base material installation jig 50.

[0058] First, a preheating process was carried out using the laser-treated aluminum substrate 110 (hereinafter referred to as "aluminum substrate") and the resin molded body 120 (hereinafter referred to as "resin molded body") prepared as described above. The aluminum substrate 110 was placed on a substrate mounting jig 50 fixed to the lower base of the hot plate welding apparatus. The temperature of the substrate mounting jig 50 was set to 210°C. The resin molded body 120 was restrained with a restraining jig 60.

[0059] Next, the heating fixtures, the molded body heating fixture 30 and the base material heating fixture 40, were moved between the aluminum base material 110 and the resin molded body 120, which were positioned opposite each other. Then, with the joint surface 111 of the base material facing the base material heating fixture 40, the lower base was moved upward along with the base material installation fixture 50 and the base material 110, thereby bringing the joint surface 111 of the aluminum base material 110 into contact with the base material heating fixture 40 and heating it. The temperature of the base material heating fixture 40 was set to 210°C. Furthermore, with the joint surface 125 of the molded body 120 facing the molded body heating fixture 30, the upper base was moved downward along with the restraining fixture 60 and the resin molded body 120, thereby heating the joint surface 125 of the resin molded body 120 without contact with the molded body heating fixture 30. The temperature of the molded body heating fixture 30 was set to 550°C. The contact heating of the aluminum substrate 110 by the substrate heating jig 40 and the non-contact heating of the resin molded body 120 by the molded body heating jig 30 were started at the same time. In both cases, the heating time by contact or non-contact with the heating jigs 30 and 40 was 20 seconds. After that, the molded body heating jig 30 and the substrate heating jig 40 were moved away from the substrate 110 and the molded body 120, and the temperatures of the joint surfaces 111 and 125 of the aluminum substrate 110 and the resin molded body 120 were measured using a temperature sensor. The joint surface 111 of the aluminum substrate 110 was 210°C, and the joint surface 125 of the resin molded body 120 was 345°C. In this embodiment, a Keyence digital radiation temperature sensor FT-H20 was used as the temperature sensor for measuring the surface temperature of the substrate 110 and the molded body 120. In Tables 1 to 3 described below, the temperatures of these bonding surfaces are expressed as "Al temperature before bonding" and "Resin temperature before bonding," respectively.

[0060] Immediately after measuring the temperature of the joining surface, the lower base was moved upward along with the base material installation jig 50 and base material 110, and the upper base was moved downward along with the restraining jig 60 and molded body 120, thereby bringing the joining surface 111 of the aluminum base material 110 and the joining surface 125 of the PPS resin molded body 120 into contact. Furthermore, a pressure of 3000N (6.58MPa) was applied to perform pressure bonding. At this time, the inner 3mm from the outermost circumference of the aluminum base material 110 was bonded to the resin molded body 120. After contact, air cooling was started immediately after pressurization, and after 60 seconds of pressurization, the pressure was released and the bonded body was removed. The pressurization time was 60 seconds. At this time, the temperature of the aluminum base material 110 measured using the above temperature sensor was 125°C, which is shown as the "removal temperature". The cycle time for producing the bonded body was a good 80 seconds. Note that the cycle time is the time from the start of heating in the preheating process to the start of pressure release in the bonding process. In other words, the cycle time is the sum of the preheating process time and the pressurization time. The resulting joints underwent airtightness testing and resin appearance verification as described below. The results are shown in Table 1.

[0061] [2. Evaluation Method] <Measurement of resin melting point> The resin melting point temperature was measured using a differential scanning calorimeter DSC7020 manufactured by Hitachi High-Tech Science Corporation. The measurement conditions were a heating rate of 5°C / min, and the peak top of the endothermic peak was defined as the resin melting point temperature. When two or more endothermic peaks were observed, indicating the presence of two or more components, the heat of fusion was calculated from each endothermic peak, and the relative abundance of the resin components was calculated based on the ratio of these heats of fusion. The intermediate melting points of the multiple components were then calculated from these relative abundances. The PPS resin used was Z-230 manufactured by DIC Corporation. The endothermic peak temperature was 285°C, which was defined as the resin melting point. The PA resin used was Asahi Kasei 53G33, and the endothermic peaks were at 210°C and 254°C. The respective heats of fusion were 9.2 J / g and 15.5 J / g, so the abundance ratio was calculated to be 1:1.69. From the abundance ratio, the intermediate melting point was calculated to be 238°C, which was taken as the resin melting point temperature.

