JPH0964241A - Resin molded electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to remove unwanted resin part from a lead frame easily and make a good outward shape, by forming a recessed part in a lead frame at a position overlapped with a resin injecting part to a cavity. SOLUTION: A lead frame 1 has a recessed part 20 just at a position overlapped with a gate 14 when the lead frame 1 is mounted on a resin mold. The position is near to an adjoining part between an exterior resin 9 formed by a cavity 17 and a gate resin part 14a of the gate 14. The resin just after resin molding is contracted by this recessed part 20 as the resin is cured in the mold. Since the resin has a narrow neck part at the recessed part 20, the resin is contracted toward the side of the exterior resin 9 with large volume, and a gap 21 is formed at an inside wall of the recessed part 20 on the gate side. Then, even when the adhesiveness between the lead frame 1 and the resin is good and stable, a half-assembled body of electronic parts is taken out from a mold easily. At the same time, unwanted resin is removed easily from the lead frame 1 only by bending the lead frame 1 when the resin is broken at the recessed part 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field relating to an electronic component capable of easily separating an unnecessary portion of the resin from the resin molded product after the resin molding in the process of manufacturing the resin molded electronic component.

[0002]

2. Description of the Related Art Generally, a resin mold type electronic component is manufactured by using a lead frame and a transfer resin molding machine. An example of the intermediate structure of the resin mold type electronic component will be described with reference to FIG. In the figure, reference numeral 1 denotes a lead frame, which supports an island 4 in the center of a rectangular frame 2 via suspension pins 3 extending from the inner circumference of the frame 2 and extends inward from the inner circumference of the frame 2. A large number of leads 5 are extended in parallel, the middle portion of each lead 5 is connected and integrated by a tie bar 6, and the free end of each lead 5 is connected to the island 4.
It is located near. Reference numeral 7 denotes an electronic component body mounted on the island 4, for example, a semiconductor pellet, 8 denotes an electrode (not shown) formed on the upper surface of the electronic component body 7, and each lead 5.
Wires 9 and 9 are electrically connected to each other, and a resin 9 covers a main part on the lead frame 1 including the electronic component body 7. FIG. 4 shows a metal mold portion of a resin molding device for coating a main portion on the lead frame 1 with a resin. In the figure, 1
Reference numeral 0 is a lower die for supporting the lead frame 1, and a cull portion 11 is formed in the central portion, and a plurality of runners 12 are extended from the cull portion 11 to the die peripheral edge, although not shown.
A plurality of lower cavities 13 are formed correspondingly to the portions of the lead frame 1 to be covered with resin, and the runner 12 and each lower cavity 13 are communicated with each other through a gate 14. 1
5 is an upper mold, and a pot 16 is provided in a portion facing the cull portion 11.
And an upper cavity 17 is formed in a portion facing the lower cavity 13. 18 is a resin tablet which is put in the pot 16 while the lead frame 1 is sandwiched between the respective molds 10 and 15, and 19 is inserted into the pot 16 to pressurize and fluidize the resin tablet so that the runner 12 and the gate 14 are formed. Shown is a plunger which is then injected into the cavities 13,17. Although air vents are formed on the abutting surfaces of the cavities 13 and 17 for expelling the compressed air injected into the cavities, they are not shown. In addition, each mold 10, 15
Are supported by a fixed platen and a movable plate, respectively, but not shown. Since the gate resin, the runner resin, and the cull resin are integrally connected to the exterior resin 9 that covers the electronic component body 7 in the lead frame 1 that is resin-coated by this device, the gate resin is better than the exterior resin. Separated to remove unnecessary resin. In this way, the electronic component intermediate structure in which the main portion of the lead frame 1 is coated with resin is cut and removed from unnecessary portions of the lead frame 1 exposed from the resin 9 such as the frame 2 and the tie bar 6 and separated into individual electronic components. It Here, when separating the unnecessary resin including the gate resin from the exterior resin 9, if the cutting position of the gate resin is improper and a large amount remains on the exterior resin 9 side, not only the appearance of the electronic component becomes poor, but also When the electronic component is mounted on a printed wiring board or the like, the protruding residual resin piece may interfere with the mounting of other electronic components, so that unnecessary resin does not remain. Therefore, as shown in FIG. 5, the wall surfaces of the cavities 13 and 17 to which the gate 14 is connected are projected inward, and the recess 9a is formed in the portion of the exterior resin 9 to which the gate resin is connected. Even if is left, it does not protrude from the outer surface of the exterior resin 9. (For example, see Jitsukai Sho 57-78644)

[0003]

