JPH05326818A - Electronic part mounting method - Google Patents

Abstract

PURPOSE:To provide the electronic part mounting method with which the separation of an electrode pattern, to be used to install the electronic part, can be prevented by a simple constitution, and the generation of deformation and come-off of a lead, when a cutting operation of a lead frame and a bending operation are conducted, can also be prevented. CONSTITUTION:The resin, to be used for resin molding of a semiconductor chip, is poured into lead parts 13a and 13b where the electronic part of a lead frame 10 is mounted, and after the lead parts 13a and 13b, where the electronic part is mounted, have been retained in a connected state using the poured-in resin, they are cut off from the lead frame and the lead is bent.

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, and more particularly to an electronic component mounting method in which a semiconductor chip is mounted on a lead frame, the semiconductor chip is resin-molded, and then the electronic component is mounted.

[0002]

2. Description of the Related Art Conventionally, as a method of mounting an electronic component together with a semiconductor chip, a method of directly mounting the semiconductor chip and the electronic component on a printed circuit board or a ceramic substrate, a semiconductor chip and an electronic component using a lead frame are used. There are known methods for implementing.

Recently, a method of mounting a semiconductor chip and an electronic component using a lead frame has attracted attention because it can be manufactured easily and at low cost depending on the scale of the electronic circuit to be mounted.

Conventionally, a method of mounting a semiconductor chip and an electronic component using a lead frame is as shown in FIG. 13, a mounting pattern 1 for mounting a semiconductor chip.
1. A plurality of electrode patterns 12 connected to this semiconductor chip, electrode patterns 13a, 13 for mounting electronic parts such as resistors, capacitors, transistors, and diodes
b, the lead frame 10 on which the tie bars 14a, 14b, etc., which serve as a resin flow stop when the mounted semiconductor chip is molded by resin is formed, is processed, and the semiconductor chip 2 is mounted on the mount pattern 11 of the lead frame 10.
0 is mounted, that is, die-bonded, and the die-bonded semiconductor chip 20 and a plurality of peripheral electrode patterns 12
Is connected with a plurality of wires 21, so-called wire bonding is performed, and then a portion including the semiconductor chip 20 is transfer-molded. FIG. 14 shows a state after the transfer molding is performed. Reference numeral 30 denotes a molding portion made of the molding resin molded by the transfer molding, and 30a denotes a gap into which the molding resin flows.

In this state, each device is individually separated from the lead frame 10. FIG. 15 shows this separated state.

By the way, according to such a method, as shown in FIG.
As shown in FIG. 5, when the device is separated from the lead frame 10, the electrode pattern 13a falls off, which makes it difficult to mount electronic parts such as resistors, capacitors, transistors, and diodes using the electrode patterns 13a and 13b. Become.

Therefore, as disclosed in Japanese Patent Application No. 62-237797, the electronic components to be mounted between the electrode patterns 13a and 13b are attached by soldering or the like and then individually separated from the lead frame 10. do it,
A method has been proposed in which the electrode pattern 13a is prevented from falling off. That is, as shown in FIG. 16, the electronic components 40 to be mounted between the electrode patterns 13a and 13b are attached by soldering or conductive adhesives 40a and 40b, and thereafter, individually from the lead frame 10 as shown in FIG. The lead 15 is cut off, bent, and attached to the printed board 50 as shown in FIG.

[0008]

However, in such a structure, since the mounting strength of the electronic component is weak, the lead 15 is deformed when it is separated from the lead frame 10, or when the lead 15 is bent. However, there is a problem that the lead 15 is removed.

Therefore, according to the present invention, the electrode pattern for attaching the electronic component can be prevented from dropping off with a simple structure, and further, the deformation and the dropping of the lead do not occur during the cutting from the lead frame and the bending process of the lead. An object is to provide a mounting method for electronic components.

[0010]

To achieve the above object, the present invention provides a method for mounting an electronic component, which comprises mounting a semiconductor chip on a lead frame, resin-molding the semiconductor chip, and then mounting an electronic component. The lead portion for mounting the electronic component is connected and held by pouring the resin used for the resin molding into the lead portion for mounting the electronic component of the lead frame.

[0011]

According to the present invention, when a semiconductor chip is resin-molded, the resin used for the resin molding is poured into a lead portion of a lead frame for mounting an electronic component, and the poured resin connects the lead portion for mounting the electronic component. Hold. This prevents the electrode pattern for mounting the electronic parts from falling off when separating from the lead frame, and since the lead parts that mount the electronic parts are reinforced by the resin, it is necessary to separate the lead patterns when separating from the lead frame and bending the leads. It does not deform or come off.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the electronic component mounting method of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of a mounting method for electronic parts according to the present invention. The lead frame 10 used in this embodiment is compared with the lead frame 10 of the conventional example shown in FIG. A part of the tie bar 14a is cut out 16
The electrode patterns 13a are formed with tie bars 17a and 17b which are cut off at and serve as a resin flow stop when the semiconductor chip is resin-molded. Other configurations are shown in FIG.
It is similar to that shown in FIG. In the following drawings, for convenience of explanation, the same reference numerals as those used in FIGS. 13 to 18 are used for the portions having the same operations as those of the conventional example shown in FIGS. 13 to 18.

