JP3054244B2 - Structure of lead frame for electronic parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a transistor or I
The present invention relates to a structure of a lead frame used when manufacturing an electronic component in which a semiconductor chip portion is packaged with a synthetic resin molded body among electronic components such as C.

[0002]

2. Description of the Related Art Conventionally, the structure of a lead frame used for manufacturing an electronic component in which a semiconductor chip portion is packaged with a synthetic resin molded body is disclosed in, for example, Japanese Patent Application Laid-Open No. 58-1983.
As described in JP-A-43552 and the like, and as shown in FIGS. 7 to 9, an island portion 2 for mounting a semiconductor chip is integrally formed on a lead frame 1 and extends toward the island portion 2. By integrally forming a plurality of lead terminals 3 and integrally forming a dam bar 4 between the respective lead terminals 3, the mold body 5 is formed.
At the time of molding, the synthetic resin in a molten state is configured to be dammed by each of the dam bars 4, while each of the dam bars 4 is formed by two-dot chain lines in FIGS. 8 and 9 after the molding of the mold body 5. As shown, the punch 6 is configured to be punched and cut by a punch 6 that moves up and down toward a receiving blade (not shown) provided on the lower surface side of the lead frame 1.

[0003]

In this conventional apparatus, each of the dam bars 4 is punched out and cut with a punch 6 after the molding of the mold body 5. When each dam bar 4 is configured so as to define the side surface of the mold body 5 in close proximity to each other, the respective dam bars 4 cannot be punched and cut by the punch 6 (the punch 6 contacts the mold body 5). Therefore, each of the dam bars 4 has to be provided at a position separated from the side surface of the mold body 5 by an appropriate dimension (S). The molten synthetic resin also enters the gaps between the side surfaces of the molded body 5 and the dam bars 4, so that the synthetic resin burrs 5 a It will inevitably occur.

Also, when each of the lead terminals 3 is configured to be fitted into a groove provided in one or both of a pair of upper and lower molds for molding the molded body 5, each of the lead terminals 3 is not required. Burrs of the synthetic resin are generated at portions protruding from the mold body 5.

Therefore, in the conventional device,. After the molding of the mold body 5, it is necessary to remove burrs of the synthetic resin generated at the portions of the lead terminals 3, and the removal of the burrs requires a great deal of trouble, so that the cost is greatly reduced. Up. . When each of the dam bars 4 is punched and cut by a punch 6 or the like, the punch 6 comes into contact with the burr of the synthetic resin. In other words, a part of the burr of the synthetic resin is removed by the punch 6. Since the punch 6 is cut at the same time, the abrasion of the punch 6 is increased, so that the durability of the punch is greatly reduced. There was a problem to say.

According to the present invention, when molding the synthetic resin molded body, the durability of a tool such as a punch is not impaired at each lead terminal portion and a side surface portion of the molded body.
An object of the present invention is to provide a lead frame in which burrs of a synthetic resin are not generated.

[0007]

Means for Solving the Problems In order to achieve this technical object, the present invention takes the following technical means.

[0008] That is, Claim 1 states that "a pair of left and right side frames, a connecting bar connecting the two side frames to each other, and a plurality of lead terminals extending from the connecting bar toward the semiconductor chip are integrated. A lead frame integrally provided between the lead terminals and continuously extending from the connection bar toward the tip of the lead terminal. And a front end of the blocking member defines a side surface of a mold body for packaging the semiconductor chip, while a shearing portion of each of the blocking portions is connected to a lead terminal. the cutting line by, and engraved so as to extend along the longitudinal side edges of the lead terminals, said damming
With the part connected integrally to the connection bar
Bendable away from the surface of the
Was . Is the thing.

