JP2000332398A - Electronic component mounting method and mounting board therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an electronic component mounting method whereby if required solder quantity differs, an exact quantity of solder can be supplied to electrodes of a board. SOLUTION: The method comprises a solder supply step of supplying cream solder S to electrodes (1a), 1b by printing, a solder chip supply step of supplying solder chips onto the electrodes 1b, an electronic component mounting step of positioning and mounting terminals (3b) of the electronic components (3) on the electrodes 1b, and a reflow heating step of reflow-heating to melt the cream solder S and the solder chips C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting method for soldering and connecting terminals of electronic components to electrodes of a substrate such as a printed circuit board, and a mounting board to which electronic components are connected by the electronic component mounting method. , Which can improve soldering quality.

[0002]

2. Description of the Related Art As shown in FIG. 5, batch soldering is known as one of the methods for mounting electronic components 2, 3, and 4 on a printed circuit board 1. FIG. That is, the printed circuit board 1
After supplying cream solder to the electrodes 1a, 1b, 1c (see FIGS. 6 to 8) by printing or the like, the terminals 2b, 3b, 4b of the electronic components 2, 3, 4 are positioned on the electrodes 1a, 1b, The entire printed circuit board 1 is put into a reflow furnace and connected by soldering all together.

There are various sizes and shapes of electronic components 2, 3, and 4 to be mounted. For example, the electronic component 2 has a lead terminal 2b with a fine pitch of about 0.5 mm from the main body 2a as shown in FIG. 6, and is connected to the electrode 1a. The electronic component 3 is of LCC (leadless chip carrier) type, and has terminals 3b formed on the side surface of the main body 3a as shown in FIG. 7, and is connected to the electrode 1b.

The electronic component 4 is an electronic component that receives an external force, such as an earphone jack or a power jack. As shown in FIG.
c.

Note that S in FIGS. 6 to 8 denotes solder. Therefore, the appropriate amount of solder to be supplied to the electrodes 1a, 1b, 1c differs depending on the type of electronic component.

That is, the amount of cream solder supplied to the electronic component 2 having the fine pitch lead terminals 2b can be as low as possible at a level at which the soldering strength can be secured and the printing process can be tolerated in order to prevent the occurrence of the solder bridge B. Less is better. On the other hand, in the LCC type electronic component 3 and the electronic component 4 subjected to external force, it is necessary to spread the solder S to the terminal 3b on the side surface of the main body 3a or to form a sufficient fillet on the terminal 4b on the side surface of the main body 4a. Therefore, it is better to supply as much solder as possible.

As described above, in order to change the solder supply amount for each electrode, a method of partially changing the thickness of the metal mask or changing the mask opening area has been adopted. If an appropriate amount of solder cannot be obtained by these methods, manufacture using a metal mask that gives priority to components with fine pitch leads, and hand solder to LCC type electronic components with insufficient solder. Solder had been added.

[0008]

The above-described conventional electronic component mounting method has the following problems. That is,
In the case where the thickness of the metal mask is partially changed, there have been problems such as a margin of printing process conditions being narrow, printing failure, and shortening of the life of the metal mask.
Also, in the method of adding solder by hand soldering,
There were problems such as an increase in the number of steps and a decrease in manufacturing efficiency.

Therefore, the present invention provides an electronic component mounting method capable of supplying an appropriate amount of solder to electrodes of a substrate even when the required amount of solder is different, and an electronic component mounting method using the electronic component mounting method. It is intended to provide a soldered mounting board.

[0010]

Means for Solving the Problems In order to solve the above problems and achieve the object, an invention according to claim 1 is a mounting method for soldering and connecting electrodes on a substrate and terminals of an electronic component. A solder supply step of printing solder on the electrode by printing, a solder chip supply step of supplying a solder chip on the electrode, and an electronic component mounting step of positioning and mounting terminals of the electronic component on the electrode. And a reflow heating step of performing reflow heating to melt the solder and the solder chip.

According to a second aspect of the present invention, in the first aspect, the solder chip supplying step is performed simultaneously with the electronic component mounting step.

According to a third aspect of the present invention, in the first aspect of the present invention, the composition of the solder chip is:
The composition was different from that of the cream solder.

