JP3277402B2 - Electronic component soldering method - 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 of soldering an electronic component in which a chip component and a lead component are both soldered to a substrate.

[0002]

2. Description of the Related Art In order to increase the mounting density of a board, electronic components such as a chip component and a lead component are sometimes mixedly mounted on both sides of the board. In such a case, the conventional soldering method is performed in the following order. ing.

[0003] First, solder for a chip component is applied to one surface of a substrate by screen printing, the chip component is mounted at the applied solder position, and then reflow processing is performed. Next, the substrate is turned over, solder for chip components is applied to the other surface by screen printing, the chip components are mounted at the applied solder positions, and then reflow processing is performed. Next, the solder for the lead component was applied again, the lead component was mounted at the position of the applied solder, and then a reflow process was further performed. That is, conventionally, mounting of chip components and mounting of lead components were performed in this order.

[0004]

However, since the soldering process of the chip component and the soldering process of the lead component are separate in the prior art, for example, the chip component and the lead component are mounted on one surface of the substrate, and When only chip components are mounted on the other surface, three solder application steps are required, and there is a drawback that many solder application steps are required.

Conventionally, in order to mount a lead component after mounting a chip component, a device capable of applying solder by avoiding the mounted chip component, that is, a special device such as a multi-dispenser device or a PIN transfer device. Requires soldering equipment.

Further, since the lead components are mounted on the applied solder, the lead insertion holes of the substrate cannot be seen, resulting in poor workability.

Accordingly, the present invention provides an electronic component which has a small number of soldering steps when a chip component and a lead component are mixedly mounted, does not require a special solder coating device, and is easy to mount the lead component. It is an object to provide a soldering method.

[0008]

According to a first aspect of the present invention, there is provided a method of soldering an electronic component.
In a method of soldering an electronic component, in which a chip component and a lead component are soldered together on the same surface of a substrate, the chip component mounting on one surface of the substrate is performed .
A first solder application step of simultaneously applying, by screen printing, the cream solder for the lead component to be mounted on the other side together with the ream solder; and, after the first solder application step, applying the cream to the one side of the substrate.
A first component mounting step of mounting on the solder, the
By inverting the substrate after the first component mounting step, the other surface of the base <br/> plate, first applying a cream solder for the chip component to be mounted on the other side by screen printing 2
And a solder coating step, after the second solder application step, when Ma <br/> mount the chip components on the solder paste on the other side and the second component mounting step for both mounting the lead component, the first After the two-part mounting process,
A reflow step of heating both sides of the substrate.

According to a second aspect of the present invention, there is provided a method of soldering an electronic component in which a chip component and a lead component are soldered together on the same surface of a substrate. a first solder application step of applying a cream solder for the chip component to be mounted on one side by screen printing, after the first solder application step, the Cree the chip component on one surface of said substrate
A first component mounting step of mounting on the solder, a first reflow step of heating one side after the first component mounting step, and a step of removing the substrate after the first reflow step.
Is rolling, the other surface of the substrate, a second solder application step of applying the cream solder for the lead component to the mounting on one side with cream solder for the chip component to be mounted on the other side at the same time by screen printing, After the second solder application step, a second component mounting step of mounting the chip component on the cream solder on the other surface of the substrate ; and after the second component mounting step,
Turn the board over and mount the lead components on one side of the board.
It comprises a third component mounting step for mounting and a second reflow step for heating the other side after the third component mounting step.

[0010]

[0011]

According to the first and second aspects of the present invention, the first
Since all the solder to be applied to one side of the board in the solder application step and all the solder to be applied to the other side of the board in the second solder application step are respectively performed, a total of two solder application steps Only needs to be done. Also, since each solder coating process is performed on the surface where no electronic components are mounted,
No special soldering equipment is required. Further, since the solder for the lead component is applied to the opposite surface to be mounted, the lead insertion hole of the substrate is visible when the lead component is mounted.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A to 1E are views showing the respective soldering steps of the first embodiment. In the first embodiment, only the chip component T is provided on one surface 2 of the substrate 1 and the chip component is provided on the other surface 3. The case where both T and the lead component L are respectively mounted is shown.

In FIG. 1A, both surfaces 2 of a substrate 1 are shown.
Lands 4 for chip components T are provided at appropriate places 3. A lead insertion hole 5 is formed at an appropriate position on the substrate 1, and a land 6 for a lead component L is provided around the lead insertion hole 5. The lands 6 for the lead components L are provided not only on the other surface 3 for mounting but also on one surface 2.

