JPH01308040A - Wire bonding of covered wire and device therefor - Google Patents

Abstract

PURPOSE:To make possible the removal of a heat-resistant covered wire and the formation of gold balls and moreover, to prevent a trouble to cause the generation of a leakage current by a method wherein a flame is irradiated on the end part of the covered wire while heat is dissipated by a gripping means to form the balls on an exposed core wire and these balls are fixed by pressure and are wire-bonded. CONSTITUTION:A covered wire 2 is fed out of a reel 11, dusts are removed by a dust removal means 12, the wire 2 is gripped by a starting end gripper 131 and one end part of the wire 2 is cut lefting a part, which corresponds to the thickness (a) of a cutting guide 153, of the one end part. Then, an oxyhydrogen gas or hydrogen gas flame from a covering removal and ball forming means 16 is irradiated on the part of the thickness (a) of one end part of the wire 2, a covering 22 is removed while heat is dissipated by a gripping means to expose a core wire 21 and a ball 23 is formed there. These balls are thermally fixed by pressure and are bonded on connecting pads 31 formed a multitude on a substrate 3. By the above method, the removal of the covering of the covered wire and the formation of the balls can be conducted; moreover, as the balls are insulated, a trouble to cause the generation of a leakage current is prevented and as the hydrogen flame or the oxyhydrogen flame is used, even a heat-resistant covering can be easily removed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to wire bonding using coated wire,
The present invention relates to a method and apparatus for removing coating from coated gold wire and forming gold balls.

[Conventional technology]

Conventionally, ball formation for metal wire ball bonding involves
For example, as described in Japanese Patent Publication No. 57-19055, a metal wire having a free end is prepared.

It has been proposed that the free end be made into a spherical shape by generating an electric discharge between the free end and a multi-layered pole disposed in the axial position of the metal wire so as to face the free end. There is.

[Problem to be solved by the invention]

In the above prior art, as shown in FIG. 21, when a ball is formed from the coated gold wire 2 using a discharge torch 165, as shown in FIG. 22, the coated gold wire 2 is required to have high heat resistance. In line 2, since the coating is not removed sufficiently, a bulge 24 of the coating with a thick part is generated, or a uneven bulge 25 is generated as shown in FIG. There is a problem in that the ball 23 is not perfectly spherical as shown in FIG. 22, or is eccentric as shown in FIG. 23, so that it cannot be formed into a sufficiently perfect spherical shape.

Furthermore, even if the coating is removed, as shown in FIG. 25, a bump-shaped bulge 26 may be formed, and if the coating is melted, the length Q of the rising portion may be longer than necessary, resulting in poor insulation. A problem had arisen.

The purpose of the present invention is to make it possible to remove coated wires or coated wires with high heat resistance, form gold balls, prevent the occurrence of failures in the generation of current between wires, and prevent wires from crossing each other or interleaving wires. An object of the present invention is to provide a coated wire bonding method and an apparatus therefor.

[Means to solve the problem]

In order to achieve the above objects, 1. In the coated wire wire bonding method of the present invention, an end portion of a coated wire in which the outer periphery of a conductive core wire is insulated is gripped by a gripping means, and the gripping means is used to radiate heat while bonding the coated wire. The coating is removed by irradiating a flame toward the end of the coated wire protruding from the gripping means, and a ball is formed on the exposed core wire, and the ball is crimped to perform wire bonding.

Furthermore, the gripping means is made of metal in order to reduce the discharge effect.

In addition, flames easily remove highly heat-resistant coatings, so
It uses a flame caused by hydrogen gas.

In addition, flames easily remove highly heat-resistant coatings, so
It uses a flame caused by hydrogen gas.

In addition, flames easily remove highly heat-resistant coatings, so
It uses a flame caused by oxyhydrogen gas.

Further, the crimping is carried out by thermocompression in order to prevent the peripheral surface of the ball and the surface of the crimping member from becoming dirty.

Further, the crimping is carried out by ultrasonic thermocompression so that the crimping can be carried out at low temperatures.

In addition, the coated wire wire bonding apparatus of the present invention includes a means for grasping the end of the coated wire in which the outer periphery of the conductive core wire is insulated, and a ball forming allowance for the end of the coated wire that protrudes from the grasping means. A means for removing the covering of the covered wire by irradiating a flame toward the ball-forming bone at the tip of the covered wire and forming a ball on the exposed core wire, and a means for bonding the ball by crimping the ball. and means for automatically controlling each of these means.