[0009] In another aspect of the present invention, "a pair of left and right side frames, a connecting bar connecting the two side frames to each other, and a plurality of lead terminals extending from the connecting bar toward the semiconductor chip are integrated. In the lead frame, a damming portion extending continuously and integrally from the connection bar toward the tip of the lead terminal is provided between the lead terminals so as to be integrally connected to each lead terminal. And a front end of the blocking member defines a side surface of a mold body for packaging the semiconductor chip, and a portion of each of the blocking portions that is continuous with the lead terminal has a longitudinal side edge of the lead terminal. While the slit extending along is cut in the damming portion at the end on the mold body side while leaving a continuous portion, a cutting line by shearing is cut in the continuous portion. To, the connecting bar the dam section
From the surface of the lead frame
It was configured to be able to bend in the away direction . "Monodea
You.

[0010]

[Operation] As described above, the side wall of the synthetic resin mold portion is defined by the damming portion formed between the lead terminals, so that the synthetic resin mold is formed by a pair of dies. In molding the body, each lead terminal is simply sandwiched between the two dies together with the damming portions on both sides thereof, and the molten synthetic resin is reliably dammed by the damming portions between the lead terminals. Since it can be stopped, it is possible to surely prevent the burr of the synthetic resin from being generated on the portion where each lead terminal protrudes from the mold body and on the side surface of the mold body where each lead terminal protrudes as in the conventional case. it can.

Further, when the burr of the synthetic resin is prevented by the damming portion as described above, if it is configured as claimed in claim 1 or claim 2, it is possible to reduce the distance between the lead terminals. Since each damming portion in (1) is discontinuous with respect to each lead terminal, a portion of each damming portion separated from the mold body , that is, the damming portion
By pushing down the tip of the part with a tool,
Each of the dams is connected to a connecting bar on the lead frame.
From the surface of the lead frame
Since become Rukoto be folded away direction, without using the punch, each damming portions, it is possible to separate from the lead terminals and the mold body.

[0012]

Therefore, according to the present invention, the formation of burrs of the synthetic resin during the molding of the mold body can be reliably prevented by the damming portion, and each of the damming portions is By separating the damming portion from the lead terminal and the molded body, the damming portion can be easily bent without using a punch, so that the durability of the device can be greatly improved and the damming portion can be punched out as in the related art. chips of metal pieces after,及
Also, no burr of resin and resin is generated .

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a first embodiment. In this figure, reference numeral 10 denotes a long strip-shaped lead frame having an appropriate width. , 12 are the lead frames 10
Are connected integrally with each other by connecting bars 13 arranged at an appropriate pitch along the longitudinal direction of the connecting bar 13 at a portion between the side frames 11 and 12 and between the connecting bars 13. Is integrally formed with an island portion 15 for mounting the semiconductor chip 14.

Further, the lead frame 10 is continuously connected from the connection bar 13 to the island portion 15.
The plurality of lead terminals 16 extending integrally are integrally formed.

At a portion between the lead terminals 16, a damming portion 17 extending continuously from the connecting bar 13 toward the island portion 15 is provided integrally with each damping portion. The portion 17 defines the left and right side surfaces 18 a of the synthetic resin molded body 18, while a portion of each of the damming portions 17 continuous with the lead terminal 16 is provided with a cutting line 19 by shearing.
Are engraved so as to extend along the longitudinal side edge of the lead terminal 16.

With this configuration, when molding the synthetic resin molded body 18 , each of the molded bodies 18
The generation of burrs of the synthetic resin in the portion between the lead terminals 16 can be reliably prevented by the respective blocking members 17, while the respective blocking members 17 are separated from the respective lead terminals 16. Because each of these dams 1
7, a portion away from the mold body 18 , that is,
As shown by a two-dot chain line in FIGS. 2 and 3, the front end portion of the damming portion 17 is pressed downward by a tool such as a punch 20 so that the damming portion 17 is pressed.
Without abutment of the tool such as the punch 20 relative to mold member 18, downward as shown in FIG. 2 by the two-dot chain line,
That is, it is connected to the connection bar 13 in the lead frame 10.
In the tied state, from the surface of the lead frame 10 downward
Since it can be bent away, it can be separated from each lead terminal 16 and the molded body 18.

