JPH081983B2 - Lead bonding method for IC parts - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting an IC component on a circuit board and joining its leads to electrodes on the circuit board.

[0002]

2. Description of the Related Art Conventionally, when an IC component is mounted on a circuit board and its leads are joined to the electrodes of the circuit board, FIG.
As shown in FIG. 5, the IC component 50 with the leads 51 protruding from the main body 50a is positioned and held in a predetermined tray, and this tray is supplied to the component mounting apparatus, and the IC in the tray is fed by the component mounting apparatus. The component 50 is held by the mounting head 52 as shown in FIG. 14, and the adhesive 54 for temporary fixing is applied to each IC component mounting position in advance, and the cream solder 56 is applied to the electrode 55 to which the lead is to be joined. The IC component 50 is mounted at a predetermined IC component mounting position on the circuit board 53, and the circuit board 53 thus mounted with the IC component 50 is inserted into the reflow furnace to melt the cream solder 56 and lead 51 and the electrode 55. I was doing solder joints.

[0003]

However, in the joining method as described above, after mounting the IC component 50, the IC
The component 50 is a fluid adhesive 54 and a cream solder 56.
Since it is only placed and supported on the IC component 50
As the pitch of the leads 51 becomes finer, the IC component 50 slightly moves due to the behavior of the adhesive 54 and the cream solder 56 immediately after mounting, the acceleration and the vibration when the circuit board 53 moves, and the leads 51 move to the cream solder 56. There is a possibility that it may fall off from the top to cause a defective joint, and even if there is a slight lift of the lead 51, a defective joint may occur, and a separate reflow process is required for the joint, so the number of processes is large. There were problems such as low productivity.

In view of the above-mentioned conventional problems, the present invention is
An object of the present invention is to provide a lead joining method for an IC component, which can reliably join the leads of a C component with high productivity.

[0005]

According to the method of joining leads of an IC component of the present invention, an IC component in which a lead is preliminarily formed so that its flat portion faces obliquely downward toward the tip ,
It is held by a mounting head equipped with a stopper corresponding to the height of the IC component and mounted at a predetermined position on the substrate, and then the mounting head pressurizes it to bend the IC component lead and thereby to bond the metal height and substrate. The flat portion of the lead is absorbed into the electrode of the substrate by absorbing the warp of the lead, and the joining metal on the electrode of the substrate is melted in that state to join the lead and the electrode.

In the present invention, the leads of IC parts are illuminated with light.
It is preferable to irradiate and melt the bonding metal on the electrodes of the substrate.
It Further, it is preferable that the stopper includes an abutting member urged by an elastic body or a spring that contracts to a height position according to the height of the IC component.

[0007]

According to the IC component lead joining method of the present invention,
Since the leads are pre-formed so that their flat portions are directed obliquely downward toward the tips, they are melt- bonded while being pressed to a predetermined position on the substrate by the mounting head.
The C component will not be misaligned after mounting and will not cause a joint failure. Also, the warpage of the substrate, the height of the joint metal formed, the variation in the lead shape of the IC component, etc. can be absorbed, and the lift of the lead can be corrected. Highly reliable joining is possible, and lead joining can be performed in a series of steps including the mounting step and the steps in the middle can be eliminated, so that productivity is also improved. Moreover,
By providing the mounting head with a stopper corresponding to the height of the IC component, it is possible to prevent overload when the mounting head is pressurized, prevent excessive deformation of the leads, and ensure reliable bonding.

Further, by providing the stopper with an abutting member urged by an elastic body or a spring that contracts to a height position corresponding to the height of the body of the IC component, the buffering effect gently leads the lead to the electrode of the substrate. It can be applied to the surface, and the leads can be securely joined by preventing misalignment and bending of the leads .

[0009]

EXAMPLE An example of applying the IC component lead joining method of the present invention to an IC component mounting apparatus for cutting and separating an IC component from a carrier film integrally formed with the IC component and mounting it on a circuit board Will be described with reference to FIGS. 1 to 13.