Furthermore, the gripping means is made of metal in order to improve the heat dissipation effect.

In addition, the covering removal/ball forming means removes the area around the tip of the covered wire and forms a ball on the core wire in a true spherical shape.
It is configured to irradiate a flame from a torch that is swingable toward the covered wire.

Further, the flame from the torch is made of hydrogen gas in order to easily remove the heat-resistant coating.

Further, the flame from the torch is composed of oxyhydrogen gas in order to easily remove the heat-resistant coating.

Further, the bonding ink means is configured to bond the ball by thermocompression bonding in order to prevent the peripheral surface of the ball and the surface of the pressure bonding member from becoming dirty.

Further, the bonding means is configured to bond the balls by ultrasonic pressure bonding in order to perform pressure bonding at a low temperature.

[For production]

In the coated wire wire bonding method described in 2, it is possible to remove the coat of the coated wire and form a ball, and since the coated wire is insulated, it may come into contact with the upper edge of the outer periphery of the connection chip, causing a leakage current failure. It is possible to prevent short circuits and edge shorts between adjacent wires.

In addition, since the gripping means is made of metal wire, it improves the heat dissipation effect and prevents unnecessary melting from rising when the coating bulges during coating removal and ball formation. can.

In addition, since the flame used was a hydrogen flame or an oxyhydrogen flame,
Even highly heat-resistant coatings can be easily removed.

Further, since the crimping is carried out by thermocompression, it is possible to prevent the peripheral surface of the ball and the surface of the crimping member from becoming dirty.

Furthermore, since the crimping is performed by ultrasonic thermocompression, balls can be ball-bonded even at low temperatures.

In addition, the coated wire wire bonding apparatus configured as described above can automatically remove the coat of the coated wire, form a ball, and bond and ink the ball, and bond the ball after removing the coat and forming the ball. Therefore, it is possible to prevent substances removed during coating removal and scattered gas from adhering to the bonding ink part, and also to prevent high temperature, such as hydrogen gas, from adhering to the bonding part, and the ball can be formed into a predetermined shape. Since bonding is performed after confirming that the ball is in good condition, it is possible to eliminate bonding defects due to defective balls.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 20 showing a coated wire bonding apparatus according to an embodiment of the present invention will be described below.

As shown in FIG. 1, a covered wire wire bonding apparatus 1 according to the present invention includes a reel 11 rotatably supported on a base 10 via a bracket 101, and a bracket 10.
1 is fixedly supported, and the target jW is reeled out from the reel 11.
A dust removing means 12 for removing dust and foreign matter (hereinafter referred to as dust) adhering to the outer peripheral surface of the M2, a gripping means 13 for gripping both ends of the coated wire 2 from the dust removing means 12, and a gripping means 13 for gripping both ends of the coated wire 2 from the dust removing means 12. A moving means 14 for moving it on the base 10, a cutting means 15 fixed at a position different from the base 10, a coating removal/ball forming means 16, and a control means 17 for automatically controlling each of the above means. It is composed of.

Further, in the covered wire 2 applied in this embodiment, the core wire 21 is made of gold, and the core wire 21 is covered with an insulating material 22.

Next, the configuration of each of the above means will be explained.

The dust removing means 12 includes two filters 122 fixed to opposite ends of a pair of dust removing members 121.
The covered wire 2 moves while holding the outer peripheral surface of the covered wire 2 at 22.
Remove dust that adheres to the outer surface of the

As shown in FIGS. 2 and 3, the gripping means 13 includes a starting end gripper 131, a terminal end gripper 132, and a magazine 1:I.
It is composed of 3. Starting end gripper 131, 132
are fixed side metal chuck 1: 311, 132, respectively.
1 and these fixed side metal chucks 1311.1321 are rotatably supported through pins 1331.1332, and the upper end is normally supported by the elastic force of springs 1313.1323. 1321
Movable metal chuck 1312.
1322 and these i'iJ 1liilJ side metal chucks 1312 and 1322 are supported on the base 10 so as to face the side surfaces of the lower ends when they reach the position where they respectively grip both ends of the covered wire 2.

The actuators 1314 and 1324 push the lower end side surface against the elastic force of springs 1313 and 1323 to release the upper end of the movable metal chuck 1312 and 1322 from the upper end of the fixed metal chuck 1311 and 1321. The magazine 133 is mounted on the movable table 143J2 of the moving means 14, fixes the fixed side metal chunk 1312 of the starting end gripper 13+ to one end, and fixes the fixed side metal chunk 1312 of the starting end gripper 13+ to the end end clipper!
32 fixed side metal chucks 1321 are supported so as to be movable according to the length of the covered wire 2, and two positioning holes 1 are provided.
331 is formed. In addition, the fixed side metal chuck 13
11.1321 and moving side metal chuck l:312.
1322 is made of silver or copper to improve the heat dissipation effect. Also, 2 digits 1 position determination hole 1 :l 3
1, after the balls 23 are formed at both ends of the covered wire 2, the holding means 15 is removed from the base 10 while holding the covered wire 2, and then the holding means 15 is attached to the base 10. This is for positioning the dice.

The first stage of movement 14 is a motor 14 fixed to the end of the base [0].
1 is driven, the screw shaft 142 rotates, and the movable base 143 screwed onto the screw shaft 142 moves together with the gripping means 13 mounted on the upper surface of the movable base 143, so that the gripping means 13 is moved.
The starting end gripper 131 and the ending end gripper 132 are positioned at the coating removal/ball forming position.

As shown in FIG.
A sliding table 152 is mounted so as to slide and hang by 11.
The drive unit +58 mounted on this sliding table 152 reciprocates in the longitudinal direction, and creates a bevel groove 1 in the longitudinal direction of the tip end.
531 and this cutting guide 1
53 are inserted on both sides thereof, and each is swingably supported on a sliding table 152, and when the rear end is moved upward by the cutting actuators 154, 155, the tip part moves up and down. two cutting blades 156 that cut the coated wire 2 using the opposing end surfaces of the cutting guide 153 as a guide;
157. Note that the thickness a of the cutting guide 153 is formed to match that of the ball-forming type.

As shown in FIG. 5, the coating removal/ball forming means 16 includes a fixed base 161, and an X-direction movable base mounted on J2 so as to be moved in the direction of the X arrow by an X-direction actuator 1621. 162, a Y-direction movable base 163 mounted on this X-direction movable base 162 so as to be movable in the direction of the Y arrow by a Y-direction actuator 1631, and when supported by this Y-direction movable base 163 and rotated, its ” A member 165 that adjusts the vertical position of the mounting base 164 on two sides, and a member 165 that is mounted on the mounting base 164 and holds the torch support 166.
The tip ejection part 167 of the torch 167 supported by the tip part of
The torch swing actuator 168 swings the torch 1 as shown in FIGS. 11 to 13. Although not shown, the torch 165 is connected to a supply source of oxyhydrogen gas or hydrogen gas.

The control means 17 is provided with a control section 171 having a storage means 172, as shown surrounded by a dashed line in FIG. portion 174 and coating removal/ball forming means 17
5 and a transportation means control section 176.
73 to 176 are connected to each means 13, 15, 16, and 14 as shown by dotted lines.

Since the coated wire bonding apparatus 1 according to the present invention is constructed as described above, its operation will next be explained with reference to FIGS. 7 to 20 based on the flowchart shown in FIG. 6.

First, as shown in FIG. 7, the coated wire 2 is fed out from the reel 11, and the dust attached to the outer peripheral surface is removed by the dust removal means 12, and the fixed side metal chuck 1 of the starting end gripper 131 is removed.
311 and the upper end of the movable metal chuck 1312.

At this time, the cutting guide 153 and the cutting blade 1.56,1
．． 57 moves in the direction of the arrow shown in FIG.
Both chucks 131 of the coated wire 2 are placed in the bevel groove 1531 of 53.
A part of the part protruding from 1°1312 is inserted. Therefore, one end of the covered wire 2 is attached to both chucks 1311 and 131.
2, a portion of the cutting guide 153 excluding the thickness a protrudes.

Thereafter, as shown in FIG. 9, the tip of one of the cutting blades 156 moves downward using the opposing surface of the cutting guide 153 as a guide to cut one end of the covered wire 2, as shown in FIG. As shown in FIG.
The cutting guide 153 is cut from 1.1312 leaving a portion corresponding to the thickness a of the cutting guide 153.

