JP2002141644A - Method and apparatus for thermocompression bonding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermocompression bonding apparatus which prevents a carbide, a metal oxide or the like from being stuck to a heater tool when a wire is thermocompression-bonded to the electrode of an electronic component so as to be metal-bonded, which increases the reliability of a thermocompression bonding operation and whose rate of operation is enhanced. SOLUTION: The thermocompression bonding apparatus is provided with a work stage 1 on which the electronic component 10 comprising a terminal electrode 11 is mounted, the heater tool 20, and an arrangement means for a metal foil 30. The arrangement means arranges the metal foil 30 between the wire 12 placed on the terminal electrode 11 and the heater tool 20. The work stage 1 and the heater tool 20 sandwich and hold the electronic component 10, the wire 12, and the metal foil 30. The heater tool 20 presses the wire 12 to the terminal electrode 11 via the metal foil 30. The heater tool 20 heats the terminal electrode 11 and the wire 12 through the metal foil 30. The terminal electrode 11 and the wire 12 are metal-bonded and connected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermocompression bonding method and apparatus for thermocompression bonding a wire to an electrode of an electronic component.

[0002]

2. Description of the Related Art Conventionally, as a thermocompression bonding method or apparatus,
A configuration using a constantly heating type heater tool as shown in FIG. 5 (or a current-carrying type heating tool which energizes in a pulse only during heating) is known (for example, Japanese Unexamined Utility Model Publication No.
-82878, JP-A-7-162143).

In FIG. 5, 1 is a work stage (pedestal), 10 is an electronic component, 20 is a heater tool, and the electronic component 10 has a terminal electrode 11 and a wire 12 to be connected to the terminal electrode 11. Thus, it is positioned and placed on the work stage 1. However, in FIG. 5, the electronic component 10 and the work stage 1 are the terminal electrodes 11.
Only the periphery of the connection portion P between the wire and the wire 12 is shown in an enlarged manner.

In the standby state of FIG. 5A, the heater tool 20 waits at the raised position, and the electronic component 10 is positioned and placed on the work stage 1 in this state.

[0005] Next, the heater tool 20 descends and directly presses the heater tool 20 against the connection portion P (FIG. 5B).
Then, pressure is applied to the wire 12 and the terminal electrode 11 for a predetermined time, and the wire 12 and the terminal electrode 11 are heated and pressed.

Thereafter, the heater tool 20 returns to the raised position after the crimping as shown in FIG. 5C, and releases the electronic component 10.
At this time, if the wire 12 is a coated wire such as a urethane-coated copper wire, the coating is heated and peeled off, and a part thereof becomes a carbide and adheres as a deposit 13 to the lower surface of the heater tool 20 after crimping.

On the other hand, there is a prior art (Japanese Unexamined Patent Publication No. 9-162544: a method for joining electronic components) in which a specific object of thermocompression bonding is a liquid crystal display panel using an anisotropic conductive adhesive for a connection portion. This prior art has a mechanism of interposing an anti-adhesion sheet (in the embodiment of the prior art made of a fluororesin) between a heater tool and a connection portion, and the anisotropic conductive material protruding at the connection portion is provided. Works to keep adhesive from sticking to the heater tool.

Further, there is disclosed a mechanism in which the adhesion preventing sheet is in a tape shape (width 6 mm, thickness 0.05 mm), and the adhesion preventing sheet is wound up with the operation of the heater tool and unused portions are arranged. You.

However, since the embodiment of the anti-adhesion sheet is a fluororesin, and the specific object of the thermocompression bonding is a liquid crystal display panel using an anisotropic conductive adhesive for a connection portion, the heating is performed at about 210 ° C. However, there is a problem in that other joining materials such as solder may be used. If the adhesion preventing sheet is made of a polymer material such as fluororesin, it cannot withstand high temperatures such as soldering, brazing or welding. In addition, the polymer material has a poor thermal conductivity, making it difficult for the heat of the heater tool to be conducted to the connecting portion. Further, the polymer material is not suitable for conducting and diffusing heat from the heated connecting portion to quickly cool it.

