JPH05152368A - Coated wire bonding device - Google Patents

Abstract

PURPOSE:To provide a device which is small, cheap, and excellent in handling properties and bonds a coated wire composed of a core wire coated with a sublimating film to a joining part of a circuit board through a reflow bonding method. CONSTITUTION:A bonding head 20 which is vertically mounted on a vertically movable column 14 that can pivot in steps by 90 deg. and composed of a tool main body 21 mounted with a chip 25 at its tip, a wire guide 22 which feeds a coated wire 5 to the tip of the chip 25, and a cutter 23 which cuts the coated wire 5 after bonding and an X-Y table 12 which is mounted on a bed 10 confronting the bonding head 20 and where a circuit board is set horizontal are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated wire bonding apparatus for reflow soldering a coated wire having a core wire coated with a thermally sublimable coating to a joint portion of a circuit board.

[0002] In recent years, for modification or repair by changing the design of a circuit board, a covered wire is used to connect predetermined connecting portions. FIG. 5 is a plan view of the circuit board, and FIG. 6 is a side sectional view during wire bonding.

In the figure, reference numeral 5 denotes a coated wire in which the outer periphery of a core wire 6 is coated with a heat sublimable coating 7 such as polyurethane resin. The coating thickness of the thermally sublimable coating 7 is about 10 μm, and it sublimes when heated to about 430 ° C.

On the other hand, the circuit board 1 has pads 2 on which circuit components such as semiconductor components are surface-mounted and leads of the semiconductor components are reflow-soldered. The pad 2 to which the lead is soldered is a joint that connects one end of the covered wire 5.

Further, the circuit board 1 has another pad 2 at a desired position, and the solder 3 is attached to the surface of the pad 2. The pad 2 is a joint that connects the other end of the covered wire 5.

Reference numeral 9 shown in FIG. 6 is a chip made of a conductor fixed to the tip of a rod-shaped tool body vertically mounted on a bonding head (not shown). An arcuate groove slightly larger than the outer diameter of the coated wire 5 is provided on the tip surface of the tip 9, and the tip 9 is heated to a desired temperature by energizing the tip 9.

In order to connect the coated wire 5 to the pad 2 using such a bonding head, first, the end of the coated wire 5 is placed along the longitudinal direction of the pad 2.
Then, the groove of the chip 9 is aligned so as to cover the coated wire 5, the bonding head is lowered, and the coated wire 5 is pressed against the pad 2 with the desired pressing force (about 150 g) at the tip of the chip 9. At the same time, the tip of the tip 9 is heated to about 430 ° C., and this state is maintained for several seconds to sublimate the thermally sublimable coating 7 of the coated wire 5 to bare the core wire 6.

Next, the temperature at the tip of the head is lowered to about 260 ° C. and the state is maintained for several seconds, the solder 3 is reflowed, and the core wire 6 of the coated wire 5 is reflow soldered to the pad 2.

[0009]

2. Description of the Related Art In a conventional covered wire bonding apparatus, as shown in FIG. 7, a turntable 11 which rotates about a vertical axis is mounted on a bed 10, and a circuit board 1 is set horizontally on the upper surface. The XY table 12 is mounted on the turntable 11.

On the other hand, a vertically movable bonding head 15
Is attached to column 14. The axis of the vertical axis of the bonding head 15 and the axis of the rotary shaft of the turntable 11 coincide with each other.

As shown in detail in FIG. 8, this conventional bonding head 15 has a tool main body in which a tip 16A is attached to a tip end portion of the head so as to vertically project downward in the center portion of the head.
16, a wire guide 17 for supplying the coated wire 5 to the tip portion of the chip, and a cutter 18 for cutting the coated wire 5 after bonding.

The upper half of the side surface of the covered wire 5 pulled out from the wire guide 17 is inserted into an arcuate groove provided on the tip surface of the tip 16A. The coated wire 5 shown in FIG. 8 has a Y-shaped wire with one end already formed on the circuit board.
It is reflow soldered to a strip-shaped pad that is long in the axial direction.

In order to reflow solder the other end of the coated wire 5 to another pad 2 which is long in the X-axis direction, first the XY table is driven to bond the pad 2 to be bonded to the bonding head. Move it to the position directly under 15. next,
The turntable 11 is rotated 90 degrees so that the longitudinal direction of the pad 2 coincides with the groove direction of the chip 16A, that is, the direction of the coated wire 5.

Then, the bonding head 15 is lowered and the coated wire 5 is pressed against the pad 2 by the tip of the chip 16A, and at the same time, the tip of the chip 16A is heated to about 430 ° C., and the state is held for several seconds. The thermally sublimable coating of the coated wire 5 is sublimated to bare the core wire.

Next, the temperature at the tip of the head is lowered to about 260 ° C. and the state is maintained for several seconds, the solder 3 is reflowed, and the core wire of the coated wire 5 is reflow soldered to the pad 2. After bonding the coated wire 5, the XY table 12 is slightly moved to move the cutter 18 right above the position where the pad 2 is removed. After that, the cutter 18 is pushed down to cut the coated wire 5.

As a result, the two joints of the circuit board are connected via the covered wire 5.

[0017]

By the way, since the conventional coated wire bonding apparatus is provided with the turntable which supports and rotates the XY table, the turntable becomes large and the coated wire bonding apparatus. However, there was a problem that the cost was high.

Further, there is a problem that a large pocket is required so that the rectangular XY table can be rotated in a horizontal plane, and the coated wire bonding apparatus becomes large and the operability is poor.

The present invention has been made in view of the above points, and an object thereof is to provide a coated wire bonding apparatus which is low in cost, small in size, and easy to handle.

[0020]

In order to achieve the above object, the present invention, as shown in FIG. 1, presses a coated wire with a tip heated to a desired temperature to thermally sublimate the coated wire. In a device for removing the conductive coating to expose the core wire and reflow soldering the core wire to a desired portion of the circuit board, the tool main body 21 having the tip 25 mounted on the tip portion, and the coated wire 5 on the tip portion of the chip. A column consisting of a wire guide 22 for supplying and a cutter 23 for cutting the coated wire 5 after bonding, which is capable of step rotation of 90 degrees and vertical movement.
The structure is provided with a bonding head 20 which is vertically mounted on the bed 14, and an XY table 12 which is mounted on the bed 10 so as to face the bonding head 20 and horizontally sets the circuit board 1.

Then, as illustrated in FIG. 2, the rotary shaft 31
The pair of electrode halves 32 and 33, which are fixed to the tips of the power supply bars 36 and 37, are fixed to the tips of the pair of electrode halves 32 and 33, which are combined in a cylindrical shape via the insulator 34. Brush that slides on the outer peripheral surface of the electrode halves 32, 33
1,39-2 and groove 3 circumscribing the upper half of the side of the coated wire
5a is formed on the tip surface, and the tool body is constituted by a tip 35 which is bridged and fixed to the tip portions of the pair of electrode halves 32, 33.

Alternatively, as shown in FIG. 3, a pair of electrode halves 42, 4 are formed by fixing the tool body to the tip of the rotary shaft 41 and combining them in a cylindrical shape via an insulator 44.
3 and a mainspring-shaped power supply band 49 having one end fixed to the tip of one power supply bar 46 and the other end fixed to one electrode half 42.
-1 and a mainspring type power supply band 49 having one end fixed to the tip of the other power supply bar 47 and the other end fixed to the other electrode half 43.
-2 and a chip 45 having a groove circumscribing the upper half of the side surface of the coated wire is formed on the tip end surface, and the tip 45 is bridged and fixed to the pair of electrode halves 42, 43.

On the other hand, as shown in FIG. 4, the coated wire is pressed by a chip heated to a desired temperature to remove the heat sublimation coating of the coated wire to expose the core wire, and the core wire is removed from the circuit board. In a device for reflow soldering to a desired position of, a bonding head 50 composed of a tool body 51 that does not rotate, a wire guide 52 and a cutter 53 that can be rotated 90 degrees in steps around the tool body 51 is moved up and down. It is freely mounted vertically on the column.

Further, the XY table for horizontally setting the circuit board facing the bonding head 50 is mounted on the bed. Then, the tip end surface 56 of the tip 55
And a cross groove 57 circumscribing the upper half of the side surface of the covered wire 5.
Shall be provided.

[0025]

According to the present invention, the bonding head having the tool main body having the above-described power feeding means, the wire guide and the cutter integrally formed is mounted on the column so as to be rotatable by 90 degrees.

Therefore, by rotating the bonding head 90 degrees in a desired direction, the wiring direction of the covered wire can be made coincident with the longitudinal direction of the bonding portion, that is, the longitudinal direction of the pad.

That is, the coated wire bonding apparatus of the present invention does not require a turntable for rotating the XY table on the bed side. Therefore, the covered wire bonding apparatus is low in cost and small in size.

In the fourth aspect of the invention, only the wire guide and the cutter are mounted so as to be freely rotatable by 90 ° steps, and the tip end surface of the cross groove circumscribes the upper half of the side surface of the covered wire 5. Is provided.

Therefore, by rotating only the wire guide and the cutter in a desired direction by 90 degrees and inserting the covered wire into the selected straight groove portion of the cross groove, the wiring direction of the covered wire is changed. Can be aligned with the longitudinal direction of the pad or the longitudinal direction of the pad.

As described above, the fourth aspect of the invention has the advantage that the tool main body does not rotate, so that the power feeding means is simple and the bonding head becomes smaller.

[0031]

The present invention will be described in detail with reference to the drawings. The same reference numerals denote the same objects throughout the drawings.

FIG. 1 is a sectional view of an embodiment of the first invention, FIG.
Is a diagram showing an essential part of the second invention, (A) is a perspective view, and (B) is
Is a cross-sectional view, FIG. 3 is a perspective view of an important part of the third invention, and FIG.
2A is a side view of the chip, FIG. 3B is a side view of the chip, and FIG. 3C is a plan view of the chip.

In FIG. 1, an XY table 12 for horizontally setting the circuit board 1 on the upper surface is mounted on a bed 10. 20 is a tool body 21 with a tip 25 attached to the tip.
And a wire guide 22 for supplying the coated wire 5 to the tip portion of the chip, and a cutter 23 for cutting the coated wire 5 after bonding.

The bonding head 20 is vertically movably mounted on the column 14 with the chip 25 facing downward. On the other hand, a motor 29 is mounted on the column 14 in parallel with the bonding head 20, and the bonding head 20 can be rotated by 90 degrees by the motor 29 via interlocking means such as gears or belts.

The upper half of the side surface of the coated wire 5 pulled out from the wire guide 22 is inserted into an arcuate groove provided on the tip surface of the tip 25. Chip 9
An arc-shaped groove slightly larger than the outer diameter of the covered wire 5 is provided on the tip surface of the wire, and the tip 9 is heated to a desired temperature by energizing the tip 9.

Using the coated wire bonding apparatus as described above, the desired two joints of the circuit board 1 are connected by the coated wires 5 as follows. First, the XY table 12 is driven to move the bonding portion to a position directly below the chip 25. And the bonding head 20
Is rotated 90 degrees in a desired direction so that the running direction of the chip groove is aligned with the longitudinal direction of the joint.

Next, the bonding head 20 is lowered and the coated wire 5 is pressed by the tip of the chip 25 to a desired pressing force (about 150).
At the same time as pressing to the joint part with g), the tool body 21 is energized to heat the tip of the tip 25 to about 430 ° C., and this state is held for several seconds to sublimate the thermally sublimable coating of the coated wire 5 to cause the core wire. To get naked. Then, the temperature at the tip of the head is lowered to about 260 ° C. and the state is maintained for several seconds to reflow the solder adhered to the joint and reflow solder the core wire of the coated wire 5 to the joint. ..

When the start end of the coated wire 5 is soldered to one joint as described above, the other joint that drives the XY table 12 is moved to a position directly below the chip 25. At this time, the coated wire 5 is pulled out from the wire guide 22 because the starting end is fixed to the joint portion.

Then, the bonding head 20 is rotated by 90 degrees in a desired direction so that the traveling direction of the chip groove coincides with the longitudinal direction of the other bonding portion. Next, the bonding head 20 is lowered to press the coated wire 5 at the tip of the chip 25 with a desired pressing force (about 150 g) to the joint, and at the same time, the tool body 21 is energized to move the tip of the chip 25 to about 430. Heat to ℃,
This state is maintained for several seconds to sublimate the thermally sublimable coating of the coated wire 5 to bare the core wire. Then, lower the temperature of the head tip to about 260 ℃, hold that state for a few seconds,
The solder adhered to the joint is reflowed, and the core wire of the coated wire 5 is reflow-soldered to the joint.

After the end of the coated wire 5 has been bonded, the XY table 12 is slightly moved to move the cutter 23 to a position right above the position where the cutter 23 has been removed. Then, the cutter 23 is pressed to cut the end side of the coated wire 5.

The above-mentioned bonding head is rotated by 90 degrees and the tool body is energized to heat the tip of the chip to a desired temperature.
Therefore, the tool body requires a pair of electrodes and a tip that bridges the tip of the electrodes.

FIG. 2 shows an embodiment of a tool body composed of the above-mentioned components. In FIG. 2, reference numeral 31 is a rotating shaft formed by extending a part of the rotating portion of the bonding head. The lower end of the rotary shaft 31 is a prism.

Reference numeral 32 is one electrode half body made of a conductive metal having a semicircular cross section, and 33 is the other electrode half body made of a conductive metal having a semicircular cross section. The electrode half body 32 and the electrode half body 33 are combined and fixed in a cylindrical shape via an insulator 34,
It is used as an electrode pillar.

The electrode column is rotated by forming a square hole in the upper part of the shaft center of the integrated electrode column and press-fitting the square hole into the square column portion of the lower tip of the rotary shaft 31 through an insulator. It is fixed to the shaft 31.

Then, approximately half of the outer peripheral portion of the lower end of the electrode column is cut so that the insulator 34 is located at the center position. 35
Is a chip made of a wedge-shaped conductive metal plate when viewed from the front. A notch 35b with an upward opening is provided at the center line of the tip 35, and an arcuate groove 35a circumscribing the upper half of the side surface of the coated wire is provided at the tip face so as to be orthogonal to the notch 35b. ..

Then, one side surface of the chip 35 is aligned with the notched surface of the electrode pillar so that the cut 35b is aligned with the insulator 34, and the electrode half 32 and the electrode half 33 are bridged to form the chip 35. It is fixed to the electrode column with screws.

Reference numerals 39-1 and 39-2 are brushes in which a large number of thin copper plates are superposed and the central portion thereof is attached. Reference numerals 36 and 37 denote power feeding bars made of a conductive metal, which are connected to a power source (not shown), and are mounted facing each other on both sides of the electrode column.

The brush 39-1 is fixed to the one power supply bar 36 so that the tip of the brush 39-1 slides on the outer peripheral surface of the one electrode half body 32. Also, so that the tip of the other brush 39-2 slides on the outer peripheral surface of the other electrode half body 33,
The brush 39-2 is fixed to the other power supply bar 37.

As described above, the tool body 30 including the chip 35, the electrode halves 32 and 33, and the brushes 39-1 and 39-2 is provided on the bonding head. In such a tool body 30, even if the position of the electrode half body 32 and the electrode half body 33 is changed by 90 degrees or 180 degrees due to the rotation of the bonding head, that is, the rotating shaft 31, any of the brushes 39-1 and 39-2. Electrode halves 3 in positions facing each other
Touching 2,33.

Therefore, when the power supply bars 36 and 37 are energized, a current flows through the brush electrode halves to the left and right halves of the chip 35. Therefore, the tip of the chip 35 can be heated to a desired temperature.

In FIG. 3, reference numeral 41 is a rotating shaft formed by extending a part of the rotating portion of the bonding head. The lower end of the rotary shaft 41 is a prism. 42 is one electrode half body made of a conductive metal having a semicircular cross section, and 43 is the other electrode half body made of a conductive metal having a semicircular cross section. The other electrode half body 43 is shorter than the one electrode half body 42.

The electrode half body 42 and the electrode half body 43 are combined and fixed in a cylindrical shape through an insulator 44 to form an electrode pillar. A square hole is provided in the upper part of the shaft center of the electrode half 42 of this electrode column, and this square hole is press-fitted into the square column portion of the lower tip of the rotary shaft 41 through an insulator, whereby the electrode column is rotated. Is stuck to.

Then, approximately half of the outer peripheral portion of the lower end of the electrode column is cut so that the insulator 44 is located at the center position. 45
Is a chip made of a wedge-shaped conductive metal plate when viewed from the front. A notch having an upper opening is provided at the center line portion of the tip 45, and an arcuate groove circumscribing the upper half of the side surface of the covered wire is provided at the tip face so as to be orthogonal to the notch.

Then, one side surface of the chip 45 is aligned with the notched surface of the electrode pillar so that the cuts coincide with the insulator 44, and the electrode half body 42 and the electrode half body 43 are bridged so that the chip 45 becomes an electrode. It is fixed to the pillar with screws.

49-1 and 49-2 are mainspring type power feeding bands made of elastic conductive thin strip metal plates (for example, phosphor bronze plates). 46 and 47 are power feeding bars made of a conductive metal, which are connected to a power source (not shown), and are mounted on one side of the electrode pillar in parallel in the vertical direction.

Then, one end of the power supply band 49-1 of the mainspring is fixed to the end of one of the power supply bars 46, the electrode column is wound approximately once, and the other end is connected to one electrode half body. It is fixed to the outer circumference of 42.

Further, one end portion of the other mainspring type power feeding band 49-2 is fixed to the end portion of the other power feeding bar 47 so that the electrode column is wound approximately once and the other end portion is connected to the other electrode. It is fixed to the outer periphery of the half body 43.

As described above, the bonding head is provided with the tool body 40 including the chip 45, the electrode halves 42 and 43, and the mainspring power feeding bands 49-1 and 49-2. Tool body like this
40 is a bonding head, that is, the rotating shaft 41 rotates,
Obviously, the chip 45 can be energized.

In FIG. 4, the bonding head 50 is
The tool body 51 is mounted so as not to rotate. The wire guide 52 that supplies the coated wire 5 to the tip of the tip 55 and the cutter 53 that cuts the coated wire 5 after bonding are arranged at symmetrical positions with respect to the tool body 51 and are integrated. It is mounted so that it can rotate 90 degrees in steps around the tool body 51.

Then, such a bonding head 50
Is vertically mounted on the column so that it can move up and down. On the other hand, although not shown, the bed of the covered wire bonding apparatus is equipped with an XY table for horizontally setting the circuit board.

Then, as shown in detail in FIGS. 4B and 4C, the coated wire 5 is attached to the tip end surface 56 of the tip 55.
A cross groove 57 is provided so as to circumscribe the upper half of the side surface. As described above, the wire guide 52 and the cutter 53 are mounted so as to be rotatable by 90 degrees without rotating the tool body 51, and the tip end surface is circumscribed on the upper half of the side surface of the covered wire 5. With the cross groove 57, the wire guide 52
Rotate the cutter 53 by 90 degrees in the desired direction to form the cross groove 57
By inserting the coated wire 5 into the selected straight groove portion, the wiring direction of the coated wire can be aligned with the longitudinal direction of the joint.

[0062]

As described above, according to the present invention, the small-sized bonding head is provided with the step rotation of 90 degrees without rotating the XY table mounted on the bed. The coated wire bonding apparatus is low cost because no turntable is required on the side.

Since the XY table having a large rectangular shape does not rotate, the pocket of the covered wire bonding apparatus can be reduced, and the covered wire bonding apparatus can be reduced in size accordingly. Further, with this miniaturization, there is an effect that operability is improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the first invention.

FIG. 2 is a diagram showing the essential points of the second invention, where (A) is a perspective view and (B) is a sectional view.

FIG. 3 is a perspective view of an essential part of the third invention.

FIG. 4 is a diagram of an embodiment of the fourth invention, (A) is a side view, (B) is a side view of the chip, and (C) is a plan view of the chip.

FIG. 5 is a plan view of a circuit board

FIG. 6 is a side sectional view during wire bonding.

FIG. 7 is a side view of a conventional bonding apparatus.

FIG. 8 is a side view of a conventional bonding head.

[Explanation of symbols]

1 circuit board, 2 pads 3 solder 5 coated wire 6 core wire 7 thermal sublimation coating 10 bed 11 turntable 12 XY table 14 column 35a groove 57 cross groove 15,20,50 bonding head 16,21,30,40 , 51 Tool body 9,16A, 25,35,45,55 Chip 17,22,52 Wire guide 18,23,53 Cutter 31,41 Rotating shaft 32,33,42,43 Electrode half 34,44 Insulator 36 , 37,46,47 Power feeding bar 39-1, 39-2 Brush 49-1,49-2 Mainspring power feeding band

Claims (4)

[Claims] 1. A coated wire is pressed by a chip heated to a desired temperature to remove a heat sublimable coating of the coated wire to expose a core wire, and the core wire is reflowed to a desired portion of a circuit board. A device for soldering, comprising a tool body (21) having the tip (25) mounted on the tip, a wire guide (22) for supplying the coated wire (5) to the tip of the chip, and a wire guide (22) after bonding. A bonding head (20), which comprises a cutter (23) for cutting the coated wire (5) and is vertically mounted on the column (14) so as to be capable of step rotation of 90 degrees and vertical movement, and the bonding head (20). ), Which is attached to the bed (10) so as to face the circuit board (1) and horizontally sets the circuit board (1). 2. An insulator fixed to the tip of the rotary shaft (31).
A pair of electrode halves (32, 33) that are combined in a cylindrical shape via (34), and are fixed to the tips of the respective feeding bars (36, 37), and the tips of the electrodes correspond to each other. A brush (39-1, 39-2) sliding on the outer peripheral surface of the half body (32, 33) and a groove (35a) circumscribing the upper half of the side surface of the coated wire are formed on the tip surface, 2. The coated wire bonding apparatus according to claim 1, further comprising a tool body (30) comprising a tip (35) cross-linked and fixed to the tip of the electrode half body (32, 33). .. 3. An insulator fixed to the tip of the rotating shaft (41).
A pair of electrode halves (42, 43) combined in a cylindrical shape via (44), one end of which is fixed to the tip of one power supply bar (46) and the other end of which is one of the electrode halves. Mainspring type power supply band (4
9-1) and a spring type power supply band (4) with one end fixed to the tip of the other power supply bar (47) and the other end fixed to the other electrode half (43).
9-2) and a chip (45) having a groove circumscribing the upper half of the side surface of the coated wire is formed on the tip surface and bridged and fixed to the tips of the pair of electrode halves (42, 43). The coated wire bonding apparatus according to claim 1, further comprising a tool main body (40). 4. A coated wire is pressed by a chip heated to a desired temperature to remove a heat sublimable coating of the coated wire to expose a core wire, and the core wire is reflowed to a desired portion of a circuit board. A device for soldering, which comprises a wire guide (52) and a cutter (53) mounted around the tool body (51) so as to be able to rotate in 90 degree steps, and vertically movable in a column. The chip head of the chip (55) is equipped with a bonding head (50) mounted thereon, and an XY table mounted on a bed facing the bonding head (50) and horizontally setting the circuit board. On the surface (56), the coated wire
A covered wire bonding apparatus characterized in that a cross groove (57) circumscribing is formed in the upper half of the side surface of (5).