JP4020957B2 - Metal material having joint part with different material and its processing method using laser - Google Patents

Description

  The present invention relates to a metal surface treatment technique for increasing the degree of bonding with dissimilar materials. In addition, the present invention relates to a technique for strongly joining a different material to a metal surface using the metal surface treatment technique.

Conventionally, mobile phone casings are lightweight (density 0.8-1.4 g / cm ³ ), and can be mass-produced by injection molding, etc., and can be reduced in price. Most of these were molded from this resin. In recent years, however, the functions of mobile phones have been increasing and diversifying, such as camera functions and music functions. As a result, the volume of electronic components mounted on the housing, the number of push buttons, and the liquid crystal display The ratio of departments is also increasing. Therefore, as the mass of electronic parts and the like increases with the improvement of the function, there is a demand for weight reduction (thinning) of a housing for mounting the electronic parts and the like. However, the resin generally has inferior mechanical properties such as tensile strength, elastic modulus, impact strength and the like as compared with a metal material. For this reason, as a result of having to reinforce by installing a rib etc. inside the case, the mountable volume is inevitably reduced. Further, when the resin casing is made thin, residual stress is generated, so that deformation is likely to occur and the thermal reliability is low.

  Therefore, recently, a housing using a metal material (for example, an aluminum alloy) instead of resin has begun to be used. Mechanical strength such as specific strength (tensile strength / specific gravity) and specific rigidity (elastic modulus / specific gravity) of metal materials (for example, aluminum alloy) greatly exceeds those of plastics, so it is thin and lightweight while ensuring mechanical strength. Can be achieved. Here, in the case of using a metal material as a housing, it is necessary to install a member such as a holding member and a screw boss for fixing an electronic substrate housed in the housing to the housing. In this case, from the viewpoint of weight reduction and workability, a resin is employed as the member, and a method of injection molding (insert molding or outsert molding) of the resin on a metal material is employed as a method for forming the member. Is preferred. At this time, especially for products that are mounted on electronic boards, such as cellular phones, that are susceptible to vibration, product damage due to peeling of metal and resin is immeasurable, so the bonding of metal materials and resin The degree must be particularly high.

  Here, as a conventional technique for increasing the degree of bonding between the metal material and the resin, there is a technique of bonding the resin onto the metal material via an adhesive, a thermal bonding sheet, a double-sided tape, or the like, for example. However, when this technology is adopted, in addition to the relatively low bonding strength, the bonding strength depends on the performance of the selected adhesive, thermal adhesive sheet, etc., and it is necessary to consider the bonding process and dedicated equipment. However, there are problems such as requiring a bonding agent in addition to the processed material, not being able to cope with a very complicated shape, and being difficult to deal with a thin rib. As another method, there is a technique in which a metal material is subjected to an organic plating process and then bonded to a resin. For example, Japanese Patent Application Laid-Open No. 2001-1445 discloses a method in which a metal material is subjected to an organic plating treatment and bonded to a resin. When this technology is adopted, it can be expected that the bonding strength will be increased because it is a covalent bond, but it must be treated before surface treatment such as anodization. It is necessary to perform pretreatment strictly for removal and activation, preferable adhesive force cannot be obtained unless the mold temperature is high at the time of molding, molding cycle becomes long, and mold release problem occurs depending on the shape, There are problems such as partial processing being difficult, visual confirmation of the state of processing being difficult, storage management of processed products being strictly required, and the number of processing steps being relatively large. As another method, there is a technique in which etching is applied to a metal material and bonded to a resin. For example, Japanese Patent Application Laid-Open No. 2004-0050488 discloses a method of performing a corrosion treatment (etching treatment) on a metal surface with a chemical and injection molding a resin on the surface. Even if this technology is adopted, the bonding strength itself can be expected to be high, but it requires treatment before surface treatment such as anodic oxidation. There are problems such as necessary, partial processing is difficult, visual confirmation of the state of processing is difficult, the number of processing steps is relatively large, and processing is limited to aluminum material.

  Furthermore, there is a technique in which laser processing is performed on a metal material and then bonded to a resin. For example, Patent Document 1 discloses a technique in which a metal surface is irradiated with a laser beam to form irregularities, and then a resin is injection-molded and coated on the irregularity forming portion. When this technology is adopted, only necessary parts can be processed, the processing unit can be easily changed on the equipment program, it is relatively safe, there are few processing steps, and it supports automation. Advantages such as easy, can be assembled in later processes other than outsert molding, can confirm processing relatively easily by observing the processing surface, and does not require other materials only by processing materials There is an excellent point.

  However, the technique of Patent Document 1 cannot achieve extremely high adhesion between a metal material and a resin. Therefore, the adhesion problem has been a barrier to applying the technology to electronic products such as mobile phones.

Therefore, the present invention uses a laser processing technique that exhibits the many merits described above, and joins a metal material and a dissimilar material (for example, resin) with extremely high adhesion in a technique for joining a metal material and a dissimilar material (for example, resin). The purpose is to provide technology.
JP 10-294024 A

  According to the present invention (1), in a metal material having a joint for joining with a different material, the joint is subjected to laser scanning in a certain scanning direction, and then another scanning direction crossing the scanning direction. It is a metal material characterized by being formed by laser scanning processing.

