JPH03217094A - Bonding method for lead of ic component - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of mounting an IC component on a circuit board and bonding its leads to electrodes on the circuit board.

2. Description of the Related Art Conventionally, when an IC component is mounted on a circuit board and its leads are connected to electrodes of the circuit board, a tC is used in which leads 51 are protruded from a zero body 50a to the periphery as shown in FIG.
The component 50 is positioned and held in a predetermined tray, this tray is supplied to a component mounting device, and the IC component 50 in the tray is held by a mounting hand 52 in the component mounting device as shown in FIG. , a circuit board 53 on which temporary fixing adhesive 54 is applied in advance to each IC component mounting position, and cream solder 56 is applied to electrodes 55 to which leads are to be connected.
The IC component 50 is mounted at a predetermined IC component mounting position, and the circuit board 53 with the IC component 50 mounted thereon is inserted into a reflow oven to melt the cream solder 56 and solder join the leads 51 and electrodes. was.

Problems to be Solved by the Invention However, in the above bonding method, the IC components 5
0, the IC component 50 is coated with a fluid adhesive 5.
4 and cream solder 56, the behavior of the adhesive 54 and cream solder 56 immediately after mounting and the acceleration of the movement of the circuit board 53 may cause damage to the IC component 5.
If the lead 51 moves slightly, the lead 51 may fall off from the cream solder 56, resulting in poor bonding.
Even if there is a slight rise in 1, there is a risk of bonding failure.Furthermore, since a separate reflow process is required for bonding, there are problems such as a large number of steps and low productivity.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a method for joining leads of IC components that can reliably and efficiently join leads of IC components.

Means for Solving the Problems The method for joining leads of IC components according to the present invention is to hold an IC component in a mounting head, mount it at a predetermined position on a board, and pressurize the IC component with a mounting head. It is characterized in that the lead portion is irradiated with a laser beam to melt the bonding metal on the electrode of the substrate, thereby bonding the lead 1ζ and the electrode.

Preferably, a mounting head having an IC component holder having a planar shape corresponding to the planar shape of the IC component is used, and a laser beam is irradiated through an opening formed in a portion of the IC component holder corresponding to the lead. Also, a pair of laser beam irradiation means placed on both sides of the axis of the mounting head are scanned to join the leads on two parallel sides of the IC component, and then this pair of laser beam irradiation means is applied to the mounting head. After rotating 90 degrees around the axis, scanning is performed to join the remaining two parallel leads of the IC component. Furthermore, the laser beam irradiation means is scanned so that the section in which the laser beam irradiation means can be scanned at a constant speed substantially coincides with the bonding range of the leads, and the laser light source is operated so that the laser output is stabilized in that section.

According to the method for joining leads of IC components according to the present invention, after the IC components are mounted with the mounting head, the lead portions are heated and bonded with a laser while the IC components are pressurized and fixed. There is no possibility of bonding defects due to misalignment, and even slight lifting of the leads is corrected, so highly reliable bonding is possible. This also improves productivity.

In addition, by applying a laser beam through an opening formed in the IC component holder with the lead fixed to the electrode under pressure in the IC component holder corresponding to the planar shape of the IC component, bonding with even higher reliability can be achieved. becomes possible.

In addition, by scanning a pair of laser beam irradiation means, rotating 90 degrees, and scanning again, I can achieve I in a short time with two scans.
All the leads protruding on all sides of the C component can be joined.

Furthermore, by making the constant speed section correspond to the bonding area when scanning the laser beam irradiation means, the bonding conditions for each lead can be made uniform without complicated scanning control, and a highly reliable bonding state can be obtained. I can do it.

EXAMPLE Hereinafter, the method for joining leads of IC components of the present invention is applied to an IC component mounting apparatus that cuts and separates IC components from a carrier film integrally formed with the IC components and mounts them on a circuit board. This will be explained with reference to FIGS. 1 to 8.

