JPH05218629A - Dispensing method of creamy solder - Google Patents

Abstract

PURPOSE:To achieve that a pad can be coated with a creamy solder in a prescribed quantity by a method wherein the dispensing method of the creamy solder with which the pad on the printed-circuit board is coated is applied to the printed-circuit board having a warp. CONSTITUTION:A printed-circuit board 1 is attached to the surface of a semicylindrical base stand 30 whose X-direction side edge 31 is arc-shaped in such a way that its rear is brought into close contact. A creamy solder is discharged continuously from a dispenser 10; a curved movement which is parallel to the X-direction side edge 31 is given to the dispenser or the base stand 30; pads in an X-direction pad row 2X are coated with the creamy solder so as to be belt-shaped. In addition, the creamy solder is discharged continuously from the dispenser 10; a rectlinear movement which is parallel to a Y-direction side edge 32 is given to the dispenser 10 or the base stand 30; pads in a Y- direction pad row 2Y are coated with the creamy solder so as to be belt-shaped. A dispensing method by using the creamy solder is constituted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dispensing creamy solder which is applied and formed on a pad of a printed board.

When mounting components on a printed board, pads are formed on the mounting surface, cream solder is applied to the surface of the pads, the leads are aligned, and the surface-mounted components are temporarily mounted on the printed board. It is often the case that the surface mount component is soldered and mounted on the printed board by placing it and then reflowing the solder.

A dispenser is used when the creamy solder is applied to the surface of the pad.

[0004]

2. Description of the Related Art FIG. 4 shows a conventional example, and FIG. 5 shows a coating process. In FIG. 4, reference numeral 10 denotes a dispenser made of glass or plastic, which is a cylinder 11 having a cavity for housing the creamy solder 5, and a cylinder 11 having a cavity protruding from the bottom of the cylinder 11 so as to communicate with the cavity. Nozzle 12 for discharging creamy solder 5 from opening 120A
It consists of 0 and.

A pipe for blowing compressed air into the cylinder 11 is connected to the lid for closing the cavity of the cylinder 11. In such a dispenser 10, a cylinder 11 portion is held by a robot hand 20 which is driven in the X-axis, Y-axis and Z-axis directions as desired.

On the other hand, the printed board 1 having the pads 2 arrayed on the mounting surface is placed horizontally on the XY table 3 and the creamy solder 5 is applied thereto. The XY table 3 may be driven in the X-axis and Y-axis directions, and the robot hand 20 may be driven only in the Z-axis direction.

In order to apply and form the solder layer 50 on the surface of the pad 2 using the dispenser 10 as described above, the robot hand 20 is operated to open the opening 120A of the nozzle 120 to the pad 2.
Compressed air is blown into the cavity of the cylinder 11 for a desired time after being aligned above.

As a result, the creamy solder 5 accommodated in the cylinder 11 is pressed down, and a desired amount of the creamy solder 5 is discharged from the opening 120A of the nozzle 120 onto the surface of the pad 2. Then, when the dispenser 10 is lifted, the creamy solder 5 is shredded into particles and adheres to and remains on the pad 2, and thereafter spreads over the entire surface of the pad 2 to form the solder layer 50.

At this time, in the case of the square pad 2 having a side of 2 mm, the inner diameter of the nozzle 120 is about 1 mm.
The gap H between the opening 120A of the 120 and the mounting surface 1A of the printed board 1 is required to be a predetermined amount (around 0.5 mm).

Therefore, conventionally, at the start of the coating operation,
The lowest point of the robot hand 20 is set so that the nozzle opening 120A has a predetermined height (about 0.5 mm) on the mounting surface of the printed board 1. After that, the dispenser 10 descends and creamy solder is discharged. A series of operations of automatically raising the dispenser 10, moving the dispenser horizontally, lowering the dispenser 10, discharging creamy solder, and raising the dispenser 10 are automatically performed.

By the way, as shown in FIG.
It is inefficient to lower the dispenser 10 to apply the creamy solder 5 to each of the above. For this reason,
As shown in (A), while holding the dispenser 10 at a predetermined height position on the first pad 2 of the pad row,
While discharging the creamy solder 5 from the opening, the dispenser 10 is horizontally moved along the pad row to apply the strip-shaped creamy solder onto the printed board 1.

The portion of the strip-shaped cream-like solder that is in contact with the surface of the base material is sucked up onto each pad 2 and divided. Therefore, as shown in FIG. 5B, the solder layer 50 is formed on each pad 2.

[0013]

By the way, the printed board often has a warp as shown in FIG. In such a warped printed board 1, in the conventional dispensing method in which the dispenser 10 is horizontally moved in the X-axis direction or the Y-axis direction, the gap between the nozzle opening and the mounting surface of the printed board 1 is set to a predetermined amount. It is not possible. If there are no gaps, the outflow resistance of the cream solder increases, and the cream solder hardly flows out. That is, if the gap is not constant, the amount of creamy solder applied becomes unstable and the soldering strength varies.

