JP3236691B2 - Sealing method and mold for electronic parts - 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 for encapsulating and molding electronic parts such as semiconductors and a mold.

[0002]

2. Description of the Related Art For example, a resin molded body is integrated on both front and back surfaces of a lead frame, and a recess for mounting an electronic component is provided on one surface thereof. There is known a method of sealing and molding an electronic component in which an inner lead is electrically connected to the inner lead via a bonding wire, and thereafter the inside and outside of the mounting recess are shielded.

In the above-mentioned conventional mold, for example, as shown in FIG. 10, an upper mold 1 and a lower mold 2 are arranged to face each other. An upper mold cavity 4 and a lower mold cavity 5 for molding a resin molded body to be integrated are opposed to each other, and the upper mold 1 has a joining portion 7 to the upper surface of the inner lead 6 in the lead frame 3.
And a core 8 for forming the electronic component mounting recess. Therefore, as shown in FIG. 11, the resin molded bodies 9 and 10 are integrated on the upper and lower surfaces of the lead frame 3 and the center of the upper surface side is formed on the molded product molded by the upper and lower molds 1 and 2. A recess 12 for mounting the electronic component 11 is formed in the portion. Then, an electrode of the electronic component 11 mounted in the recess 12 and the inner lead 6 are electrically connected via a bonding wire 13 or an electrode portion of the IC chip is directly connected. After that, it is possible to obtain a finished product in which the inside and outside of the recess 12 are shielded and the electronic component is sealed and molded. Note that Japanese Patent Application Laid-Open
No. 3,396,612 discloses a tree in the inner lead.
Prevents resin burrs from forming on grease burrs
Means for doing so are disclosed. This is, first, the cavity
Press the resin burr adhesion prevention surface on the cavity surface
The first resin molding machine that forms a resin molded body to support
Process, and then place the lead frame in the predetermined position of the cavity.
With a resin burr on the inner lead
The resin whose adhesion preventing surface is formed in the first resin molding step.
Via a molded body, the second fixed to a predetermined position of the cavity.
Perform the second step, then fill the cavity with resin
The second resin molding step is performed. Therefore, this
According to the means, the resin burr adhesion prevention surface of the inner lead is
Since it can be fixed at a predetermined position in the cavity,
Prevents resin burrs from forming on inner leads
The expected effect is expected. However, this means
In advance, perform the first resin molding process to
Make sure that the resin burr adhesion prevention surface of the
It is necessary to manufacture a resin molding to support the pressure.
In addition, at the time of molding , the resin molded body is
Must be supplied to the predetermined position of the tee and fitted
There is a trouble in molding. Also,
No. 83045 discloses a lead wire in a cavity.
In order to mold the lower surface of the frame to a certain resin thickness,
With the support pin integrated with the load frame between the mold surfaces
Molding the resin in the sandwiched state, and for this,
After molding, from the resin molded product (mold package)
Regarding insulation means for support pins that will be exposed to the outside
Is disclosed. The insulating means of the support pin is made of resin.
Mold with the support pins inside the mold exposed to the outside.
When the exposed support pin is cut by punching
In other words, the support pins inside the resin molding are exposed to the outside.
As a means for molding in the state of being
By providing a convex part to support the cutting point of the holding pin
And the internal support pins are exposed to the outside of the molded resin
It is described that a molding hole is formed. Immediately
That is, after molding, the supporting pins inside the resin molded body are formed.
For cutting off the insulation for insulation with the outside
Is proposed.

[0004]

The problem to be solved by the present invention is shown in FIG.
In the conventional mold structure, there is a problem that resin burrs are easily generated on the upper surface of the inner lead 6 in the lead frame. Further, due to this, serious adverse effects on quality such as insufficient or impossible electrical connection of the bonding wire 13 connecting the upper surface of the inner lead 6 and the electrode of the electronic component 11 are caused. is there. Also,
In order to eliminate such adverse effects, it is necessary to remove the resin burrs of the inner leads 6 described above. In this case, however, the operation of removing the resin burrs requires a great deal of work and the overall molding time becomes longer. There is a problem.