[0010]

As shown in the prior art, for example, Japanese Unexamined Patent Application Publication No. H10-41152: Surface Mount Type Coil, Japanese Unexamined Patent Application Publication No. H11-176659: Low Profile Chip Type Coil Element, etc. It is known to thermocompress a site. According to that, the end of the winding is thermocompression bonded to the electrode formed on the core case (case core),
(1) A method of thermocompression bonding (the wire coating is melted by heat to form an alloy of copper and an electrode and fixed) without removing the coating of the winding end, and (2) Soldering of the winding end in advance It is stated that there is a method of soldering to the electrodes.

In either method, as shown in FIG. 5, the heater tool is raised and lowered in a standby state, a press-fit state, and after the press-fit. The end of the winding is placed on the electrode, and pressed from above with a heater tool in a crimped state. At this time, an energized heating type heater tool that energizes and heats the heater tool for a predetermined time is used, or a constantly heated type heater tool that constantly heats is used.

[0012] However, in any of the heating-type heater tools, carbides (for example, carbide of wire coating), metal oxides, and the like generated from the connection material due to the thermal influence at the time of thermocompression bonding adhere to the heater tools. Figure 5
Attachment 1 at lower end of heater tool 20 shown after crimping of (C)
3｝. The connection is not stable and the quality of the connection is poor, such as the poor transfer of heat from the heater tool to the connection part and the uneven pressurization of the connection part by the heater tool. It was a detrimental factor.

For this reason, when the carbide or metal oxide adheres to the heater tool and is removed, the heater tool is cleaned by mechanically polishing or the like by the adhered matter removing means. Further, the disadvantage that the usable life is shortened due to the wear of the heater tool cannot be avoided.

According to the joining method using a polymer material adhesion preventing sheet disclosed in the prior art of Japanese Patent Application Laid-Open No. 9-162544, a fluororesin is used for the adhesion preventing sheet. Cannot withstand high temperatures such as In addition, the polymer material has a poor thermal conductivity, making it difficult for the heat of the heater tool to be conducted to the connecting portion. Further, the polymer material is not suitable for conducting and diffusing heat from the heated connecting portion to quickly cool it. For this reason, it is not suitable for use in which a wire is thermocompression-bonded to an electrode of an electronic component for metal bonding.

In view of the above, the present invention prevents the adhesion of carbides, metal oxides, etc. to a heater tool when a metal is bonded to an electrode of an electronic component by thermocompression bonding of a wire, and the reliability of the thermocompression operation is improved. It is an object of the present invention to provide a thermocompression bonding method and apparatus capable of improving the performance and improving the operation rate of the apparatus.

Other objects and novel features of the present invention will be clarified in embodiments described later.

[0017]

According to a first aspect of the present invention, there is provided a thermocompression bonding method in which a wire is placed on an electrode of an electronic component, and a wire is placed between the wire and a heater tool. Arranging a metal foil, pressing the wire to the electrode through the metal foil with the heater tool and heating the electrode and the wire through the metal foil with the heater tool, the electrode and the wire It is characterized by being connected by metal bonding.

The thermocompression bonding method according to the invention of claim 2 of the present application
2. The method according to claim 1, wherein the thickness of the metal foil is 5 μm to 30 μm.
m.

The thermocompression bonding method according to the invention of claim 3 of the present application
The metal foil according to claim 1, wherein, when heated, heat diffusion of the metal foil to the electrode and the wire,
It is assumed to be negligible compared to the thermal diffusion between the electrodes and wires.

The thermocompression bonding method according to the invention of claim 4 of the present application is:
In claim 1, 2 or 3, the metal foil has a melting point higher than the melting point of the wire, and has a stable oxide film on the surface even when heated.

The thermocompression bonding apparatus according to the invention of claim 5 of the present application is
A work stage on which an electronic component having an electrode is placed; a heater tool; and metal foil arranging means, wherein the arranging means arranges the metal foil between the wire mounted on the electrode and the heater tool. Then, the work stage and the heater tool sandwich the electronic component, the wire, and the metal foil, the heater tool presses the wire against the electrode via the metal foil, and the heater tool The electrode and the wire are heated through the metal foil, and the electrode and the wire are connected by metal bonding.

The thermocompression bonding apparatus according to the invention of claim 6 of the present application is
In claim 5, wherein the metal foil is a metal foil tape,
The arrangement means is provided with a feeding mechanism and a winding mechanism of the metal foil tape.