Therefore, conventionally, holes are arranged in a base on which the printed board is placed, air is sucked from the holes to vacuum-adhere the printed board to the surface of the base to correct the warp of the printed board. The application work was carried out.

However, when the amount of warpage is large,
When the printed board has a twisted warp, it is difficult to correct the warp of the printed board by the vacuum suction means. The present invention has been made in view of the above points, and an object of the present invention is to provide a dispensing method that can be applied to a warped printed board to apply a predetermined amount of cream-like solder onto a pad. There is.

[0016]

In order to achieve the above-mentioned object, the present invention is such that the back surface is closely attached to the front surface of a semi-cylindrical base 30 having an X-direction side edge 31 as an arc as shown in FIG. Then, the printed board 1 is attached.

Then, while continuously discharging the cream-like solder from the dispenser 10, a curvilinear motion parallel to the X-direction side edge 31 is applied to the dispenser 10 or the base 30, and the pads of the X-direction pad row 2X are applied. The creamy solder 5 is applied in a strip shape.

Further, while the creamy solder is continuously discharged from the dispenser 10, a linear motion parallel to the Y-direction side edge 32 is applied to the dispenser 10 or the base 30, and the pads of the Y-direction pad row 2Y are strip-shaped. Creamy solder shall be applied to.

Alternatively, as shown in FIG. 2, a semi-cylindrical base 30 having a side edge 31 in the X direction as an arc is attached to the XY table 3, and the back surface of the base 30 is closely adhered to the printed board. Put on 1.

On the other hand, a support bar 40 whose lower tip abuts the surface of the peripheral portion of the base 30 is attached to the dispenser 10, and the dispenser 10 is held so as to follow the vertical movement of the support bar 40. Then, while the creamy solder is continuously discharged from the dispenser 10, the XY table 3 is driven in the X-axis direction to apply the creamy solder 5 in a strip shape to the pads of the X-direction pad row 2X. Also, set the XY table 3 to Y
It is assumed that the cream-like solder 5 is applied in a strip shape to the pads of the Y-direction pad row 2Y by driving in the axial direction.

Alternatively, as shown in FIG. 3, a semi-cylindrical attachment base 45 having an X-direction side edge 45A as an arc is attached to the XY table 3. A curved base 30-1 having a constant plate thickness, the X-direction side edge 31-1 of which is equal to the arc of the mounting base 45, is mounted on the mounting base 45 so as to be slidable in the X-axis direction. , Base 30
The printed board 1 is attached by sticking the back surface to the front surface of -1.

Then, the creamy solder is continuously discharged from the dispenser 10 held at a predetermined height, and the base 30-1 is slidably driven on the attachment base 45 in the X-axis direction.
Band-shaped cream solder 5 on the X-direction pad row 2X
Apply. Further, it is assumed that the XY table 3 is driven in the Y-axis direction and the cream-like solder 5 is applied to the pads of the Y-direction pad row 2Y in a strip shape.

[0023]

According to the present invention, as described above, the base on which the printed board is attached has a semi-cylindrical shape which is close to the warped shape of the printed board. Therefore, the back surface of the warped printed board easily adheres to the front surface of the base.

On the other hand, when applying the strip-shaped cream solder to the pads in the X-direction pad row, an arc motion parallel to the X-direction side edge of the arc is applied to the dispenser or the base. When applying the strip-shaped cream-like solder to the pads of the directional pad row, a linear motion parallel to the Y-direction side edge is applied to the dispenser 10 or the base.

That is, since the gap between the nozzle opening of the dispenser and the printed board is kept constant, a predetermined amount of creamy solder flows onto the pad and is applied.

[0026]

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 diagram showing the principle of the present invention, FIG. 2 is a diagram of an embodiment of the present invention, and FIG. 3 is a diagram of another embodiment of the present invention. In FIG. 1, reference numeral 30 denotes a semi-cylindrical base having a Y-direction side edge 32 that is a straight line and an X-direction side edge 31 that is an arc, and is mounted on the XY table 3. In addition, this X direction side edge 31
The shape of the arc is approximately 2 mm in height at the center point of the chord and the arc.

A U-shaped straightening frame 35 having one opening in the Y direction is adhered and fixed to the surface of the base 30, and the printed board 1 is provided with the U-shaped groove of the straightening frame 35 from the opening side of the straightening frame 35. By being inserted into 36, the back surface of the printed board 1 is brought into close contact with the front surface of the base 30. That is, the printed board 1 is attached to the base 30 in a state where the printed board 1 is warped in a kamaboko shape.