In the configuration of this embodiment shown in FIG.
Since a part of the tie bar 14a is cut off at the cutout portion 16, at the time of transfer molding of a portion including the semiconductor chip 20, the molding resin flows through the cutout portion 16 and electronic parts such as resistors, capacitors, transistors and diodes are formed. Pattern 13a for mounting
And 13b are filled, and the electrode pattern 1 is formed by molding resin.
Connect between 3a and 13b.

FIG. 2 shows a state after transfer molding, and 30b shows a portion filled with the molding resin that has flowed in through the notch 16. If the lead frame 10 is individually separated in this state, the electrode patterns 13a and 13b are connected by the molding resin 30b as shown in FIG. There is no. Further, since the electrode patterns 13a and 13b are firmly connected by the molding resin 30b, the leads are not deformed when they are separated from the lead frame 10.

In the state shown in FIG. 3, the lead is bent, and as shown in FIG.
0, and then the electronic component 40 is soldered or electrically conductive adhesive 40a between the electrode patterns 13a and 13b,
Install by 40b.

Here, since the electrode patterns 13a and 13b are firmly connected to each other by the molding resin 30b, the leads 15 do not fall off when the leads 15 are bent.

FIG. 15 is a flowchart showing a device assembling process relating to the electronic component mounting method of this embodiment described above.

First, the lead frame 10 as shown in FIG. 1 is processed (step 101). The lead frame 10 can be processed by a known method such as using a precision press.

Next, the semiconductor chip 20 is mounted on the mount pattern 11 of the lead frame 10, that is, die-bonded (step 102). In this die bond, for example, Ag paste is applied to the mount pattern 11 of the lead frame 10, and the mount pattern 11 is formed.
This is performed by pressing the semiconductor chip 20 onto the.

Subsequently, wire bonding is performed to connect the semiconductor chip 20 and the plurality of peripheral electrode patterns 12 with a plurality of wires 21 (step 103). This wire bonding is performed for each electrode pattern 12, for example, thermocompression bonding using a gold wire.

When wire bonding is completed, transfer molding of the portion including the semiconductor chip 20 is performed (step 104). This transfer mold is performed by setting the integrated circuit device assembled on a lead frame in a heated mold, high-frequency preheating the powdered resin powder into the mold, and filling and molding it with a plunger. Be seen. During the transfer molding process, the molding resin is applied to the electrode patterns 13a and 13b through the notches 16 of the lead frame 10.
To flow between the electrode patterns 13a and 13b to connect them.

Upon completion of transfer molding, lead solder plating processing is performed (step 105), and then solder paste printing or application is performed on the electrode patterns 13a and 13b for mounting electronic components (step 107).
Leads are cut and electronic parts are mounted (Step 10
8), after performing the reflow process (step 109), wash (step 109). After that, the electrical characteristics of this device are measured and the device assembly process is completed.

By the way, in the above embodiment, FIG.
As shown in FIGS. 9A and 9B by extracting the portions of the electrode patterns 13a and 13b in the plan view and the side view thereof, the electrode patterns 13a and 13b are formed in the lead frame
It is connected by the molding resin 30b poured through the notch portion 16. However, in addition to this molding resin 30b, the space between the electrode patterns 13a and 13b is covered with the molding resin to further improve the connection strength between the electrode patterns 13a and 13b. It may be configured to increase.

FIG. 7 shows another embodiment of the present invention constructed as described above. In this embodiment, the molding resin 3 is formed on the upper surface between the electrode patterns 13a and 13b.
Covered by 00a and 300b.

In the structure shown in FIG. 7, the upper surfaces of the electrode patterns 13a and 13b are covered with the molding resins 300a and 300b, but as shown in FIG.
The upper and lower surfaces of the electrode patterns 13a and 13b may be covered with the molding resins 301a and 301b. With this configuration, the connection strength between the electrode patterns 13a and 13b is further increased.

FIG. 9 shows still another embodiment of the present invention. In this embodiment, the molding resin 302 is used to form the electrode patterns 13a and 13b between the electrode patterns 13a and 13b. The pocket 302a is formed to guide the positioning for the electronic component to be connected. The pocket 302a is formed during the transfer molding process, and the pocket 3a
02a makes it possible to extremely easily attach the electronic component between the electrode patterns 13a and 13b.