  The present invention (2) is the metal material according to the present invention (1) in which both of the laser scanning process in the certain scanning direction and the different scanning direction are performed in a superimposed manner.

  According to the present invention (3), the laser scanning processing in the certain scanning direction and the other scanning direction is carried out with a hatching width of 0.02 to 0.6 mm, according to the invention (1) or (2) It is a metal material.

  The present invention (4) is the metal material according to any one of the inventions (1) to (3), wherein an angle at which the certain scanning direction crosses the other scanning direction is 45 ° or more.

  The present invention (5) is the metal material according to the invention (4), wherein an angle at which the certain scanning direction and the other scanning direction cross each other is approximately 90 °.

  According to the present invention (6), any one of the inventions (1) to (5), wherein the joint portion has an uneven shape, and at least a part of the convex portion has a bridge shape or an overhang shape. Or one metal material.

  In the present invention (7), when the specific resin is bonded to the bonding portion by injection molding, the specific resin bonded to the metal material has a peel strength of 4 MPa or more when destroyed according to JIS K6850, It is any one metal material of invention (1)-(6).

  The present invention (8) is the metal material according to any one of the inventions (1) to (7), wherein the dissimilar material is a thermoplastic resin, a thermosetting resin, an elastomer, or a plastic alloy.

  The present invention (9) is the metal material according to any one of the inventions (1) to (8), wherein the metal material is aluminum, magnesium or stainless steel.

  The present invention (10) is the metal material according to any one of the inventions (1) to (9), wherein the metal material is a component for an electric / electronic device.

  The present invention (11) is the metal material according to the invention (10), wherein the electrical / electronic device component is a casing for a mobile phone.

  It is a dissimilar-material joining metal material by which a dissimilar material is joined on the said junction part of any one metal material of this invention (1)-(11).

  The present invention (13) is the dissimilar material-bonded metal material according to the invention (12), wherein the dissimilar material-bonded metal material is a component for electric or electronic equipment.

  The present invention (14) is an electrical or electronic device in which an electrical or electronic component is mounted on the electrical or electronic device component of the present invention (13).

  The present invention (15) is the electrical or electronic device of the invention (14), wherein the electrical or electronic device is a mobile phone.

  The present invention (16) includes a step of laser scanning a metal surface in a certain scanning direction and a step of laser scanning the metal surface in another scanning direction crossing the scanning direction. It is a laser processing method of the metal surface for forming the junction part for joining with material.

  The present invention (17) is the method according to the invention (16), wherein both the laser scanning processing in the certain scanning direction and the different scanning direction are performed in a superimposed manner a plurality of times.

  The present invention (18) is the method according to the invention (16) or (17), wherein the laser scanning process in the certain scanning direction and the other scanning direction is performed with a hatching width of 0.02 to 0.6 mm. is there.

  The present invention (19) is the method according to any one of the inventions (16) to (18), wherein an angle at which the certain scanning direction and the other scanning direction cross each other is 45 ° or more.

  The present invention (20) is the method according to the invention (19), wherein an angle at which the certain scanning direction and the other scanning direction cross each other is approximately 90 °.

  As for this invention (21), while the said junction part has comprised uneven | corrugated shape, at least one part of the said convex part has comprised bridge | bridging shape or overhang shape, Any of the said invention (16)-(20) Is one way.

  The present invention (22) has a peel strength of 4 MPa or more when the specific resin bonded to the metal material is broken according to JIS K6850 when the specific resin is bonded to the bonding portion by injection molding. The method according to any one of the inventions (16) to (21).

  The present invention (23) is the method according to any one of the inventions (16) to (22), wherein the dissimilar material is a thermoplastic resin, a thermosetting resin, an elastomer, or a plastic alloy.

  The present invention (24) is the method according to any one of the inventions (16) to (23), wherein the metal material is aluminum, magnesium or stainless steel.

  The present invention (25) includes the steps of any one of the above-described inventions (16) to (24), and includes a metal material having a joint portion for joining to a dissimilar material. It is a manufacturing method.

  The present invention (26) includes the steps in any one of the methods (16) to (24), and a step of bonding a dissimilar material to the metal surface subjected to the laser scanning process. This is a method of joining a metal surface and a dissimilar material.

  The present invention (27) is the method according to the invention (26), wherein the joining step comprises injection molding of a different material on the metal surface.

  The present invention (28) is a method for producing a dissimilar material-bonded metal material, comprising the steps of the method of the invention (26) or (27).

  The present invention (29) is a method for producing an electric or electronic device, comprising each step in the method of the invention (28) and a step of mounting an electric or electronic component on the metal component.

  According to the present invention (1) and (12), the metal surface has a joining portion composed of a large number of protrusions (uneven portions) derived from the cross-shaped laser scanning process and having an excellent anchor effect. Compared with a conventional metal surface treated with a laser, the present invention has an effect of exhibiting a bonding strength with a very different material.

  According to the present invention (2), in addition to the above-described effect, the laser scanning process is performed a plurality of times in a superimposed manner, so that the shape of the protrusion at the joint is further complicated and exhibits a superior anchor effect. There is an effect.

  According to the present invention (3), in addition to the above effects, the laser scanning process is performed with a hatching width of 0.02 to 0.6 mm, so that the unprocessed part is formed as a projecting shape having a certain periodicity. As a result, there is an effect that a more excellent anchor effect is exhibited.