The back surface may be attached in close contact with the front surface of the base 30 by appropriately clamping the periphery of the printed board 1 without attaching the correction frame 35. On the other hand, the dispenser 10 for discharging the creamy solder has an X-axis, a Y-axis and a Z-axis.
The cylinder portion is held by the robot hand 20 that is driven in the desired axial direction.

Robot hand when applying creamy solder
20 is in a state where the height H between the surface of the base 30 and the robot hand 20 is maintained at a predetermined level (the height at which the nozzle opening of the dispenser 10 is maintained at about 0.5 mm on the mounting surface of the printed board). Pre-programmed to drive.

More specifically, the movement in the X-axis direction is the side edge in the X-direction.
An arc motion parallel to 31 is performed, and a movement in the Y-axis direction is a linear motion parallel to the Y-direction side edge 32. Now
To apply the cream solder to the pads of the X-direction pad row 2X, the robot hand 20 is driven to move the dispenser 10 to a predetermined height position (about 0.5 mm) on the first pad of the X-direction pad row 2X. Position the nozzle opening of.

Then, while discharging the cream-like solder from the dispenser 10, an arc motion in the X-direction pad row 2X is applied to the dispenser 10 to apply the strip-shaped cream-like solder to the surface of the X-direction pad row 2X.

The portion of the strip-shaped cream-like solder that is in contact with the surface of the base material is sucked up and divided by each pad, so that a solder layer is formed on each pad.

While the creamy solder is continuously discharged from the dispenser 10, linear motion parallel to the Y-direction side edge 32 is applied to the dispenser 10 to apply the strip-shaped creamy solder on the surface of the Y-direction pad row 2Y. To do.

In FIG. 2, a semi-cylindrical base 30 having a side edge 31 in the X direction as an arc is attached to the XY table 3, and the back surface of the base 30 is closely attached to the printed board 1 to which the printed board 1 is attached. There is. On the other hand, the dispenser 10 that discharges the creamy solder 5 is
Robot hand that drives in the desired directions of the axes, Y-axis and Z-axis
The cylinder portion is held by 20.

The dispenser 10 includes a cylinder having a cavity for accommodating the creamy solder 5 and a nozzle for ejecting the creamy solder 5 straight from the bottom of the cylinder so as to communicate with the cavity and ejecting the creamy solder 5 from the opening at the tip. A tube for blowing compressed air into the cylinder is connected to the lid configured to close the cavity of the cylinder.

On the other hand, a guide member is horizontally attached to the cylinder so as to grip the cylinder, and a long guide groove is provided in the guide member in the horizontal direction. A support bar 40 is vertically fixed so that the head can slide in the guide groove.

In order to apply the creamy solder to the pads of the Y-direction pad row 2Y after having such a structure, the robot hand 20 is driven so that the nozzle opening of the dispenser 10 is first moved to the Y-direction pad row 2Y. Position it on the first pad at a predetermined height (about 0.5 mm).

Then, the position to be fixed to the guide member of the support bar 40 is appropriately selected so that the lower end of the support bar 40 contacts the surface of the peripheral portion of the base 30. Thereafter, the grip of the robot hand 20 is loosened only in the Z-axis direction so that the cylinder can move up and down, the creamy solder 5 is discharged from the dispenser 10, and the robot hand 20 is driven to move the cylinder, that is, the support bar 40 in the Y-axis direction. Moving.

At this time, since the lower end of the support bar 40 performs a sliding movement parallel to the Y-direction side edge 32 on the surface of the base 30, the gap between the nozzle opening of the dispenser 10 and the surface of the printed board 1 is constant. The dispenser 10 moves while being kept.

To apply the cream solder to the pads in the X-direction pad row 2X, the robot hand 20 is driven so that the nozzle opening of the dispenser 10 is first moved to the X-direction pad row 2X.
Position it on the first pad at a predetermined height (about 0.5 mm).

Then, the position to be fixed to the guide member of the support bar 40 is appropriately selected so that the lower tip of the support bar 40 contacts the surface of the peripheral portion of the base 30. After that, the grip of the robot hand 20 is loosened only in the Z-axis direction so that the cylinder can move up and down, the creamy solder 5 is discharged from the dispenser 10, and the robot hand 20 is driven to move the cylinder, that is, the support bar 40 in the X-axis direction. Moving.

At this time, the lower tip of the support bar 40 makes a sliding movement parallel to the side edge 31 in the X direction on the surface of the base 30, so that the dispenser 10 makes an arc movement. Therefore, the dispenser 10 moves with the gap between the nozzle opening of the dispenser 10 and the surface of the printed board 1 kept constant.

