JPH0749149B2 - Soldering method and device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering method and apparatus, and more particularly to a soldering method and apparatus for bonding an IC lead on a substrate.

[0002]

2. Description of the Related Art A reflow soldering method is used as one of the methods for mounting an IC component on a printed wiring board. In this reflow soldering method, a solder paste is printed or applied on a printed circuit board by a dispenser or the like, IC parts are aligned and mounted on the printed circuit board, and the viscosity of the solder paste fixes the IC parts on the board. That is, that is, in a state where the external leads protruding to the side surface of the IC package are fixed on the solder paste, the entire substrate is heated in a reflow furnace to solder-bond each lead to the wiring pattern of the substrate.

In such a reflow soldering method, a light beam soldering method of locally heating only the lead portion is used when it is necessary to particularly prevent thermal influence on the IC package. A laser beam, a xenon lamp, a halogen lamp, or the like is used as a light source of this light beam. Of these, halogen lamp light sources using near-infrared rays are widely used as excellent because of their high heat absorption rate to metal, durability, maintainability, device configuration and control simplicity, and cost associated with them. Has been.

By using such a near infrared halogen lamp, (1) high energy efficiency can be obtained,
(2) The lamp rises quickly, (3) the ratio of radiant heat is high, (4) excellent heat resistance and impact resistance of the lamp itself, (5)
A soldering device suitable for heating metal by near-infrared irradiation is achieved.

On the other hand, in recent years, TAB (Tape Automated Bondi)
ng) has been used to implement an IC mounted on a flexible tape and an IC mounted on a thin flexible substrate. I on such a TAB or flexible substrate
When soldering C or the connection terminal, the tape or the substrate is easily deformed by heat and the position of the lead is easily displaced. Therefore, using a heating jig made of an electric resistor such as molybdenum, the portion to be soldered is While directly pressing, the heating jig was energized for soldering.

[0006]

However, in recent years I
With the miniaturization of C and the high density of packaging, the lead pitch has also been miniaturized. For example, QFP (Quad Flat Package) type ICs have been greatly miniaturized from the conventional 0.5 to 0.65 mm to 60 to 85 μm. When such an IC component is soldered by the conventional reflow soldering method, the lead may be deformed and separated from the paste during IC handling such as when aligning the IC component after applying the solder paste. Was not achieved in some cases.

On the other hand, when an IC is soldered to a conventional TAB or flexible substrate, the heating capacity of the heating jig for pressing the tape or the substrate is large, so that the rising process is slow and an efficient soldering process cannot be performed. Also, because a thick cable is connected to the heating jig to pass a large current,
The jig replacement and maintenance were troublesome and could not be automated, and the efficiency of the soldering work could not be achieved.

The present invention has been made in view of the above-mentioned drawbacks of the prior art. It is possible to perform rapid heating with a short rise time in a state where the leads of the IC are securely pressed to the substrate surface, and the automation is easy. It is intended to provide a simple soldering method and device.

[0009]

In order to achieve the above object, the soldering method according to the present invention is a method of soldering a work to be soldered to a soldering surface with a pressing member. Is heated by non-contact heating using a heating wire.

Further, the soldering apparatus according to the present invention includes a primary heating source for non-contact heating an object by irradiating heat rays, and
The secondary heating source is heated by the secondary heating source, and the pressing means presses the secondary heating source against the work to be soldered.

[0011]

The work (IC lead) is pressed against the soldering surface (substrate surface) by the pressing member, and in this state, the pressing member is non-contactly heated by the primary heating source such as a halogen lamp, and the pressing member is secondary. The work is heated as a heating source to solder the work.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram showing the basic structure of the present invention. An IC component 2 such as a QFP is mounted on the printed wiring board 1. Bent external leads 3 on the side surface of the IC component 2
Are formed to project. The external leads 3 are adhered to the solder paste 4 applied on the printed board 1 by a known means such as printing or a dispenser. The external lead 3 is pressed against the printed board 1 by the pressing member 5 as indicated by an arrow A, and is pressed onto the solder paste 4. In this state, the pressing member 5 is irradiated with the heating beam B by the halogen lamp 6. As a result, the pressing member 5 is heated above the melting point of the solder, and the external lead 3 is soldered to the wiring pattern (not shown) of the printed board 1.

The pressing member 5 is made of a black body material having a small heat capacity and a large heat transfer coefficient in order to absorb the heating beam B well and accelerate the rising. Such a material is appropriately selected in consideration of the material of the solder, the characteristics of the heating beam, the material and the size of the external lead 3, and the like. This pressing member 5 is
It may be a type in which the leads of the four sides of the IC component 2 are pressed simultaneously, or a type in which the two sides arranged in parallel are pressed or a type in which only one side is pressed.

The pressing member 5 as described above can be configured to be held by a robot arm or the like to automatically perform positioning and pressing operations. Alternatively, the heat ray irradiation may be performed in a state of being manually held and then fixedly held on the substrate by an appropriate holding means.

After the solder paste is applied on the substrate 1 by the dispenser, the IC component 2 is gripped and transported when the IC component 2 is transported and fixed on the substrate 1 by the positioning hand (chip mounter). Is used as the pressing member 5, the IC component 2 is aligned and the lead is fixed on the solder paste, the heating beam is radiated to the hand to heat the hand, and the hand is soldered through the hand. You may join. With such a configuration, it is possible to carry out the method of the present invention using an existing soldering device.