FIG. 13 showing the overall configuration of the IC component mounting apparatus.
In the above, a board carrying means 5 for carrying a printed circuit board (hereinafter referred to as a board) 3 to the front portion of the upper surface of the main body 4 and positioning it at a predetermined position is provided with carrier films 1 to I at the rear portion.
Cutting means 6 for separating and cutting the C component 2 are provided respectively. Between the cutting means 6 and the substrate transfer means 5, an IC
A mounting head 7 capable of holding the component 2 is moved between the cutting means 6 and an arbitrary position on the substrate 2 positioned X
-Y robot 8 is provided. Further, a supply means 9 for supplying the carrier film 1 in which the IC component 2 is integrally formed with the cutting means 6 is disposed behind the main body 4.

IC parts 2 are integrally formed on the carrier film 1 at appropriate intervals in the longitudinal direction. That is, the inner lead and the outer lead are formed in advance on the carrier film 1, and I and I are formed on the carrier film.
By mounting the C chip, joining the bumps to the inner leads, and integrally sealing the carrier film 1, the IC chip, and the inner leads with resin, the main body 2a of the IC component 2 is formed as shown in FIG. Further, leads (outer leads) 11 are formed that project in four directions from the carrier film 1 around the main body 2a.

The IC component holder of the mounting head 7 is shown in FIG.
As shown in FIG. 3, the suction hole 16 is formed at the axial center position and the suction nozzle 15 is biased by a spring 17 so as to project.
Is formed in the same plane shape as the carrier film 1 around the main body 2a of the IC component 2 and the IC is formed on the lower surface thereof.
A recess 18 into which the main body 2a of the component 2 is fitted is formed. Further, stoppers 19 project downward from the four corners of the lower end 15a of the suction nozzle 15 as shown in FIG.

After cutting the carrier film 1, the die in the cutting means 6 bends the base portion of the lead 11 so that the flat portion 11a at the tip thereof is located below the base portion by h1 as shown in FIG. Further, the flat portion 11a is formed so as to be three-dimensionally formed into a shape that is slanted downward toward the tip by h2 at an angle of θ.

The mounting head 7, as shown in FIG.
-The movable portion 8a of the Y robot 8 is provided with a lifting / lowering body 21 that is driven up and down by a lifting / lowering motor 22 and a feed screw mechanism 23, and a mounting shaft 25 extends downward from the lifting / lowering body 21.
The suction nozzle 15 is attached to the lower end thereof so as to be able to move up and down and urged downward by a spring 17. The mounting shaft 25 is rotatably attached to the elevating body 21 about its axis, and can be positioned at an arbitrary rotational position by a rotational positioning motor 24. Further, a suction passage 26 communicating with the suction hole 16 of the suction nozzle 15 is formed in the mounting shaft 25, and is connected to a suction source (not shown) via a swivel joint 27 arranged on the mounting shaft 25.

A bracket 28 provided with a penetrating cylinder portion 29 through which the mounting shaft 25 penetrates concentrically is fixed to the movable portion 8a. A pulley 31 is rotatably attached to the penetrating cylinder portion 29 via a bearing 30, and the rotary frame 3 is attached to the pulley 31.
2 is fixed. The pulley 31 is configured to be rotationally driven by a rotation motor 33 fixed to a bracket 28 via a drive pulley 34 and a toothed belt 35.

A movable body 37 is attached to the rotary frame 32 via a slide bearing 36 so as to be linearly movable.
The moving motor 38 and the rack and pinion mechanism 3 fixed to the
It is configured to be driven by 9.

A pair of distance adjusting bodies 40a and 40b, which are movable toward and away from each other about the axis of the mounting shaft 25 in the direction orthogonal to the moving direction, are attached to the moving body 37. The distance adjusting bodies 40a and 40b are attached to the distance adjusting bodies 40a and 40b. A laser beam irradiation means 41 for irradiating a laser beam to the leads 11 of the IC component 2 held by the suction nozzle 15 and mounted on the substrate 3 through the four peripheral portions of the suction nozzle 15 is attached. .

