JP3063587B2 - Electronic component and method of manufacturing electronic component - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component having leads extending from a mold and a method for manufacturing the electronic component .

[0002]

2. Description of the Related Art As electronic components, for example, QFP and SOP
As described above, a chip mounted on a land is molded with a molded body made of a synthetic resin, and leads are extended from the molded body. This type of electronic component is soldered to a substrate as follows.

[0003] FIG. 3 (a) is a cross-sectional view of an electronic component mounted on a conventional substrate, FIG. 3 (b) is a sectional view of the electronic component during the reflow. 3 (a), the electronic component 1 is made by molding with a mold body 4 comprising a chip 3 mounted with a bond 10 on the land 2 of a synthetic resin, lead 5 from the mold body 4 downwardly It is bent in a hook shape and extends. Reference numeral 6 denotes a wire connecting the electrode of the chip 3 and the lead 5. The electronic component 1 is mounted with the tips of the leads 5 landing on the solder portions 9 formed on the lands 8 of the substrate 7.

[0004] substrate 7 on which an electronic component 1 is mounted as shown in FIG. 3 (a) is heated in a heating furnace. The heating temperature is equal to or higher than the melting temperature of the solder portion 9, and is generally equal to or higher than 200 ° C. Figure 3 (b) shows a state during reflow in the heating furnace. When the electronic component 1 is heated in the heating furnace, the electronic component 1 is deformed in a downward convex shape as shown in the figure. The reason is as follows.

That is, the coefficient of thermal expansion of the chip 3 made of silicon is considerably smaller than the coefficient of thermal expansion of the mold body 4 made of synthetic resin. The chip 3 includes a mold 4
Is molded at a position displaced upward from the center line NA. Therefore, the portion below the center line NA thermally expands greatly, while the portion above the center line NA does not thermally expand so much due to the presence of the chip 3 having a small thermal expansion coefficient. For this reason, the mold body 4 is deformed in a downward convex shape.

[0006]

As shown in FIG. 3 (b), at the time of reflow, the molded body 4 is thermally deformed in a downward convex shape, so that the leads 5 are lifted up and the soldering state by the solder portions 9 is changed. There was a problem that it was easy to be defective. In particular, in recent years, large electronic components tend to increase, but large electronic components are more likely to cause the above-described problem due to large thermal deformation in a downward convex shape.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electronic component and a method of manufacturing an electronic component that do not cause a defective soldering state due to thermal deformation of a mold during reflow.

[0008]

According to the present invention, there is provided an electronic component comprising:
Displace the tip above the center line of the mold
On the land of the frame
The protruding lead was bent toward the chip and molded.
Further, in the method for manufacturing an electronic component according to the present invention, the chip is molded
Displace it above the center line of the body
On the chip and the chip electrodes and lead frames.
The process of connecting the leads of the
Of the mold with the mold body and the lead on the chip side
And forming it by bending.

[0009]

According to the above construction, the lead extending from the mold is displaced in the direction pressed against the land due to the thermal deformation of the mold during reflow, so that the lead is firmly soldered on the land.

[0010]

[0011]

[0012]

[0013]

[0014]

Example will be described actual施例of the present invention. Figure 1 is a schematic view for illustrating a manufacturing process of the electronic components of the actual施例of the present invention, FIG 2 is a cross-sectional view of an electronic component during the reflow. First of all,
The fabrication method will be described. The lead frame shown in FIG.
As shown in FIG. 1B, the land 12 of the
It falls down below the lead 13 by lace processing. t
Is the drop amount. Next, bond 14 on land 12
The chip 15 is attached, and the electrode of the chip 15 and the lead 1
3 are connected by wires 16 (FIG. 1C). Next, the mall
The chip 15 and the wire 16 are molded by pressing.
The molded body 17 is formed of a synthetic resin (FIG. 1).
(D)). In the state shown in FIG. 1 (d), the chip 15 is displaced above the centerline NA of the mold body 17 lands
12 is mounted .

Next, as shown in FIG.
The chip 15 is landed by inverting the
12 and the lead 13 is connected to the chip 15 side.
(Downward in FIG. 1 (e)) and bent into a key shape to form
The electronic component 19 is completed. The electronic component 19 completed in this way is mounted on the substrate 21 as shown in FIG. 2 , and reflow is performed in a heating furnace. Then mode by was upside down
Small chips 15 coefficient of thermal expansion than the shield member 17 is Mo
Since located under the center line NA of the shield member 17, motor Lumpur <br/> de body 17 thermally deformed upward convex, the lower end portion of the lead 13 is below
, That is, displaced in the direction pressed against the land 22
Therefore, as shown in FIG.
The solder is firmly soldered on the solder portion 23 melted above .

[0016]

According to the present invention, when the mold body is thermally deformed during reflow, the lead extending from the mold body is displaced in the direction pressed against the land of the substrate, so that the lead can be firmly soldered on the land.

[Brief description of the drawings]

Illustration of a manufacturing process of the electronic components of the actual施例Next Patent

Sectional view of the electronic component during reflow of the real施例of the present invention; FIG

3A is a cross-sectional view of a conventional electronic component mounted on a substrate, and FIG. 3B is a cross-sectional view of the conventional electronic component during reflow.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Lead frame 12 Land 13 Lead 15 Chip 16 Wire 17 Molded body 19 Electronic component 21 Substrate 22 Land 23 Solder part

Claims (3)

(57) [Claims] 1. A chip is positioned above a center line of a mold body.
Displaced and mounted on the land of the lead frame,
The lead protruding from the mold is bent toward the chip.
An electronic component characterized by being molded by being slid. 2. The chip is positioned above the center line of the mold body.
Process of displacing and mounting on land of lead frame
And the wire of the chip electrode and the lead of the lead frame.
Connecting process and molding the chip and wire with a mold
And bending the lead to the chip side and molding
And a method for manufacturing an electronic component. 3. The lead frame is turned upside down.
The chip to the lower surface side of the land,
And bends the chip toward the tip to form the chip.
The method for manufacturing an electronic component according to claim 2.