In FIG. 3, reference numeral 45 denotes a semi-cylindrical attachment base having an X-direction side edge 45A as an arc and a Y-direction side edge 45B as a straight line. The attachment base 45 is attached to the XY table 3. Has been. Reference numeral 30-1 is a curved base whose side edge 31-1 in the X direction is equal to the arc of the mounting base 45 and whose plate thickness is constant.

Both side edges of the base 30-1 in the X direction slidably contact a pair of guide members (not shown). Then, by attaching a rod (not shown) to one side edge in the Y direction and driving the rod, the back surface of the base 30-1 is attached to the attachment base.
It slides on the surface of 45 and makes a reciprocal curvilinear motion in the X-axis direction.

Further, the printed board 1 is attached so that the back surface is in close contact with the front surface of the base 30-1. To apply the cream solder to the pads in the X-direction pad row, the robot hand 20 is driven so that the nozzle opening of the dispenser 10 is
It is located at a predetermined height (about 0.5 mm) on the first pad of the X-direction pad row.

Then, the cream-like solder is discharged from the dispenser 10 and the base 30-1 is driven to attach the mounting base.
It slides on the surface of 45 and slides in the X-axis direction. To apply the cream solder to the pads in the Y-direction pad row, the robot hand 20 is driven so that the nozzle opening of the dispenser 10 is located at a predetermined height position (about 0.5 mm).

Then, the creamy solder is discharged from the dispenser 10, and the XY table 3 is driven to move the attachment table 45, that is, the base 30-1 in the Y-axis direction.

[0049]

As described above, according to the present invention, a printed board having a warp is closely attached to a camber-shaped base close to the warped shape, and the pad and the X-direction pad of the Y-direction pad row are attached. A cream-like solder is applied to a row of pads, which has a practically excellent effect in that it can be applied to a warped printed board to apply a predetermined amount of cream-like solder onto a pad.

[Brief description of drawings]

FIG. 1 is a diagram showing the principle of the present invention.

FIG. 2 is a diagram of an embodiment of the present invention.

FIG. 3 is a diagram of another embodiment of the present invention.

FIG. 4 is a diagram of a conventional example.

5 (A) and (B) are diagrams showing a coating process.

FIG. 6 is a diagram of a warped printed board.

[Explanation of symbols]

1 printed board 2 pad 2X X direction pad row 2Y Y direction pad row 3 XY table 5 cream solder 10 dispenser 11 cylinder 20 robot hand 30,30-1
Base 31 Side edge in X direction 32 Side edge in Y direction 35 Straightening frame 36 Groove 45 Mounting base 50 Solder layer

Claims (3)

[Claims] 1. A printed board (1) is attached to the front surface of a semi-cylindrical base (30) having a side edge (31) in the X direction as an arc, and the cream board is dispensed from the dispenser (10). The solder is continuously discharged, and a curvilinear motion parallel to the X-direction side edge (31) is applied to the dispenser (10) or the base (30) to form a strip-shaped pad on the pad in the X-direction pad row (2X). The creamy solder is applied to the dispenser (10), the creamy solder is continuously discharged from the dispenser (10), and a linear motion parallel to the Y-direction side edge (32) is applied to the dispenser (10) or the base (30). ) Is applied to the pad of the Y-direction pad row (2Y) to apply the cream-like solder in a strip shape. 2. A kamaboko-shaped base (30) having a side edge (31) in the X direction as an arc is attached to an XY table (3), and the back surface is closely attached to the front surface of the base (30). A support bar where the printed board (1) is attached and the lower tip of the board contacts the peripheral surface of the base (30).
(40) is attached to the dispenser (10), the dispenser (10) is held so as to follow the vertical movement of the support bar (40), and cream solder is continuously supplied from the dispenser (10). At the same time as discharging, the XY table (3) is driven in the X-axis direction to apply the cream solder (5) in a strip shape to the pads of the X-direction pad row (2X), and the XY table (3X) is applied. ) Is driven in the Y-axis direction to apply the cream-like solder (5) in a band shape to the pads of the Y-direction pad row (2Y). 3. A kamaboko-shaped attachment base (45) having an X-direction side edge (45A) as an arc is attached to an XY table (3), and the X-direction side edge (31-1) is attached. A curved base (30-1) having a constant plate thickness, which is equal to the circular arc of the base (45), is mounted on the mounting base (45) so as to be slidable in the X-axis direction. Printed board (1) with the back side in close contact with the front side of (-1)
The solder paste is attached and the creamy solder is continuously discharged from the dispenser (10) held at a predetermined height, and the base (30-1) is placed on the attachment base (45) in the X-axis direction. By slidingly driving, the cream solder is applied to the pads of the X-direction pad row (2X) in a strip shape, and the XY table (3) is driven in the Y-axis direction to move the Y-direction pad row (2Y). A method for dispensing creamy solder, which comprises applying creamy solder in a strip shape to a pad.