JPS58219756A - Lead frame for semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the generation of burrs by blocking the outflow of resin at the time of a mold process by a method wherein dummy leads are placed side by side between each external lead, and then the top end of this dummy lead is arranged in proximity to a mold part. CONSTITUTION:A mounting part 13 whereon a semiconductor element is placed is arranged inside surrounded by the longitudinal frame 11 and the transverse frame 12 of a frame. In the periphery of the mounting part 13, many internal leads 14 are so arranged as to put the top ends in proximity to each other, and then joined to the transverse frame 12 by the external lead 15 which is the extension of the lead 14. The dummy leads 20 are arranged between the external leads 15 and joined to the transverse frame 12. The top end of the dummy lead 20 is set in parallel to and sufficiently in proximity to the mold part 17, but the clearance of 0.1mm. at least is provided. Further, supporting pieces 21 serving also to prevent the outflow of resin are arranged outside the external leads 15 at both ends, and joined to the longitudinal frame 11.

Description

[Detailed description of the invention] [Technical field of the invention]
The present invention relates to a lead frame for a semiconductor device that has a function of preventing paris from forming in a mold resin when manufacturing semiconductor devices of the package type and the SIP (single in-line package) type.

[Technical background of the invention]

Conventionally, for example, a lead frame for a DIP type package and a SIP type package, as shown in FIG. 1 and FIG. A mounting part 13 for mounting a semiconductor element that is not attached to the mounting part 13, an inner lead 14 whose tip end is adjacent to the mounting part 13, and an outer lead 15 extending from the inner lead in the direction of the horizontal frame 12 are arranged. , the extended ends of the external leads are connected to the frame 12. The dam part 16 is perpendicular to the external lead 15 and connected to the external lead and the vertical frame, so as to mechanically hold the lead and prevent mold resin from flowing out. That is, a semiconductor element is installed in the mounting part 11, and each electrode of the element is connected to each internal lead 14.
Each? After bonding and connection, a resin mold portion 17 shown by chain lines in the figure is filled with resin, and the semiconductor element is resin-molded.

[Problems with background technology]

That is, the structure is such that a space 18 is actually formed between the dam part 16 and the mold part 17 shown by the chain line.

Therefore, a thickness Δ is generated in the space 18 due to the outflow of the mold resin. Moreover, variations in the thickness of the lead frame,
Depending on factors such as the precision of the clearance of the mold, the flatness of the parting surfaces that sandwich the lead frame, the melt viscosity and curing time of the resin, and the molding pressure, the resin will develop from the space 18, and the outer lead 15 and Dam part 16. [Objective of the Invention] This invention improves the above-mentioned drawbacks, prevents the resin from flowing out during the molding process, and prevents the occurrence of flash or twisted flash. The object of the present invention is to provide a lead frame for a semiconductor device that can sufficiently reduce the square.

That is, in the lead frame according to the present invention, dummy leads are placed side by side between the external leads, and the tips of the dummy leads are placed close to the mold part to minimize the gap between the die leads and the mold part. It is something.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Figure 3 shows the configuration for a DIP type package.
A mounting part 13 on which a semiconductor element (not shown) is mounted is arranged in the center, and the mounting part 13 is connected to and supported by the vertical frame 11 by a support 19. Further, a large number of internal leads 14 are arranged around the attachment part 130 with their tips close to each other, and external leads 15 which are extensions of each internal lead 14 are arranged.
It is connected to the horizontal frame 12 by. At this time, inside the chain line,
The mold portion 17 includes the tab attachment portion 13, the support body 19, the tip of the internal lead 14 to be bonded, and a portion that encloses the semiconductor element (not shown). Furthermore, dummy leads 20 are arranged between the external leads 15, and these dummy leads 2° are connected to the horizontal frame 12, respectively. In this case, the tip of each dummy lead 20 is set parallel to and sufficiently close to the mold part 17, with a gap of at least 0.1 m11. Further, both sides of the dummy lead are set sufficiently close to the sides of each external lead 15, and the gap therebetween is, for example, 0.
05 to 0.50. Further, support pieces 21 are provided outside the external leads 16 at both ends and serve to prevent resin from flowing out, and are connected to the vertical frame 1.

In addition, the one for the SIP type package can be constructed in the same way as the DIP type mentioned above, and the fourth
The result will be as shown in the figure. In FIG. 4, the same reference numerals as in FIG. 3 indicate the same parts. According to the lead frame provided with such dummy leads 20, an unnecessary space around the mold part 170 is closed by the dummy leads 20. becomes. therefore,
In the resin molding process, the tips of the dummy leads 20 are designed to prevent the resin from flowing out, and therefore the occurrence of thickness Δ is reliably prevented. Further, since the gaps between both sides of the door 20 and the side portions of each external lead 16 are sufficiently small, resin does not flow into these portions, and therefore no thin flakes occur.

That is, when a process such as plating or solder dipping is performed after the dummy lead 20 is cut and separated at the same time as the external lead 15 of the molded or molded frame is cut, the process can be carried out smoothly without any problem because there is no parting. It is possible.

FIGS. 5 and 6 show other embodiments of the DIP type and the SIP type, respectively. A dam part 16 similar to that shown in FIG. 1 is provided, and a dummy A lead 20 is formed therein. In this way, since the dam portion 16 directly supports each lead, the structure is strong and there is no worry of distortion during the molding process. 5 and 6, the same components as those in FIGS. 3 and 4 are given the same reference numerals, and the explanation thereof will be omitted.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent mold resin from flowing out from the mold part in the resin molding process of semiconductor elements.
Since this is prevented at the tip of the -IJ- lead, the occurrence of thick flash is eliminated, and furthermore, the occurrence of thin flash that occurs on both sides of the dummy lead and each external lead can be reliably prevented.

Therefore, since unnecessary particles are not attached to the lead frame during the molding process, processes such as plating or soldering digging can be performed smoothly.

[Brief explanation of drawings]

1 and 2 are plan views showing the structure of a conventional lead frame, respectively, and FIG. 3 is a D according to an embodiment of the present invention.
The plan view showing the structure of the lead frame for the IP type cage, FIG. 4, is the same (the plan view showing the structure of the lead frame for the SIP type cage, FIG. 5, and FIG. It is a plan view showing an example. 11... Vertical frame, 12... Horizontal frame, 13... Attachment part,
14...Internal lead, 16...External lead, 16.
...Dam part, 17...Mold part, 18...Space,
19... Support body, 20... Dat-V-do, 21...
・Support piece. Applicant's representative Patent attorney Takehiko Suzue No. 1B 2 Figure 2 Figure 3vA Figure 4

Claims (1)

[Claims] a mounting portion for mounting a semiconductor device; a plurality of internal leads that extend close to the periphery of the mounting portion of the semiconductor device and selectively connect to the lead-out terminal portion of the semiconductor device; and a plurality of internal leads extending from the internal leads respectively. A plurality of external leads are formed, and a plurality of dummy leads are arranged between each of the external leads, and the tip of each of the dummy leads is set close to the periphery of the resin molded part corresponding to the internal lead part. A lead frame for a semiconductor device, characterized in that: