JP5690051B2 - Method of joining members using laser - Google Patents

Description

  In the present invention, a first member made of resin and a second member made of metal are overlapped with each other and irradiated with laser light, and the first member is melted or softened by the energy of the laser light, so that the first and second members The present invention relates to a method for joining members using a laser for joining together.

  Conventionally, as a method for joining members using this type of laser, for example, as shown in Patent Document 1, a first member made of acrylic resin as a resin material and a second member made of tin as a metal material are used. The boundary surface of the two members with the first member is polished with sandpaper to form an uneven surface, the first member is superimposed on the uneven surface of the second member, and the semiconductor laser light is irradiated from the first member side to the boundary surface A method of joining both members by melting or softening a resin is known. According to this joining method, by making the metal boundary surface uneven, the laser light absorption rate is increased by the unevenness, whereby the boundary surface is heated and the surrounding resin is melted or softened, This means that the so-called anchor effect in which the resin bites into the unevenness is exerted, thereby increasing the bonding strength between the two members. However, according to this joining method, the variation in joining strength is large, and the members are peeled off from the boundary surface, so that it is difficult to form a stable joining between the members.

  In Non-Patent Document 1, stainless steel and non-crystalline polyamide resin are overlapped and directly bonded by irradiating a high-power laser beam of about 200 W or more. In this joining method, bubbles are generated by thermally decomposing the resin material on the joining surface, and the strength is obtained by bringing the molten resin into close contact with the metal surface by the pressure of the bubbles, but even if the bubbles are too small, they are too large. The strength also decreases. However, since air bubbles are generated, the appearance of the bonded product is deteriorated, and the product value is lowered. Further, since the irradiation power of the laser beam is high, there is a problem that the scale of the apparatus is increased and the cost required for forming the junction is increased. Furthermore, this joining method has a problem that it lacks versatility as a joining method for members because there are restrictions on the types of members that can be joined.

JP 2006-15405 A

Seiji Katayama, et al., “Laser Direct Joining of Stainless Steel and Amorphous Polyamide Resin”, Transactions of the Japan Welding Society, published by the Japan Welding Society, 2007, Vol. 25, No. 2, pp. 316-322

  The present invention is intended to solve the above-described problem. The first member made of resin material and the second member made of metal are overlapped with each other and irradiated with laser light, so that a sufficient space is provided between the first and second members. An object of the present invention is to provide a method of joining members using a laser that can be reliably joined with strength and has a good appearance at the joined portion.

In order to achieve the above object, the present invention is characterized in that a resin-made first member and a metal-made second member that transmit laser light are superposed on each other, and laser light is irradiated to the boundary surface. A joining method in which the first member and the second member are joined by melting or softening the first member with energy so that the laser light can be absorbed by the boundary surface of the second member before the laser light irradiation. The object is to form a porous layer having minute holes with a diameter of less than 1 μm by anodizing treatment on the boundary surface that has been made uneven, and further subjected to anodization.

Metal materials to which the present invention can be applied are those in which a porous layer having fine pores having a diameter of less than 1 μm is formed by anodizing, and can be anodized, such as aluminum, titanium, magnesium, tantalum, and niobium. , Tungsten, and the like. The resin material may be a thermosetting resin such as a phenol resin, an epoxy resin, or polyurethane in addition to a thermoplastic resin such as acrylic, polycarbonate, or acetal resin. In addition, about the formation of the uneven | corrugated state of a boundary surface, the process by sandblasting, the grinding | polishing process using sand paper, electrical discharge machining, an etching process, a press work, etc. is possible. Further, as the laser, a semiconductor laser that transmits a resin material, a YAG laser, an excimer laser, or the like is preferable.