[0062] <Airtightness inspection> A hose manufactured by Kohshin Rubber (dimensions: inner diameter 15.9 mm, outer diameter 25 mm) was inserted into one pipe section 126 of the resin molded body of the joint. For the other pipe section, a hose sealed with a hose nipple on one end was inserted. This joint was placed in a water tank, and air was blown in from the unsealed hose end using a compressor, applying an air pressure of 0.1 MPa inside the joint. It was confirmed that there was no air leakage from the joint interface of the joint to determine whether the airtightness was good. The appearance of the resin was also checked for any clear deformation. "OK" was used to indicate that there were no air leaks and the airtightness was good. "NG" was used to indicate that there were air leaks and the airtightness was not good, or that the resin was deformed and had a poor appearance.

[0063] [Examples 2-6] The joints of Examples 2 to 6 were obtained in the same manner as in Example 1, except that the temperatures of the molded body heating jig, substrate heating jig, and substrate mounting jig of the hot plate welding apparatus were changed to the conditions shown in Table 1. Evaluations were performed in the same manner as in Example 1. The airtightness of all obtained joints was good. It was also confirmed that there was no significant deformation in the resin appearance. The results are shown in Table 1.

[0064] [Comparative Examples 1-5] The joints of Comparative Examples 1 to 5 were obtained in the same manner as in Example 1, except that the temperatures of the molded body heating jig, substrate heating jig, and substrate placement jig of the hot plate welding apparatus, and the pressurization time were changed to the conditions shown in Table 1. Evaluations were performed in the same manner as in Example 1. Air leaks were confirmed in the joints obtained in Comparative Examples 1-4 through airtightness testing. In Comparative Example 5, although the airtightness of the obtained joint was good, the cycle time was 140 seconds, which was longer than the cycle time of the example, so it was judged to be unsatisfactory (NG). The results are shown in Table 1.

[0065] [Examples 7-13] Except for changing the resin molded body to PA 53G33 manufactured by Asahi Kasei Corporation, and changing the temperatures of the molded body heating jig, substrate heating jig, and substrate setting jig of the hot plate welding apparatus, as well as the time of the preheating process, to the conditions shown in Table 2, the joined bodies of Examples 7 to 13 were obtained in the same manner as in Example 1. The airtightness of all the resulting joints was good. Furthermore, it was confirmed that there was no significant deformation in the resin's appearance. The results are shown in Table 2.

[0066] [Comparative Examples 6-10] The joints of Comparative Examples 6 to 10 were obtained in the same manner as in Example 7, except that the temperatures of the molded body heating jig, base material heating jig, and base material placement jig of the hot plate welding apparatus, the time of the preheating process, and the pressurization time were changed to the conditions shown in Table 2. Air leaks were confirmed in the joints obtained in Comparative Examples 6 to 9 by airtightness testing. In Comparative Example 10, although the airtightness was good, the cycle time was 135 seconds, which was longer than the cycle time of the example, so it was judged to be defective (NG). The results are shown in Table 2.

[0067] [Example 14] The preheating and joining processes were modified from those in Example 1. First, a preheating process was carried out using the same aluminum substrate and resin molded body as described above. An aluminum substrate was placed on a substrate mounting jig fixed to the lower base of an infrared (IR) welding device manufactured by Cosmo System Co., Ltd. (model number not specified), and a resin molded body was restrained in a restraining jig.

[0068] Next, an IR heating jig was placed between the aluminum substrate and the resin molded body, which were positioned opposite each other at their joint surfaces. This IR heating jig had a first IR light source corresponding to the molded body heating jig and a second IR light source corresponding to the substrate heating jig, with the first and second IR light sources each irradiating infrared rays toward opposite sides. The joint surface of the aluminum substrate was irradiated with IR light from the second IR light source at an output of 23% for 30 seconds. 24 seconds after the start of irradiation of the aluminum substrate, the joint surface of the resin molded body was irradiated with IR light from the first IR light source at an output of 33% for 6 seconds. After that, the IR heating jig was moved, and the temperatures of the joint surfaces of the aluminum substrate and the resin molded body were measured using the same temperature sensor as described above. The joint surface of the aluminum substrate was 220°C, and the joint surface of the resin molded body was 295°C. In Table 3, described later, the temperatures of these bonding surfaces are expressed as "Al temperature before bonding" and "Resin temperature before bonding," respectively.