In FIG. 8 showing the overall configuration of the IC component mounting apparatus, a board transport stage 5 for transporting a printed circuit board (hereinafter referred to as a board) 3 to the front part of the upper surface of the main body 4 and positioning it at a predetermined position is shown in the rear part. Cutting means 6 for separating and cutting the IC component 2 from the carrier film 1 are respectively disposed. An X-Y robot 8 is placed between the cutting means 6 and the substrate transport means 5 and moves a mounting head 7 capable of holding the IC component 2 between the cutting means 6 and an arbitrary position on the positioned substrate 2. is installed. Furthermore, a supply means 9 is disposed behind the blank body 4 for supplying the carrier film 1 on which the IC component 2 is integrally formed to the cutting means 6.

IC components 2 are integrally formed on the carrier film 1 at appropriate intervals in its longitudinal direction.

That is, an inner lead and an outer lead are formed on the carrier film 1 in advance, and an IC chip is mounted on this carrier film, and the hump and the inner lead are joined, so that the carrier film 1, the IC chip, and the inner lead are integrated. By sealing with resin, as shown in FIG. 7, a wooden body 2a of the IC component 2 is formed, and leads (outer leads) 11 protruding from the blank body 2a in all directions are formed. Note that the carrier film 1 is notched at the lead 11 portion.

As shown in FIG. 5, the IC component holding portion of the mounting head 7 has a suction hole 16 formed at the axial center position and a spring 17.
The lower end 15a of the suction nozzle 15 is formed in the same planar shape as the IC component 2, and the main body 2a of the IC component 2 is fitted into the suction nozzle 15. A recess 18 is formed. The cutting means 6 is configured to cut the carrier film 1 between the punch and the mold while holding the carrier film 1 between the punch and the suction nozzle 15. Further, as shown in FIG. 6, openings 19 are formed in the four circumferential parts of the tip 15a of the suction nozzle 15, at the portions facing the leads 11 of the IC component 2. As shown in FIG.

Furthermore, the planar shape and dimensions of the tip 15a of the suction nozzle 15 are set so that a portion of the carrier film 1 remains at the tip of the lead 11 of the cut and separated IC component 2, as shown in FIG. , 8 tips of the leads 11 are reinforced by being connected to each other by a narrow frame 20 made of a carrier film.

As shown in FIG.
A mounting shaft 25 extends downward from the lifting body 21, and a suction knoll 15 is attached to the lower end of the mounting shaft 25 so that it can move up and down. It is attached in a biased state. The mounting shaft 25 is attached to the elevating body 2l so as to be rotatable around the axis, and is configured to be positionable at any rotational position by the 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 disposed at the upper part of the mounting shaft 25.

Further, a bra cant 28 is fixed to the movable portion 8a, and is provided with a through-cylindrical portion 29 through which the mounting shaft 25 concentrically passes. A pulley 31 is rotatably attached to the through cylinder portion 29 via a bearing 30.
is attached, and a rotating frame 32 is fixed to this pulley 3. The pulley 3I is configured to be rotatably driven by a rotation motor 33 fixed to the bracket I.28 via a drive pulley 34 and a toothed belt 35. In the rotating frame 32,
A moving body 37 is attached to be capable of linear movement via a slide bearing 36, and a moving motor 38 is fixed to the rotating frame 32.
It is configured to be able to be driven by a rack and pinion mechanism 39. The moving body 37 has a mounting shaft 2 in a direction perpendicular to the moving direction.
A pair of spacing adjusting bodies 40a, 40b that can move toward and away from each other around the axis of the suction nozzle 15 are attached to the spacing adjusting bodies 40a, 40b. The IC component 2 is held on the board 3 by the glue board II.
A laser beam irradiation means 41 is attached to irradiate the laser beam. The spacing adjusters 40a and 40b are space adjusters that rotatably drive the feed screw mechanism 43 and the feed screw shaft 42, which are provided with feed screw shafts 42 formed with opposite threads on the left and right sides about the axial center position of the mounting shaft 25. They are driven synchronously by a motor 44. Further, a suction means 45 is disposed near the laser beam irradiation means 41 for sucking and discharging the fumes generated during bonding by irradiating the laser beam.

Next, the mounting operation of IC components will be explained.

