JP2003008195A - Electronic component mounting method and mounting device - Google Patents

Abstract

(57) [Problem] To provide a jig for automatically removing a weight while preventing lifting of a lead portion of an IC. SOLUTION: A first step of mounting a weight on an electronic component mounted on a substrate, a second step of mounting the electronic component on the substrate by reflow of solder, and removing the weight from the electronic component In the electronic component mounting method having the third step, in the third step, the weight is removed from the electronic component by releasing the weight suction means to lower the weight suction means and then to lift the weight to release the weight from the electronic component. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting method and mounting apparatus for electronic components.

[0002]

2. Description of the Related Art FIG. 7 shows an IC mounted on a board by a mounting machine.
(VQFP ... Very thin Quad Flat Package), which has a large number of lead portions a on four sides. When such an IC 6 is passed through a reflow furnace and mounted on the substrate by reflowing the solder, the lead portion a of the IC 6 is lifted from the substrate when the solder is melted, depending on the conditions during the reflow and the processing accuracy of the IC 6. Lifting may cause soldering failure. As a measure against the floating, for example, Japanese Patent Laid-Open No. 2000-352052 discloses a method of mounting a weight having a constant weight to improve the soldering quality. However, there is no disclosure of how to place this weight on the IC. Further, as a flow of the mounting manufacturing process, it is necessary to remove the weight after passing through the reflow furnace, which has been conventionally removed manually, but such a process has the following problems. Immediately after passing through the reflow furnace, the weight reached around 200 ° C, which is a safety issue. It is not only dangerous for an operator to touch the substrate, but also various problems are likely to occur in terms of quality, electrical and mechanical. Especially when dropping weights,
The board and equipment may be damaged. If the weight is left behind, for example, an accident may occur due to the weight being dropped in a subsequent process such as a visual inspection machine. Therefore, it is desired to remove the other parts efficiently without causing any adverse effect on other parts without leaks.

Further, Japanese Patent Laid-Open Nos. 5-335311 and 6-314763 also describe that a semiconductor device mounted on a substrate is loaded with a weight, but how to load is described. It has not been. Of course, there is no disclosure of removing the weight after passing through the reflow furnace. It seems that the above problems are occurring.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a mounting method and a mounting apparatus for an electronic component capable of removing a weight without relying on manpower.

[0005]

Means for Solving the Problems The above problems include a first step of placing a weight on an electronic component to be mounted on a substrate, and a second step of mounting the electronic component on the substrate by reflowing solder. A third removing the weight from the electronic component
A method of mounting an electronic component, comprising:
In the step, after the weight suction means is lowered to suck the weight, the weight is lifted to release the weight from the electronic component, and the electronic component is mounted and released. First means for placing a weight on the electronic component to be mounted, second means for mounting the electronic component on the substrate by reflow of solder, and third means for removing the weight from the electronic component. In the electronic component mounting apparatus, the third means includes a weight suction means and an elevating means. The elevating means lowers the weight suction means to suck the weight and then raises the electronic component. The electronic device mounting apparatus is characterized in that the weight is detached from and released.

With the above configuration, for example, a weight is placed on the semiconductor device to prevent the semiconductor device terminal portions (leads and solder bumps) from rising from the substrate terminal portion during reflow, and the weight is easily and reliably provided after the substrate reflow. By removing it, manpower can be saved and the quality of the product can be improved.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1, FIG. 2 and FIG. 3 schematically showing the whole IC mounting apparatus according to the present embodiment.
Will be described with reference to. In FIG. 1, the conveyor 9 conveys the substrate 8 from the previous step into the apparatus (jig) according to the present invention. On the board 8, the IC 6 which has already been soldered in the previous reflow step and the weight 5 made of a magnetic material for pressing the IC 6 toward the board by gravity at that time are mounted by the mounting machine or the like in the step before the previous step. ing. In side photoelectric switch 1
Detects the arrival of the substrate 8 into the device. After that, the substrate 8 stops at a predetermined position on the conveyor 9 due to the rise of the substrate stopper 2. The out-side photoelectric switch 3 detects that the substrate 8 has reached the predetermined stop position. When the substrate 8 stops at a predetermined position, the electromagnet 4 approaches the weight 5 on the IC 6 by the action of the elevating cylinder 7 by pneumatic pressure or electric power, and is energized and excited to attract the weight 5. Lifting cylinder 7 after adsorption
Raises the electromagnet 4 with the weight 5 still adsorbed. After that, the substrate stopper 2 is lowered and the conveyor 9 moves the substrate 8 to the next step. When the out-side photoelectric switch 3 detects that the substrate 8 has been carried out by the conveyor 9, the electromagnet 4 is de-energized, and the weight 5 falls and is recovered by the recovery box 10. FIG. 2 shows a control block for performing the above operations. FIG. 3 shows the control flow.