A method for joining members using the laser of the present invention will be described with reference to FIGS. Before the laser light irradiation, the unevenness 13a is formed on the boundary surface 13 of the metal second member 12 with the first member 11 (see FIGS. 1 and 2), so that the laser light absorption rate is increased. Further, by performing anodizing treatment on the boundary surface 13, an infinite number of minute holes 13b having a diameter of less than 1 μm are formed on the surface of the irregularities 13a, thereby forming a porous layer (see FIG. 3). The laser light absorption rate is further increased by the anodizing treatment. When the laser beam 16 is applied to the boundary surface 13 from the first member 11 side in a state in which the first member 11 is superimposed on the boundary surface 13 of the second member 12 and brought into close contact with the pressing pressure (see FIG. 4), the laser beam is irradiated. 16 is absorbed by the uneven boundary surface 13, and the resin-made first member 11 around the boundary surface 13 is locally melted or softened by the energy. Thereby, the resin bites into the irregularities 13a of the boundary surface 13 of the second member 12, and further, bites into the minute holes 13b having a diameter smaller than 1 μm formed in the irregularities 13a by the anodic oxidation treatment of the second member 12 (FIG. 5). FIG. 6).

As a result, according to the present invention, in addition to the anchor effect due to the resin biting into the unevenness 13a of the boundary surface 13, the anchor effect due to the biting into the minute hole 13b having a diameter smaller than 1 μm by the anodizing process overlaps. A strong and stable joint is formed between the two members. Moreover, according to this invention, the range of selection of the material of resin 1st member and metal 2nd member is wide, and it can apply to a wide use. In addition, when anodizing is performed, generally, a pretreatment for removing a contaminated layer such as an oxide film is necessary. However, in the present invention, the unevenness 13a may be formed on the boundary surface 13 of the second member. Since it also serves as a pretreatment for the subsequent anodic oxidation treatment, pretreatment by another method becomes unnecessary. Furthermore, in the present invention, since bonding can be formed by irradiation with low-power laser light, bonding with a good appearance without bubbles or the like can be obtained, and the product value of the bonded product can be increased and the bonded product can be provided at low cost. .

Another feature of the present invention is that the first member made of resin and the second member made of metal are superimposed on each other and irradiated with laser light, and the first member is melted or softened by the energy of the laser light. A joining method for joining between a first member and a second member, wherein a porous layer having micropores having a diameter of less than 1 μm is formed by subjecting the boundary surface of the second member to an anodizing treatment before laser beam irradiation. The other surface is formed in an uneven state so that the opposite surface of the second member can absorb the laser beam, and the opposite surface side is irradiated with the laser beam.

  The metal material is aluminum or the like that can be anodized. The resin material is the same as described above. Furthermore, the formation of the uneven state on the opposite surface is the same as described above. In addition to the above-described laser, a carbon dioxide laser that does not transmit resin can be used as the laser.

A member joining method using a laser, which is another feature, will be described with reference to FIGS. Prior to the laser light irradiation, irregularities 14a are formed on the surface 14 opposite to the boundary surface 13 of the metal second member 12 with the first member 11 (see FIG. 7) to increase the laser light absorption rate. . Furthermore, by applying anodizing treatment to the boundary surface 13 of the second member 12, an infinite number of minute holes 13b having a diameter of less than 1 μm are formed in the boundary surface 13 to form a porous layer. When the laser beam 16 is irradiated onto the opposite surface 14 of the second member 12 in a state where the first member 11 is superimposed on the boundary surface 13 of the second member 12 and is brought into close contact with the pressing pressure (see FIG. 8), the laser beam 16 is irradiated. Is absorbed by the opposite surface 14 in an uneven state, the opposite surface 14 generates heat, and the heat is transmitted to the boundary surface 13. Therefore, the resin-made first member 11 around the boundary surface 13 is locally melted or softened so that the resin has a minute diameter smaller than 1 μm formed on the boundary surface 13 by the anodic oxidation of the second member 12. It bites into the hole 13b. As a result, according to the present invention, the anchor effect is exerted by the resin biting into the minute hole 13b having a diameter smaller than 1 μm by the anodizing treatment of the boundary surface 13, and a strong and stable joint is formed between both members. Is done. In this case, even if the resin material of the first member does not transmit laser light, both members can be firmly and stably bonded. Further, in the present invention, since bonding can be formed by irradiation with low-power laser light, bonding with a good appearance without bubbles or the like can be obtained, the product value of the bonded product can be increased, and the bonded product can be provided at low cost. .