The spacing adjusters 40a and 40b are mounted on the mounting shaft 25.
Is driven in synchronization with a feed screw mechanism 43 having a feed screw shaft 42 in which left and right screw threads are formed with respect to the axial center of the feed screw mechanism 43 and an interval adjusting motor 44 that rotationally drives the feed screw shaft 42. . Further, in the vicinity of the laser light irradiating means 41, a gas injecting means 45 for irradiating the laser light and blowing out the flux smoke generated at the time of joining is arranged.

Next, the mounting operation of the IC component will be described.

The carrier film 1 is supplied to the cutting means 6 by the supply means 9, and the mounting head 7 is positioned in front of the cutting means 6. The IC component 2 is separated and cut from the carrier film 1 by the operation of the driving means (not shown) of the cutting means 6, and the leads 11 are formed as shown in FIGS. 12 and 4. Next, the lower part of the die of the cutting means 6 slides toward the front to position the IC component 2 at the front position, and the lifting motor 22 operates to move the suction nozzle 15 via the lifting body 21 and the mounting shaft 25. And the molded IC component 2 is sucked by the suction nozzle 15.

After that, the lifting motor 22 is driven in the opposite direction, the suction nozzle 15 is raised via the lifting body 21 and the mounting shaft 25, the XY robot 8 is then driven, and the mounting head 7 causes the substrate transfer means 5 to move. Is moved toward the substrate 3 positioned at a predetermined position in, and positioned immediately above the IC component mounting position.

As shown in FIG. 1, a bonding metal 10 is previously provided on the electrode 3a made of a copper pattern to which the lead 11 of the IC component 2 of the substrate 3 is bonded. The bonding metal 10 is provided by applying cream solder on the substrate 3 and then reflowing it, forming solder plating, or performing solder dipping.

Next, the lifting / lowering body 21 is driven to be lowered by the lifting / lowering motor 22, and the suction nozzle 15 is lowered via the mounting shaft 25 as shown by a white arrow A in FIG.
The component 2 is mounted, and the suction nozzle 15 further descends to a position retracted by a predetermined amount against the biasing force of the spring 17 and stops. In this way, as shown in FIG. 3, the IC component 2 is fixed by being pressed by the urging force of the spring 17 as indicated by the white arrow B at the mounted position. The mounting posture of the IC component 2 is adjusted by rotating the mounting shaft 25 with the rotation positioning motor 24.

Next, the bonding metal 10 is heated and melted by irradiating the lead 11 portion of the IC component 2 projecting from the laser light irradiating means 41 to the periphery of the suction nozzle 15 with the laser light from the optical path of the white arrow C. Then, the lead 11 and the electrode 3a are joined.

When the leads 11 are joined by this laser light irradiation, first, the moving body 37 is moved while irradiating the laser light from the pair of laser light irradiating means 41 to move the laser light along the two parallel sides of the IC component 2. To scan. By moving the moving body 37 once, the leads 11 on the two parallel sides of the IC component 2 are joined at one time. Next, the rotary frame 32 is rotated 90 ° by the rotary frame motor 33, and then the moving body 37 is moved while irradiating the laser beam by the laser beam irradiating means 41, and the laser beam is scanned to scan the IC component 2. The leads 11 on the remaining two sides are also joined.

Further, the scanning by the movement of the moving body 32 and the control of the laser light irradiation by the laser light irradiating means 41 are performed so that the section which can be scanned at a constant speed coincides with the bonding range of the lead 11 and is also scanned. At the beginning of the start section, laser light irradiation is started before scanning, and the lead 11
Is preheated so that uniform bonding is performed. Further, in order to prevent the substrate from burning in the latter half of the scanning, the scanning speed is increased in the latter half of the scanning, or the laser light irradiation means 41 is used.
The output of may decrease gradually.