The thermocompression bonding apparatus according to the invention of claim 7 of the present application is
According to a fifth aspect of the present invention, the metal foil is an endless metal foil tape, and the arranging means includes a traveling mechanism for traveling the endless metal foil tape.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a thermocompression bonding method and apparatus according to the present invention will be described below with reference to the drawings.

A first embodiment of the thermocompression bonding method and apparatus according to the present invention will be described with reference to FIGS. In these figures, an electronic component 10, which is an object to which a wire is thermocompression-bonded to an electrode, has a terminal electrode 11 and constitutes, for example, a coil. Here, if the electronic component 10 is described as a coil, a hatched portion indicates a core case (case core) 15, and the terminal electrode 1 is provided on the core case.
1 is provided. The configuration of the terminal electrode 11 is an electrode layer formed by printing and baking a metal paste such as silver or copper and then performing electrolytic plating or electroless plating with at least one of copper, nickel, lead, and tin.

FIGS. 1 and 2 show a main part of the thermocompression bonding apparatus. A work stage (pedestal) 1 fixed to a base of the thermocompression bonding apparatus has an electronic component 10 having a connection portion P positioned and mounted thereon. It is a place where it is placed. The heater tool 20 is a partial view in which only a lower end portion is drawn. The heater tool 20 moves up and down with respect to the work stage 1 as a unit including a lower end portion and a portion extending further upward. That is, although not shown, the thermocompression bonding apparatus includes a stand portion fixed to the base and protruding upward, and a guide mechanism for slidably guiding the heater tool 20 in a predetermined direction (here, a direction of ascending and descending) on the stand portion. Is provided. With this guide mechanism, the heater tool 20 can move up and down only in a predetermined direction with respect to the work stage 1.

Under the above configuration, the lower end of the heater tool 20 moves up and down with respect to the work stage 1 in the standby state of FIG. 1A, the crimped state of FIG. 1B, and the crimped state of FIG. The states are shown sequentially. The illustrated heater tool 20 is an energization heating type heater tool that energizes in a pulse only during heating.

The metal foil 30 disposed between the wire 12 on the electronic component 10 side and the heater tool 20 is, for example, SUS3
No. 04, a so-called 18-8 stainless steel foil. The thickness of the exemplary foil is 10 μm. The width of the metal foil in a direction perpendicular to the paper is slightly wider than the connection portion P, and is a tape-like shape extending from left to right on the paper and shows a part thereof. The thickness of the metal foil 30 is not limited to 10 μm,
The range may be 5 μm to 30 μm. If the thickness is less than 5 μm, manufacturing becomes difficult and the cost increases. If the thickness is more than 30 μm, the heat conduction of the heater tool 20 is hindered, the power consumption of the heater tool 20 increases, and the amount of materials increases. Is not preferred.

As shown in FIG. 1A, the electronic component 10, that is, the core case 15 having the terminal electrodes 11 is placed on the work stage 1. On the terminal electrode 11, for example, if the electronic component 10 is a coil, a wire 12 which is a winding end is placed. At this time, the core case 15, the terminal electrode 11, the wire 12 at the winding end, and the metal foil 30 are aligned on a center line extending the center of the direction in which the heater tool 20 moves up and down to the work stage 1. And

When the heater tool 20 is lowered in this state, the lower end of the heater tool 20 comes into contact with the upper surface of the metal foil 30 and is pushed down as shown in FIG. Core case 1 between the lower end surface of heater tool 20 and the mounting surface of work stage 1.
5, a terminal electrode 11, a wire 12 at a winding end, and a metal foil 30
Are sandwiched and a predetermined pressure is applied to create a crimped state. Further, a predetermined current is applied to the heater tool 20 for a predetermined time, and the heater portion of the heater tool 20 generates heat, thereby heating the upper surface of the metal foil 30 from the lower end surface. Metal foil 30
When the upper surface is heated, heat is transferred to the lower surface to heat the wire 12 at the winding end, and the terminal electrode 11 is further heated via the wire 12 at the winding end or directly from the lower surface of the metal foil 30. . The wire 12 at the winding end and the terminal electrode 11 are thermocompression-bonded at the connection site P by this crimping and heating.

