JPH0613736A - Reflow bonding device - Google Patents

Abstract

PURPOSE:To obtain a reflow bonding device capable of rapidly cleaning a bonding tool without fail. CONSTITUTION:Within a reflow bonding device provided with a bonding tool 30 thermal sublimating the coating of a thermal sublimating coated wire 50 by pulse-heating step as well as soldering a wire onto a printed-circuit board 40, a heating power supply 11 feeding heating current to the bonding tool 30 and a controller 1 controlling the power supply of the heating power supply 11, the controller 1 thermally sublimates the wire coating material coagulated and deposited on the bonding tool 30 by energizing the heating power supply 11 in the no-load state of the bonding tool 30. Preferably, the controller 1 is to be energized by exceeding the specific number of bonding shots loaded with a thermally sublimating coated wire 50 or by turning a manual switch 31 ON or a timer 80 counting a specific time so as to energize the heating power supply 11 in the no-load state of the bonding tool 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflow bonding apparatus. More specifically, the head portion of a bonding tool is loaded with a thermally sublimable coating wire, and pulse heat is applied to the head portion to thermally sublimate the coating. The present invention relates to a reflow bonding device for soldering a wire to a printed board.

This type of device is used when a jumper strap line is added to a printed board unit. However, as the apparatus is used many times, the wire sublimation material, which has been sublimated by heat, solidifies and deposits around the bonding tool whose temperature has been lowered, and therefore the material must be cleaned regularly. Therefore, it is desired to provide a reflow bonding device that can perform such cleaning quickly and reliably.

[0003]

2. Description of the Related Art FIG. 8 is a diagram for explaining a conventional reflow bonding method, in which 30 is a bonding tool,
30 ₁ is the head part, 31 is the bonding tool 30
A support / pushdown member for the bonding tool 32
, A micro switch with a spring provided between the member 31 and the member 31, 40 is a printed board, 40 ₁ is a footprint whose surface is gold-plated, 41 ₁ is a lead of a soldered electronic component, 42 is a pre-coated solder layer, Reference numeral 50 is a thermally sublimable coated wire, 50 ₁ is a core wire made of oxygen-free copper having a diameter of 0.12 mm, 50 ₂ is an inner coating made of a polyurethane layer having a thickness of 10 μm, and 50 ₃ is an outer side made of nylon having a thickness of about 1 μm. , 61 is a power supply control section for generating an alternating pulse heating current, and 62 is a so-called welding transformer.

As shown in the figure, when the bonding tool 30 is placed on the thermally sublimable coated wire 50 and pressure is applied in the direction of arrow a, the micro switch 32 is closed with a predetermined load (for example, 150 g) or more. As a result, the power supply control unit 61 is energized, power is supplied to the transformer 62, and a pulse heat current flows through the bonding tool 30. FIG. 9 is a diagram showing a heat sequence of a conventional bonding tool.

When the supply of the heat current is started, the temperature of the head portion 30 ₁ of the bonding tool 30 rises to about 430 ° C. due to the heat capacity of the bonding portion and the like, whereby the wire coatings 50 ₂ and 50 ₃ are instantaneously (1 Within seconds). After that, the temperature is lowered to about 260 ° C and the core wire 5 is set in about 2 seconds.
Solder 0 ₁ . However, when the temperature of the head portion 30 ₁ drops from a high temperature to a low temperature, the coating material sublimated in the surrounding air is solidified and accumulated around the head portion 30 ₁ . Then, if the bonding is continued with the unclean tool, problems such as deterioration of the bonding quality and rebonding occur. Therefore, the bonding tool 30 must be regularly cleaned.

Conventionally, the deposits are incinerated and removed by a high-temperature flame such as a hydrogen torch every 10 shots. Or it was wiped off with gauze or absorbent cotton. However, according to the former, the number of man-hours increases, and it is extremely inconvenient to perform such cleaning work during the bonding. Further, according to the latter, the groove portion at the tip of the head portion 30 ₁ cannot be sufficiently cleaned.

[0007]

As described above, in the conventional reflow bonding apparatus, since the bonding tool is cleaned with a hydrogen torch, gauze or the like, the number of working steps is increased, or sufficient cleaning cannot be performed. It was An object of the present invention is to provide a reflow bonding device that can clean the bonding tool quickly and reliably.

