JP2001071171A - Metal joining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously implement the excellent metal joining, and to improve the quality and yield of a joined metal part. SOLUTION: In a jig 13 to press a metal member by closely attaching or imposing an organic film 12 to a laser beam irradiation side of the metal member through the irradiation of the laser beam to join at least two metal members, a releasing material 14 heat-resistant against the heat generated during the joining is provided on a surface in contact with the organic film 12 of the jig 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal bonding apparatus using laser light.

[0002]

2. Description of the Related Art Soldering, spot welding and the like are generally used for metal joining. In addition, laser beams and electron beams are energy beams that can locally supply high-density power in a short period of time. However, laser beams are generally used more often than electron beams due to less thermal distortion. Have been. Further, a laser beam has an advantage that it can be easily incorporated into an automation device from the viewpoint of labor cost reduction and the like. In recent years, a laser beam has been frequently used as a metal bonding means in an automatic device.

[0003] As a laser beam, a CO ₂ laser, an excimer laser, a YAG laser or the like is used.

[0004]

In recent years, in a metal bonding apparatus using a laser, an organic film has been formed on the upper part (laser irradiation side) of a metal member to be bonded due to an increase in laser energy absorption and protection of a metal surface. Intervening increased.

However, in a conventional metal bonding apparatus using a laser, the organic film melted by the laser irradiation is welded to a jig for holding a bonding member (metal member), which hinders insertion of the next bonding member. There was a problem after joining, such as coming.

An object of the present invention is to provide a metal bonding apparatus capable of solving the problem of welding at a joint portion, which is an adverse effect caused by using the organic film, and improving the quality and yield of metal bonded parts.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for joining two or more metal members by irradiating the metal member with a laser beam. In a metal bonding apparatus having a jig for holding the metal member in close contact with or interposing a film, a release material having heat resistance to withstand heat generated at the time of bonding is provided on at least a surface of the jig which is in contact with the organic film. It is characterized by being carried out.

According to the present invention, by providing a release member made of a heat-resistant material film or an aggregate of fine particles or the like that withstands the heat generated at the time of bonding, at a predetermined position of the jig for holding the metal member. , Eliminating the welding of the organic film to such a jig, it is possible to perform good bonding continuously,
It is possible to improve the quality and the yield of the metal bonded parts.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of the configuration of a metal bonding apparatus according to the present invention. In FIG. 1, 11 is a laser light guide tube, 12 is a laser light absorbing film (organic film),
13 is a jig for holding the metal member to be joined, 14 is a release material provided on the jig 13, 15 is one joining metal member,
Reference numeral 16 denotes the other bonding metal member, reference numeral 17 denotes a mounting table, reference numeral 18 denotes an opening for laser light irradiation, reference numeral 19a denotes a laser light absorption film feeding roller, and reference numeral 19b denotes a laser light absorption film take-up roller.

In the configuration of the present apparatus, the organic film 12
Can be continuously fed to the upper surface (the laser irradiation side) of the metal member 15 by the rollers 19a and 19b. Further, the metal members 15 and 16 to be joined can be continuously supplied onto the mounting table 17.

At the time of joining, the jig 13 descends, and the release material 14
The laser light is emitted from the laser light guide tube 11 through the opening 18 provided in the jig 13 in a state where the organic film 12 and the metal member 15 are in close contact with each other at the portion having.

When the joining is completed, the jig 13 is raised, the rollers 19a and 19b are rotated by a predetermined amount to newly feed out the organic film, and a member to be newly joined is supplied on the mounting table 17, and thereafter, the same operation is performed. Joining can be performed continuously.

At this time, in the apparatus of the present invention, since the release member 14 having releasability is provided on the surface of the jig 13 which comes into contact with the organic film 12, the organic film 12 is melted by the irradiation of the laser beam. However, welding to the jig 13 is prevented, continuous good bonding can be performed, and high quality metal bonded parts can be produced with high yield.

Specific examples of the release material 14 include polystyrene, polyamide, polyimide, and polytetrafluoroethylene for organic materials, and ceramics (Al ₂ O ₃ , SiO ₂ , ZrO ₂ , and Cr for inorganic materials).
₂ O ₃ , BaTiO ₃ , Fe ₂ O ₃ , LiTaO ₃ , BN
Etc.), phosphate or chromium, nickel, gold, silver,
Platinum, their alloys or oxides are mentioned.

The release material 14 preferably has heat resistance enough to withstand the heat generated at the time of joining and has a melting point higher than the melting point of the organic film 12, and more preferably 50 degrees than the melting point of the organic film 12. Those with a melting point higher than ℃ are good.