  Moreover, in this invention, it is preferable that formation of an uneven | corrugated state is performed by the grinding | polishing process by sandblasting and sandpaper. As a result, the boundary surface or the opposite surface of the second member can be brought into a high laser light absorption rate by a simple operation.

According to the present invention, before the laser light irradiation, the boundary surface of the second member is made uneven so as to be able to absorb the laser light, and further, the anodized treatment is performed on the interface surface made uneven. The light is absorbed by the uneven surface, and the resin first member around the boundary surface is locally melted or softened, so that the resin bites into the uneven surface of the second member, The two-membered anodizing process bites into innumerable minute holes having a diameter of less than 1 μm formed on the boundary surface. As a result, according to the present invention, in addition to the anchor effect due to the resin biting into the unevenness of the boundary surface, the anchor effect due to the biting into the minute holes having a diameter of less than 1 μm by the anodizing process overlaps, so that both members A strong and stable bond is formed between them.

Also, according to the present invention, before the laser light irradiation, the boundary surface of the second member is anodized so that the opposite surface of the second member is in an uneven state so as to be able to absorb the laser light. By irradiating with laser light, the opposite surface generates heat and the heat is transmitted to the boundary surface. Therefore, by locally melting or softening the first resin member around the boundary surface, the resin is formed into innumerable minute holes having a diameter smaller than 1 μm formed on the boundary surface by anodizing treatment of the second member. Bite. As a result, according to the present invention, the anchor effect is exerted by the resin biting into a minute hole having a diameter smaller than 1 μm by the anodizing treatment of the boundary surface, and a strong and stable joint is formed between both members. .

It is a schematic diagram which shows the relationship between the 1st member which is Example 1 of this invention, and a 2nd member. It is a schematic diagram which expands and shows the uneven | corrugated | grooved part of a 2nd member. It is a schematic diagram which expands and shows the part which gave the anodizing process of the 2nd member. It is a schematic diagram which shows the state which superimposed the 1st member and the 2nd member and irradiated the laser beam. It is a mimetic diagram showing the state where the 1st member and the 2nd member were joined. It is a schematic diagram which expands and shows the junction part of a 1st member and a 2nd member. It is a schematic diagram which shows the relationship between the 1st member which is Example 2, and a 2nd member. It is a schematic diagram which shows the state which superimposed the 1st member and the 2nd member and irradiated the laser beam. It is a graph which shows the relationship between the pre-processing state of the boundary surface of a 2nd member, and a laser beam absorptance. It is a graph which shows the relationship between the pre-processing state of the boundary surface of a 2nd member, and the joint strength between the 1st and 2nd member.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to FIG. 6, the first member 11 made of transparent acrylic resin as the resin material of Example 1 and the second member 12 made of aluminum as the metal material are overlapped, and irradiated with the semiconductor laser light 16. A process of forming a bond between the first and second members 11 and 12 is schematically shown.

  The first member 11 has a thickness of 3 mm, and the second member 12 has a thickness of 0.2 mm. The boundary surface 13 of the second member 12 is first processed by sandblasting for 5 seconds to be in an uneven state. Here, the particle size of the propellant for sandblasting is preferably No. 60 or No. 120. No. 220 or more is sufficient for laser light absorption, but the processing time of 5 seconds is insufficient for removing the contaminated layer, and the processing time needs to be longer. As a result, the laser light absorptance at the boundary surface 13 is increased, and when the boundary surface 13 is irradiated with laser light, the boundary surface 13 generates heat enough to melt or soften the surrounding resin material. Furthermore, by applying anodizing treatment to the boundary surface 13 as an electrochemical treatment, an infinite number of pores 13b having a diameter smaller than 1 μm are formed on the surface of the irregularities 13a to form a porous layer. The laser light absorption rate is further increased by the anodizing treatment. The anodizing treatment was carried out using an 8 wt% phosphoric acid aqueous solution for 20 minutes under the conditions of an applied voltage of 10 V and a temperature of 25 ° C. Here, the treatment of the boundary surface 13 with the irregularities 13a also serves as a pretreatment (contamination layer removal) for anodic oxidation, so that it is not necessary to remove the contamination layer by another method.