Accordingly, the present invention provides a method for sealing electronic components which can efficiently and reliably prevent various adverse effects caused by the generation of resin burrs, such as the upper surface of the inner lead in the above-described lead frame. An object of the present invention is to provide a stop molding method and a mold for sealing and molding an electronic component used in the method.

[0006]

According to the present invention, there is provided a method of sealing and molding an electronic component, which is capable of preventing the adhesion of resin burrs on a lead frame when a fixed mold and a movable mold are clamped. Performing a high pressure supporting step of the lead frame for strongly supporting the surface; A primary resin sealing molding step of sealing and molding the primary resin sealing area with a resin is performed, and then, after the first resin sealing molding step , the first resin sealing molding except for the resin burr adhesion preventing surface on the lead frame. A secondary resin sealing molding step of sealing and molding the secondary resin sealing area with resin.
It is characterized by performing .

Further, a mold for sealing and molding an electronic component according to the present invention for solving the above technical problem is a mold for sealing and molding an electronic component in which a fixed mold and a movable mold are arranged to face each other. And a high-pressure support member of the lead frame for strongly supporting the resin-burr-adhesion preventing surface of the lead frame at the time of clamping of both the fixed mold and the movable mold, and the high-pressure support member for preventing the resin burr from adhering to the lead frame. While the surface is strongly supported, a primary resin sealing molding portion for sealing and molding the primary resin sealing area of the lead frame with a resin, and a secondary resin sealing portion other than the resin burr adhesion preventing surface on the lead frame. And a second resin sealing molding portion for sealing and molding the resin sealing area with a resin.

[0008]

According to the method of the present invention, at the time of the first resin sealing molding step, the resin burr adhesion preventing surface of the lead frame such as the upper surface of the inner lead of the lead frame is strongly supported. It is possible to efficiently and reliably prevent the resin burrs from adhering to the resin burr adhesion preventing surface. Further, in the second resin sealing molding step, the second resin sealing area other than the resin burr adhesion preventing surface of the lead frame can be sealed and molded with the resin.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in FIGS. FIG. 1 is a main part of a primary resin sealing molding part in a sealing molding die of an electronic component,
This shows the mold clamping state. FIG. 2 is a main part of a secondary resin sealing molded part of the mold corresponding to FIG. 1 and shows a clamped state thereof. FIGS. 3 and 4 show a main part of a molded product formed by a mold corresponding to FIGS. 1 and 2.

As shown in FIG. 1, the mold for encapsulating and molding the above-mentioned electronic component comprises a fixed upper mold 101 and a movable lower mold 102 opposed to the fixed upper mold 101. The molding part, as shown in FIG. 2, the fixed upper mold 101, and the fixed upper mold 10
1 and a secondary resin-sealed molded part comprising a movable lower mold 102 opposed to the second mold.

The upper and lower dies (1.
01 and 102), an upper mold cavity 104 for molding and integrating resin moldings on the upper and lower surfaces of the lead frame 103.
And the lower mold cavity 105 are opposed to each other. The upper die 101 is provided with a joint portion 107 of the lead frame 103 to the upper surface side of the inner lead 106 and a core 108 for forming a mounting recess for the electronic component. The lower die 102 has the lead frame 10
3, the inner lead 106 is provided so as to be able to freely contact and separate from the lower surface side of the inner lead 106, and when the upper and lower dies (101 and 102) are clamped, the inner lead 106 is pressed toward the joint 107 of the upper die to The high-pressure support member 11 of the lead frame (inner lead 106) for supporting the upper surface side of the lead, that is, the resin-burr-adhesion-preventing surface side, on the upper die joining portion 107 side in a high pressure state
4 are provided.

The upper and lower molds (101 and 102) in the secondary resin sealing molded part are fitted with the resin molded bodies (109 and 110) molded in the primary resin sealing molded part. Upper and lower cavities (104, 105) are provided opposite to each other.