As a specific combination with the organic film 12 when an organic material is used as the release material 14, for example, when polyethylene terephthalate (melting point: 265 ° C.) is used as the organic film, polyimide (melting point) is used as the release material. : 400 ° C), polytetrafluoroethylene (melting point: 330 ° C), polyphenylene sulfide (melting point: 290 ° C) and the like can be used. When polyethylene (melting point: 141 ° C.) is used as the organic film, polypropylene (melting point: 176 ° C.) and polyamide (melting point: 21 ° C.) other than the above materials are used as the release material.
6 ° C.), polystyrene (melting point: 250 ° C.), polyethylene terephthalate (melting point: 265 ° C.), and the like.

[0017]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Embodiment 1) In this embodiment, an example will be described in which the apparatus of the present invention as shown in FIG. 1 is used for manufacturing a solar cell as shown in FIG.

In FIG. 2, 21 is a positive electrode terminal member, 22 is a transparent electrode, 23 is a photoelectric conversion layer, 24 is a back reflection layer, 25 is a stainless steel substrate, 26 is a negative electrode terminal member, and 27 is a diode.

(1) Formation of Back Reflection Layer Rolled stainless steel substrate 25 made of SUS430BA
After cleaning, the substrate was put into a DC sputtering apparatus by a roll-to-roll method, and a Cr film to be the back reflection layer 24 was deposited to a thickness of 200 nm.

(2) Formation of Photoelectric Conversion Layer Next, the stainless steel substrate was put into an RF plasma CVD film forming apparatus, and an amorphous silicon photoelectric conversion layer 23 having a thickness of 400 nm comprising an n-layer, an i-layer, and a p-layer was formed using silane gas.
Was formed.

(3) Formation of Transparent Electrode Next, the stainless steel substrate was put into a resistance heating evaporation apparatus, and In ₂ O ₃ (IT) having a function of preventing reflection was used.
O) An 80 nm-thick transparent electrode 22 made of a thin film was formed.

(4) Cutting Next, the unnecessary part of the ITO layer is removed by a paste agent containing an ITO etching agent such as ferric chloride or hydrochloric acid, and then the solar cell is divided into a predetermined size to obtain a solar cell. Produced.

(5) Passivation The electrolytic cell is filled with a 10% aqueous solution of AlCl ₃ , the back surface of the stainless steel substrate 25 of the solar cell is covered with a plastic insulating film, immersed in the electrolytic cell, and Voltage of −4 V is applied to the
Hold for 2 seconds. In this step, the ITO and a part of the defective part in the shunt part were removed, and thereafter, washing and drying were performed.

(6) Formation of Negative Electrode Hard copper (thickness: 100 μm, width: 7 mm) was bonded to the back surface of the substrate as a negative electrode terminal member 26 by a YAG laser.

(7) Formation of Positive Electrode Insulating adhesive (silicone adhesive thickness 50 μm / polyimide thickness 25 μm / silicone adhesive thickness 25 μm
/ Polyethylene terephthalate thickness 75 μm / silicone adhesive thickness 50 μm) were bonded to both sides such that the polyimide surface side was arranged in the non-power generation region. Next, as a current collecting electrode (not shown), a carbon / silver-clad copper wire was placed at regular intervals on the surface of the substrate in consideration of prevention of migration, and the ends were fixed with the insulating adhesive. next,
Silver-plated hard copper (having a thickness of 10
(0 μm, width 5.5 mm) on the current collecting electrode and the insulating adhesive. Next, in order to adhere the current collecting electrode to the transparent electrode layer, heat compression was performed at 200 ° C. under a pressure of 1 kg / cm ² for 1 minute. Next, in order to make the collecting electrode and the positive electrode terminal member 21 more closely contact each other, the positive electrode terminal member was heated at 200 ° C. and a pressure of 5 kg.
/ Cm ² for 15 seconds.

(8) Hard Coat The back surface of the solar cell was covered with an insulating film made of plastic and immersed in an electrolytic cell so that the back surface was not electrodeposited. As the electrodeposition paint, an acrylic cationic electrodeposition paint having a solid content of 20% was used, and a voltage of -10 V was applied, the electrodeposition was maintained for 10 seconds to perform electrodeposition, and then the coating was held at 180 ° C. for 30 minutes to cure.

