JPS6343915B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a flat package type electronic component such as an IC, an LSI, etc., which is accurately positioned on a printed wiring board and immediately soldered at that position. Related to soldering equipment.

[Technical background of the invention and its problems] A flat package type electronic component is formed from a molded main body and a large number of lead terminals protruding around the main body, and the pitch of these lead terminals is very small. , 1.27 for small ones,
There are 0.8 mm, 0.6 mm, etc., and the number of lead terminals is 10 to 20 or more on one side. By the way, conventional soldering equipment is of the resistance welding type and is equipped with one electrode head, and the operator corrects the deformation of the lead terminal while looking through a magnifying glass and positions the lead so that it is in the center of the pattern. Later, this device was used to weld the lead terminals one by one. Therefore, it is extremely inefficient and not suitable for mass production. Moreover, it must be carried out by an experienced person as it relies on the intuition of the operator, and depending on the contact position of the electrode, there have been problems with the reliability of the bonding. .

[Purpose of the invention]

The present invention aims to provide an apparatus that uses two symmetrically arranged electrodes to position and simultaneously solder a flat package type electronic component at high speed and accurately.

[Summary of the invention]

A positioning jig having a suction mechanism for suctioning and fixing a flat package electronic component coated with preliminary solder and a guide pin to be inserted into a positioning hole provided in a printed wiring board is movable up and down with respect to the printed wiring board. In order to immediately weld the lead terminals of the flat package type electronic component at that location using a resistance heat source, two symmetrical electrode heads are installed independently of the positioning jig. The structure is such that the electrode head is intermittently rotated so that it faces the lead terminal, and then it is pressed against the lead terminal by a constant pressure and automatically soldered to the pattern. This is what I did.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the accompanying drawings. Reference numeral 1 in Figure 1 shows a flat package type electronic component (hereinafter simply referred to as an electronic component) such as an IC or LSI. It is formed from a large number of protruding lead terminals...3. Reference numeral 4 denotes a printed wiring board, on the surface of which a flat package pattern (hereinafter simply referred to as pattern) 5 similar to the shape of the electronic component 1 and a plurality of guide holes 4a for positioning the electronic component are formed. Next, FIGS. 2 and 3 show the electronic component 1.
A jig 6 for correcting deformation of the lead terminal 3...
, a fitting portion 7 into which the main body portion 2 and the lead terminals 3 are fitted is provided. This fitting part 7 has a recess 8 provided in the center that fits with the main body part 2 of the electronic component 1, and a large number of concavities 8 that are continuously provided on each side of this recess 8 and that fit with the lead terminals 3. It is formed from grooves 9... Next, 10 in FIG. 4 is an XY table on which a printed wiring board 4 is mounted. This XY
A soldering mechanism 11 is provided above the table 10. And this soldering mechanism 1
1 and the XY table 10 are constructed as one unit, and this soldering mechanism is controlled by an NC device and operates in conjunction with the XY table 10 at high speed and with high precision. The soldering mechanism 11 includes a drive shaft 12 that can be raised and lowered by a lifting mechanism (not shown). An adapter 13 is attached to the upper end of the drive shaft 12 so as to be slidable in the axial direction. A large diameter portion 15 having a vacuum suction hole 14 communicating with a vacuum source is formed in the middle of the drive shaft 12 . Below this large diameter portion 15, a slider 17 containing a buffer coil spring 16 and the electronic component 1 are mounted and fixed, and a positioning jig is used to allocate the solder positions of the lead terminals 3 of the electronic component 1. 18 is fitted and inserted so that the center of the drive shaft 12 coincides with the center of the electronic component 1. Since the vacuum suction hole 14 communicates with the lower end of the drive shaft 12, the drive shaft 12 attracts the electronic component 1 and positions it with respect to the positioning jig 18. A fitting part 7 having the same shape as the fitting part 7 of the jig 6 shown in FIGS. 2 and 3 is formed on the lower surface of the positioning jig 18, and two guides are provided on the upper surface. pin 1
9 and 19 are provided to guide the vertical movement of the slider 17. Next, a housing 21 having a neck portion 20 that is rotatable with respect to the drive shaft 12 is mounted below the adapter 13 that is mounted around the drive shaft 12 . A gear 22 is provided on the neck 20 and meshes with a spline gear 23 that rotates as shown by arrow a. The housing 21 is the adapter 13
A vertical mechanism (not shown) provided at the top allows the device to move up and down along the drive shaft 12 independently of the drive shaft 12 and to rotate together with the rotation of the spline gear 23 . Two guide rods 24, 24 are fitted into the housing 21 symmetrically with respect to the center line of the drive shaft 12, and electrode heads 25, 25 that come into contact with the lead terminals 3 of the electronic component 1 are provided at the lower ends of the guide rods 24, 24. Electrode head Honda 26,2
It is supported and attached to 6. Also, by adjusting the adjustable knobs 27, 27 attached to the guide rods 24, 24, the gap of the electrode head holders 26, 26 can be changed, and the electrode head 2
5 and 25 are adjusted. Furthermore, temperature sensors 28, 28 are provided below the electrode heads 25, 25 to sense the soldering temperature. On the other hand, a pressure mechanism 29 is provided below the housing 21 to press the electrode heads 25, 25 against the lead terminals 3. That is, a support plate 31 is fixed to the drive shaft 12 below the housing 21 for supporting coil springs 30, 30 fitted into the guide rods 24, 24. Adjustable knobs 32, 32 screwed into threaded portions provided on a part of the guide rods 24, 24 are then moved upward or downward to increase or decrease the elasticity of the coil springs 30, 30. This makes it possible to adjust the pressing force of the electrode heads 25, 25 against the lead terminals 3, 3. Pressure sensors 33, 3 are provided between the upper ends of the coil springs 30, 30 and the lower surface of the housing 21.
3 is provided. And this pressure sensor 3
3 and 33 are connected to a constant voltage device via a micro switch (not shown). Further, the electrode heads 25, 25 are connected and supported by a lower housing 34. Further, at the tip of the lower housing 34, positioning pins 35 are attached to be inserted into the guide holes 4a.