According to a fourth aspect of the present invention, there is provided a solder supply step of supplying cream solder on an electrode by printing,
A solder chip supplying step of supplying a solder chip on the electrode, an electronic component mounting step of positioning and mounting a terminal of an electronic component on the electrode, and a reflow heating for performing reflow heating to melt the solder and the solder chip Through the steps, a mounting board on which the electronic component was mounted was obtained.

[0014]

FIG. 1 is a perspective view showing an appearance of an electronic component mounting apparatus 10 according to an embodiment of the present invention. FIG. 2 is a partial view of a high-speed mounting machine 30 incorporated in the electronic component mounting apparatus 10. FIG. 3 is a cutaway perspective view, FIG. 3 is a perspective view showing a tape T mounted on an electronic component supply unit 31 incorporated in the high-speed mounting machine 30 and containing a solder chip C, and FIG. It is a figure which shows the state which supplies.

The electronic component mounting apparatus 10 includes a cream solder printing machine 20, a high-speed mounting machine 30, and a multi-function mounting machine 40.
, A reflow device 50, and a transport mechanism 60 for transporting the printed circuit board 1 along the direction of arrow α in FIG.

The cream solder printing machine 20 has a function of applying the cream solder S to the electrodes 1a and 1b of the printed circuit board 1 by printing with the same thickness.

As shown in FIG. 2, the chip mounter 30 includes an electronic component supply unit 31 for supplying an electronic component 2 housed in a tape T, an electronic component such as a chip resistor and a chip capacitor, and a solder chip C. A chip mounter 32 for mounting the electronic component and the solder chip C supplied by the component supply unit 31 on the electrodes 1a and 1b of the printed circuit board 1.
And a stage 33 for positioning the printed circuit board 1. The chip mounter 32 includes a component suction nozzle 34 as shown in FIG. In addition, tape T
Is a paper tape or an embossed tape, and an electronic component such as the electronic component 2 or a solder chip C is held by a release paper Ta.

The multi-function mounting machine 40 connects the electronic component 3 to the electrode 1
b.

The reflow device 50 heats the entire printed circuit board 1 so that the cream solder S on the electrodes 1a and 1b is heated.
And a function of melting the solder chips C and soldering them together.

The electronic component mounting apparatus 1 thus configured
At 0, the electronic components 2 and 3 are mounted on the printed circuit board 1 as follows. That is, the printed circuit board 1 before mounting is introduced into the cream solder printing machine 20 by the transport mechanism 60.

In the cream solder printing machine 20, the cream solder S having the same thickness is applied to the electrodes 1a and 1b of the printed circuit board 1.
Is applied. At this time, the supply amount of the cream solder S is
The solder bridge B is not generated, the soldering strength can be secured, and the printing process is at an acceptable level. The metal mask used at this time (not shown)
Is a constant thickness.

Next, the high-speed mounting machine 30
The printed circuit board 1 is introduced into the device. In the high-speed mounting machine 30, the electronic component 2 and the solder chip C housed in the tape T are supplied from the electronic component supply unit 31 to the chip mounter 32.
In the chip mounter 32, the electronic component 2 and the solder chip C are mounted on predetermined electrodes 1a and 1b using the component suction nozzle. That is, on the electrode 1a to which the cream solder S is applied, an electronic component such as the electronic component 2 having the fine pitch lead terminals 2b and having a small solder supply amount is placed. On the other hand, as shown in FIG. 4, the solder chip C is mounted on the electrode 1b which requires a larger amount of solder than the electrode 1a for forming a fillet.

Next, the multifunctional mounting machine 4 is
The printed circuit board 1 is introduced at 0. In the multi-function mounting machine 40, the LCC type electronic component 3 or a deformed component (not shown)
Is placed on the electrode 1b.

Next, the reflow device 5 is transported by the transport mechanism 60.
The printed circuit board 1 is introduced at 0. In the reflow device 50, the entire printed circuit board 1 is heated, the cream solder S and the solder chip C are melted, and soldering is performed. Thus, the electronic components 2 and 3 are mounted on the printed circuit board 1.