Next, one of the cutting blades 156 is lifted up and the cutting guide 15
3 simultaneously retreats to the original position, the torch 167 provided in the coating removal/ball forming means 16 swings at a low speed of, for example, 1.7 wa/see, as shown in FIG. As shown in FIG. 12, a flame 1672 of oxyhydrogen gas or hydrogen gas from a spouting part 1671 at the tip irradiates a part corresponding to the thickness a of one end of the covered wire 2, removes the Nl 22 and cores. W: Expose A21.

Subsequently, by irradiating the exposed core wire 21 with a flame 1672 while swinging the torch 167, a ball 23 is formed at one end of the covered wire 2, as shown in FIG.

Note that the heat generated by the flame 1672 during the removal of the coating 22 and the formation of the balls 2 and 3 is radiated by both chucks 1311 and 1312, so that it is possible to prevent the coating from scorching or from rising more than necessary. When the ball 23 is formed at one end of the covered wire 2, the torch 167 stops swinging and the ejection part 1671 at its tip stops irradiating the flame 1672, and then the moving means 14 The motor 141 is driven.

Rotate the screw shaft 142 to move the end gripper 132 and move the end gripper 132 itself into the magazine 13.
3 and adjust it to correspond to the length of the covered wire 2.

Then, when the end gripper 132 reaches a predetermined position, both chucks 1321 and 1322 of the end gripper 132 grip the other end of the covered wire 2, and both chucks 1321
, 1322, the other end of the covered wire protrudes from the cutting guide 1.
53 is inserted into the bevel groove 1531.

After that, as shown in Fig. 14, the other cutting blade +5
7 moves downward using the facing surface of the cutting guide 153 as a guide to cut the other end of the coated wire 2. Therefore, the other end of the coated wire 1iA2 is attached to both chucks 1321 as shown in FIG. .1322 is cut leaving a portion corresponding to the thickness a of the cutting guide 153.

Then, the other cutting blade 157 is lifted up and the cutting guide 15 is removed.
When the torch 167 of the coating removal/ball forming means 16 is moved back simultaneously to the original position as shown in FIG.
While swinging at a low speed, a flame 1672 of oxyhydrogen gas or hydrogen gas is emitted from a spouting part 1671 at the tip of the Ni1
Irradiate the part corresponding to the thickness a of the other end of 1A2, and
As shown in FIG. 7, the covering 22 is removed to expose the core wire 21.

Subsequently, when the exposed wick #I21 is irradiated with flame while swinging the torch 167, a ball 23 is formed at the other end of the covered wire 2 as shown in FIG. 18, and a ball 23 is formed as shown in FIG. After the coated wire 2 is formed, these balls 23 are bonded onto the connection pads 3I formed in large numbers on the substrate 3 by thermocompression bonding or ultrasonic thermocompression bonding, as shown in FIG.

〔Effect of the invention〕

Since the present invention has been described in more than 1, it has the effects described in 5 and below.

In the coated wire wire bonding method of the present invention, it is possible to remove the coat of the coated wire and form a ball, and since the coated wire is insulated, it is possible to prevent problems such as leakage current generation due to contact with the upper edge of the outer periphery of the connecting chip. It is possible to prevent short circuits and edge shorts between adjacent wires.

In addition, since the first gripping means is made of metal wire, the heat dissipation effect is improved, and this prevents the coating from rising and excessive melting when removing the coating and forming the ball.

In addition, since the flame used was a hydrogen flame or an oxyhydrogen flame,
Even highly heat-resistant coatings can be easily removed.

Further, since the crimping is carried out by thermocompression, it is possible to prevent the peripheral surface of the ball and the surface of the crimping member from becoming dirty.

Furthermore, since the crimping is performed by ultrasonic thermocompression, balls can be ball-bonded even at low temperatures.