  According to the present invention (4), in addition to the above-mentioned effect, by setting the cross angle in laser scanning processing to 45 ° or more, the strength against a force from any direction can be maintained while maintaining a specific direction. As a result, it is possible to expect excellent bonding strength.

  According to the present invention (5), in addition to the above effects, the cross angle in the laser scanning process is set to approximately 90 °, thereby exhibiting an excellent bonding strength even with respect to the force from any direction. Play.

  According to the present invention (6), in addition to the above-described effect, the projection having a bridge shape has a foreign material solidified in a state where the foreign material has entered the hole, and the projection having an overhang shape has a foreign material. Since the dissimilar material is solidified in a state of enveloping the head, there is an effect that a more excellent anchor effect is exhibited.

  According to the present invention (7), in addition to the above effect, since the peel strength is 4 MPa or more, a high bonding strength that has so far had to be bonded to dissimilar materials using a strong adhesive or the like. It can be used for various products that are required.

  According to the present invention (8), in addition to the above effect, since it is a principle of holding a different material with a physical holding force called an anchor effect, any one of general-purpose materials such as a thermoplastic resin, a thermosetting resin, an elastomer, or a plastic alloy can be used. There is an effect that it can be joined without any problem.

  According to the present invention (9), in addition to the above effects, in the case of laser scanning processing, it is possible to form joints by changing laser processing conditions for general-purpose materials such as aluminum, magnesium or stainless steel. Compared with an etching process etc., there exists an effect that the breadth of material selection spreads.

  According to the present invention (10), (13) and (14), in addition to the above effects, the bonding strength between the metal material and the dissimilar material is extremely high. As a result that the joint portion is not easily damaged even by an impact such as dropping or vibration of the device, it is possible to effectively prevent a failure of the electric / electronic device caused by the damage of the joint portion.

  According to the present invention (11) and (15), in addition to the above-mentioned effects, because of its regularity or portability, it is applied to a mobile phone having the highest frequency of dropping / vibration among electric / electronic devices. There is an effect that it is possible to effectively prevent a mobile phone failure or the like due to the breakage of the joint portion.

  Further, according to the methods of the present invention (16) to (29), the effects relating to the product obtained by the method are as described above. However, if the effects of the method itself are listed, the machining shape and conditions can be freely set by a program. Unlike organic plating and etching, which can be used universally, it is easy to perform the required amount of processing at a predetermined location, and is safer than chemical etching using chemicals. Due to the nature, the work surface before processing does not require degreasing and is easy to manage. Compared to other processing methods, the number of processes is small and it is easy to handle automation. 01-0.1mm), it is easy to check whether it has been processed or not, and it can be processed with both surface-treated and untreated products such as anodized, so there is a high degree of freedom within the process. Not only outsert molding, but it is possible to join the resin and metal by heating and combining the metal members to the temperature at which the resin melts.If the resin can be poured into the bridge-shaped part, for example, the joint surface of the resin can be formed with chemicals. A wide range of applications, such as melting and pressurizing and bonding to the bridge-shaped part, and welding the resin to the bridge-shaped part by frictional heat generation using ultrasonic waves, is not limited to molding, and can be used for painting and plating. The improvement of the degree of joining by the anchor effect can be expected, and only the workpiece material is used, and other effects are not required.

First, the metal material according to the present invention is not particularly limited, and examples thereof include aluminum, magnesium, and stainless steel. When used as a casing for electric / electronic devices such as mobile phones and laptop computers, from the viewpoint of weight reduction, a single light metal having a density of 5 g / cm ³ or less, such as aluminum or magnesium, or these light metals as a main component. It is preferable to use an alloy. Further, the metal material may or may not be subjected to surface treatment such as anodic oxidation treatment or coating, and it has been confirmed that any metal material forms a bridge shape by laser scanning treatment described later.

  Next, the metal material which concerns on this invention has a junction part with a dissimilar material in the surface. Here, the joint portion has an uneven shape, and preferably, at least a part of the convex portion has a bridge shape or an overhang shape. Here, the “bridge shape” refers to a shape in which the tops of the generated convex portions are melted and connected to form an arch shape with a hole in the lower portion. Note that not all of the protrusions have a bridge shape, and some of the protrusions are overhanging to form a mushroom or cedar tree, or are simply convex without overhanging. Also good. Here, FIG. 1 shows an example of the bridge-like conceptual diagram. First, FIG. 1A shows a shape in which a hole is formed between both convex bodies so that both the one convex body and the other convex body collapse. Next, FIG. 1B shows a shape in which a hole is formed between both convex bodies so that one convex body collapses into the other convex body. Next, FIG. 1 (c) shows a shape in which a hanging bridge is hung between both convex bodies as a result of melting of one convex body and the upper part of the other convex body. Next, FIG.1 (d) is the shape (tunnel shape) by which the hole was formed in the center in the state which one convex body and the other convex body integrated.

  For example, when a bridge shape exists, the joint portion forms a fine three-dimensional network shape. When dissimilar materials are joined to the joint portion of such a surface structure (for example, resin is joined by injection molding), the dissimilar material enters into the pores under the concave portions / bridge portions of the fine three-dimensional network shape, resulting in a joining surface. As the surface area in contact with the dissimilar material increases, an extremely high anchor effect is exhibited. This makes it possible to bond the metal and the dissimilar material firmly and stably without using a bonding agent such as an adhesive or treating the metal surface with a chemical.