Next, the details of the jig will be described with reference to FIGS. 4 and 5. FIG. 4 shows the jig in the reflow process of FIG. 3 in the state of FIG. 3B. That is, the in-side photoelectric switch 1, the out-side photoelectric switch 3, and the electromagnet 4 are integrally moved up and down by the lifting cylinder 7 (driven by hydraulic pressure or pneumatic pressure). In FIG. 4, these are in the raised position, but in the flow process of FIG. 3A, they are in the lowered position, and the in-side photoelectric switch 1 and the out-side photoelectric switch 3 are
Is configured to reliably detect the front end portion of the substrate 8 coming in close proximity. In the present embodiment, two ICs 6 are mounted on one board 8, and a flat weight 5 is placed on them. Although wiring of a predetermined pattern is formed on the substrate 8, it is omitted in the drawing. The lead portion a of the IC 6 is also omitted in the figure. Two electromagnets 4 are arranged corresponding to the weight 5, and an electromagnetic coil is wound around the E-shaped core. The electromagnetic coil is energized as the electromagnet 4 descends. A few seconds later, weighed 5 and reached 5
Adsorb.

FIG. 5 shows that the electromagnet 4 is adsorbing the weight 5 and ascending. When it rises to a predetermined height, it stops raising, the stopper 2 goes down, and the substrate 8 is carried out to the left in the figure. A few seconds after the OUT-side photoelectric switch 3 is turned off, the electromagnet 4 descends again and the current is cut off. The weight 5 that has been adsorbed falls into the recovery box 10 below.

In the above description, a part of the conveyor 9 is shown, and only one substrate is shown in the figure. However, in reality, the conveyor 9 is longer and faces the central portion thereof as shown in FIG. The downward traveling portion of the belt 9a is pressed downward by the pulleys 22 and 22 attached to both ends of the shaft driven by the motor 21 disposed so as to tension the belt 9a around the driven rollers 20a and 20b. It can be rotated. Note that, in FIG. 6, the pedestal K that supports the upper traveling portion of the belt 9a shown in FIGS. 4 and 5 is omitted. Also, the upper electromagnet and the lifting device are omitted in the figure.
With such a conveyor 9, for example, three substrates can be simultaneously subjected to the weight removing action by the jig described above. For this reason, three in-side photoelectric switches 1 and three out-side photoelectric switches 3 are provided, and the three substrate stoppers 2 are driven substantially in synchronization with each other, and the preceding substrate partially overlaps with the following substrate. Is prevented. By such a synchronizing action, it is possible to efficiently remove the weight from the IC 6. Of course, as shown in FIGS. 4 and 5, the weight may be removed only from one substrate.

As described above, according to the present embodiment, the high-temperature weight 5 is automatically removed, and no manpower is required.
It is possible to solve the problems that have occurred conventionally and prevent the lead portion from rising.

Although the embodiments of the present invention have been described above, needless to say, the present invention is not limited to these, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the electromagnet is used as the weight attracting means, but a vacuum attracting device may be used instead of the electromagnet. In this case, the weight may be made of a material other than the magnetic material.

Further, in the above embodiment, the IC (VQFP) is applied as the electronic component, but it is needless to say that the electronic component is not limited to this and may be another electronic component. For example, as shown in FIG. 9, the package electronic component 30 may have a plurality of lead portions b only on a pair of opposite sides instead of the four sides, or may be another type of semiconductor chip or electronic component. Good. Further, the weight 5 may be made of tungsten Lang W and iron Fe (magnetic material) as shown in FIG. By utilizing the fact that the specific gravity of Tungslan W is larger than that of iron, the volume with respect to the total weight can be reduced. Of course, other metals may be used.