[0008]

The above-mentioned problems can be solved by the structure shown in FIG. That is, the reflow bonding apparatus of the present invention includes a bonding tool 30 for thermally subliming the coating of the thermally sublimable coated wire 50 by pulse heating and soldering the wire to the printed board 40, and a heat for supplying a heating current to the bonding tool 30. Power supply unit 11,
The control unit 1 controls the power supply of the heat power source unit 11. The control unit 1 solidifies and deposits on the bonding tool 30 by energizing the heat power source unit 11 when the bonding tool 30 is in an unloaded state. The wire coating material is thermally sublimated.

[0009]

In the reflow bonding apparatus of the present invention,
The control unit 1 normally uses the bonding tool 3 as shown in the figure.
When the heat sublimation coated wire 50 is loaded (contacted) to 0, the heat power source unit 11 is energized to instantaneously sublimate the wire coating by a predetermined pulse heat in consideration of the heat capacity of the load, and at the same time, to wire the printed board 40 with the wire. 50 ₁ is soldered. In this way, after performing the bonding work several times, the heating power supply unit 11 is energized when the bonding tool 30 is in an unloaded state (a state where the bonding tool 30 is not in contact with the thermally sublimable coated wire 50). As a result, the bonding tool 30 is now subjected to pulse heating in the unloaded state, and the temperature thereof overshoots beyond the normal time. As a result, the wire coating material that has solidified and accumulated around the bonding tool 30 and in the groove portion is completely sublimated again by heat, whereby the bonding tool 30 can be cleaned quickly and reliably.

Preferably, the control means is provided with a counting means 70 for counting the number of times the pulse heat is applied to the bonding tool 30 under load and a comparing means 71 for comparing the count number C of the cowout means 70 with a predetermined number N. The unit 1 is energized by the comparison and coincidence of the comparison unit 71, and energizes the heat power supply unit 11 when the bonding tool 30 is in an unloaded state.

Also preferably, the manual switch 3 ₁
The control unit 1 is energized when the manual switch 3 ₁ is turned on, and energizes the heat power supply unit 11 when the bonding tool 30 is in an unloaded state. Further, preferably, a timer means 80 for starting time measurement from the start of use of the bonding tool 30 and periodically outputting a timing signal T is provided, and the control section 1 is energized by the timing signal T of the timer means 80 to be bonded to the bonding tool. The heat power supply unit 11 is energized when 30 is in an unloaded state.

[0012]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals denote the same or corresponding parts throughout the drawings. FIG. 2 is an external perspective view of the reflow bonding apparatus according to the embodiment. In the figure, 1 is a CPU that performs main control of the apparatus, 3 is an operation panel, and 4 is a hard disk device (D
SK), 5 is a floppy disk device (FD) for inputting a jumper / strap line wiring program, etc., 6 is an image processing device for processing fine image information on a printed board, 7 is its display device (CRT), 9 Is an adhesive dispenser for fixing jumper / strap wires, 1
0 is an ultraviolet (UV) irradiation device for curing the adhesive,
11 is a heat power source for supplying power to the bonding tool, 1
3 is a bonding head part that houses various tools,
Reference numeral 14 is a microscope, 18 is an XY table, 19 is a θ table, 20 is a patrite, and 40 is a printed board.

FIG. 3 is a block diagram of the reflow bonding apparatus of the embodiment. In the figure, 1 is a CPU, 2 is a memory (MEM) for storing the control program of FIG. 3 ₁ is a switch for inputting a bonding head cleaning command, 4 is a hard disk device (DSK), 5 is a floppy disk device (FD), 6 is an image processing device, 7 is a display device (CRT), 8 is a CPU 1 Common bath, 9 is an adhesive dispenser device, 10 is an ultraviolet (UV) irradiation device, 11
Is a heat power supply unit, 12 is a bonding head control unit, 1
3 is a bonding head part, 14 is a microscope, and 15 is X-.
A Y table control unit, 16 is a θ table control unit, 17 is a table mechanism unit, 18 is an XY table, 19 is a θ table, and 40 is a printed board.