Next, the physical properties of the joint portion having the bridge shape will be described. The peel strength when a specific resin (standard sample) is bonded to the bonded portion is preferably 4 MPa or more, more preferably 6 MPa or more, and further preferably 10 MPa or more. It is. If this level of peel strength is achieved, the metal and the dissimilar material can be firmly and stably bonded without using a bonding agent such as an adhesive or without treating the metal surface with a chemical. However, the strength is a peel strength when a “specific resin” is bonded to the end, and the actual peel strength varies depending on the type of “different material”. For example, when an elastomer (elastic body) is used as the “dissimilar material”, the actual peel strength itself is low (however, since the elastomer is strongly bonded to the joint, the actual peel strength Is measured at the level where the elastomer remains peeled on the joint surface). The “peel strength” in the claims and in the present specification shall be performed in accordance with “Test method for tensile shear bond strength of adhesive-rigid adherend” in JIS K6850. The test is generally performed by fixing both ends of the test piece to the chuck, applying a tensile load at a constant speed, and recording the load when the joint surface peels or the load when the material breaks (tensile strength). To do. Here, so that only a horizontal tensile load is applied to the test piece (so that no vertical load is applied), as shown in FIG. 2 (B), the support is applied to both the resin surface and the metal surface to adjust the thickness. . Further, the “specific resin” serving as the standard sample is a PBT resin (for example, “Toray Toraycon (registered trademark) 1101G30 Bk”). For reference, FIG. 2A shows a measurement example of the peel strength in this specification. Here, in the figure, “1” indicates a metal material, “2” indicates a specific resin (PBT), “3” indicates a support, and “A” indicates a joint area. However, since the peel strength is a value obtained by dividing the tensile strength by the area of the joint, it is not basically restricted by the conditions shown in FIG. In this example, Toyo Seiki Strograph V10-C (trademark) is used as the tensile tester, the distance between chucks (the distance between the upper and lower chuck tips) is set to 30 mm, and the pulling speed is set to 5 mm / min. went.

  Next, a method for forming the joint will be described. The joint is formed by irradiating a laser beam and processing the metal surface under the conditions of grooving, melting, and re-solidifying. More specifically, the laser scanning process is performed in a certain scanning direction, and then the laser scanning process is performed in another scanning direction crossing the scanning direction. Hereinafter, with regard to suitable conditions for cross laser scanning, first, suitable conditions relating to “cross angle” and “number of repeated processes”, which are particularly important parameters, will be explained, and then preferred conditions relating to other parameters will be explained sequentially. .

  First, the cross angle (processing direction) is preferably such that the angle between one scanning direction and another scanning direction is 10 ° or more, and more preferably 45 ° or more. That is, it is important that the scanning direction of the next processing is not the same as that of the previous processing. Furthermore, it is optimal that the cross angle is approximately 90 ° in that a high bonding strength can be obtained with respect to a tensile load from any direction.

  Next, the number of times of repeated processing (the number of times of superimposition and the number of cross hatching) is appropriately determined by those skilled in the art based on the type, cross angle (processing direction), output, etc. of the metal material to be processed. Here, generally, when the number of times of repeated processing is too small, it is difficult to form a joint portion having a high anchor effect (for example, a convex portion has a bridge shape or an overhang shape). On the other hand, when the number of times of repeated processing is too large, the processing time increases, and the joint portion having a high anchor effect may be damaged. For example, when the cross angle is approximately 90 °, 8 to 10 times is preferable for SUS, and 4 to 5 times is preferable for Mg. Here, the processing conditions of a certain process and the subsequent process may be changed. For example, a mode in which deep surface roughening is performed with a relatively large output at the first time and the shape is adjusted at the second time can be exemplified. In addition, regarding the laser processability due to the difference in color, it is generally said that the processability of silver-based systems, and even wine red and orange systems, will be degraded due to the difference in reflectance at the same output. . However, since the processing is repeated many times while changing the scanning direction, it has been confirmed that there is no significant difference in the processed surface even if processing is performed under the same conditions. Further, for example, it has been confirmed that the same effect can be obtained even if the processing method is rotated by 45 ° and processed four times after processing in the scanning direction of 0 °.

  Next, preferable conditions for other parameters relating to laser scanning will be described in detail. First, other parameters include processing machine output, hatching width, balance between laser beam spot diameter and hatching width, and the like. The suitable conditions for these parameters vary depending on the type of metal material to be processed, the required peel strength, the output of the laser device used, and the like. Hereinafter, general preferred conditions for each parameter will be described.

  First, the “processing machine output” is preferably set to 80% or more and more preferably 92 to 95% in a model having an average output of about 20 W. For equipment with large output, increasing the set output can reduce the number of machining operations and shorten the machining time. For example, the workability is higher at 40 W than at 20 W (the laser scanning set speed / frequency can be increased). In this case, the number of cross-hatchings can be reduced somewhat (for example, in the case of SUS, it is 8 to 10 times at 20 W, but about 6 to 8 times at 40 W). In the case of a metal material that has not been anodized, the output needs to be set higher than that of an anodized material.