As described above, all the leads 11 of the IC component 2 are bonded to the respective electrodes 3a of the substrate 3, and the mounting of the IC component 2 on the substrate 3 at a predetermined position is completed. The IC components 2 are sequentially mounted on the board 3 by repeating the above operation.

At this time, in the lead 11 of the IC component 2, as shown in FIG. 4, the flat portion 11a is positioned below the base portion of the lead 11 by h1 and is inclined by the height h2 at the angle θ. On the other hand, the height H between the lower surface of the tip portion 15a of the suction nozzle 15 and the lower surface of the stopper 19 is set to the sum of the height h1 of the lead 11 and the height of the electrode 3a on the substrate 3. Therefore, as shown in FIG.
The height of the lead 11 changes from h1 + h2 to h1 after joining during the transition from the state where the C component 2 is sucked to the state shown in FIG. That is, when the angle θ of the flat portion 11a of the lead 11 is deformed from the initial angle to almost 0 °, variations in the height of the bonding metal 10 and the warp of the substrate 3 are absorbed by this deflection,
The contact between the lead 11 and the electrode 3a is secured, and a highly reliable joint is secured.

Next, a second embodiment will be described with reference to FIG. In FIG. 5, an elastic body 19a is attached to the tip of the stopper 19 of the suction nozzle 15. This elastic body 19
a is designed to be contracted by a height h, and the h is designed to be substantially the same as the height h2 of the flat portion 11a of the lead 11.

As a result, the angle θ of the flat portion 11a of the lead 11 is deformed to almost 0 ° from the initial angle, so that the height variation of the bonding metal 10 and the warp of the substrate 3 are absorbed by this deflection. In addition, due to the buffering effect of the elastic body 19a, the lead 11 can be gently fitted to the electrode 3a of the substrate 3, and the lead 11 can be securely joined by preventing misalignment and bending.

FIG. 6 shows a third embodiment. In this embodiment, a spring 19c is used instead of the elastic body 19a of the second embodiment.
An abutting member 19b that is urged to project is attached to the lower end of the stopper 19. The contact member 19b is also configured to be elastically retractable by the height h, and has the same effect as that of the second embodiment shown in FIG.

Next, reference examples of the method of pressing the lead 11 with a thin plate will be described with reference to FIGS. 7 to 10.

In the first reference example shown in FIG. 7, an outer pressure thin plate 20a for pressing the tip of the flat portion 11a of the lead 11 is vertically mounted on the outer peripheral portion of the suction nozzle 15, and is attached to the lower surface of the suction nozzle 15. The height H'between the lower ends of the outer pressing thin plates 20a is designed to be the same as the height h1 of the leads 11. As a result, the flat portion 11 of the lead 11 of the IC component 2 is
Since a is directly pressed by the outer pressurizing thin plate 20, the contact between the lead 11 and the electrode 3a is secured, and a highly reliable joint is secured.

[0034] In a second reference example shown in FIG. 8, the suction nozzle 15, the inner pressure圧薄plate 20b to press the base end side end portion of the flat portion 11a of the lead 11 is mounted, first shown in FIG. 9
3 In the reference example , the outer pressure thin plate 2 is attached to the suction nozzle 15.
0a and an inner pressure thin plate 20b are provided .

In the fourth reference example shown in FIG. 10, a divided pressure thin plate 20c divided into an appropriate width is attached to the suction nozzle 15 by being biased by a spring (not shown).
By thus dividing the pressing thin plate and urging it so as to project, it is easy to adapt to the warp of the substrate 3, and it is not necessary to strictly align the parallelism of the lower ends of the pressing thin plate.

In the above embodiment, an example of irradiating with laser light to heat is shown, but other light beams such as infrared light may be irradiated to heat.

Further, instead of scanning the light beam (including the laser beam) with the moving body 32, another scanning system such as a reflecting mirror may be adopted. A cylindrical lens may be added to the irradiation means so that the irradiation range of the light beam substantially coincides with the bonding range of the lead 11 and heating is performed collectively.

