JPH06302944A - Soldering equipment for electronic component - Google Patents

Abstract

PURPOSE:To suitably solder electrodes of an electronic component to a circuit pattern of a mount object like a printed board, with excellent thermal efficiency. CONSTITUTION:A component suction tool 10, a nitrogen supplyier 68 and a heating bar 80, and a seal cover 84 mutually independently elevate. After the component suction tool 10 mounts an electronic component 12 on a printed board 14, and the seal cover 84 descends to form a closed space, the nitrogen gas supplier 68 drscends together with the heating bar 80 while supplying nitrogen gas, and the heating bar 80 comes into contact with the tip part 22 of a lead 20, and heats it effectively. Since the nitrogen gas is supplied, the lead 20, cream solder 26, and a circuit pattern of the printed board 14 are scarcely oxidized, and the deterioration of wetting property of the cream solder can be prevented. Thus the lead 20 can be excellently bonded to the printed board 14. In stead of nitrogen gas, a low oxygen concentration atmosphere is formed with a vauum equipment, and heating may be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for soldering electrodes of electronic parts to a circuit pattern of an object to be mounted such as a printed circuit board.

[0002]

2. Description of the Related Art Electrodes for electronic parts are used as printed circuit boards and MCMs.
Soldering to a circuit pattern of a mounting target such as (Multi Chip Module) is widely performed. The solder is applied to a predetermined position of the circuit pattern or an electrode of the electronic component, and the solder is melted by being heated by a heating device in a state where the electrode of the electronic component and the circuit pattern are in contact with each other via the solder. , The electrodes are joined to the circuit pattern.

As a soldering device for that purpose, there is a device for heating an inert gas such as nitrogen gas or argon gas and blowing it onto the solder to heat and melt the solder. With this configuration, the space containing the electrodes and the solder is filled with the inert gas during heating, the electrodes, the solder, and the circuit pattern are hardly oxidized during heating, the wettability of the solder is prevented from decreasing, and the electrodes are connected to the circuit pattern. It is well soldered.

[0004]

However, this soldering device has a problem of low thermal efficiency. When the hot gas is blown to heat the electrode, the hot gas heats the electrode and the solder and escapes to the space around them. Therefore, heat is wasted by the amount of this escaped hot gas, and the thermal efficiency is poor. It is an object of the inventions of claims 1 and 2 to provide an apparatus capable of soldering an electrode to a circuit pattern with high thermal efficiency and a high degree of bonding.

[0005]

In order to solve the above-mentioned problems, an electronic component soldering apparatus according to the invention of claim 1
(A) A contact-type electrode heating device that heats an electrode of an electronic component by heat conduction from a heating member, and (B) an inert gas supply device that supplies an inert gas to the periphery of the electrode and the circuit pattern. Composed. The invention of claim 2 is
(A) a contact-type electrode heating device that heats an electrode of an electronic component by heat conduction from the heating member; and (b) cover means that hermetically covers the periphery of the electrode, the circuit pattern, and the heating member.
(C) A vacuum device for creating a negative pressure in the inner space of the cover means.

[0006]

In the electronic component soldering apparatus according to the first aspect of the invention, the electrodes are heated by the heat conduction from the heating member and the solder is heated, and the electrodes are soldered to the circuit pattern. At this time, since the inert gas is supplied around the electrodes and the circuit pattern, the heating is performed in the inert gas atmosphere, and the electrodes, the circuit pattern, and the solder are hardly oxidized. Moreover, since the electrodes are heated by the heat conduction from the heating member to heat the solder and the inert gas is not used as the heat medium, the inert gas excludes the air (oxygen) around the electrodes. The amount of inert gas that escapes to the surroundings can be small. Further, the inert gas is heated by a heating member or the like, but the temperature of the inert gas that escapes to the surroundings is lower than when the inert gas is used as the heat medium. Also in the electronic component soldering apparatus according to the invention of claim 2, the electrodes are heated by the heat conduction from the heating member and the solder is heated, and the electrodes are soldered to the circuit pattern.
At this time, a negative pressure is applied to the space surrounding the electrodes, the circuit pattern, and the heating member, and the oxygen concentration is lowered, so that the electrodes, the circuit patterns, and the solder are favorably prevented from being oxidized during heating.