  Next, in general, the “hatching width” is preferably 0.02 to 0.6 mm. When the setting value of the hatching width is small, the amount of program increases and a load is imposed on the equipment, and the machining cost increases due to an increase in machining time. On the other hand, when the set value is large, the pitch width is too wide and it is difficult to form an uneven shape with a high anchor effect. FIG. 14 shows the concept of hatch width. The hatching width is preferably determined by the type of metal material. For example, a material with good workability, such as Mg, is set to have a wide hatching width because the unevenness is crushed unless the hatching width is relatively wide. On the other hand, a material with not so good workability, such as SUS, The hatch width can be set in a relatively wide range. Furthermore, when the output of the processing machine is increased, the workability is improved and the influence on the periphery of the processed portion is large, and flat processing is likely to be performed. Therefore, it is preferable to set the hatching width positively.

  Next, “the balance between the laser beam spot diameter and the hatching width” is preferably set to 50 to 300% of the beam spot diameter, and more preferably to 60 to 150%. For example, when the laser beam spot diameter of the 20W model is set to Φ0.1 mm, the setting hatching width is 0.05 to 0.3 mm, and more preferably 0.06 to 0.15 mm.

  Next, the use of the metal material having such a joint will be described. Since this metal material can be firmly joined to a different material at the joint, it is suitable to be used as a part for an electric or electronic device in which impact such as dropping or vibration is not preferable. For example, it is useful as a housing for electric / electronic devices having a resin boss, a holding member and the like inside. Here, as a case for electric / electronic devices, in addition to mobile phones, cases for portable video electronic devices such as cameras, video integrated cameras, digital cameras, notebook computers, pocket computers, calculators, electronic notebooks , Portable information such as PDC, PHS, mobile phone, etc., housing of communication terminals, MD, cassette headphone stereo, housing of portable acoustic electronic equipment such as radio, LCD TV / monitor, telephone, facsimile, hand scanner, etc. A housing of household appliances and the like can be given.

  Here, the “dissimilar material” is not particularly limited as long as it is a material that can be bonded at a temperature lower than the melting point of the metal material, and examples thereof include a thermoplastic resin, a thermosetting resin, an elastomer, and a plastic alloy. it can. Furthermore, it may be a material that cures by heat other than heat, such as a material that is cured by energy other than heat, such as a photo-curing resin, or a material that is chemically solidified by mixing a plurality of components. More specifically, as the thermoplastic resin (general purpose resin), for example, polyethylene (PE), polypropylene (PP), polystyrene (PS), acrylonitrile / styrene resin (AS), acrylonitrile / butadiene / styrene resin (ABS), Examples of methacrylic resin (PMMA), vinyl chloride (PVC), and thermoplastic resin (general-purpose engineering resin) include polyamide (PA), polyacetal (POM), ultrahigh molecular weight polyethylene (UHPE), polybutylene terephthalate (PBT), Examples of GF-reinforced polyethylene terephthalate (GF-PET), polymethylpentene (TPX), polycarbonate (PC), modified polyphenylene ether (PPE), and thermoplastic resin (super engineering resin) include polyphenylene. Sulfide (PPS), polyetheretherketone (PEEK), liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polyetherimide (PEI), polyarylate (PAR), polysulfone (PSF), polyethersulfone ( PES), polyamideimide (PAI), and thermosetting resin include, for example, phenol resin, urea resin, melamine resin, unsaturated polyester, alkyd resin, epoxy resin, diallyl phthalate, and elastomer as thermoplastic elastomer and Examples of the rubber include styrene / butadiene, polyolefin, urethane, polyester, polyamide, 1,2-polybutadiene, polyvinyl chloride, and ionomer. Furthermore, what added the glass fiber to the thermoplastic resin, a polymer alloy, etc. can be mentioned.

  Further, when bonding different materials (for example, resin) to the metal material, it is preferable to perform bonding by a well-known injection molding. The injection molding may be either outsert molding or insert molding. Here, from the viewpoint of the necessity of firmly transferring the laser bridge processed surface, it is more preferable that the mold temperature and the resin temperature are set higher and the injection pressure is higher because transferability is better. However, since the surface roughness of the laser bridge processing surface is 0.05 to 0.1 in terms of the maximum height (Rmax), it can be sufficiently flowed to the processing surface without forcibly setting the resin temperature high. .

  Hereinafter, in order to deepen the understanding of the present invention, more specific description will be given with reference to examples. Note that the technical scope of the present invention is not limited in any way by this example. Here, the laser marker used in the present embodiment is Cobra, manufactured by Electrox {Laser type: continuous wave / Nd with Qswitch: YAG, oscillation wavelength: 1.064 μm, maximum rated output: 20 W (average)}. Further, “XY” in the “scanning situation” means that after the scanning process in the X ° direction, the operation process is performed in the Y ° direction.

Example 1 (Measurement of peel strength for each base material)
For each of aluminum (A1050-H24), magnesium (AZ31) and stainless steel (SUS316), after forming joints under the laser processing conditions shown in Table 1, the molding shown in Table 2 is performed according to the protocol shown in FIG. Under the conditions, a standard material (PBT resin) was applied on the joint, and then the tensile shear strength was measured. The results are shown in Table 3. The numerical values in Table 3 are peel strengths, which are values obtained by dividing the tensile shear strength (N) by the bonding area (0.5 cm ² ). 3 and 4 show an SEM image of the joint formed on the magnesium surface and an SEM image of the joint formed on the stainless steel surface. Furthermore, the SEM image of the junction part cross section formed in FIG. 5 at the stainless steel surface is shown. The beam spot diameter was set to about 130 μm.