The wire 12 is generally made of a urethane-coated copper wire, but the winding end of the urethane-coated copper wire remains coated with the urethane coating except for the cut end face, and the wire 12 at the winding end is crimped. Then, the urethane film is peeled off on the lower surface of the metal foil 30 by the heating. The peeled urethane film adheres to the lower surface of the metal foil 30 and partially carbonizes by heating. A part does not adhere to the lower surface of the metal foil 30 but adheres or remains around the terminal electrode 11. The wire 12 at the winding end where the urethane film was peeled off was pressed and heated,
It is flattened by being crushed in the crimping direction, and the wire 12 at the end of the winding and the terminal electrode 11 are connected by metal bonding due to mutual thermal diffusion.

At this time, the setting of the pressing load and the heating temperature is important.
Crimping dimension that becomes flat at 0 ° C to 500 ° C is 50 to 55 μm
become. Heating temperature 350 ° C assuming a crimping load of 100g
The crimping dimension becomes 56-87 μm at ~ 500 ° C, the crimping dimension becomes 94-111 μm at a heating temperature of 350 ° C-500 ° C when the crimping load is 150g, and the crimping dimension at the heating temperature 350 ° C-500 ° C when the crimping load is 200g. Is 132 ~
It has been confirmed to be 135 μm. Also, assuming that the terminal electrode 11 is an Sn electrode, the heating temperature is about 450 ° C. and the connection strength shows the largest value when the crimping load is 150 g. If the terminal electrode is a Ni electrode, the connection temperature is about 550 ° C. It has been confirmed that it shows the largest value. The heating temperature at which the connection strength shows the largest value is about 450 for the Sn electrode.
° C, about 550 ° C for the Ni electrode.

At these heating temperatures, the metal foil 30 is chemically stable without being deteriorated, and is chemically stable even if it is heated so that metal bonding or the like does not easily occur with the wire 12 or the terminal electrode 11 at the end of the contacting winding. Is desirable. In other words,
The metal foil 30 has a higher melting point than the terminal electrodes 11 and the wires 12, and the thermal diffusion of the metal foil 30 to the terminal electrodes 11 and the wires 12 during heating is higher than that between the terminal electrodes 11 and the wires 12. Can be ignored
Further, it is desirable that the surface has an oxide film that is stable even when heated. In addition, in order to reliably contact the lower end surface of the heater tool 20 and heat the connection portion P, the metal foil 30 is made of a material that maintains a predetermined mechanical strength even when heated and has a predetermined thermal conductivity. Select.

Stainless steel, SUS30, already exemplified
The foil No. 4 is an example of an optimum material from these viewpoints. SUS304 has a thermal conductivity of 12 W / m · K,
Even if it is heated to 800 to 900 ° C., it is chemically stable in the air, and no metal bond or the like occurs with the wire 12, the terminal electrode 11, or the like that comes into contact. Thermal conductivity is 43W of carbon steel
/ M · K or 275 W / m · K of copper
/ 23 is small. However, if the heat conductivity is too large, the heat is transmitted to a wide area of the metal foil 30, so that the heat is diffused to an extra portion of the metal foil 30 and the heat used is reduced. We believe that the disadvantages that require measures such as protection from high temperature due to the spread of heat generation will be noticeable.

As another material, the thermal conductivity of titanium is 1
The material is 3 W / m · K, is stable in the atmosphere even when heated, and does not cause metal bonding or the like to occur with the wires 12, the terminal electrodes 11, and the like that come into contact. However, SUS304
It is much more expensive and difficult to choose economically. Comparing these materials with a fluororesin (PTFE) known as an anti-adhesion sheet, the fluororesin generally has a thermal conductivity of 0.18 W / m ·
K, the melting point is 327 ° C., and the maximum continuous use temperature is 260 ° C. Although the usable temperature range is chemically stable in the atmosphere, the wire 1 at the winding end is connected to the terminal electrode 11.
The heating temperature for thermocompression bonding of 2 does not reach not only the maximum continuous use temperature but also the melting point. Furthermore, the metal foil 30 of SUS304 is an example of an optimum material at both the heating temperature and the heat conductivity, though the heat conductivity is low and is not suitable for thermocompression bonding of the wire 12 at the winding end to the terminal electrode 11.

The lower end of the heater tool 20 is made of molybdenum or the like, and is made of a metal material that does not easily diffuse heat.
The metal foil 30 does not adhere to the heater tool 20 side.