Next, FIGS. 4 to 6 show a second embodiment.

In the second embodiment, each of the damming portions 1
7, a slit 19 a is formed in a portion continuous with the lead terminal 16 by cutting the cutting line 19 by shearing.
Continuation of the appropriate length L ₁ to the end of the 8 side while engraving leaving (slit without parts) 19b, the continuous portion 19b
A cutting line 19c is formed by shearing.

Also in this case, each damming portion 17
Is separated from each lead terminal 16, and a portion of each damming portion 17, which is separated from the mold body 18, is formed by a punch 2 as shown by a two-dot chain line in FIGS. 5 and 6.
By pressing downward with a tool such as 1, each of the damming portions 17 can be moved downward as shown by a two-dot chain line in FIG. 5 without contacting the tool such as the punch 21 with the mold body 18. To the lead frame 10
With the connection bar 13
Can be folded away from the surface of the frame 10.
Since kill, it is possible to cut from the lead terminals 16 and the mold body 18.

[Brief description of the drawings]

FIG. 1 is a plan view of a lead frame according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged perspective view showing a main part of FIG. 1;

FIG. 4 is a plan view of a lead frame according to a second embodiment of the present invention.

FIG. 5 is an enlarged sectional view taken along line VV of FIG. 4;

FIG. 6 is an enlarged perspective view showing a main part of FIG. 4;

FIG. 7 is a plan view of a conventional lead frame.

FIG. 8 is an enlarged sectional view taken along line XI-XI of FIG. 7;

FIG. 9 is a perspective view showing a main part of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lead frame 11, 12 Side frame 13 Connecting bar 14 Semiconductor chip 15 Island part 16 Lead terminal 17 Damming part 18 Synthetic resin molded body 18a Side surface of molded body 19 Cutting line by shearing 19a Slit 19b Continuous part 19c Cutting line by shearing

Continuation of the front page (56) References JP-A-60-84850 (JP, A) JP-A-59-36955 (JP, A) JP-A-2-105448 (JP, A) JP-A-62-156844 (JP) , A) JP-A-61-253844 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 23/50 H01L 23/28

Claims (2)

(57) [Claims] 1. A lead frame integrally comprising a pair of left and right side frames, a connecting bar connecting the side frames to each other, and a plurality of lead terminals extending from the connecting bar toward the semiconductor chip. A damming portion extending continuously and integrally from the connection bar toward the tip of the lead terminal is provided between the respective lead terminals so as to be integrally connected to the respective lead terminals. While defining the side surface of the mold body for packaging the semiconductor chip at the tip of the terminal, a cutting line by shearing is formed along a longitudinal side edge of the lead terminal in a portion of each of the damming portions which is continuous with the lead terminal. The damming part is integrated with the connecting bar.
Direction away from the lead frame surface
A lead frame structure for an electronic component, characterized in that the lead frame is configured to be able to be bent . 2. A lead frame integrally comprising a pair of left and right side frames, a connecting bar connecting the side frames to each other, and a plurality of lead terminals extending from the connecting bar toward the semiconductor chip. A damming portion extending continuously and integrally from the connection bar toward the tip of the lead terminal is provided between the respective lead terminals so as to be integrally connected to the respective lead terminals. While defining the side surface of the mold body that packages the semiconductor chip at the tip of the slit, the slit extending along the longitudinal side edge of the lead terminal is provided in a portion of each of the damming portions that is continuous with the lead terminal. While the continuous portion is engraved while leaving a continuous portion at the end on the mold body side of the damming portion, a cutting line is cut in the continuous portion by shearing, and the damming portion is formed. Integrally connected to the connection bar
Bent away from the lead frame surface
A structure of a lead frame for electronic parts, wherein the lead frame is configured to be capable of being used.