Example 2 (Peel strength test by difference in surface treatment)
We investigated how the strength of the metal surface subjected to laser scanning changes depending on the surface treatment. Specifically, for aluminum (A1050-H24, t = 0.6 mm), (1) anodized silver (silver), (2) anodized black (black), (3) anodized After forming a joint part under the laser processing conditions shown in Table 4 for each of those not subjected to the treatment (nothing), a standard is formed on the joint part under the molding conditions shown in Table 5 according to the protocol shown in FIG. The material (PBT resin) was applied and then the tensile shear strength was measured. The results are shown in Table 6. Here, the numerical values in Table 6 are peel strengths, which are values obtained by dividing the tensile shear strength (N) by the bonding area (0.5 cm ² ). The beam spot diameter was set to about 130 μm.

Example 3 (joint surface state confirmation test due to difference in the number of machining operations)
It was confirmed by SEM how the joint (joint surface) changed when the number of processings was changed. Specifically, a joint was formed on magnesium (AZ31, t = 0.4 mm) under the laser processing conditions shown in Table 7. The results are shown in Table 8. Further, FIG. 6 (1) is an SEM image showing the surface state of the joint when the number of times of machining is three, and FIG. 6 (2) is a diagram of the joint when the number of times of machining is five. It is a SEM image which showed the surface state. The beam spot diameter was set to about 130 μm.

Example 4 (Tensile strength test when different material 1 is used)
The tensile strength when different materials actually applied to products were joined to the joints of each metal material was examined. Specifically, it is shown in Table 9 for each of aluminum (A1050-H24, t = 0.6 mm), magnesium (AZ31, t = 0.4 mm) and stainless steel (SUS316, t = 0.4 mm). After forming the joint under the laser processing conditions, ABS resin (Denka Marekka ( Denka Marekka) is formed on the joint under the molding conditions shown in Table 10 (molding machine: Yamashiro Seiki, vertical molding machine, 50t) according to the protocol shown in FIG. (Registered trademark) K-095 Bk, normal molding temperature: 230 ° C.), and then the tensile shear strength was measured. The results are shown in Table 11. For SUS, standard sample (PBT) data is also shown. The beam spot diameter was set to about 130 μm.

Example 5 (Tensile strength test when different materials 2 are used)
The tensile strength when different materials different from Example 4 were joined to the joint portion of the metal material was examined. Specifically, after forming a joint portion with stainless steel (SUS316, t = 0.4 mm) under the laser processing conditions shown in Table 12, the molding conditions (molding) shown in Table 13 are performed according to the protocol shown in FIG. Machine: Yamashiro Seiki, vertical molding machine, 50t), PC resin (polycarbonate; Mitsubishi Iupilon (registered trademark) GS2030MKR) was applied onto the joint, and then the tensile shear strength was measured. The results are shown in Table 14. The standard sample (PBT) data is also shown. The beam spot diameter was set to about 130 μm.

Example 6 (Tensile strength test when different material 3 is used)
The tensile strength when different materials different from those in Examples 4 and 5 were joined to the joint portion of the metal material was examined. Specifically, after forming a joint portion on stainless steel (SUS304CSP, t = 0.25 mm) under the laser processing conditions shown in Table 15, molding conditions (molding) shown in Table 16 are followed according to the protocol shown in FIG. Machine: Yamashiro Seiki, vertical molding machine, 50t) PPS resin {Tosoh SUSTEEL (registered trademark) GS40 3202 (GF40%)} and standard resin (PBT resin) are applied on the joint, and then tensile shear strength Was measured. The results are shown in Table 17. The beam spot diameter was set to about 130 μm.

Example 7 (Tensile strength test when different materials 4 are used)
In Examples 4 to 6, a thermoplastic resin was used as a different material, but in this example, a case where a thermoplastic elastomer was used as a different material was tested. Specifically, FIG. 2 shows each of aluminum (A1050-H24, t = 0.6 mm), magnesium (AZ31, t = 0.4 mm), and stainless steel (SUS316, t = 0.4 mm). According to the protocol (however, the processing area was 4.5 mm × 9 mm = 40.5 mm ² ), after forming the joint part under the laser processing conditions shown in Table 18, polyester was formed on the joint part under the molding conditions shown in Table 19 A thermoplastic elastomer (Mitsubishi Primalloy (registered trademark) AN1600N 68 degrees) was applied, and then the tensile shear strength was measured. The results are shown in Table 20. The beam spot diameter was set to about 130 μm.

Example 8 (Temperature cycle test of metal-dissimilar material joint member)
With respect to the joining member according to Example 1 in which a standard material (PBT resin) was applied to aluminum, a temperature cycle test was performed under the conditions shown in FIG. And the intensity | strength measurement test was done before and after the said test, and the influence of the intensity | strength with respect to a temperature change was investigated. The outline of the test is that a 20-cycle test is performed in the range of −20 to 100 ° C. with 4 hours as one cycle (test machine: ETAC HIFLEX TH4114 (trademark) ). The results are shown in Table 21 and FIG. In addition, the underline in Table 21 indicates material destruction (not the bonded portion but the resin material itself is broken).