FIG. 4 is a conceptual configuration diagram of the bonding head portion of the embodiment. In the figure, 13 ₁ is a bonding head mechanism portion, 13 ₂ is an ultraviolet (UV) lamp, 13 ₃ is a dispenser tool, 30 is a bonding tool, and 13 ₄ Is a wire guide, 50 is a thermally sublimable coated wire, and 13 ₅ is a camera head. The bonding head mechanism section 13 ₁ has a function of supporting various tools as shown in the drawing and moving them to a predetermined position. Although not shown, a wire cutter, a strength checker for the joint, an illumination lamp, etc. are also mounted on the bonding head 13.

The printed board 40 is moved in the XY direction as shown by the XY table 18 and the .theta. Table 19 and is rotated in the .theta. Direction. The tools are shifted onto the X-Y direction by the bonding head mechanism portion 13 _1, and is vertical to the Z direction, and is rotated if necessary θ direction. FIG. 5 is a block diagram of the heat power supply unit of the embodiment,
In the figure, 30 ₂ is a temperature sensitive element (for example, a thermocouple) provided near the tip of the bonding tool 30, 11 is a heat power source unit, and 11 ₁ is an interface for exchanging signals with the CPU 1 via the common bus 8. (IF), 11 ₂ is a D / A converter (D / A), 11 ₃ is an AC that controls the generation / stop of AC power and the amount of power under the control of the CPU 1.
-AC converter, 11 _4, for example AC350mV, 6
A welding transformer capable of outputting 00A, 11 ₅ is an amplifier (AMP) for detecting the temperature of the temperature sensitive element 30 ₂ , and 11 ₆ is an A / D converter (A / D).

The AC-AC converter 11 ₃ receives an AC power source from the outside as an input and outputs AC power having a power according to the output of the D / A converter 11 ₂ . However, when the output voltage of the D / A converter 11 ₂ is 0 V, the output AC power is also “0”. As a result, under the control of the CPU 1, it is possible to output AC power of arbitrary power. Therefore, even if a bonding tool having different characteristics is used, it is possible to generate a predetermined pulse heat on the bonding tool. Depending on the use of bonding tools with different characteristics, transformer 1
1 ₄ may be switched to tap on the primary side or the secondary side.

Further, the CPU 1 is provided with a temperature information feedback loop composed of the temperature sensitive element 30 ₂ , the amplifier 11 ₅ and the A / D converter 11 ₆ , so that the heat sequence of the bonding tool as described below can be arbitrarily and accurately performed. It is possible to control. FIG. 6 is a diagram showing a heat sequence of the bonding tool of the embodiment. In the figure, the characteristic shows a heat sequence when the bonding tool 30 is loaded. This is almost the same as the characteristic shown in FIG. On the other hand, the characteristic shows the heat sequence when the bonding tool 30 is in an unloaded state (the bonding tool 30 is floated in the air) and the same current as that of the characteristic is applied. As described above, in this embodiment, the bonding tool 30 is simply put into an unloaded state and the same current as that under load is flowed, so that a desired high temperature (for example, about 60 at 430 ° C. under load) is obtained.
0 ° C.) is obtained. Therefore, the CPU 1 does not have to perform any special temperature control. As a result, when the bonding tool 30 needs to be cleaned, the CPU 1 simply controls the heating power source component 11 in the unloaded state of the bonding tool 30 in the same manner as in the normal case, and the heat sequence of the tool 30 is as shown in the figure. Overshoot,
The wire-covered debris attached to the tool 30 can be completely sublimated again at a high temperature.

By the way, if the temperature of the bonding tool 30 becomes higher than necessary or is kept at a high temperature for a longer time than necessary, the life of the bonding tool 30 will be shortened. Therefore, the CPU 1 may control the heat sequence of the bonding tool 30 under no load as shown in the characteristics of the figure. FIG. 7 is a flowchart of the reflow bonding control of the embodiment.

In step S1, the number of times of bonding is calculated.
Of a counting counter C (corresponding to the counting means 70 in FIG. 1)
Set the content to "0". In step S2, the printed board 40
X-Y movement and θ rotation if necessary. Step
In S3, the wire guide 13 _FourAgain in step S4
Is the camera head 13_FiveTo drop each. Step S5
Then, the operator monitors the display device 7 and
Id 13_FourDetermine whether the descent position of is appropriate. Proper
If not, the position is set by manipulating in step S6.
It is corrected, and if appropriate, step S6 is skipped.