[0013] Resin encapsulation using an encapsulation mold for an electronic component having the above configuration is performed as follows.
First, the lead frame 103 is fitted and set at a predetermined position on the mold surface of the lower mold 102 in the primary resin sealing molded portion,
The lower mold 102 is moved upward to clamp the upper and lower molds (101 and 102). At this time, the primary resin sealing area of the lead frame 103 is fitted into the upper and lower cavities (104 and 105). Next, the high-pressure support member 114 is moved upward to press the inner lead 106 toward the joining portion 107 of the upper die, and the upper surface side (the resin burr adhesion preventing surface side) of the inner lead 106 is strongly pressed toward the joining portion 107 side. A step of strongly supporting the lead frame to be supported in the state is performed. Next, the upper and lower cavities
(104, 105).
04 ・ 105) Resin sealing molding is performed for the primary resin sealing area fitted and set inside. At this time, since the upper surface of the inner lead 106 is strongly supported by the upper joint 107 side, the upper surface of the inner lead 106 and the upper mold 107 are connected to each other.
The molten resin material does not penetrate into the gap. For this reason, it is possible to prevent the occurrence of resin burrs due to the infiltration of the molten resin material. Next, the lead frame 103
Is released from the first resin-sealed molded part, and the lead frame 103 is fitted and set at a predetermined position of the second resin-sealed molded part. At this time, the resin molded body (109, 110) molded in the primary resin sealing molded part is, as shown in FIG.
04 ・ 105). Next, the lead frame
103, the second resin sealing area other than the resin burr adhesion preventing surface, that is, the high pressure supporting member of the first resin sealing molded part
A molten resin material is injected and filled into a space 115 in a lower mold cavity 105 formed corresponding to the shape of 114, and a resin molded body 116 (see FIG. 3) is molded and integrated in the space 115. A second resin sealing molding step is performed.

Therefore, firstly, the molded article formed by performing the first resin encapsulation molding step and then performing the second resin encapsulation molding step has the following features, as shown in FIG. 3 and FIG. Resin molded bodies (109, 110, 11
6) are integrated, and a recess 112 for mounting the electronic component 111 is formed in the center on the upper surface side. Further, as described above, since no resin burr is generated on the upper surface of the inner lead 106 of the molded product, the electric potential of the bonding wire 113 connecting the upper surface of the inner lead 106 and the electrode of the electronic component 111 is reduced. Connection can be reliably performed.

The above-described embodiment is described, for example, in FIGS.
The present invention can be applied to a mold for encapsulation molding of other electronic components shown in FIG. FIGS. 5 and 6 show a main part of a first resin sealing molding portion in a mold for encapsulation molding of an electronic component having a heat radiating plate, and show a clamped state thereof. 7 and 8
Is a main part of the secondary resin sealing molded portion of the mold corresponding to FIGS. 5 and 6, and shows a mold-clamped state. FIG.
Indicates a main part of a molded product molded by a mold corresponding to FIGS. 5 to 8.

As shown in FIGS. 5 and 6, a mold for encapsulating and molding the electronic component includes a fixed upper mold 101 and the fixed upper mold 101.
And a fixed lower mold 101 as shown in FIGS. 7 and 8.
And a secondary resin-sealed molded part comprising a movable lower mold 102 disposed opposite to the fixed upper mold 101.

The lead frame in this embodiment
103 is provided with a heat radiating plate 117, and electronic components are mounted on the lead frame 103 in advance. Therefore, the surface of the heat radiating plate 117 (the lower surface side of the heat radiating plate in FIG. Except that the electronic parts are exposed to the outside to prevent resin burrs from adhering to the surface of the heat radiating plate 117, and that the electronic component is resin-sealed and molded in the first resin-sealing molding step, etc. It has substantially the same purpose, structure, and effect as those of the first embodiment. Therefore, the same components as those of the embodiment are denoted by the same reference numerals as those of the previous embodiment, and the detailed description is omitted.

The present invention is not limited to the above-described embodiment, but may be arbitrarily and appropriately changed and selected as necessary within a range not departing from the gist of the present invention. It is.

For example, a configuration may be adopted in which the above-described high-pressure support member 114 is elastically protruded toward the upper mold joint 107 via an appropriate elastic member. Further, the high-pressure support member 114 may be configured as a lower mold core arranged to face the upper mold joint 107.