Comparative Example 1 (Comparison of strength with thermal adhesive sheet / adhesive)
Instead of joining the metal material and the dissimilar material via the joint formed by laser processing, the metal material and the dissimilar material were joined via the thermal adhesive sheet and the adhesive, and the tensile strength was measured. Specifically, first, for the thermal adhesive sheet, a thermal adhesive sheet (NITTO M-5205 (trademark) , t = 90.0 μm) is temporarily attached to the joint portion of a metal test piece (SUS316, t = 0.4 mm). The resulting product was attached to a mold, subjected to outsert molding and bonded to a resin, and then the tensile shear strength was measured. Table 22 shows the molding conditions. Next, as for the adhesive, a metal piece (SUS316, t = 0.4 mm) is degreased with toluene, and then an adhesive (2 liquid epoxy resin adhesive: Konishi Quick 5 (trademark) ) is applied and molded in advance. The resin part was affixed and fixed, and left for 2 days, and then the tensile shear strength was measured. The results are shown in Table 23 and FIG. In addition, the data of the stainless steel of Example 1 are shown for comparison.

  Next, the following embodiment is an embodiment in which the present invention is applied to a drawn product in the image of a liquid crystal side exterior panel of a mobile phone. The “peel strength” described in the following examples was obtained by a measurement method different from the above-described peel strength (strength based on a measured value according to JIS K6850), and is therefore only a reference value. Should be recognized as.

Example 9 (anodized aluminum)
Material: Aluminum A1050-H24 Plate thickness = 0.5 mm Anodized product Anodized product (plate thickness 0.5 mm) was modeled on the liquid crystal side exterior panel of a mobile phone. Then, as shown in FIG. 10, laser marking was performed in the vicinity where the boss shape was outsert-molded. Here, Table 24 shows the processing conditions for Example 9A {alumite (blue)}, and Table 25 shows the processing conditions for Example 9B {alumite (silver)}. The beam spot diameter was set to about 124 μm.

  Example 9A {Alumite (blue)} and 9B {Alumite (silver)} both have slight differences in the shape of the processed surface, but a shape in which the convex and concave portions are overhanged is obtained. By turning around, a surface that can be firmly joined by the anchor effect was obtained. Here, FIG.11 and FIG.12 shows the uneven | corrugated shaped electrophotography formed in the metal surface part (joining part) of Example 9A and Example 9B. First, FIG. 11 is an electrophotographic image according to Example 9A, FIG. 11 (1) is an electrophotographic image from the upper surface of the processed surface, and FIGS. 11 (2) and 11 (3) are processed images of the processed surface. It is an electrophotography from an angle of 30 ° (difference in scale). As can be seen from FIGS. 11 (2) and 11 (3), when viewed from the perspective, a very complicated bridge shape can be observed. Next, FIG. 12 is an electrophotographic image according to Example 9B, FIG. 12 (1) is an electrophotographic image from the upper surface of the processed surface, and FIGS. 12 (2) and 12 (3) are processed surfaces. It is an electrophotography from 30 degrees diagonally (difference in scale). As can be seen from FIG. 12 (2) and FIG. 12 (3), when viewed from the perspective, intricate anchor shapes and holes are seen in the standing wall.

Subsequently, according to the protocol shown in FIG. 10, this processed product was subjected to outsert molding to produce a composite member of metal and resin. After molding, the resin part was peeled off and the joint surface was observed. As a result, it was confirmed that the resin chipped firmly and the pieces of resin that had been peeled off were left behind in the metal groove part and transferred sufficiently. Then, as a result of measuring the peel strength according to the protocol of FIG. 10, Example 9A is 17.0 kg · cm / cm ² (166.6 N / cm), and Example 9B is 20.0 kg · cm / cm ² ( 196.0 N / cm). This is a remarkably high bonding strength compared to bonding with other adhesives or thermal bonding sheets. Moreover, the embodiment implemented this time is less than half of the processing area of the adhesive and the heat bonding sheet as shown in the figure below. Therefore, when the processing ranges are compared with the same area, it is predicted that this difference will further widen. The peel strength was calculated according to the following calculation formula.

Furthermore, as a result of carrying out the temperature cycle test and the drop impact test, no peeling of the joint was observed, and in the fracture strength measurement performed thereafter, no great difference was seen compared to the untested product. The test method is as follows.
Temperature cycle test −20 ° C. 2 hours to 100 ° C. A 20 cycle test is performed under the setting conditions of 2 hours.
Drop impact test After fixing 56.2 g of stainless steel dummy block to four bosses with M1.7L = 3 self-tapping screws, drop it once from each of six directions in the direction of 1500 mm to Check for damage.

Example 10 (anodized untreated aluminum)
Material: Aluminum A1050-H24 Thickness = 0.5mm Anodized untreated product A drawn product (thickness 0.5mm) that imaged the liquid crystal side exterior panel of a mobile phone was used. Then, as shown in FIG. 10, laser marking was performed in the vicinity where the boss shape was outsert-molded. Here, Table 27 shows the processing conditions of Example 10. The beam spot diameter was set to about 130 μm.