When the printed wiring board 4 is placed on the XY table 10, the XY table 10 moves to the soldering mechanism 11 and stops. The electronic component 1 whose deformation has been corrected by the jig 6 is fitted into a positioning jig 18 and positioned, is vacuum-adsorbed via the positioning jig 18, and is lowered together with the housing 34. The housing 34 has a positioning pin 35.
is attached and inserted into the guide hole 4a of the printed wiring board 4. If the positioning pin 35 and the guide hole 4a do not match at this time, the XY table 10 is automatically moved and corrected so that they match. When the positioning is completed, the center line of the drive shaft 12 of the soldering mechanism 11 and the center line of the electronic component 1 match. Then, the drive shaft 12 of the soldering mechanism 11 located above the electronic component 1 is lowered, and the electronic component 1 is fixedly crimped onto the pattern 5 of the printed wiring board 4. Further, the support plate 31 of the soldering mechanism 11 is also lowered together with the drive shaft 12, and the tips of the electrode heads 25, 25 come into contact with the lead terminals 3, 3, as shown in FIG. Electrode heads 25 are fixed at predetermined positions on two lead terminals facing each other. Then, when the pressure exceeds a certain level, the power is turned on and these two points are soldered. Next, the housing 21 rises,
Electrode heads 25, 25 rise from lead terminals 3, 3. At this time, the positioning jig 18 continues to hold down the electronic component. Next, as the spline gear 21 rotates, the housing 21 also rotates to the next position as shown by arrow b in FIG. 5, so that the electrode heads 25, 25 face the adjacent lead terminals 3, 3. Then, as the housing 21 is lowered, the electrode heads 25, 25 are lowered and the lead terminals 3, 3 are soldered in the same manner as described above. Thereafter, the electrode heads 25, 25 repeatedly move up and down and rotate, and the soldering is automatically completed by rotating the electrode heads 25, 25 from the position A-A' to the position D-D'.
Then, after the completion is detected, the vacuum source is automatically cut off and the drive shaft 12 is raised to complete one cycle.

〔Effect of the invention〕

As explained above, the present invention provides a method for fitting the main body and lead terminals of an electronic component mounted on a flat package pattern on a printed wiring board into the fitting portions of a positioning jig that can be raised and lowered with respect to the printed wiring board. The lead terminals are automatically soldered by vertically moving and intermittently rotating the electrode heads arranged on the same circumference at that position, which are then fixed to the printed wiring board. Therefore, the positioning of electronic components becomes accurate, which not only improves quality but also improves work efficiency. Furthermore, since soldering is performed by rotating the electrode head, the soldering parts are not on a straight line but on the same circumference, so there are few parallel parts of the soldering parts between adjacent leads, and bridges are not formed. This has the effect of preventing soldering defects caused by the like.

[Brief explanation of drawings]

The drawings show one embodiment of the invention.
The figure is a perspective view of an electronic component and a printed wiring board, and FIG. 2 is a plan view of a jig for correcting deformation of the electronic component.
Figure 3 is a sectional view taken along the - line in Figure 2, Figure 4 is a partially cutaway front view of the soldering device, and Figure 5 is a plan view showing the operation of the electrode head for soldering lead terminals. be. DESCRIPTION OF SYMBOLS 1... Flat package type electronic component, 2... Main body, 3... Lead terminal, 4... Printed wiring board, 5... Flat package pattern, 7... Fitting part, 18... Positioning jig, 11... Soldering mechanism, 25... Electrode head, 35... Positioning pin.

Claims (1)

[Claims] 1. In a soldering device for mounting a flat package type electronic component on a printed wiring board on which a flat package pattern is formed in accordance with the flat package pattern, a positioning guide hole is provided in the printed wiring board and the printed wiring board is provided with a positioning guide hole. A positioning jig is provided facing the wiring board and has a positioning pin that can be raised and lowered and is inserted into the guide hole and positioned with respect to the flat package pattern when lowered. In addition to providing a fitting portion for fitting the terminal, a vacuum suction mechanism for fitting and adsorbing the electronic component is provided in the fitting portion, and a plurality of lead terminals of the electronic component are positioned in a flat package pattern and soldered. A vertically movable and rotatable soldering mechanism is provided in which electrode heads are arranged at symmetrical positions on the same circumference, and the electrode heads are rotated to apply a predetermined pressing force to the lead terminals for soldering. A flat package type electronic component soldering device characterized by the following.