  Next, the semiconductor laser 16 is irradiated onto the boundary surface 13 from the first member 11 side in a state where the first member 11 is superimposed on the boundary surface 13 of the second member 12 and is brought into close contact with the pressing pressure. The semiconductor laser to be irradiated has a wavelength of 920 nm, a maximum output of 50 W, continuous oscillation, and a beam mode of a top hat type. The semiconductor laser irradiation conditions were an irradiation spot spot diameter of 1 mm, an output of 35 W, a scanning speed of 1 mm / s, and a scanning distance of 10 mm.

  Here, the relationship between the pretreatment state of the boundary surface 13 of the second member 12 and the laser light absorption rate will be described with a specific example. Samples were buffed and anodized, and were sandblasted with propellant particle sizes # 60, # 120, # 220 (SB # 60, SB # 120, SB # 220) A total of 8 types were combined with this anodizing treatment. The laser absorptance was measured using an inverse problem solving method combining temperature measurement of the sample surface and heat conduction analysis. The test results are shown in FIG. Those subjected to buffing had very small irregularities, and therefore the laser light absorption rate was also low. Those subjected to the sandblast treatment had a laser light absorption rate in the range of about 30 to 40%. Further, the laser light absorption rate tended to be increased by adding an anodizing treatment. As a result, it has been clarified that the one subjected to the sandblast treatment or the one subjected to the anodization treatment is heated to a sufficient temperature by laser light irradiation.

The laser light 16 output from the semiconductor laser oscillator is transmitted through an optical fiber, output from a collimator, and irradiated so as to have a spot diameter set at the boundary surface between the first and second members 11 and 12 that are superimposed. Thereby, the semiconductor laser light is absorbed by the unevenness 13a of the boundary surface 13 of the second member 12, and the unevenness 13a portion generates heat, thereby locally melting or softening the surrounding acrylic material, so that the resin becomes the second member. 12 bite into the irregularities 13 a of the boundary surface 13. Furthermore, the molten or softened resin bites into countless minute holes 13b having a diameter smaller than 1 μm formed on the boundary surface 13 by the anodic oxidation treatment of the second member 12. As a result, according to Example 1, in addition to the anchor effect due to the resin biting into the unevenness 13a of the boundary surface 13, the anchor effect due to the biting into the minute hole 13b having a diameter smaller than 1 μm by the anodizing process overlaps. Thus, a strong and stable joint is formed between the members 11 and 12. Moreover, according to Example 1, it is not limited to the kind of the resin material of the 1st member 11, and the metal material of the 2nd member 12, Both members can be joined firmly stably. Furthermore, in Example 1, since bonding can be formed by irradiation with low-power laser light, bonding with a good appearance without bubbles or the like is obtained, and the product value of the bonded product is increased and the bonded product is provided at low cost. The

  Next, a specific example of the relationship between the processing state of the boundary surface of the second member and the bonding strength between the first and second members will be described. Three types of samples were combined with sand blasting (SB # 60, SB # 120, SB # 220) with particle sizes of 60, 120 and 220 and anodizing, and buffed to remove the contaminated layer. There are a total of six types, which are a combination of the sandblasting treatments with the grain sizes of No. 60, No. 120, and No. 220 and the anodizing treatment. The joint strength was measured by a shear test. The joint strength was determined by dividing the force required to shear and break the joint between both members by the joint area. The test results are shown in FIG.

  There was no significant difference in bonding strength depending on the presence or absence of buffing, except for sand blasting with a particle size of # 220. These bonding strengths are about 30 MPa or more on average, which is greatly improved compared to about 10 MPa in the case of conventional sandblasting alone. The reason why the variation in the bonding strength data is large is considered to be due to the variation in the measured values of the bonding areas of both members. In addition, for those subjected to sand blasting with a grain size of 220, the bonding strength was low although buffing was not performed. However, when the sand blasting treatment was performed for 5 seconds with a grain size of 220, a surface oxide film or the like was used. This is probably because the contaminated layer could not be sufficiently removed, and therefore the anodizing treatment was not properly performed. Even when the grain size is 220, it is confirmed that when the anodization is performed after the contaminated layer is sufficiently removed by setting the sandblasting treatment time to 30 seconds, the bonding strength is comparable to the other cases.