[0069] Immediately after measuring the temperature of the bonding surface, the lower base was moved upward along with the substrate mounting jig and substrate, and the upper base was moved downward along with the restraining jig and molded body, thereby bringing the bonding surface of the aluminum substrate and the bonding surface of the PPS resin molded body into contact. Pressure bonding was performed by applying 3000N (6.58MPa). At this time, the inner 3mm from the outermost edge of the aluminum substrate was bonded to the resin molded body. After contact, air cooling was started immediately after pressurization, and after 60 seconds of pressurization, the pressurization was released and the bonded body was removed. The pressurization time was 60 seconds. At this time, the temperature of the aluminum substrate measured using the above temperature sensor was 149°C, which is indicated as the "removal temperature". The airtightness of the obtained bonded body was good. The cycle time for producing the bonded body was a good 90 seconds. It was also confirmed that there was no clear deformation in the appearance of the resin. The results are shown in Table 3.

[0070] [Examples 15-18] The bonded structures of Examples 15-18 were obtained in the same manner as in Example 14, except that the IR heating irradiation conditions were changed to those shown in Table 3. Evaluations were performed in the same manner as in Example 1. All of the obtained bonded structures showed good airtightness. It was also confirmed that there was no significant deformation in the resin appearance. The results are shown in Table 3.

[0071] [Comparative Examples 11-15] The joints of Comparative Examples 11 to 15 were obtained in the same manner as in Example 14, except that the IR heating irradiation conditions and pressurization time were changed to the conditions shown in Table 3. Air leakage was confirmed in the joints obtained in Comparative Examples 11 to 14 by airtightness testing. The joint obtained in Comparative Example 15 had good airtightness, but the cycle time was 165 seconds, which was longer than the cycle time of the example, so it was judged to be unsatisfactory (NG). The results are shown in Table 3.

[0072] [Table 1]

[0073] [Table 2]

[0074] [Table 3]

[0075] [Consideration] As can be seen from the results described above, in the method for manufacturing a joined body of the present invention according to Examples 1 to 18, in the preheating step, the substrate joining surface and the molded body joining surface are heated in a non-contact state. At this time, the substrate joining surface is heated to a temperature range from above the resin melting point temperature - 80°C to above the resin melting point temperature + 100°C, with a lower limit of a temperature below the resin melting point temperature and an upper limit of a temperature 100°C above the resin melting point temperature. The molded body joining surface is heated to a temperature range above the resin melting point temperature and below the resin melting point temperature + 100°C. As a result, according to Examples 1 to 18, even with non-contact heating of the molded body where the molded body heating jig and the molded body joining surface do not come into contact, it was possible to join the bodies while maintaining the airtightness of the interface between the substrate and the molded body created by the joining. Furthermore, by performing non-contact heating of the molded body, it was possible to raise the heating temperature of the molded body joining surface to above the resin melting point temperature while avoiding contamination of the jig by molten resin adhering to the jig. Furthermore, in Examples 1 to 18, the heating temperature in the preheating step was set as described above, and the bonding method involved directly bonding the substrate and the molded body without heating. As a result, in Examples 1 to 18, the temperature of the substrate after bonding (removal temperature) after a predetermined time had elapsed since the start of bonding could be rapidly reduced to the point where the resin of the molded body had solidified when the pressurized state was released. In this way, Examples 1 to 18 were methods that made it easy to reduce the cycle time by reducing the cooling time required for the substrate temperature to decrease.

[0076] In contrast, in Comparative Examples 1-3, 6-8, and 11-13, where the temperature of either the substrate bonding surface or the molded body bonding surface was below the lower limit of the aforementioned temperature range, it was not possible to bond the substrate and the molded body resin while maintaining airtightness at the interface. From this, it can be inferred that if the heating temperature of the substrate bonding surface or the molded body bonding surface is too low, even if the molded body receives heat from the substrate during bonding, it may not be possible to cause sufficient melting of the resin to fill the rough surface structure of the substrate.