FIG. 2 shows a state in which a deposit 14 such as a carbide or a metal carbide adheres to the lower surface of the metal foil 30 after the pressure bonding. When the heater tool 20 descends and the lower end pushes down the upper surface of the metal foil 30, the lower surface of the metal foil 30 is pressed against the connection part P, and the heater tool 20 generates heat and heats the connection part P. In the case of a coated copper wire, the urethane film is heated and partly turns into carbide with peeling. Further, the copper wire and the terminal electrode 11 from which the urethane film has been peeled off,
When heated, a connection is formed by thermocompression bonding such as metal bonding, and a part of the connection becomes a metal carbide. These carbides or metal carbides and the like become the deposits 14, and the metal foil 30 reacts with these deposits 14 to form no SUS3.
04 is suitable. For example, a thermocompression bonding temperature of 500 ° C.
When thermocompression bonding is attempted under the following conditions, the thickness is 10 μm.
SUS304 stainless steel foil with metal foil 3
It was confirmed that good thermocompression bonding was possible without being affected by the heat capacity of the metal foil 30 by using 0.

According to the first embodiment, the following effects can be obtained.

(1) A metal foil 30 is arranged between the connection part P of the electronic component 10 and the heater tool 20, and the terminal electrode 11 and the wire 12 are pressurized via the metal foil, and the terminal electrode is connected via the metal foil. 11 and the wire 12 are heated, and the terminal electrode 11 and the wire 12 are connected (or joined) by metal bonding.
A metal foil such as stainless steel, which is chemically stable in the atmosphere even when heated to 800 to 900 ° C., is connected to a typical copper wire or a Sn electrode or a Ni electrode constituting a terminal electrode. By arranging between the part P and the heater tool 20, it is possible to prevent the adherence of the urethane film, carbide of the urethane film, and metal carbide to the heater tool 20 in connection (or joining) by metal bonding.

(2) The metal foil 30 is made of a material such as stainless steel or titanium having a melting point higher than the melting point of the wire 12 and having a stable oxide film on the surface even when heated. Metal foil electrode 11 and wire 12
Is negligible compared to the heat diffusion between the electrode 11 and the wire 12, and the metal foil 30 does not adhere to the electrode 11 or the wire 12, and a smooth crimping operation is possible.

(3) The thickness of the metal foil is 5 μm to 30 μm.
By setting the range of m, it is possible to secure appropriate heat conduction that can transfer the heat of the heater tool 20 to the connection portion P, and to reduce the manufacturing cost of the metal foil.

FIG. 3 shows a second embodiment of the present invention, which is an example having an arrangement means for disposing a metal foil on the lower end portion of the heater tool 20, wherein the arrangement means moves the position of the metal foil. It has a function to make it work.

In FIG. 3, the metal foil is formed as a metal foil tape 30A having a width in a direction perpendicular to the paper surface, and the arranging means includes a metal foil supply roll 41 as a feeding mechanism for the metal foil tape 30A and a winding mechanism. And a metal foil take-up roll 42. Then, the metal foil 30A drawn from the metal foil supply roll 41 in which the new metal foil tape 30A is wound in a coil shape is stretched around guide pins 44, a guide roller 43, a drive roller 45, a brake roller 46, and the like. To the metal foil take-up roll.

The metal foil supply roll 41 is rotatably suspended around a shaft provided at a predetermined position.
Numeral 2 is suspended on a drive shaft provided at a predetermined position, and the drive shaft is rotationally driven by a drive means such as an electric motor, so that the metal foil winding roll 42 winds the metal foil tape 30A. Guide pin 4
4, guide rollers 43, drive rollers 45, brake rollers 46, etc. are provided at predetermined positions, but FIG. 3 shows only the arrangement and omits the others.