First, all the lands 4 and 6 on the one surface 2, that is, the lands 4 for the chip components T mounted on the one surface 2 and the lead components L mounted on the other surface 3 with the one surface 2 of the substrate 1 facing upward. Cream solder 7 is applied on land 6 for use with a screen printing device (first solder application step).

Next, as shown in FIG.
The chip component T is mounted on the cream solder 7 of the land 4 (first component mounting step).

Next, as shown in FIG. 1C, the substrate 1 is turned over and the other surface 3 is turned upward. The chip component T that has been lowered does not drop due to the adhesiveness of the cream solder 7. The land 4 on the other surface 3, that is, the other surface 3
The cream solder 7 is applied on the land 4 for the chip component T to be mounted on the substrate by a screen printing device (second solder application step).

Next, as shown in FIG.
Mount the chip part T on the cream solder 7 lands 4 and the lead interpolation lead portion L ₁ of the lead component L
It is inserted into the inlet hole 5 and mounted such that the tip penetrates through the cream solder 7 (second component mounting step). Here, since the cream solder 7 is not applied to the lands 6 on the other surface 3 and the lead insertion holes 5 are visible, the work is easy.

Finally, if the both sides 2 and 3 of the substrate 1 are reflowed collectively, the cream solder 7 is melted and then solidified to complete the soldering as shown in FIG. 1E (reflow step). .

In the first embodiment, all the solder is applied on one side 2 of the substrate 1 in the first solder application step, and all the solder is applied on the other side 3 of the substrate 1 in the second solder application step. Only two solder applications are required, and
It can be performed only by screen printing. And screen printing equipment has high solder application accuracy,
Since the amount of solder applied can be easily controlled by the squeegee angle, printing pressure, and speed, productivity and quality are also improved in this respect as compared with the case where a special device is used.

In the first embodiment, the cream solder 7 is used. However, when a solder having no tackiness is used, a process of bonding the chip component T mounted on one surface 2 to the substrate 1 with an adhesive or the like is performed. is necessary.

Further, in the first embodiment, the order of the first solder application step → component mounting → substrate inversion → second solder application step → component mounting → reflow is the order, but the first solder application step → substrate inversion → first (2) The order of solder application process → component mounting → substrate inversion → component mounting → reflow may be adopted. By doing so, the number of times of substrate reversal is increased by one. However, since the first and second solder coating processes and the two component mounting processes are both continuous, the position of the screen printing device and the component mounting device are different. It is convenient.

Further, in the first embodiment, the case where the chip component T and the lead component L are mixedly mounted only on the other surface 3 of the substrate 1 has been described.
The present invention can also be applied to a case in which a chip component T and a lead component L are mixedly mounted on the respective components 3. That is,
The cream solder 7 is simultaneously applied to the land 6 of the lead component L mounted on one surface in the second solder application step. Then, in the second component mounting step, not only the chip component T and the lead component L are mounted on the other surface 3 but also the lead component L may be mounted on the one surface 2.

FIGS. 2A to 2C and FIGS. 3A to 3C.
FIGS. 4A and 4B are views showing each soldering process of the second embodiment. In this second embodiment, both the chip component T and the lead component L are provided on one surface 2 of the substrate 1. The case where only the chip component T is mounted on the other surface 3 is shown.

In FIG. 2A, lands 4 for chip components T are provided at appropriate places on both surfaces 2 and 3 of the substrate 1 as in the first embodiment. A lead insertion hole 5 is formed at an appropriate position on the substrate 1, and a land 6 for a lead component L is provided around the lead insertion hole 5. The lands 6 for the lead components L are provided not only on the other surface 3 for mounting but also on one surface 2.

First, the screen 1 is mounted only on the land 4 for the chip component T on one side 2 (excluding the land 6 for the lead component L mounted on the other side 3) with the one side 2 of the substrate 1 facing upward. To apply the cream solder 7 (first solder application step).

Next, as shown in FIG.
The chip component T is mounted on the cream solder 7 of the land 4 (first component mounting step).

Next, the one surface 2 of the substrate 1 is reflowed. Then, the cream solder 7 is melted and then solidified to complete the soldering as shown in FIG. 2C (first reflow step).