[0077] Furthermore, in Comparative Examples 4, 9, and 14, where the temperature of the substrate bonding surface exceeded the upper limit within the aforementioned temperature range, when the pressurizing time was set to 60 seconds, it was not possible to bond the substrate and the molded body while maintaining airtightness at the interface. From this, it can be inferred that when the heating temperature of the substrate bonding surface is too high, excessive heat from the substrate is supplied to the molded body during bonding. In this case, it can be inferred that the removal temperature when the pressurizing is released and the bonded body is removed has not decreased sufficiently, and as a result of removing the molded body before the resin contained in it has solidified, the bonding quality deteriorates.

[0078] Furthermore, in Comparative Examples 5, 10, and 15, where the temperature of the substrate bonding surface exceeded the upper limit within the aforementioned temperature range, extending the pressurization time to 120 seconds resulted in removal temperatures of 232°C, 145°C, and 232°C, respectively, allowing for bonding while maintaining airtightness at the interface between the substrate and the molded body. In this case, it is presumed that extending the pressurization time lowered the removal temperature, causing the resin to solidify upon removal. However, in this case, extending the pressurization time necessitates relatively long cycle times of 140 seconds, 135 seconds, and 165 seconds, respectively, suggesting that this method does not allow for a reduction in cycle time. [Explanation of Symbols]

[0079] 1...Zygote 10...Base material 11…Base material bonding surface 12…The side opposite to the substrate bonding surface 20…Molded body 21... Molded object joint surface 30… Heating jig for molded body 40…Substrate heating jig 50…Substrate installation jig 60… Restraint fixtures 110…Aluminum base material 111...Bonding surface of aluminum substrate 112...Bonding surface and opposite surface of the aluminum substrate 120…Resin molded body 121...Cavity part 122...Top part 123…Side part 124…Opening 125...Opening end surface 126...Pipe section

Claims

1. A method for manufacturing a jointed body in which a substrate containing metal or ceramics and a molded body containing thermoplastic resin are directly joined, The substrate has a substrate bonding surface that is joined to the molded body, The molded body has a molded body joining surface that is joined to the substrate, A surface roughening step to form a rough surface structure on the substrate bonding surface, A preheating step for heating the substrate bonding surface and the molded body bonding surface, The invention comprises a joining step of joining the substrate and the molded body by placing the heated substrate joining surface and the molded body joining surface facing each other, and applying pressure while the substrate joining surface and the molded body joining surface are in contact, In the preheating step, the substrate bonding surface and the molded body bonding surface are heated in a non-contact state with each other. In the preheating step, the molded body joining surface is heated by non-contact heating from the surface side. In the preheating step, the substrate bonding surface is heated to a range of 80°C or higher and 100°C or lower, which is the melting point of the thermoplastic resin, and the molded body bonding surface is heated to a range of 100°C or higher and 100°C or lower, In the joining process, the substrate and the molded body are joined without heating. A method for manufacturing a jointed body, characterized by the above.

2. The method for manufacturing a bonded body according to claim 1, wherein in the preheating step, the heating temperature of the molded body bonding surface is higher than the heating temperature of the substrate bonding surface.

3. The method for manufacturing a bonded body according to claim 2, wherein in the preheating step, the heating temperature of the substrate bonding surface is in the range of the resin melting point - 70°C or higher and the resin melting point or lower, and the heating temperature of the molded body bonding surface is in the range of the resin melting point or higher and the resin melting point + 30°C or lower.

4. The method for manufacturing a joined body according to claim 1, wherein in the preheating step, the substrate and the molded body are heated with the substrate joining surface and the molded body joining surface facing each other.

5. The method for manufacturing a joined body according to claim 1, wherein the joining step is performed within 30 seconds after the preheating step.

6. The method for manufacturing a bonded body according to claim 1, wherein the heating method for heating the molded body in the preheating step is at least one selected from the group consisting of radiant heating, convection heating, high-frequency dielectric heating, microwave heating, and laser heating.

7. The method for manufacturing a bonded body according to claim 1, wherein the heating method for heating the substrate in the preheating step is at least one selected from the group consisting of conduction heating, radiation heating, convection heating, high-frequency dielectric heating, microwave heating, induction heating, and laser heating.

8. The method for manufacturing a bonded body according to claim 1, wherein the molded body includes a filler.

Images