The two drive rollers 45 are used for the metal foil tape 30.
A, and the driving roller 45 is driven to rotate in the direction of the arrow by driving means such as an electric motor. The metal foil tape 30 </ b> A is configured to be moved by the outer periphery of the driving roller 45 sandwiched between the metal foil tape 30 </ b> A and the driving roller 45.
A is taken up by the metal foil take-up roll 42 following. The two brake rollers 46 sandwich the metal foil tape 30A, and the brake roller 46 applies a tension in the opposite direction to the movement of the metal foil tape 30A by a torque motor or the like.
Then, the driving roller 45 runs the metal foil tape 30A against the brake roller 46, and the metal foil tape 30A
Is between the drive roller 45 and the brake roller 46,
By applying a torque in the opposite direction to the movement of the metal foil tape 30A to the brake roller 46, the tension is adjusted. Further, the guide roller 43 and the guide pin 44 stabilize the position of the metal foil tape 30A in the direction perpendicular to the moving paper surface, and the driving rotation of the drive roller 45 is performed by thermocompression bonding so that the deposit 14 adheres to the lower surface of the metal foil tape 30A. It is set according to the situation to be performed so that the same portion of the metal foil tape 30A is not continuously used for thermocompression bonding. Alternatively, when the metal foil tape 30A is continuously used a predetermined number of times, the metal foil tape 30A is fed by a predetermined amount (accordingly, intermittent feeding) within a range where the thermocompression bonding can be favorably continued, and the metal foil tape 30A having the attached matter 14 adhered to the lower surface.
Are sequentially wound around a metal foil winding roll 42.

The material of the metal foil tape 30A is the same as in the first embodiment, and the thermocompression bonding operation for the electronic component 10 is performed in the same manner as in the first embodiment.

According to the second embodiment, a new metal foil tape 30A can be automatically supplied, a used metal foil tape with an attached matter can be wound up, and a metal foil replacement operation can be performed. Therefore, the number of times the apparatus is stopped can be reduced to increase the operation rate.

FIG. 4 shows a third embodiment of the present invention, which is another example having an arrangement means for disposing a metal foil on the lower end portion of the heater tool 20. It has a function to move.

In FIG. 4, the metal foil is formed as an endless metal foil tape 30B having a width in a direction perpendicular to the paper surface, and the arranging means has a traveling mechanism for traveling the endless metal foil tape 30B.

The endless metal foil tape 30B has a width in a direction perpendicular to the plane of the paper, and the endless metal foil tape 30B is endless without a start end and an end. Endless metal foil tape 30B
Are the guide pin 44, the guide roller 43, the drive roller 4
5, circulates around the brake roller 46 and the like. The endless metal foil tape 30B, which is an endless tape, is stretched in a quadrilateral shape inside the connection portion P between the work stage 1 and the electronic component 10. Guide roller 43 for holding four corners, guide pin 44 for following from outside at four corners, drive roller 4
5, brake rollers 46, etc. are provided at predetermined positions, but FIG. 4 shows only the arrangement and omits the others.

The two drive rollers 45 arranged on the left side sandwich the endless metal foil tape 30B,
Reference numeral 5 denotes driving means such as an electric motor, which is driven to rotate in the direction of the arrow. The endless metal foil tape 30 </ b> B is
5, two brake rollers 46 arranged on the right side hold the endless metal foil tape 30B, and the brake roller 46 is connected to the endless metal foil tape 30B by a torque motor or the like. Gives tension in the opposite direction to the circulating movement. Then, the drive roller 45 circulates and moves on the endless metal foil tape 30B against the brake roller 46. The tension of the endless metal foil tape 30B is adjusted between the drive roller 45 and the brake roller 46 by applying a torque to the brake roller 46 in a direction opposite to the circulating movement of the endless metal foil tape 30B. Further, the circular brush 48 is arranged in contact with the lower surface of the endless metal foil tape 30B passing through the lower end of the heater tool 20, and the guide roller 47 is arranged on the upper surface of the endless metal foil tape 30B at that position. The circular brush 48 is driven and rotated by an electric motor (not shown), and the brush tip brushes the lower surface of the endless metal foil tape 30B in the direction opposite to the direction of the circulating movement. The guide roller 47 has a function of pressing the endless metal foil tape 30B so as not to float. Further, wiping pads 49 are provided on the upper surface side and the lower surface side of the endless metal foil tape 30B at the subsequent positions, and the upper surface side wiping pad 49 and the lower surface side wiping pad 49 sandwich the endless metal foil tape 30B. Wiping pad 4 by circulating movement of endless metal foil tape 30B
9 wipes the upper and lower surfaces of the endless metal foil tape 30B.
There is an advantage that the same endless metal foil tape 30B can be used repeatedly.