[0007]

As described above, according to the invention of claim 1,
Since the electrodes, the solder and the circuit pattern are hardly oxidized at the time of heating, the wettability of the solder does not deteriorate and the electrodes can be well soldered to the circuit pattern. Further, the consumption amount of the inert gas is small, and the amount of heat wasted by the supply of the inert gas is small, so that the thermal efficiency is improved. Similarly in the invention of claim 2,
Since the electrodes, solder, and circuit pattern are difficult to oxidize, deterioration of solder wettability can be satisfactorily avoided, and the electrodes can be satisfactorily soldered to the circuit pattern, and thermal efficiency can be improved by heating by heat conduction from the heating member. Can be improved. In particular, when heating under negative pressure, heat is not taken away as in the case of supplying an inert gas, and heating can be performed extremely efficiently.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment in which the invention of claim 1 is applied to an apparatus for soldering electronic parts to a printed circuit board will be described in detail with reference to the drawings. In FIG. 1, reference numeral 10 denotes a component suction tool, which takes out the electronic component 12 from the component supply device and mounts it on the printed circuit board 14. In the electronic component 12, a large number of leads 20 as electrodes are extended at equal intervals from four side surfaces of a square body 18. Each lead 20 is extended from the side surface of the main body 18 at a right angle, then is bent obliquely in the thickness direction of the electronic component 12, and the tip portion 22 is formed at a right angle to the side surface of the main body 18, It is joined to the printed circuit board 14 at the tip 22.

The base ends of the leads 20 are connected to each other by a square V-shaped resin film 24. In this electronic component 12, the leads 20 are formed by exposing and etching a copper foil laminated on a resin film, and after the film-holding electronic component to which a chip is attached is separated from the resin film, the leads 20 are The resin film 24 is left in the manufacturing process of the electronic component 12, and connects a large number of leads 20 to each other to prevent the leads 20 from bending.

The tip portion 2 of the lead 20 of the printed circuit board 14
The creamy solder 26 is provided at each of the positions where 2 is fixed.
Has been applied. The printed circuit board 14 is moved in one direction in the horizontal plane (this direction is the Y direction) by a moving device (not shown).

The component suction tool 10 is moved by an unillustrated moving device in the X direction orthogonal to the Y direction in the horizontal plane and in the vertical direction (Z direction). This moving device includes an X slide that is moved in the X direction by rotating a screw shaft by a servo motor, and a Z slide that is mounted on the X slide and is moved up and down by rotating the screw shaft by the servo motor. The component suction tool 10 is mounted on the Z slide.

The component suction tool 10 has a suction tool body 30 and a suction tube 32. A fitting hole 34 that opens to the lower surface is formed in the suction tool body 30, the fitting portion 36 of the suction tube 32 is fitted so as to be slidable in the axial direction, and a space is formed between the fitting hole 34 and the bottom surface of the fitting hole 34. The suction tool body 3 is provided by the spring 38 provided.
It is biased in a direction projecting from 0. Spring 38
The urging force is defined by fitting both ends of the pin 40, which is fitted through the suction tube 32 in the radial direction, into the pair of elongated holes 42 formed in the suction tool body 30. There is.

The suction tool body 30 of the fitting portion 36 of the suction tube 32
An adsorption portion 46 is provided at the lower end portion protruding from the suction portion 46. The suction part 46 has a rectangular box-shaped cross section, and has a square-shaped suction projection 48 protruding downward. The suction protrusion 48 is formed to have a size just corresponding to the resin film 24 of the electronic component 12. An air passage 50 opening to the lower surface of the suction protrusion 48 is formed in the suction portion 46, and air formed in the suction tool body 30 through the air passage 52 and the fitting hole 34 in the fitting portion 36. It communicates with the passage 54.

The component suction tool 10 is attached to the Z slide by holding the suction tool body 30 by a chuck provided on the Z slide. Adsorption tool body 30
By being held by the chuck, the air passage 54 formed in the suction tool body 30 is connected to the air passage formed on the Z slide side and is connected to a vacuum device (not shown), so that the suction protrusion 48 is provided. Vacuum is supplied.