In step S7, the first bonding is performed. That is, while raising the camera head 13 ₅ ,
The bonding tool 30 is shifted to a predetermined position, the tool 30 is lowered, the first bonding heat is performed in synchronization with the ON detection of the microswitch 32, the tool 30 is raised, and the original position is shifted. Step S
At 8, the counter C is incremented by 1.

In step S9, the dispenser 13₃Where
It descends to a fixed search position and prints at step S10.
The plate 40 is moved XY. Work in step S11
Position where the person looks into the microscope 14 and dispenses the adhesive
Judge whether (distance) is appropriate, and if not, step
In step S12, the position is corrected by the manipulating operation. Well
If appropriate, step S12 is skipped. Step
In S13, the dispenser 13₃To lower the thermal sublimation
An adhesive is applied to the covering wire 50, and in step S14, the adhesive is applied.
The position of is irradiated with ultraviolet rays UV to cure the adhesive. Su
In step S15, rotate the printed board 40 by θ if necessary.
In step S16, the dispenser 13 ₃The search position
Raise to the place. At step S17, the dispensing ends.
It is determined whether or not it is completed, and if it is not completed, the process returns to step S10.
It

When the dispensing is completed, step S
Proceeding to 18, the dispenser 13 ₃ is raised. The step S19 printed circuit board 40 in by X-Y movement, lowers the camera head 13 ₅ step S20. In step S21, the operator monitors the display device 7 and determines whether or not the position of the wire guide 13 ₄ is proper. If it is not proper, the position is corrected by manipulating operation in step S22, and if it is proper, step S22 is skipped.

In step S23, the second bonding is performed. That is, the camera head 13 ₅ is raised, the bonding tool 30 is shifted to a predetermined position, the tool 30 is lowered, and the second bonding heat is performed in synchronization with the ON detection of the micro switch 32. The printed board 40 is moved backwards and moved slightly in the XY direction. The counter C is incremented by 1 in step S24, and the wire 50 is cut in step S25. Step S
At 26, the wire guide 13 ₄ is raised, and step S2 is performed.
In 7 the cleaning command switch 3 ₁ of the bonding tool 30
It is determined whether or not is ON. If not ON, step S2
At 8 it is determined whether the content of the counter C is equal to a predetermined number N (for example, 10) (corresponding to the comparing means 71 in FIG. 1). If it is not the predetermined number N, it is determined in step S29 whether or not the bonding is completed. If it is not completed, the process returns to step S2. If it is finished, the bonding process is finished.

If the switch 3 ₁ is turned on or the content of the counter C is equal to the predetermined number N in the determination in step S27 or S28, the process proceeds to step S30 to clean the bonding head 30. That is, at this point, the bonding tool 30 is in an unloaded state,
Pulse heat is applied to 0 to completely thermally sublime the deposits / deposits of the bonding tool 30 in the air. Preferably,
At that time, the printed board 40 is moved in the X-Y direction and offset to a predetermined position to prevent the printed board 40 from being contaminated due to precipitation and adhesion of the heat sublimate. In step S31, the counter C is reset and the process proceeds to step S29.

As described above, in the above embodiment, the cleaning of the bonding tool 30 is urged by the contents of the counter C or the ON / OFF state of the switch 3 ₁ . Besides this,
For example, in step S1 of FIG.
C (corresponding to the timer unit 80 in FIG. 1) is started, and a timer interrupt is generated by the timer counter TC at a predetermined time interval until the bonding is completed in the determination of step S29, and in the interrupt processing. The cleaning flag F of the bonding tool 30 is set, and step S28 is performed.
Alternatively, the cleaning flag F may be checked in a determination process provided after step S28, and if the flag F is set, the cleaning flag F may be reset and the process may proceed to step S30.