FIG. 10 shows a modification of the embodiment shown in FIG.
This shows a state in which the electronic component 40 is connected between the electrode patterns 13a and 13b. The electronic component 40 is inserted into the pocket 302a for this positioning, and the electronic component 40 is soldered or conductive adhesive 40a, It is attached between the electrode patterns 13a and 13b by 40b. FIG. 11 shows a state in which the semiconductor device thus configured is attached to the substrate 50. In FIG. 11, the electronic component 40 is a pocket 3 for this positioning.
It is inserted in 02a and attached between the electrode patterns 13a and 13b, and the electrode patterns 13a and 13b are connected by the molding resin 30b and the molding resin 302.

In the above embodiment, one electronic component is mounted, but a plurality of electronic components may be mounted as shown in FIG.

In the embodiment shown in FIG. 12, a molding resin 303 is used to guide the positioning of electronic parts.
Two pockets 303a, 303b, 303c are formed, and the electronic components 41, 42, 43 are mounted in the pockets 303a, 303b, 303c, respectively.
Here, in the pockets 303a and 303b, leads are exposed on the upper surface and the lower surface, and electronic components are attached to both surfaces. With such a configuration, high-performance multi-chip modules can be mounted at high density.

[0031]

As described above, according to the present invention,
The resin used to mold the semiconductor chip is poured into the lead parts that mount the electronic components of the lead frame,
Since the resin that is poured in is used to connect and hold the lead part that mounts the electronic component, the electrode pattern for mounting the electronic component can be prevented from falling off with a simple structure, and the lead frame can be separated from the lead frame and the lead can be bent. This has the effect of preventing deformation and falling of the leads during processing.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a method for mounting electronic components of the present invention, showing a state in which a semiconductor integrated circuit is mounted on a lead frame.

FIG. 2 is a plan view showing a state after transfer molding is performed in the embodiment shown in FIG.

FIG. 3 is a plan view showing a state in which the devices are individually separated from the lead frame in the transfer-molded state of FIG.

FIG. 4 is a side view showing a state where the device shown in FIG. 3 is mounted on a substrate.

FIG. 5 is a flowchart for explaining a processing process of the embodiment shown in FIGS. 1 to 4.

FIG. 6 is an electrode pattern 1 of the embodiment shown in FIGS.
The top view which extracted and showed the part of 3a and 13b, and its side view.

FIG. 7 shows another embodiment of the present invention, and is a plan view and a side view showing extracted electrode patterns 13a and 13b.

FIG. 8 shows still another embodiment of the present invention, and is a plan view and a side view showing extracted electrode patterns 13a and 13b.

FIG. 9 shows another embodiment of the present invention and is a plan view showing a state after transfer molding.

10 is a plan view showing a state where the devices are individually separated from the lead frame in the transfer-molded state of FIG.

11 is a side view showing a state where the device shown in FIG. 10 is mounted on a substrate.

FIG. 12 shows still another embodiment of the present invention, and is a side view showing a state in which a device to which a plurality of electronic components can be attached is mounted on a substrate.

FIG. 13 is a plan view showing a conventional mounting method of electronic components, showing a state in which a semiconductor integrated circuit is mounted on a lead frame.

14 is a plan view showing a state after transfer molding is performed from the state shown in FIG.

15 is a plan view showing a state in which the devices are individually separated from the lead frame in the transfer-molded state of FIG.

FIG. 16 is a plan view showing another example of a conventional electronic component mounting method, showing a state after transfer molding.

FIG. 17 is a plan view showing a state where the devices are individually separated from the lead frame in the transfer-molded state of FIG.

FIG. 18 is a side view showing a state where the device shown in FIG. 17 is mounted on a substrate.

[Explanation of symbols]

 10 Lead Frame 11 Mount Pattern 12 Electrode Pattern 13a, 13b Electrode Pattern 14a, 14b Tie Bar 15 Lead 16 Notch 16 17a, 17b Tie Bar 20 Semiconductor Chip 30 Molding Resin 30a, 30b Molding Resin 300a, 300b Molding Resin 301a, 301b Molding Resin 302 Molding resin 302a Pockets 303a, 303c, 303c Pocket 40 Electronic component 40a, 40b Solder or conductive adhesive 41, 42, 43 Electronic component 50 Printed circuit board

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Nakamura 10 Ouron Co., Ltd.

Claims (1)

[Claims] 1. A method of mounting an electronic component, comprising mounting a semiconductor chip on a lead frame, resin-molding the semiconductor chip, and then mounting an electronic component, comprising: By pouring the resin used for resin molding,
A method of mounting an electronic component, characterized in that a lead portion for mounting the electronic component is connected and held.