However, recently, in order to improve the moisture resistance and to cope with the increase in the amount of heat generated due to high integration, a resin having good adhesion to the lead frame has been adopted. In the case where the gate portion is polymerized with a part of the lead frame 1 to cover the resin, it is difficult to separate the lead frame and the resin, and the cutting position of the gate portion resin is not constant, and the recessed portion 9 is formed in the exterior resin. However, the residual resin pieces may protrude from the exterior resin, and improvement has been desired.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed for the purpose of solving the above-mentioned problems, and an island is disposed in a frame via a hanging pin, and one end is disposed in the vicinity of the island and a middle portion is a tie bar. The electronic component body mounted on the island of the lead frame composed of a large number of leads connected to each other is electrically connected to the lead, and the main part including the electronic component body is surrounded by the mold cavity. In a resin mold type electronic component formed by injecting a resin into a cavity from a portion overlapping with a part of a lead frame to cover the electronic component body and cutting and removing an unnecessary portion of the lead frame exposed from the resin, Provided is a resin-molded electronic component, characterized in that a recess is formed on a lead frame that overlaps with a resin injection portion into the cavity.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
Let's start with. In the figure, the same reference numerals as those in FIG. 3 denote the same items, and a duplicate description will be omitted. The figure shows an intermediate structure of an electronic component in which a major portion of the lead frame 1 is covered with an exterior resin 9, and 20 is formed in a portion which overlaps with the gate 14 when the lead frame 1 is placed on a resin mold. In the recessed portion, the exterior resin 9 and the gate 14 by the cavity 17 are formed.
It is formed at a portion adjacent to the gate portion resin 14a. Due to the recess 20, the resin immediately after the resin molding shrinks in the mold as the curing progresses, but the resin is constricted at the position of the recess 20, and the resin shrinks to the side of the exterior resin 9 having a large volume, and the gate 14 side recess A gap 21 is formed on the inner wall. Therefore, even if the adhesion between the resin and the lead frame 1 is good, the intermediate structure of the electronic component taken out of the mold is
If the resin is easily broken at the position and the resin is broken at the position of the recess 20, the unnecessary resin can be easily separated from the lead frame 1 by bending the lead frame 1. Thus, after removing the unnecessary resin, the unnecessary portion of the lead frame 1 exposed from the exterior resin 9 can be removed to obtain an electronic component having a good appearance.

[0006]

FIG. 2 shows an embodiment of the present invention. In the figure,
3 that are the same as those in FIG. 3 indicate the same things, and duplicate explanations are omitted. Only the concave portion 22 is different from the electronic component (intermediate structure) shown in FIG. 1 in the drawing. An eaves portion 22a is formed on the inner wall of the recess 22 on the gate 14 side. The eaves portion 22a can be easily formed by pressing the eaves portion to be formed after forming the concave portion 22. The eaves portion 22a becomes an obstacle to the flow of the resin when the resin is injected, and air remains inside the eaves portion 22a, and this air locally blocks the adhesion of the resin to the concave portions 22 and promotes the peeling at the time of resin contraction. . Therefore, it is possible to reliably separate the gate resin even if a resin having higher adhesion to the lead frame is used. In the electronic component (intermediate structure) of FIGS. 1 and 2, the resin injection portion (gate portion resin) 1 in the recesses 20 and 22.
By setting the resin thickness of 4a smaller than the depth of the recesses 20 and 22, the flexural deformation of the lead frame 1 can be prevented from occurring in the recess 2
It is possible to concentrate on the constricted portion of the resin within 0 and 22 and to reliably cut the resin. The present invention is not limited to the above-described embodiments. For example, the electronic component body 7 is not limited to semiconductor pellets, but passive electronic components such as resistors and capacitors, semiconductor pellets, and various electronic components are integrally incorporated. It can be applied to general electronic components such as a hybrid integrated semiconductor device.

[0007]

As described above, according to the present invention, it is possible to realize an electronic component which can easily remove the unnecessary resin connected to the lead frame after the resin molding, has a good appearance and does not hinder mounting.

[Brief description of drawings]

FIG. 1 is a side sectional view of an essential part of an electronic component (intermediate structure) showing an embodiment of the present invention.

FIG. 2 is an electronic component (intermediate structure) showing an embodiment of the present invention.
Side sectional view of main part of

FIG. 3 is a partial cross-sectional perspective view showing an example of a resin mold type electronic component intermediate structure.

FIG. 4 is a side sectional view of a main part of a resin molding device used for manufacturing the device shown in FIG.

FIG. 5 is a perspective view showing another example of the resin mold type electronic component.

[Explanation of symbols]

 1 Lead Frame 2 Frame 3 Hanging Pin 4 Island 5 Lead 6 Tie Bar 7 Electronic Component Body 9 Exterior Resin 13 Cavity 14a Resin Injection Port (Gate Resin) 17 Cavity 20 Recess 22 Recess 22a Eaves

Claims (3)

[Claims] 1. A lead frame island, which comprises an island arranged in a frame via suspension pins, and a large number of leads, one end of which is arranged in the vicinity of the island and the middle portion of which is connected by tie bars. The electronic component body and the lead that are placed are electrically connected, the main part including the electronic component body is surrounded by the mold cavity, and resin is injected into the cavity from the portion that overlaps with a part of the lead frame In a resin-molded electronic component that is formed by covering the body of the component and cutting and removing unnecessary parts of the lead frame exposed from the resin, a recess is formed on the lead frame that overlaps with the resin injection part into the cavity. Characteristic resin mold type electronic parts. 2. The resin mold type electronic component according to claim 1, wherein an eaves portion is formed on an inner wall of the resin inflow side of a recess formed on the lead frame which overlaps with the resin injection portion into the cavity. 3. The resin-molded electronic component according to claim 1, wherein the resin thickness of the resin injection portion in the recess is set smaller than the depth of the recess.