The material of the endless metal foil tape 30B is the same as in the first embodiment, and the thermocompression bonding operation for the electronic component 10 is performed in the same manner as in the first embodiment.

According to the third embodiment, extraneous matter can be circulated and supplied from the endless metal foil tape 30B, and it is not necessary to stop the apparatus for replacing the metal foil.

In each of the embodiments, an example has been described in which the electronic component is a coil. However, the present invention is applicable to any electronic component having a structure in which a wire is thermocompression-bonded to an electrode.

The wire is not limited to a wire having a circular cross section, but may be a flat wire, a lead frame, or the like.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and various modifications and changes can be made within the scope of the claims. There will be.

[0057]

As described above, according to the present invention, a metal foil is arranged between a connecting portion of an electronic component and a heater tool,
A method and apparatus for pressing an electrode and a wire via a metal foil, heating the electrode and the wire via the metal foil, and connecting (or joining) the electrode and the wire by metal bonding. As described using SUS304 and titanium as examples of the metal foil, such a metal foil is 800 to 9 times larger than a typical wire such as a copper wire or a Sn electrode or a Ni electrode constituting an electrode.
It is chemically stable in the atmosphere even when heated to 00 ° C,
These metal foils are placed between the connection part and the heater tool to connect (or join) the electrodes and wires by metal bonding.
In this case, it is possible to prevent the urethane film and carbides of the urethane film and metal carbide from adhering to the heater tool.

When a metal foil is formed as a tape and a metal foil arranging means having a metal foil tape feeding-out mechanism and a winding-up mechanism is provided, the metal foil tape is sequentially fed so that a new portion is compatible with a heater tool. In this position, the work can be continued without being bothered by the deposits while the metal foil is sequentially fed. This has the effect of facilitating automation of the thermocompression bonding apparatus and stabilizing the operation rate.

When a metal foil is formed on an endless tape and a means for removing extraneous matter is provided at a portion passing through a position corresponding to the heater tool, the same metal foil can be repeatedly used.

[Brief description of the drawings]

FIG. 1 is a first embodiment of a thermocompression bonding method and apparatus according to the present invention, and is an explanatory view showing a standby state and a compression bonding state.

FIG. 2 is an explanatory view showing a state after pressure bonding.

FIG. 3 is an explanatory diagram showing a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a third embodiment of the present invention.

FIG. 5 is an explanatory view of a conventional thermocompression bonding method and apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Work stage 10 Electronic component 11 Terminal electrode 12 Wire 13,14 Deposit 15 Core case 20 Heater tool 30 Metal foil 30A Metal foil tape 30B Endless metal foil tape P Connection site

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasuichi Abe 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDC Corporation F-term (reference) 5E319 AA07 AB01 CC12 GG20

Claims (7)

[Claims] 1. A wire is placed on an electrode of an electronic component, a metal foil is arranged between the wire and a heater tool, and the heater tool presses the wire against the electrode via the metal foil. A thermocompression bonding method comprising: heating the electrode and the wire through the metal foil with the heater tool; and connecting the electrode and the wire by metal bonding. 2. The thermocompression bonding method according to claim 1, wherein the thickness of the metal foil is 5 μm to 30 μm. 3. The metal foil according to claim 1, wherein the heat diffusion of the metal foil to the electrode and the wire during heating is negligible compared to the heat diffusion between the electrode and the wire. Thermocompression bonding method. 4. The thermocompression bonding method according to claim 1, wherein the metal foil has a melting point higher than the melting point of the wire, and has a stable oxide film on the surface even when heated. 5. A work stage on which an electronic component having an electrode is placed, a heater tool, and means for arranging a metal foil, wherein the arranging means is provided between a wire placed on the electrode and the heater tool. The work stage and the heater tool sandwich the electronic component, the wire and the metal foil, and the heater tool presses the wire against the electrode via the metal foil. A heating tool that heats the electrode and the wire through the metal foil and connects the electrode and the wire by metal bonding. 6. The thermocompression bonding apparatus according to claim 5, wherein the metal foil is a metal foil tape, and the arranging means includes a feeding mechanism and a winding mechanism for the metal foil tape. 7. The metal foil is an endless metal foil tape,
The thermocompression bonding apparatus according to claim 5, wherein the arranging means includes a traveling mechanism for traveling the endless metal foil tape.