A soldering device 60 is mounted on the X slide. The soldering device 60 has a nitrogen gas supply device 62, an electrode heating device 64, and a cover device 66. The nitrogen gas supply device 62 is in the shape of a double prism and is a nitrogen gas supply body 68 arranged outside the component suction tool 10.
Have. A nitrogen gas supply passage 70 is formed in the nitrogen gas supply body 68 and is connected to a nitrogen gas supply source (not shown) to supply the nitrogen gas. The nitrogen gas supply body 68 and the nitrogen gas supply source constitute the nitrogen gas supply device 62. Further, the lower end portion of the nitrogen gas supply body 68 is inclined in a direction away from the component adsorption tool 10, and the opening of the nitrogen gas supply passage 70 is just the lead 20.
To the tip 22 of the.

The electrode heating device 64 has a casing 76 in the shape of a double prism which is integrally provided with the nitrogen gas supply body 68. The casing 76 and the nitrogen gas supply body 6 are also provided.
8 is integrally lifted by an air cylinder (not shown) provided on the X slide. The casing 76 is provided on the outside of the nitrogen gas supply body 68, the heater 78 is housed inside, and a heating bar 80 as a heating member having a rectangular tubular shape is provided on the lower surface so as to project. The heating bar 80 is used for the electronic component 12 sucked by the component suction tool 10.
It has a size just corresponding to the tip 22 of the lead 20 and is heated by the heater 78.

The cover device 66 is in the form of a container that opens downward, and has a seal cover 84 having a size capable of covering the component adsorption tool 10, the nitrogen gas supply device 62 and the electrode heating device 64. A heat-resistant rubber seal member 86 is attached to the open end of the seal cover 84, and a gas hole (not shown) is provided in the upper portion of the seal cover 84 to allow the escape of gas. .
The seal cover 84 is lifted and lowered independently of the component suction tool 10, the heating device 64, and the nitrogen gas supply device 62 by an air cylinder (not shown) provided on the X slide.

When mounting the electronic component 12 on the printed circuit board 14, the component suction tool 10 is moved to the component take-out position, and after the electronic component 12 is taken out from the component supply device, it is moved onto the printed circuit board 14. The electronic component 12 is mounted. During this movement, an error in the posture of holding the electronic component 12 by the component suction tool 10 is detected and corrected together with the positioning error of the printed board 14, but these detections and corrections are not directly related to the present invention. Illustration and description are omitted.

After the component suction tool 10 is moved to the component mounting position on the printed circuit board 14, it is lowered to the electronic component 12.
Are placed on the printed circuit board 14. This descending amount is sufficient to bring the tip 22 of the lead 20 into contact with the cream-like solder 26 applied on the printed circuit board 14, and the excessive descending amount is between the suction tool body 30 and the suction tube 32. It is absorbed by relative movement.

The seal cover 84 is lowered in parallel with the mounting of the electronic component 12 on the printed circuit board 14.
The seal member 86 is brought into contact with the printed circuit board 14 to form a closed space. Then, the nitrogen gas supplier 68 and the heating bar 80 are lowered. At this time, the heating bar 80 is heated to a temperature necessary for heating the lead 20, and the nitrogen gas supply body 68 is lowered while supplying the nitrogen gas. Therefore, as the nitrogen gas supply body 68 descends, the air in the airtight space formed by the seal cover 84 is replaced with nitrogen gas.

In particular, as the nitrogen gas supply member 68 becomes closer to the printed circuit board 14, the flow of the nitrogen gas becomes stronger, and the air near the surface of the printed circuit board 14 is expelled, so that the nitrogen gas is satisfactorily replaced with the nitrogen gas. Further, since the nitrogen gas supply body 68 is provided between the heating bar 80 and the adsorption pipe 32 and supplies the nitrogen gas from the inside of the heating bar 80 to the outside, the air is heated by the heating bar 80 and the seal cover. It is discharged well through 84.

As described above, since the nitrogen gas is supplied into the limited space covered with the seal cover 84, the air in the space is almost completely replaced with the nitrogen gas. Therefore, when the heating bar 80 is lowered to a position where it contacts the tip 22 of the lead 20 and the cream solder 26 is heated with the lead 20 sandwiched between the printed board 14, the tip 22 of the lead 20 and the cream solder 26. An atmosphere containing a large amount of nitrogen is formed around the circuit pattern of the printed circuit board 14. When the creamy solder 26 is heated by the heating of the lead 20 and melts, the lead 20, the creamy solder 26 and the circuit pattern are oxidized. Hardly occurs, the deterioration of wettability is prevented, and the lead 2
0 is well soldered to the circuit pattern. Nitrogen gas is supplied even while the leads 20 are being heated, and the periphery of the leads 20, the cream solder 26 and the circuit pattern is kept filled with nitrogen gas.