Although the automatic reflow bonding apparatus is shown in the above embodiment, the invention is not limited to this. The present invention can also be applied to a simple manual reflow bonding apparatus having a shape like a normal soldering iron. Further, although the manual switch 3 ₁ is provided on the operation panel 3 in the above embodiment, the present invention is not limited to this. For example, an operation lever (not shown) can be provided on the side surface of the bonding tool 30 shown in FIG.
The micro switch 32 may be closed when the operating lever is pushed up at an appropriate time with no load, and the CPU 1 detects this to urge the heat power supply unit 11. Therefore, the operating lever in this case corresponds to the manual switch 3 ₁ in FIG.

Further, the power feeding control section 61 having the structure shown in FIG.
In the case where the above-mentioned operation lever is provided on the side surface of the bonding tool 30 whose power supply is controlled by, the power supply control unit 61 of FIG. 8 plays a role corresponding to the control unit 1 of FIG.

[0028]

As described above, according to the present invention, the bonding tool 30 and the bonding tool 30 for soldering the wire to the printed board 40 while thermally subliming the coating of the thermally sublimable coated wire 50 by pulse heating. Heat power supply 11 for supplying a heating current and heat power supply 1
And a controller 1 for controlling the power supply of the wire 1. The controller 1 energizes the heat power source 11 when the bonding tool 30 is in the no-load state to solidify and deposit the wire coating material on the bonding tool 30. Heat sublimates
For this reason, a complicated mechanism is not required, the bonding tool 30 can be cleaned quickly and easily and completely, the bonding quality of the printed wiring is improved, and stable reflow bonding can always be performed.

In addition, the cleaning of the bonding tool 30 in the present invention can be performed anytime and anywhere as long as the tool 30 is in an unloaded state, so that it can be performed without affecting the original bonding work.

[Brief description of drawings]

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

FIG. 2 is an external perspective view of the reflow bonding apparatus of the embodiment.

FIG. 3 is a block diagram of a reflow bonding apparatus according to an embodiment.

FIG. 4 is a conceptual configuration diagram of a bonding head unit of the embodiment.

FIG. 5 is a block diagram of a heat power supply unit of the embodiment.

FIG. 6 is a diagram showing a heat sequence of the bonding tool according to the embodiment.

FIG. 7 is a flowchart of reflow bonding control according to the embodiment.

FIG. 8 is a diagram illustrating a conventional reflow bonding method.

FIG. 9 is a diagram showing a heat sequence of a conventional bonding tool.

[Explanation of symbols]

30 Bonding Tool 50 Thermally Sublimable Coated Wire 50 ₁ Core Wire 40 Printed Board 40 ₁ Footprint 42 Solder Layer 1 Control Section 11 Heat Power Supply Section 70 Counting Means 71 Comparison Means 3 ₁ Switch 80 Timer Means

Claims (4)

[Claims] 1. A heat-sublimable coated wire (50) is heat-sublimated by pulse heating to cover a printed board (4).
0) a bonding tool (30) for soldering a wire, a heating power supply section (11) for supplying a heating current to the bonding tool (30), and a control section (1) for controlling power supply of the heating power supply section (11). ) And the control unit (1) activates the heating power supply unit (11) when the bonding tool (30) is in an unloaded state, so that the wire coating material coagulated and deposited on the bonding tool (30) is removed. A reflow bonding device characterized by thermal sublimation. 2. A count means (70) for counting the number of times pulse heat is applied to the bonding tool (30) under a load condition, and a count number (C) of the cowout means (70) and a predetermined number (N). The control unit (1) is energized by the comparison and coincidence of the comparison unit (71) to energize the heat power supply unit (11) when the bonding tool (30) is in an unloaded state. The reflow bonding apparatus according to claim 1, wherein 3. A bonding tool (30) comprising a manual switch (3 ₁ ), wherein the control unit (1) is energized by turning on the manual switch (3 ₁ ).
The reflow bonding apparatus according to claim 1, wherein the heat power supply unit (11) is energized when the load is in an unloaded state. 4. A timer means (80) for starting time measurement from the start of use of the bonding tool (30) and periodically outputting a timing signal (T), wherein the control section (1) is a timer means (80). 2. The reflow bonding apparatus according to claim 1, wherein the heat power supply section (11) is energized when the bonding tool (30) is energized by the timing signal (T) of FIG.