Next, Example 2 will be described with reference to the drawings.
The first member 11 and the second member 12 are the same as in the first embodiment. As shown in FIG. 7, the contamination layer is first removed by buffing the boundary surface 13 of the second member 12, and the opposite surface 14 is made uneven 14a by sandblasting. Thereafter, the boundary surface 13 is anodized to form a porous layer composed of innumerable minute holes 13b having a diameter smaller than 1 μm . When the first member 11 is superposed on the boundary surface 13 of the second member 12 and brought into close contact with the pressing pressure, as shown in FIG. The light 16 is absorbed by the opposite surface 14 in the uneven state, the opposite surface 14 generates heat, and the heat is transmitted to the boundary surface 13. Therefore, the first resin member 11 around the boundary surface 13 is locally melted or softened, and the diameter of the second member 12 formed in the boundary surface 13 by the anodic oxidation treatment of the second member 12 is smaller than 1 μm. Bite.

As a result, according to Example 2, the anchor effect by the resin biting into the minute hole 13b having a diameter of 1 μm smaller than 1 μm by the anodizing treatment of the boundary surface 13 is exerted, and a strong and stable joining is achieved between the two members. It is formed. In Example 2, even if the resin material of the first member 11 does not transmit laser light, both members can be bonded firmly and stably. Further, in the second embodiment, as in the first embodiment, since the bonding can be formed by irradiation with a low-power laser beam, it is possible to obtain a bonding with a good appearance without bubbles and the like, and to increase the product value of the bonded product. Goods are provided at low cost.

  In Examples 1 and 2, the bonding formation between the acrylic plate and the aluminum plate is described, but other than that, which can be anodized, such as titanium, magnesium, tantalum, niobium, tungsten, etc. Bonding with thermoplastic resins such as polycarbonate and acetal resin, thermosetting resins such as phenol resin, epoxy resin, and polyurethane is also possible. In addition, the method of joining the members using the semiconductor laser shown in the first and second embodiments is merely an example, and various modifications can be made without departing from the gist of the present invention.

In the present invention, before the laser light irradiation, the boundary surface of the metal second member is made uneven so as to be able to absorb the laser light, and further, the diameter of the uneven surface is subjected to anodization treatment. Forming a porous layer having fine pores smaller than 1 μm , irradiating the boundary surface with laser light, locally melting the resin-made first member, and forming the resin with irregularities and anodes on the boundary surface of the second member It is useful because a strong and stable joint can be formed between both members by biting into innumerable minute holes having a diameter smaller than 1 μm formed on the boundary surface by the oxidation treatment.

DESCRIPTION OF SYMBOLS 11 ... 1st member, 12 ... 2nd member, 13 ... Boundary surface, 13a ... Concavity and convexity, 13b ... Minute hole smaller than 1 micrometer, 14 ... Opposite surface, 14a ... Concavity and convexity, 16 ... Semiconductor laser beam.

Claims (3)

A resin-made first member that transmits laser light and a metal-made second member are superposed on each other and irradiated with laser light on the boundary surface, and the first member is melted or softened by the energy of the laser light. A joining method for joining the first and second members by:
Before irradiating the laser beam, the boundary surface of the second member is made uneven so as to be able to absorb the laser light, and the anodized surface is subjected to anodic oxidation so that the diameter becomes 1 μm or more. A method for joining members using a laser, wherein a porous layer having small minute holes is formed. The first member made of resin and the second member made of metal are overlapped with each other and irradiated with a laser beam, and the first member is melted or softened by the energy of the laser beam, so that the first member is separated from the second member. A joining method for joining
Prior to the laser light irradiation, the boundary surface of the second member is anodized to form a porous layer having minute holes with a diameter of less than 1 μm , and the opposite surface of the second member is placed on the opposite surface of the laser light. A method for joining members using a laser, characterized in that the opposite surface side is irradiated with a laser beam in a concavo-convex state so that it can be absorbed.   The method for joining members using a laser according to claim 1 or 2, wherein the formation of the uneven state is performed by a sandblasting or sandpaper polishing process.

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