By this treatment, a shape in which the convex and concave portions were overhanged was obtained. Here, FIG. 13 shows an uneven-shaped electrophotographic image formed on the metal surface portion (joint portion) of Example 11. FIG. First, FIG. 13 (1) is an electrophotography from the upper surface of the processed surface, and FIGS. 13 (2) and 13 (3) are electrophotographic images from an oblique 30 ° of the processed surface (difference in scale). . As can be seen from FIGS. 13 (2) and 13 (3), the bridge shape and the anchor shape can be observed when viewed from the perspective. The peel strength was measured and found to be 13.0 kg · cm / cm ² (127.4 N / cm). Further, no peeling of the joint was observed in the temperature cycle test.

Comparative Example 2 (various adhesives)
1. Modified silicone adhesive Konishi FD107 (trademark)
2. Epoxy adhesive Konishi Quick 5 (trademark)
The boss formed in advance was adhered to a predetermined position on the back surface of the metal panel with an adhesive, and the breaking strength was measured. Here, the contact area per boss portion was 62.60 mm ² . In the case of the adhesive, the contact area is larger than that of other joints because the adhesive protrudes all around the contact area in addition to the contact area. As a result of measuring the peel strength, the adhesive 1 was 0.4 kg · cm / cm ² (4.07 N / cm), and the adhesive 2 was 1.3 kg · cm / cm ² (12.5 N / cm). Met.

Comparative Example 3 (thermal adhesive sheet)
1. Thermo Bond Film Sumitomo 3M TB F615EG (trademark) t = 62.5μm
2. NITTO M-5205 (trademark) t = 90.0μm
A thermal adhesive sheet was temporarily attached to the outsert molding position of the metal panel in advance, and the metal panel was molded under the same conditions as in Example 1, and the fracture strength was measured. As a result, the thermal adhesive sheet 1 was 2.1 kg · cm / cm ² (21.5 N / cm), and the thermal adhesive sheet 2 was 1.6 kg · cm / cm ² (16.0 N / cm).

FIG. 1 shows an example of a “bridge-like” conceptual diagram on the laser-treated surface (joint portion). FIG. 2 shows an outline of a method of measuring “peel strength” according to JIS K6850, as referred to in the claims and in the present specification. 2A is an example of measurement of “peel strength”, and FIG. 2B shows a state in which the thickness of the support is applied to both the resin surface and the metal surface. is there. FIG. 3 is an SEM image of the joint formed on the magnesium surface in Example 1. FIG. 4 is an SEM image of a joint formed on the stainless steel surface in Example 1. FIG. 5 is an SEM image of a cross-section of the joint formed on the stainless steel surface in Example 1. FIG. 6 shows the result of the joint surface state confirmation test in Example 3. Here, FIG. 6 (1) is an SEM image showing the surface state of the joint when the number of times of machining is three, and FIG. 6 (2) is the joint when the number of times of machining is five. It is the SEM image which showed the surface state of. FIG. 7 shows an outline of the temperature cycle test in Example 8. FIG. 8 shows the results of the temperature cycle test in Example 8. FIG. 9 shows the results of the tensile strength test in Comparative Example 1. In the figure, “1” is laser processing, “2” is an adhesive, and “3” is a thermal bonding sheet. FIG. 10 describes the measurement method of “peel strength” in Example 9 and below (different from “peel strength” defined in the claims and the like). FIG. 11 is an uneven-shaped electrophotographic image formed on the metal surface portion (joint portion) of Example 9A. FIG. 12 is an uneven-shaped electrophotographic image formed on the metal surface portion (joint portion) of Example 9B. 13 is an uneven-shaped electrophotographic image formed on the metal surface portion (joint portion) of Example 10. FIG. FIG. 14 shows the concept of hatching width.

Claims (13)

  Laser bonding of a metal surface in a certain scanning direction, and laser scanning of the metal surface in another scanning direction crossing the scanning direction. A laser processing method of a metal surface for forming a joint.   The method according to claim 1, wherein both the laser scanning processing in the one scanning direction and the other scanning direction are performed in a plurality of times in a superimposed manner.   The method according to claim 1 or 2, wherein both the laser scanning processing in the one scanning direction and the other scanning direction are performed with a hatching width of 0.02 to 0.6 mm.   The method according to claim 1, wherein an angle at which the certain scanning direction and the other scanning direction cross each other is 45 ° or more.   The method according to claim 4, wherein the crossing angle between the one scanning direction and the other scanning direction is approximately 90 °.   The method according to claim 1, wherein the joint portion has an uneven shape, and at least a part of the convex portion has a bridge shape or an overhang shape.   When joining specific resin to the said junction part by injection molding, peeling strength when destroying specific resin joined with the said metal material according to JISK6850 is 4 Mpa or more The method according to claim 1.   The method according to claim 1, wherein the different material is a thermoplastic resin, a thermosetting resin, an elastomer, or a plastic alloy.   The method according to claim 1, wherein the metal material is aluminum, magnesium, or stainless steel.   The manufacturing method of the metal material in which the junction part for joining with a dissimilar material was formed including each process in the method as described in any one of Claims 1-9.   Each step in the method according to any one of claims 1 to 9, and a step of bonding a dissimilar material to the metal surface that has been subjected to the laser scanning process. Joining method.   The method according to claim 11, wherein the joining step includes injection molding of a dissimilar material on the metal surface.   A method for producing a dissimilar material-joined metal material, comprising each step in the method according to claim 11 or 12.