As described above, according to the electronic component mounting apparatus 10 of the present embodiment, the solder chip C is supplied by the high-speed mounting machine 30 to the electrode having a large amount of required solder, so that the LCC type electronic component is provided. In this case, defective soldering such as unsoldering can be prevented. For this reason, even when the amount of solder differs for each electrode, a metal mask having a constant thickness can be used in the cream solder printing machine 20, and the life of the metal mask can be maintained long. Also, since only a minimum necessary amount of solder needs to be supplied to an electrode requiring a small amount of solder, the quality of solder printing can be improved, and the occurrence of solder bridges can be prevented. Further, since it is not necessary to manually add solder in a later step, manufacturing efficiency can be improved.

On the other hand, by using the tape T to supply the solder chip C, a general-purpose electronic component mounting machine such as the high-speed mounting machine 30 can be used similarly to the other electronic components 2, so that special equipment is required. Need not be added.

The printed board 1, which is an electronic component mounting board on which the electronic components 2 and 3 are mounted as described above, has a high soldering quality and therefore has a high quality.

In the above example, the cream solder S
Although the solder composition of the solder chip C and the solder composition of the solder chip C are not specified, it is possible to supply a solder having a solder composition suitable for an electronic component by making the solder composition of the cream solder S different from the solder composition of the solder chip C. it can.

There are various reasons for changing the solder composition depending on the electronic component. For example, the heat capacity is large and the temperature does not rise sufficiently during reflow heating, or the lower surface of the component such as a BGA (ball grid array) type electronic component. When the temperature of the central part becomes lower than that of the part arranged on the outer periphery during reflow heating, good soldering should be performed by using a solder with a composition with a low melting point. Can be.

In the above-described example, the high-speed mounting machine 30 mounts the electronic component 2 and the solder chip C, and the multi-function mounting machine 40 mounts the electronic component 3, but the mounting is performed using the same mounting machine. Is also good. Further, the solder chip C may be mounted after mounting the electronic component 3.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

[0032]

According to the present invention, it is possible to supply a proper amount and composition of solder to the electrodes of the substrate even when the required amount of solder is different.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a high-speed mounting machine incorporated in the electronic component mounting apparatus.

FIG. 3 is a perspective view showing a tape for accommodating a solder chip supplied to a chip mounter incorporated in the high-speed mounting machine.

FIG. 4 is a diagram showing a state in which a solder chip is supplied by the chip mounter.

FIG. 5 is a perspective view showing an example of a printed circuit board on which electronic components are mounted.

FIG. 6 is a plan view showing a solder bridge in an electronic component having fine pitch lead terminals.

FIG. 7 is a perspective view showing an LCC component having electrodes formed on a side surface of the main body.

FIG. 8 is a perspective view showing an electronic component in which electrodes are formed on a side surface of a main body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Printed circuit board 1a, 1b, 1c ... Electrode 2, 3, 4 ... Electronic component 2b, 3b, 4b ... Terminal 10 ... Electronic component mounting apparatus 20 ... Cream solder printing machine 30 ... High-speed mounting machine 40 ... Multi-function mounting machine 50 … Reflow device 60… Transport mechanism

Claims (4)

[Claims] 1. A mounting method for soldering and connecting an electrode on a substrate to a terminal of an electronic component, comprising: a solder supply step of supplying solder on the electrode by printing; and a solder chip for supplying a solder chip on the electrode. A supply step, an electronic component mounting step of positioning and mounting the terminal of the electronic component on the electrode, and a reflow heating step of performing reflow heating to melt the solder and the solder chip. Electronic component mounting method. 2. The method according to claim 1, wherein the solder chip supplying step is performed simultaneously with the electronic component mounting step.
Electronic component mounting method according to the item. 3. The electronic component mounting method according to claim 1, wherein a composition of the solder chip is different from a composition of the cream solder. A solder supply step of supplying cream solder on the electrode by printing; a solder chip supply step of supplying a solder chip on the electrode; and an electronic device for positioning and mounting terminals of an electronic component on the electrode. A mounting board, wherein the electronic component is mounted by a component mounting step and a reflow heating step of performing reflow heating to melt the solder and the solder chip.