In addition, in the covered wire wire bonding device configured as described above, it is possible to automatically remove the covering of the covered wire and bond the ball shape J 戊 and the ball.
In addition, since the balls are bonded after the coating is removed and the ball is formed, it is possible to prevent substances removed during coating removal and scattered gas from adhering to the bonding part, and also to prevent high temperature, such as hydrogen gas, from adhering to the bonding part. Moreover, since bonding is performed after confirming that the ball is formed into a predetermined shape, it is possible to eliminate bonding defects due to defective balls.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a coated wire bonding apparatus which is an embodiment of the present invention, FIG. 2 is an enlarged perspective view showing a starting end gripper and a terminal end gripper of the gripping means, and FIG. 33 shows a magazine of the gripping means. FIG. 4 is an enlarged perspective view showing the cutting means, FIG. 5 is an enlarged perspective view showing the coating removal/ball forming means, FIG. 6 is a flowchart showing the operation sequence, and FIGS. 7 to 20 The figure is an operation process diagram, Figure 21 is an explanatory diagram showing a conventional coated wire before being formed into a ball with a discharge torch, and Figures 22 to 24 are a diagram showing a conventional coated wire being formed into a ball with a discharge torch. It is an explanatory view showing a state when it is formed. DESCRIPTION OF SYMBOLS 1... Covered wire wire bonding device, 2... Covered wire, 3... Substrate, 10... Base, 11... Reel, 12... Dust removal means, 13... Gripping means , 14
...Movement means, 15.. Cutting means, 16.. Coating removal/ball forming means, 17.. Control means. Representative Patent Attorney Masami Akimoto No. 2 Figure 3-2---4afi 1311, 1321---
-It side 1A'rvt7131---Year 1 smooth grip 1312. 1322---possible vJ1 to metal nayag +32-*shimarisu, bass 1313. 1323
---Harne 133-・-7J7”nn 13+
4.1324--A2 + Yuator 4th = 5th E5
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+s2+
168---)-'r'I-m actuator No. 6 Fig. 7 Fig. 802.53 /' No. 90 1st Q''; 2--) Leather, 1L 131-111 Naro chestnut, high 153--Zunofukimachi γ ID 12・-cho C spout?J+摸 +311-11 intestinal tidying side meeting 7156・-pη 吋B1312--1 possible wJ small 1 meal Kemaaku Figure 11 Figure 14 Figure 15 Prisoner 20 (; Figure 21 Figure 23 Figure 22 Figure 124

Claims (1)

[Scope of Claims] 1. The end of a coated wire in which the outer periphery of a conductive core wire is insulated is gripped by a gripping means, and the end of the coated wire protrudes from the gripping means while dissipating heat with the gripping means. A coated wire wire bonding method in which the coating is removed by irradiating flame toward the core wire, a ball is formed on the exposed core wire, and the ball is wire bonded by crimping. 2. The coated wire bonding method according to claim 1, wherein the gripping means is made of metal. 3. The coated wire bonding method according to claim 1, wherein the flame is a hydrogen flame using hydrogen gas. 4. The coated wire bonding method according to claim 1, wherein the flame is an oxyhydrogen flame using oxyhydrogen gas. 5. The coated wire wire bonding method according to claim 1, wherein the crimping is carried out by thermocompression bonding. 6. The coated wire wire bonding method according to claim 1, wherein the crimping is ultrasonic thermocompression bonding. 7. means for gripping the end of a coated wire in which the outer periphery of a core wire of a conductive material is insulated; means for cutting the tip of the coated wire protruding from the gripping means leaving a ball forming allowance; and the tip of the coated wire A coated wire comprising a means for removing the coating by irradiating the ball forming margin with flame and forming a ball on the exposed core wire, a means for bonding the ball by crimping, and a means for automatically controlling each of these means. Wire bonding equipment. 8. The covered wire wire bonding apparatus according to claim 7, wherein the gripping means is made of metal. 9. The covered wire wire bonding apparatus according to claim 7, wherein the covering removing/ball forming means is configured to irradiate a flame from a swingable torch toward the tip of the covered wire. 10. The coated wire wire bonding apparatus according to claim 7 or 9, wherein the flame is a hydrogen gas flame. 11. The coated wire wire bonding apparatus according to claim 7 or 9, wherein the flame is constituted by a flame of oxyhydrogen gas. 12. The covered wire wire bonding apparatus according to claim 7, wherein the bonding in the bonding means is thermocompression bonding. 13. The coated wire wire bonding apparatus according to claim 7, wherein the bonding in the bonding means is ultrasonic thermocompression bonding.