The carrier film 1 is supplied to the cutting means 6 by the supply means 9, and at the same time, the mounting end 7 is positioned directly above the cutting means 6, and the lifting motor 22 moves the carrier film 1 through the lifting body 21 and the mounting shaft 25. Then, the suction nozzle 15 is lowered, and stops at a position where the suction nozzle 15 has retracted by a predetermined amount against the biasing force of the guard spring 17. In this way, the carrier film 1 is supported between the punch of the cutting stage 6 and the mounting nozzle 15, and as the punch rises in this state, the carrier film l is cut between it and the mold, as shown in FIG. The IC component 2 in this state is separated and cut while being sucked and held by the suction nozzle 15.

After that, the lifting motor 22 is driven in the opposite direction, and the lifting body 2
1. The suction nozzle 15 is raised via the mounting shaft 25, and then the X-Y robot 8 is driven, and 1. The mounting head 7 is moved toward the substrate 3'' positioned at a predetermined position by the substrate transport means 5. It is moved and positioned directly above the IC component mounting position. As shown in FIG.
A bonding metal layer 10 is formed in advance. The bonding metal layer 10 is formed by applying cream solder onto the substrate 3 and then reflowing it, applying solder plating, or performing solder die/pumping.

Next, the elevating body 21 is driven downward by the elevating motor 22, and the suction nozzle 15 is moved by the arrow A in FIG.
The suction nozzle 15 descends as shown by , and the IC part 2 is mounted on the substrate 3, and the suction nozzle 15 further descends against the biasing force of the spring 17 to a position where it retracts by a predetermined amount and stops. In this way, as shown in FIG. 2, the IC component 2 is fixed in the installed position by being pressurized by the biasing force of the spring 17 as shown by the white arrow B. Note that the mounting posture of the IC component 2 is adjusted by rotating the mounting shaft 25 using the rotary positioning motor 24.

1 2 Next, the lead 11 portion of the IC component 2 is irradiated with laser light from the laser light irradiation means 41 through the opening 19 of the suction nozzle 15, whereby the bonding metal layer 10 is heated and melted, and the lead 11 and the electrode are bonded. Ru. When joining the leads 11 by this laser beam irradiation, as shown in FIG.
A laser beam is scanned along two mutually parallel sides of the C part 2. By one movement of the movable body 37, the two parallel sides of the IC component 2 are joined at once. Next, as shown by arrow D, the rotating frame 32 is rotated by 90 degrees using the rotating frame motor 33, and then the movable body 37 is moved while irradiating the laser beam with the laser beam irradiating means 41, and the moving body 37 is moved as shown by the broken line arrow E. By scanning the laser beam as shown in , the leads 11 on the remaining two sides of the IC component 2 are also bonded.

In addition, during this joining, as shown in FIG. 6, since the tips of the leads 11 of the IC component 2 are reinforced while being connected to each other by the narrow frame 20, bending of the leads 11 is prevented. Highly reliable bonding is ensured without occurrence of defects. Furthermore, when the leads 11 are bonded, the tips and bases of the leads 11 except for the aperture 19 for laser beam irradiation are pressurized by the suction nozzle 15 toward the electrodes of the substrate 3.
Contact between the electrode and the electrode is ensured, and a highly reliable bond is ensured.

Further, the timing of scanning by the movement of the moving body 32 and the irradiation of laser light by the laser light irradiation means 41 are controlled as shown in FIG. That is, the scanning start point is set so that the movable body 32 moves at a constant speed within the length range to be soldered and uniform speed scanning is performed, and the laser is only used while scanning the length range to be soldered. To ensure that the light output is at full power, a timer is counted after scanning starts, the laser shutter is opened after a certain period of time, and the encoder of the moving motor 38 is moved to a position a predetermined distance before reaching the end point of the length range to be soldered. The number of pulses is detected and the laser shutter is closed at this position. Thus, when the laser irradiation operation start signal is turned on, the movable body 32 starts moving and the timer operates, and when the timer expires, the laser shutter is opened and the laser beam is fully applied to the length range to be soldered. It is irradiated with high power and scanned at a constant speed. The laser beam is uniformly irradiated onto the bonded area using simple scanning control, resulting in highly reliable bonding.