Next, as shown in FIG. 3A, the substrate 1 is turned over and the other surface 3 is turned upward. Then, cream is applied to all the lands 4 and 6 on the other surface 3, that is, the lands 4 for the chip components T mounted on the other surface 3 and the lands 6 for the lead components L mounted on the one surface 2 by a screen printing device. The solder 7 is applied (second solder application step).

Next, as shown in FIG.
The chip component T is mounted on the cream solder 7 on the land 4 of FIG. 1, and then the substrate 1 is inverted as shown in FIG. The lower chip component T is cream solder 7
It will not fall off due to its stickiness. And FIG.
(A), the insert from one surface 2 side leads L ₁ of the lead component L to the lead insertion hole 5, is mounted in a state where its tip penetrates through the cream solder 7 (second component mounting step). Here, since the cream solder 7 is not applied to the lands 6 on the one surface 2 and the lead insertion holes 5 are visible, the work is easy.

Finally, the other surface 3 of the substrate 1 is reflowed. Then, the cream solder 7 on the other side 3 is melted,
Thereafter, it is solidified and the soldering is completed as shown in FIG. (Second reflow step).

[0031]

As described above, claims 1 and 2
According to the second aspect of the present invention, since the solder for the lead component is applied to the opposite surface to be mounted, the solder application on both sides of the substrate is simply performed in two solder application steps. This has the effect of reducing the number of processes and requiring no special solder coating device. Further, since the solder for the lead component is applied to the surface opposite to the mounting surface, there is an effect that the lead insertion hole of the substrate is visible at the time of mounting, and the mounting operation is easy.

Furthermore, according to the invention of claim 1 and claim 2, since a solder coating in the first and second solder coating step was carried out by screen printing, of as multi-dispenser apparatus or the like PIN transfer device prior Compared with the case where a special device is used, there is also an effect that the solder application accuracy is high and the probability of occurrence of microbridge failure is extremely low, thereby improving productivity and quality. Also, screen printing uses solder
High coating accuracy, squeegee angle, printing pressure and speed
This makes it easy to control the amount of solder applied
Therefore, in this respect as well, the production
Productivity and quality are improved.

[Brief description of the drawings]

FIGS. 1A to 1E each show a soldering step (first embodiment).

FIGS. 2A to 2C are diagrams each showing a first half soldering step (second embodiment).

FIGS. 3A to 3C are diagrams each showing a middle-stage soldering process (second embodiment).

FIGS. 4A and 4B are diagrams showing a latter half of the soldering step (second embodiment).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... One side 3 ... Other side 7 ... Cream solder (solder) T ... Chip part L ... Lead part

Claims (2)

(57) [Claims] 1. A method for soldering an electronic component, wherein a chip component and a lead component are soldered together on the same surface of a substrate, wherein the other surface is mounted on one surface of the substrate together with the cream solder for the chip component mounted on the one surface. A first solder application step of simultaneously applying the cream solder for the lead component to be mounted on the substrate by screen printing; and after the first solder application step , mounting the chip component on the cream solder on one surface of the substrate. A first component mounting step, and inverting the substrate after the first component mounting step;
The other surface of the substrate, a second solder application step of applying a cream solder for the chip component to be mounted on the other side by screen printing, after the second solder application step, the chip components on the other side both before and mounted on the cream solder
A method of soldering an electronic component, comprising: a second component mounting step of mounting the lead component; and a reflow step of heating both sides of the substrate after the second component mounting step. 2. A method of soldering an electronic component in which a chip component and a lead component are soldered together on the same surface of a substrate, wherein cream solder for the chip component mounted on one surface of the substrate is screen-printed on one surface of the substrate. A first solder application step of applying the chip component, and after the first solder application step, a first component mounting step of mounting the chip component on the cream solder on one surface of the substrate ; and after the first component mounting step. 1st heating one side
And reflow process, the invert the substrate after the first reflow process, the other surface of the substrate, the solder paste for the lead component to the mounting on one side with cream solder for the chip component to be mounted on the other side A second solder application step of applying the same at the same time by screen printing; and after the second solder application step, a second step of mounting the chip component on the cream solder on the other surface of the substrate .
A two- component mounting step, and inverting the substrate after the second component mounting step;
Third part for mounting the lead component on one side of the substrate
Product mounting step and a second step of heating the other side after the third component mounting step.
A method for soldering electronic components, comprising a reflow process.