Further, in the above-described embodiment, an example in which the IC component 2 is cut and separated from the carrier film 1 integrally formed with the IC component 2 and molded and then mounted on the substrate 3, the present invention is not limited to this. It goes without saying that this can be done when the IC components supplied in any other form are held by the mounting head, mounted on the substrate, and the leads are joined.

[0039]

According to the lead joining method for an IC component of the present invention, after the IC component is mounted by the mounting head, the mounting head pressurizes as it is and the joint is performed in that state, so that the IC component is displaced after mounting. Therefore, even if there is unevenness in the height of the joining metal or the warp of the substrate, the lead is bent to the electrode on the joining metal, so the contact between the lead and the electrode is secured. In addition, it is possible to perform highly reliable bonding without raising the leads, etc., and it is also possible to perform lead bonding in a series of steps including the mounting step and eliminate intermediate steps, so that productivity is improved. Exert. Equipped with a stopper yet mounting heads
Without breaking the forming shape of the IC component by that, it is possible to ensure a reliable contact leads and electrodes under a load.

By providing an abutting member urged by an elastic body or a spring at the tip of the stopper, it is possible to gently adapt the lead to the electrode due to its cushioning effect and prevent misalignment or bending of the lead. More reliable joining is possible .

[Brief description of drawings]

FIG. 1 is a sub-sectional view showing a state immediately before lead bonding of an IC component according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a holding state of an IC component by a suction nozzle.

FIG. 3 is a vertical cross-sectional view showing a lead joint state of an IC component.

FIG. 4 is an enlarged view showing a lead shape of an IC component.

FIG. 5 is a vertical sectional view showing a holding state of an IC component by a suction nozzle according to a second embodiment of the present invention.

FIG. 6 is a vertical sectional view showing a holding state of IC components by a suction nozzle according to a third embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view showing a holding state of an IC component by a suction nozzle according to a first reference example .

FIG. 8 is a vertical cross-sectional view showing a holding state of an IC component by a suction nozzle according to a second reference example .

FIG. 9 is a vertical cross-sectional view showing a holding state of IC components by a suction nozzle according to a third reference example .

FIG. 10 is a perspective view of a suction nozzle according to a fourth reference example .

FIG. 11 is a vertical sectional view of a mounting head.

FIG. 12 is a perspective view of an IC component.

FIG. 13 is a perspective view showing an overall schematic configuration of an IC component mounting apparatus.

FIG. 14 is a front view showing a process of joining leads of a conventional IC component.

FIG. 15 is a perspective view of an IC component.

[Explanation of symbols]

 2 IC parts 3 Substrate 3a Electrode 7 Mounting head 10 Bonding metal layer 11 Lead 11a Flat part 15 Adsorption nozzle 19 Stopper 19a Elastic body 19b Contact member 19c Spring 20a Outside pressure thin plate 20b Inner pressure thin plate 20c Split pressure thin plate 41 Laser Light irradiation means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keiji Saeki Keiji Saeki 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A-60-182798 (JP, A) JP-A-63-246892 (JP, A) JP-A-60-86893 (JP, A) JP-A-4-199593 (JP, A)

Claims (3)

[Claims] 1. An IC component in which a lead is preliminarily formed so that a flat portion thereof faces obliquely downward toward a tip ,
It is held by a mounting head equipped with a stopper corresponding to the height of the IC component and mounted at a predetermined position on the substrate, and then the mounting head pressurizes it to bend the IC component lead and thereby to bond the metal height and substrate. The lead joining method for the IC component, characterized in that the flat portion of the lead is absorbed into the electrode of the substrate by melting the warp of the lead, and the joining metal on the electrode of the substrate is melted in that state to join the lead and the electrode. . 2. An IC component lead is irradiated with light to expose the substrate.
The 1C component according to claim 1, wherein the joining metal on the electrode is melted.
Lead bonding method. 3. A stopper IC component according to claim 1 or 2, characterized in that it comprises a biased contact member by the elastic body or spring shrinks to a height position corresponding to the height of the IC component Lead bonding method.