Through the above steps, all the wires 1 of the IC component 2 are bonded to the electrodes of the board 3, and the mounting of the IC component 2 at a predetermined position on the board 3 is completed. Thereafter, the above operations are repeated to sequentially mount the IC components 2.

In the above embodiment, an example was shown in which the IC component was cut and separated from a carrier film integrally formed with the IC component, mounted on the board, and the leads were joined to the electrodes of the board. is an IC supplied in any other form
Needless to say, the present invention can be applied to cases in which a component is held by a mounting head, mounted on a board, and leads are joined.

Effect 15 of the Invention According to the IC component lead bonding method of the present invention, after the IC component is mounted by the mounting head, the lead is laser heated and bonded while the IC component is pressurized and fixed.
Since the C component does not shift its position after installation and cause a bonding failure, and even some lead lifting is corrected, highly reliable bonding is possible, and lead bonding can be achieved in a series of processes including the mounting process. This has the effect of improving productivity by eliminating intermediate steps.

In addition, using a mounting head having an IC component holder corresponding to the planar shape of the IC component, the laser beam is inserted through the opening formed in the IC component holder while the lead is directly pressurized and fixed to the electrode in the IC component holder. Irradiation with light enables even more reliable bonding.

Also, by scanning this using a pair of laser beam irradiation means, 9
By scanning again after 0' rotation, all the leads protruding on all sides of the IC component can be joined in two scans, the lead joining time can be shortened, and productivity can be improved.

-16 Furthermore, by making the constant speed section correspond to the joining area when scanning the laser beam irradiation means, the joining conditions for each lead can be made uniform without complicated scanning control, and a highly reliable joining state can be achieved. Obtainable.

[Brief explanation of drawings]

1 and 2 are longitudinal cross-sectional views showing the lead bonding process of IC components in one embodiment of the present invention, FIG. 3 is a perspective view showing the scanning procedure of the radiation light irradiation means during lead bonding, and FIG. The figure is a timing diagram of the operation of the laser beam irradiation means, FIG. 5 is a longitudinal cross-sectional view of the mounting head, FIG. 6 is a perspective view of the tip of the suction nozzle of the mounting head, FIG. 7 is a perspective view of the JC component, and FIG. The figure is a perspective view showing the overall schematic configuration of the IC component mounting apparatus, FIG. 9 is a front view showing the conventional IC component board bonding process, and FIG.
Figure 0 is a perspective view of the same IC component. 2----- IC parts 3-1-11--- Board 7 ---------1 Mounting head 10 1 1-------- 15 19 3 2 ------1 1 ------- 3 7 ------- 41 Bonding metal layer lead suction nozzle opening rotating frame moving body laser light irradiation means.

Claims (4)

[Claims] (1) Hold the IC component with the mounting head and mount it on a predetermined position on the board, and while applying pressure with the mounting head, irradiate the lead part of the IC component with laser light to bond it on the electrode of the board. A method for joining leads of IC components, which is characterized by melting metal and joining leads and electrodes. (2) A mounting head having an IC component holder having a planar shape corresponding to the planar shape of the IC component is used, and a laser beam is irradiated through an opening formed in a portion of the IC component holder corresponding to the lead. The method for joining leads of an IC component according to claim 1. (3) A pair of laser beam irradiation means placed on both sides of the axis of the mounting head are scanned to join the leads on two parallel sides of the IC component, and then the pair of laser beam irradiation means are placed on the axis of the mounting head. 3. The method for joining leads of an IC component according to claim 1, wherein the leads on the remaining two parallel sides of the IC component are joined by scanning after rotating the IC component by 90 degrees. (4) Scanning the laser light irradiation means so that the section where the laser light irradiation means can be scanned at a constant speed almost matches the bonding range of the leads, and operating the laser light source so that the laser output is stabilized in that section. Claim 1 characterized by:
3. The method for joining leads of IC components according to 2 or 3.