Further, since the heating bar 80 contacts the lead 20 and heats it, the heat does not escape so much and the heating can be performed efficiently.

Moreover, since the leads 20 are heated by the heat conduction from the heating bar 80 to heat the creamy solder, the nitrogen gas is not used as a heat medium and is not heated by the heated nitrogen gas. Is the tip portion 22 of the lead 20, the cream solder 26, and the printed circuit board 1.
It suffices that the air (oxygen) around the circuit pattern of No. 4 be supplied at a flow rate sufficient to eliminate it, the amount of nitrogen gas escaping to the surroundings can be small, and thermal efficiency is good. Further, the nitrogen gas is heated by the heating bar 80 or the like, but the temperature of the nitrogen gas escaping to the surroundings is lower than that in the case where the nitrogen gas is used as the heat medium, and thus the heating can be performed with high thermal efficiency.

Further, the heating bar 80 is applied to the tip end portion 22 of the lead 20, and together with the printed circuit board 14, the lead 20.
Since the leads 20 are lifted in the vertical direction or the warp of the printed circuit board 14 is downward due to heating by sandwiching, the leads 20 are pressed by the heating bar 80 to correct the lift and warp. The leads 20 are securely soldered to the printed circuit board 14.

Further, the nitrogen gas supplier 68 is a heating bar 80.
And the adsorption tube 32, the heating bar 8
When the lead 20 is heated by 0, heat radiation to the electronic component 12 is prevented, and the influence of heat on the electronic component 12 can be reduced.

Further, the suction protrusion 48 of the suction pipe 32 has a box shape, and when the resin film 24 is sucked, the electronic component 12 is sucked.
Since the main body 18 is covered, the influence of heat on the main body 18 can be reduced in this respect as well.

According to the invention of claim 2, the flip chip is MCM.
An embodiment applied to a soldering device will be described with reference to FIG. The flip chip 90 is a semiconductor chip 92.
The solder bumps 94 are formed on a plurality of electrodes exposed on the surface of the solder, and the solder 98 applied on the MCM 96.
It is joined to MCM96 by. Therefore, in the component suction tool 100, the surface of the semiconductor chip 92 opposite to the side on which the solder bumps 94 are formed is suctioned by the suction tube 102 by vacuum. This component suction tool 100
Like the component suction tool 10, is moved in the X and Z directions by an X slide and a Z slide (not shown), and the MCM 96 is moved in the Y direction. .

A soldering device 104 is attached to the X slide.
Is installed. The soldering device 104 includes an electrode heating device 106, a vacuum device 108 and a cover device 11.
Has 0. The electrode heating device 106 has a rectangular tubular heating member 114 having a larger diameter than the adsorption tube 102 and smaller than the semiconductor chip 92. The heating member 114 is heated by a heater (not shown) and moved up and down by an air cylinder (not shown).

Further, the cover device 110 has a container-shaped seal cover 116 having a size sufficient to surround the flip chip 90, the heating member 114 and the solder 98, and a lower end portion of the seal cover 116 is provided at a lower end portion thereof. A seal member 118 made of heat resistant rubber is attached. Seal cover 1
16 is also lifted and lowered by an air cylinder independently of the heating member 114 and the component suction tool 100. Further, in the vacuum device 108, the seal cover 116 has the MCM9.
The air in the airtight space formed by being lowered onto the vacuum chamber 6 is sucked by the vacuum source 120. The vacuum source 120 is a vacuum source shared with the adsorption tube 102.

At the time of soldering, the flip chip 90 sucked by the component suction tool 100 is placed on the MCM 96, the solder bumps 94 are placed on the solder 98, and then the seal cover 116 is lowered to be placed on the MCM 96. To be With the airtight space thus formed, the vacuum device 108 sucks the air in the seal cover 116 to reduce the oxygen concentration, and then the heating member 114.
Are lowered and brought into contact with the semiconductor chip 92.
As a result, the semiconductor chip 92 is heated and the solder bumps 94 and the solder 98 are heated by heat conduction and melted, and the flip chip 90 is bonded to the MCM 96.