Further, by appropriately setting the wavelength of the heating beam from the halogen lamp 6 according to the material of the solder to be joined, the heat ray absorption rate for the solder can be maximized, and the rising can be further accelerated. The efficiency can be improved.

FIG. 2 is a schematic view of the essential parts showing an example of the soldering apparatus according to the present invention. FIG. 6A shows the tip of the robot arm that holds the pressing member. In this example, a turret 8 is provided at the tip of the arm 7, and a plurality of pressing members 5a and 5b of different sizes are detachably attached to the turret 8. An IC to be joined by driving the arm 7 by selecting the pressing member of the turret 8 and making it slightly protrude
The components are aligned in the XY directions and lowered in the Z direction to press the leads of the IC components.

FIG. 1B is a top layout diagram showing an example of the overall structure of the soldering apparatus according to the present invention. The arm 7 in FIG. 7A having the turret 8 at the tip performs the soldering process at the position of the soldering station 9. After the soldering process is performed a predetermined number of times or for a predetermined time, it is swung as shown by an arrow C to wash the used pressing member at the washing station 10, and then returns to the soldering station again to repeat the soldering work. When the cleaning is repeated after a predetermined number of times and the cleaning becomes impossible, or when the pressing member is replaced with another pressing member in order to change the size, the arm 7 is further swung as shown by an arrow C, and at the replacement station 11, the tip of the arm is replaced. After using, the pressing member is removed, and a new pressing member (not shown) is selected and attached.

FIG. 3 is an overall perspective view of another example of the soldering device according to the present invention. XY table 16 on base 15
Is installed. The printed circuit board 1 is mounted on the XY table 16. IC to be soldered on the printed board 1
The component 2 is adhered to a predetermined position via a solder paste. Above the printed circuit board 1, there is provided a heating head 14 including a pair of halogen lamps 6 that simultaneously irradiate the leads on the two sides of the IC component 2. An arm unit 12 is provided on the base 15 adjacent to the XY table 16.
The arm unit 12 includes an arm 7 that is rotatable and expandable via a joint 13, and is rotatable about the Z axis and movable in the Z axis direction (vertical direction). The above-mentioned pressing member 5 is detachably attached to the tip of the arm 7.

The arm unit 12 is driven based on the XY position information of the IC component 2, the pressing member 5 is aligned with the IC component 2 to be soldered and lowered, and the IC lead is pressed to onto the printed circuit board 1. Hold it fixed by pressing. In this state, the halogen lamp 6 is turned on and the pressing members 5 that press the leads on the two sides of the IC component 2 are irradiated from both sides and heated. As a result, the temperature of the pressing member 5 rises above the melting point of the solder, and the leads on the two sides of the IC component 2 are soldered to the pattern (not shown) of the printed board 1. Then, by operating the arm unit 12, the pressing member 5 is rotated 90 degrees and I
The leads on the other two sides of the C component 2 are soldered in the same manner.

Such a soldering operation is performed on the printed circuit board 1
Repeat for the other IC components above. In this case, the pressing member 5 may be cleaned at the cleaning station 10 (FIG. 2) after every predetermined number of soldering operations. Further, the pressing member 5 may be replaced at the replacement station (FIG. 2) every predetermined number of times or according to the shape of the IC component. The cleaning work and the replacement work may be performed manually by an operator, manually, or automatically by a program.

[0022]

As described above, in the present invention, the pressing member is heated by irradiating it with heat rays using a non-contact primary heating source such as a halogen lamp, and the heated pressing member is secondarily heated. As a source, the solder is melted and soldered while pressing the work to be soldered, so that the fine I
When soldering a C lead or the like, the solder can be heated and melted in a state where each lead is securely pressed against the pattern of the substrate to be soldered, and the reliability of the solder joint can be improved. . Moreover, since the non-contact primary heating source is used for indirect heating, the rise time can be shortened with high energy efficiency, and a soldering device excellent in heat resistance and durability and suitable for metal heating can be obtained. . Also,
Since the power cable and the like are not connected to the pressing member itself which is the secondary heating source, the handling is easy, and the automation of the soldering work can be easily achieved by using the robot arm or the like, and the efficiency of the soldering work can be improved. .

[Brief description of drawings]

FIG. 1 is a diagram illustrating the basic configuration of the present invention.

FIG. 2 is a structural explanatory view of an example of a soldering device according to the present invention.

FIG. 3 is a perspective view of another example of the soldering device according to the present invention.

[Explanation of symbols]

1; printed circuit board, 2; IC component, 3; lead, 4; solder paste, 5; pressing member, 6; halogen lamp,
7; arm, 8; turret, 9; soldering station, 10; cleaning station, 11; exchange station, 12; arm unit, 13; joint, 14; heating head, 15; base, 16; XY table.

Claims (2)

[Claims] 1. In a state where a work to be soldered is pressure-bonded to a soldering surface using a pressing member made of a material that absorbs heat well , the pressing member is heated in a non-contact manner by using a heating wire to solder. A soldering method characterized by performing soldering. 2. A primary heating source that heats an object in a non-contact manner by irradiation with heat rays, a secondary heating source that is heated by the primary heating source, and a pressure contact of the secondary heating source to a workpiece to be soldered. Pressing means for controlling
A soldering device for carrying out the described soldering method .