Further, in the above embodiment, the jig for removing the weight after the reflow has been described, but in addition to this, the above jig may be used in the process before entering the reflow furnace. That is, the jig after reflow may be used as it is in the mounting machine before entering the reflow furnace. That is, this allows the weight to be automatically placed on the IC mounted on the substrate.

Further, in the above embodiment, two substrates are provided.
Although the case of mounting one IC 6 has been described, it goes without saying that the number of ICs is not limited to this and can be applied to the case of mounting one IC on the substrate. It can also be applied to the case of mounting three or more substrates.

Further, in the above embodiments, two electromagnets are used corresponding to two ICs, but one electromagnet may adsorb two or all weights.

[0018]

As described above, according to the electronic component mounting method and mounting apparatus of the present invention, while preventing the lead portion of the electronic component from rising from the substrate, for example, the weight placed on the IC is automatically It is possible to remove it, so that it will not be forgotten and will not adversely affect the subsequent process.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an entire IC mounting apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of the control circuit.

FIG. 3 is a diagram showing a flow of the same action.

FIG. 4 is a perspective view showing a jig for a substrate on which an IC is mounted in the reflow furnace in FIG.

FIG. 5 is a perspective view showing an intermediate action of the jig.

FIG. 6 is a perspective view showing the relationship between the entire conveyor and the IC applied to the embodiment of the present invention.

FIG. 7 is an enlarged perspective view of an IC applied to this embodiment.

FIG. 8 is a perspective view showing a modified example of the weight.

FIG. 9 is a perspective view showing another example of an electronic component.

[Explanation of symbols]

2 ... Substrate stopper, 4 ... Electromagnet, 5 ... Weight, 6 ...
... IC, 7 ... Lifting cylinder, 8 ... Substrate, 9 ... Conveyor, 10 ... Recovery box.

Claims (10)

[Claims] 1. A first step of placing a weight on an electronic component mounted on a substrate, a second step of mounting the electronic component on the substrate by reflow of solder, and a step of placing the weight on the electronic component. In the third step of removing, the electronic component mounting method comprising: removing the weight from the electronic component by lowering the weight adsorption means to adsorb the weight in the third step; A method for mounting electronic components, characterized in that 2. The weight suction means is lowered after the substrate on which the electronic component on which the weight is placed is mounted is transported by a transport means and stopped at a predetermined position. Item 1. A method of mounting an electronic component according to Item 1. 3. The electronic component mounting method according to claim 1, wherein the weight attracting means is an electromagnet, and the weight is wholly or partially made of a magnetic material. 4. In the first step, the weight suction means causes the weight to be adsorbed and lowered to place the weight on the electronic component, and then the weight is released from the adsorbing force and then raised. The electronic component mounting method according to claim 3, wherein 5. The electronic component mounting method according to claim 1, wherein the weight suction means is a vacuum suction means. 6. A first means for mounting a weight on an electronic component mounted on a board, a second means for mounting the electronic component on the board by reflowing solder, and a weight for mounting the weight on the electronic component. An electronic component mounting apparatus having a third means for removing, the third means comprises a weight suction means and an elevating means,
An electronic component mounting apparatus, characterized in that the weight suction means is lowered by the elevating means to suck the weight and then lifted to separate the weight from the electronic component and release the weight. 7. The weight adsorbing means is lowered by the elevating means after the electronic component on which the weight is mounted has the electronic component mounted thereon transferred by a transfer means and stopped at a predetermined position. The electronic component mounting apparatus according to claim 6, which is characterized in that. 8. The electronic component mounting apparatus according to claim 6, wherein the weight attracting means is an electromagnet, and the weight is wholly or partially made of a magnetic material. 9. The first means comprises a weight suction means and an elevating means, and the weight suction means sucks a weight,
The electronic component mounting apparatus according to claim 8, wherein the electronic component mounting apparatus is configured to be lowered by the elevating means, to place a weight on the electronic component, to release the weight from the suction force, and then to rise. . 10. The electronic component mounting apparatus according to claim 6, wherein the weight suction means is a vacuum suction means.