After the above-described first resin encapsulation molding step is completed, for example, the high-pressure support member 114 is retracted to the bottom position of the lower mold cavity 105, and the lower pressure generated by the retraction of the high-pressure support member 114 is reduced. A second resin sealing molding step of injecting and filling a molten resin material into the space 115 in the mold cavity 105 may be performed. In this case, there is an advantage that the configuration of the mold can be simplified because the first resin sealing molding portion and the second resin sealing molding portion can also be used.

[0021]

According to the method of the present invention, the resin burr adhesion preventing surface of the lead frame is strongly supported during the first resin encapsulation molding step, so that the resin burr adhesion preventing surface is prevented from adhering to the resin burr adhesion preventing surface. The prevention can be performed efficiently and reliably . For this reason, an electronic component encapsulation molding method capable of efficiently and reliably preventing the above-described various adverse effects caused by resin burrs adhering to a lead frame, and a method of sealing an electronic component used in the electronic component. An excellent practical effect such that a mold for sealing molding can be provided can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially cutaway vertical cross-sectional view showing a main part of a primary resin encapsulation molding part in an electronic component encapsulation molding die according to the present invention, wherein a lead frame is fitted and set. This shows a tightened state.

FIG. 2 is a partially cutaway longitudinal sectional view showing a main part of a secondary resin sealing molded portion of the mold corresponding to FIG. 1, showing a mold-clamped state.

FIG. 3 is a partially cutaway longitudinal sectional view showing a main part of a molded product formed by a mold corresponding to FIGS. 1 and 2;

FIG. 4 is a longitudinal sectional view taken along line AA of the molded product corresponding to FIG.

FIG. 5 is a partially cut-away longitudinal sectional view showing a main part of a primary resin sealing molded portion in another mold according to the present invention, in which a lead frame provided with a heat sink is fitted and set. This shows a tightened state.

FIG. 6 is a longitudinal sectional view of the mold corresponding to FIG. 5, taken along line BB.

FIG. 7 is a partially cutaway longitudinal sectional view showing a main part of a secondary resin sealing molded portion of the mold corresponding to FIG. 5, and shows a clamped state thereof.

8 is a vertical sectional view of the mold corresponding to FIG. 7, taken along line CC.

FIG. 9 is a longitudinal sectional view of a molded product formed by a mold corresponding to FIGS. 5 to 8;

FIG. 10 is a partially cutaway longitudinal sectional view showing a configuration example of a conventional mold for sealing and molding an electronic component, showing a state in which a lead frame is fitted and set and the mold is clamped.

11 is a partially cutaway longitudinal sectional view showing a main part of a molded product formed by a conventional mold corresponding to FIG. 101 Fixed upper die 102 Movable lower die 103 Lead frame 104 Upper die cavity 105 Lower die cavity 106 Inner lead 107 Joint 108 Core 109 Resin molded body 110 Resin molded body 111 Electronic component 112 Depression 113 Bonding wire 114 High pressure support member 115 Space 116 Resin molded body 117 Heat sink

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI // B29L 31:34 B29L 31:34

Claims (2)

(57) [Claims] 1. A make strong pressure supporting process of the lead frame at the time of clamping the fixed mold and the movable mold to strong pressure support resin burr adhesion preventing surface of the lead frame, then, the lead frame by strong pressure supporting step of the lead frame Perform a first resin sealing molding step of sealing and molding the first resin sealing area in the lead frame with a resin in a state of preventing the resin burr adhesion preventing surface from adhering to the resin burr , After the primary resin encapsulation molding step, a secondary resin encapsulation molding step of encapsulating and molding the secondary resin encapsulation area with a resin other than the resin burr adhesion preventing surface of the lead frame is performed. Molding method for electronic components. 2. A mold for sealing and molding an electronic component having a fixed mold and a movable mold opposed to each other, wherein a resin burr adhesion preventing surface on a lead frame when the fixed mold and the movable mold are clamped. A high-pressure support member of a lead frame that strongly supports the
In a state where the resin burr adhesion preventing surface of the lead frame is strongly supported by the high pressure support member, a first resin sealing molding portion for sealing and molding a first resin sealing area in the lead frame with a resin; A secondary resin sealing molding portion for sealing and molding the secondary resin sealing area other than the resin burr adhesion preventing surface of the lead frame with resin.
A mold for encapsulating and molding electronic parts, characterized in that it is made .