(9) Mounting Next, using the metal bonding apparatus of the present invention as shown in FIG. 1, the positive electrode terminal member 21 is arranged so that the current generated by the solar cell manufactured by the above process flows in one direction. A diode 27 for preventing reverse bias was attached between the negative electrode terminal member 26 and the solar cell with the diode 27 attached in series. Here, the diode 27 corresponds to one metal member 15 and the positive electrode terminal member 21
Alternatively, the negative electrode terminal member 26 corresponds to the other metal member 16.

First, in order to reduce the laser energy for metal bonding, a polyethylene terephthalate (melting point: 265 ° C.) tape-like film is used as the laser light absorbing film 12, and the diode as the bonding member 15 and a polytetrafluoroethylene film (melting point) are used. : 330 ° C.) and a jig 13 provided with a release material 14.

Next, the jig 13 is lowered by an external force, the jig 13 is brought into close contact with the laser light absorbing film 12 and the diode, and the YAG laser light is irradiated from the laser light guide tube 11 to the irradiation point shown in FIGS. 28 and were bonded. At that time, a part of the laser light absorbing film 12 was melted by heat generated at the time of laser joining.
Due to the effect of 4, when the external force was removed and the jig 13 was raised, the jig 13 and the laser light absorbing film 12 were not welded.

As described above, due to the action of the release material 14, the laser beam absorbing film welding failure due to the laser heat does not occur, and the metal bonding apparatus of the present invention operates without trouble at the next bonding portion, and as a result, the stability and the yield of the product are obtained. Improved.

(Embodiment 2) In Embodiment 1, a polytetrafluoroethylene film was coated as the mold release material 14. However, the release material 14 does not have to be in the form of a film. Effects were obtained, and as a result, the stability and yield of the product were improved as well.

(Embodiment 3) In Embodiment 1, the difference between the melting points of the laser light absorbing film 12 and the release material 14 is 65 ° C., but in this embodiment, the laser light absorbing film 12 is similarly made of polyethylene terephthalate having a melting point of 265 ° C. Use
A polyphenylene sulfide film (melting point difference: 25 ° C.) having a melting point of 290 ° C. was used as the release material 14, and the diode was joined by a laser in the same manner as in Example 1. As a result, there was some surface welding, though not to the extent of failure.

Further, when various combinations of the laser light absorbing film 12 and the release material 14 were verified,
In the present invention, it was found that the difference between the melting points of the laser light absorbing film 12 and the release material 14 is desirably 50 ° C. or more.

[0035]

As described above, according to the present invention,
When two or more metal members are joined by irradiating a laser beam guided by an optical system, a metal jig having a jig for holding the metal member by contacting or interposing an organic film on the laser irradiation side of the metal member In the apparatus, by providing a release material having heat resistance to withstand the heat generated at the time of bonding, at least on the surface of the jig that is in contact with the organic film, to eliminate the welding of the organic film to the jig, continuous As a result, good joining can be performed, and the quality and yield of the metal joined parts can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a metal bonding apparatus according to the present invention.

FIG. 2 is a perspective view illustrating a configuration of a solar cell used in an example.

FIG. 3 is a top view showing a diode junction position by laser light in the solar cell of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Laser light guide tube 12 Laser light absorption film 13 Joining member pressing jig 14 Release material 15 One metal member to be joined 16 The other metal member to be joined 17 Mounting table 18 Laser light irradiation opening 19a Laser light absorption film delivery Roller 19b Laser light take-up film take-up roller 21 Positive electrode terminal member 22 Transparent electrode 23 Photoelectric conversion layer 24 Backside reflection layer 25 Stainless steel substrate 26 Negative terminal member 27 Diode 28 Laser irradiation place at the time of diode bonding

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshifumi Takeyama 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 4E068 CE09 CG05 DB10 DB12 5F051 BA14 CB27 CB30

Claims (5)

[Claims] When joining two or more metal members by irradiating a laser beam, a metal jig has a jig for holding the metal member by contacting or interposing an organic film on the laser beam irradiation side of the metal member. A metal bonding apparatus, wherein a release material having heat resistance to withstand heat generated at the time of bonding is provided on at least a surface of the jig that contacts the organic film. 2. The metal bonding apparatus according to claim 1, wherein a melting point of the release material is higher than a melting point of the organic film. 3. The metal bonding apparatus according to claim 1, wherein the release material is made of any one of polystyrene, polyamide, polyimide, and polytetrafluoroethylene. 4. The metal bonding apparatus according to claim 1, wherein the release material is made of ceramic or phosphate. 5. The method according to claim 1, wherein the release material is chromium, nickel, gold,
The metal bonding apparatus according to claim 1, wherein the metal bonding apparatus is made of any one of silver and platinum, or an alloy or oxide thereof.