Since such heating of the solder is performed in an atmosphere of low oxygen concentration, deterioration of the wettability due to oxidation of the solder is prevented and the degree of bonding can be increased. Further, since the heating member 114 is brought into contact with the semiconductor chip 92 to heat it, the heating can be performed with high thermal efficiency. Also,
Unlike the case where oxidation is prevented by an inert gas, the inert gas does not escape with heat, and this also improves the thermal efficiency. Further, the vacuum device 108 and the component suction tool 100 share the vacuum source 120, so that an increase in device cost can be suppressed. However, sharing is not essential, and a vacuum source may be provided for each.

In the embodiment shown in FIG. 1, nitrogen gas is supplied as the inert gas, but other inert gas such as argon gas may be supplied.

As shown in FIG. 1, when the electronic component 12 having the leads 20 is joined to a mounting object such as a printed circuit board, a low oxygen concentration state is formed by a seal cover and a vacuum device instead of supplying an inert gas. Then, soldering may be performed.

On the contrary, the flip chip 9 as shown in FIG.
An inert gas may be supplied around the solder when the 0 is bonded to the mounting target.

Further, when the inert gas is supplied, the seal cover 8 is mounted after mounting the printed circuit board 14 of the electronic component 12.
4 may be lowered and placed on the printed circuit board 14. When the flip chip 90 is placed on the MCM 96 when forming a low oxygen concentration atmosphere, the seal cover 116 is placed at the same time.
May be lowered and placed on the MCM 96.

Further, it is not essential to provide a seal cover to cover the electrodes, the circuit pattern and the heating member when supplying the inert gas, and the seal cover may be omitted. This is because the atmosphere near the electrodes can be made to have a low oxygen concentration by supplying an inert gas without providing a seal cover.

Further, in the embodiment shown in FIG. 1, it is not essential to adsorb the resin film 24 of the electronic component 12 to cover the main body 18, and the main body 18 can be attached by the component adsorbing tool similar to the component adsorbing tool 100 shown in FIG. May be adsorbed and held.

Further, in the case of an electronic component such as the electronic component 12 shown in FIG. 1 in which the leads 20 are respectively extended from the four side surfaces of the main body 18, in the above embodiment, the leads 20 on the four side surfaces are provided. A square tubular heating bar 80
However, the heating may be performed by one side or two sides. The heating bar and the electronic component are sequentially moved relative to each other to heat the lead 20 on each side. By adjusting the position of the heating bar, a plurality of types of electronic components having different sizes can be obtained by one heating device. The reed can be heated.

Further, in each of the above-described embodiments, the component suction tool moves in the X and Z directions, and the mounting object moves in the Y direction. However, the mounting object moves in the X and Y directions. The component suction tool may move only in the Z direction, or the component suction tool may move in the X direction and the Y direction.
The present invention can also be applied to a soldering device of an electronic component mounting device that moves in the Z direction and the Z direction, and the mounting target is provided in a fixed position. The present invention can be applied to soldering in an apparatus in which a component suction tool and a mounting object move relative to each other to mount an electronic component.

In addition, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a soldering device according to an embodiment of claim 1. FIG.

FIG. 2 is a front sectional view showing a soldering device according to an embodiment of claim 2;

[Explanation of symbols]

 12 electronic parts 20 lead 26 cream solder 60 soldering device 62 nitrogen gas supply device 64 electrode heating device 66 cover device 80 heating bar 84 seal cover 90 flip chip 94 solder bump 96 MCM 104 soldering device 106 electrode heating device 108 vacuum device 110 cover device 114 heating member 116 seal cover

Claims (2)

[Claims] 1. A contact-type electrode heating device for heating an electrode of an electronic component by heat conduction from a heating member, and an inert gas supply device for supplying an inert gas to the periphery of the electrode and the circuit pattern, An electronic component soldering device that solders electrodes to the circuit pattern of a mounting target such as a printed circuit board. 2. A contact type electrode heating device for heating an electrode of an electronic component by heat conduction from a heating member, a cover means for hermetically covering the periphery of the electrode, the circuit pattern and the heating member, and an inner space of the cover means. A vacuum device having a negative pressure inside, and an electronic component soldering device for soldering the electrode to a circuit pattern of a mounting target such as a printed circuit board.