JPS63302545A - Resin sealed type semiconductor lead frame - Google Patents

Abstract

PURPOSE:To obtain a resin sealed type semiconductor device, punch lifetime of which can be lengthened while preventing the cracking of packaging and on which resin chips do not adhere, by forming an auxiliary lead capable of cutting a dam lead section without being brought into contact with a resin intruding among outer leads in a postprocess in which the dam lead section is cut. CONSTITUTION:Dam leads 7 minimally stopping the intrusion of a resin among outer leads in a resin sealing process are shaped to a lead frame 5 used for a resin sealed type semiconductor device, Auxiliary leads 8 capable of cutting said dam lead 7 sections without being brought into contact with a resin 4 penetrating among the outer leads 2 in a postprocess in which said dam lead 7 sections are cut are formed. The auxiliary lead 8 sections are pressed by protruding sections 9 in tie-bar cutting punches 6 first in a tie-bar cutting process, and the connection of the dam leads 7 as minimum connecting sections and the outer leads 2 are cut. The connecting sections of the auxiliary leads 8 and the outer leads 2 are cut by cutting sections 10 for the tie-bar cutting punches 6, and lastly unnecessary dam leads 7 and auxiliary leads 8 are cut and removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lead frame used in a resin-sealed semiconductor device.

[Conventional technology]

FIG. 3 is a plan view showing a conventional resin-sealed semiconductor lead frame and a tie bar cut punch in a tie bar cutting process, and 4th rIA is a sectional view.

In the figure, 1 is a package in which a semiconductor element is sealed with resin, 2 is an outer lead wired to the semiconductor element and provided outside the package 1, and 3 is this outer lead 2.
A tie bar 4 is surrounded by the outer lead 2 and the tie bar 3, and there is a gap between the leads which occurs in the resin sealing process, 5 is a lead frame, and 6 is a tie bar cut punch for cutting the tie bar 3.

Next, the effect will be explained.

The tie bar 3 connecting the outer leads 2 has the effect of stopping inter-lead burrs 4 generated in the vI4e sealing process and increasing the strength of the lead frame 5 during the manufacturing and transporting process of resin-sealed semiconductor devices. Further, in order to minimize the occurrence of inter-lead burrs 4, it is necessary to position the tie bars 3 close to the package 1.

The tie bar 3 configured for the above purpose is cut by a quiver cut punch 6 in a tie bar cutting process. The tie bar cut punch 6 is provided with a clearance so as not to damage the package 1 or the outer leads 2, and to minimize the remaining amount of the gap 4 between the leads.
The inter-lead burr 4 made of I and the tie bar 3 are cut and removed at the same time. In addition, the tie bar 3 is moved away from the package 1, and a space is provided in the gap 4 between the leads for a punch 6 to be inserted in order to remove the gap 4 between the leads.
In some cases, the inter-lead burr 4 is cut and removed before the step i.

[Problems to be Solved by the Invention] Since the conventional resin-sealed semiconductor lead frame is configured as described above, it is necessary to cut off the inter-lead burrs 4 generated during the resin-sealing process. Resin cutting debris scatters and adheres to the product and mold.

Moreover, cracks occur in the package 1 when cutting the burr 4 between the blades. Furthermore, there were other problems such as a short life span of the punch for cutting the burrs 4 between the leads.

This invention has been made to solve the above-mentioned problems, and it is possible to extend the life of punches in Vt41111 sealed semiconductor manufacturing equipment, and to produce resin without package cracks and without resin chips attached. The object is to obtain a semiconductor lead frame that can provide a sealed semiconductor device.

[Means for solving problems]

The resin-sealed semiconductor lead frame according to the present invention has a dam lead portion close to the package and is provided with an auxiliary lead connected to the dam lead portion. Furthermore, the dam lead part and the auxiliary lead part are each connected to the outer lead part, so that the number of connections between the dam lead and one outer lead is minimized in each connection part.

[Effect]

The IT-sealed semiconductor lead frame in this invention includes:
By placing the dam lead close to the package, it is possible to reduce the spall between the leads that occurs during the resin sealing process, and also connect the dam lead to the auxiliary lead, as well as connect the dam lead to the dam lead.
By minimizing the connection of the outer lead, the dam lead and outer lead can be easily disconnected by applying pressure to the auxiliary lead.

〔Example〕

The invention will be explained below with reference to the drawings.

FIG. 1 is a plan view showing a lead frame and a tie bar cut punch in a tie bar cutting process according to an embodiment of the present invention, and FIG. 2 is a sectional view.

In the figure, 1 indicates the semiconductor element t! l4II! A sealed package, 2 is an outer lead wired to the semiconductor element and provided outside the package 1, 4 is a gap between the leads, 5 is a lead frame, 6 is a tie bar cut punch, 7 is a dam lead, and 8 is the dam lead. 7 is an auxiliary lead connected to the outer lead 2, 9 is a protrusion forming the tie bar cut punch 6, and 10 is a cutting portion.

Next, the effect will be explained.

First, since the dam leads 7 are located close to the package 1, the occurrence of gaps 4 between the leads during the resin sealing process is extremely reduced.

Further, the dam lead 7 is connected to an auxiliary lead 8 and an outer lead 2, and the auxiliary lead 8 is also connected to the outer lead 2. In this connection, the connection portion between the dam lead 7 and the outer lead 2 is minimized. In this state, when the protrusions 9 and cutting parts 10 provided on the tie bar cut punch 6 in the tie bar cutting process shown in FIG. 2 are arranged and processed in the layout shown in FIG. 1, first the protrusion of the tie bar cut punch 6 is The auxiliary lead 8 section is pressurized by the section 9, and the connection between the dam lead 7 and the outer lead 2, which is the minimum connection section, is severed.

Next, the connecting portion between the auxiliary lead 8 and the seventh lead 2 is cut by the cutting portion 10 of the tie bar cut punch 6. Finally, unnecessary dam leads 7 and auxiliary leads 8 are cut and removed. Further, in this case, the tie bar cut punch 6 and the inter-lead burr 4 do not come into contact at all.

In addition, in the above embodiment, the tie bar cut punch 6 was provided with the protrusion 9 and the cutting part 10, but the tie bar cut punch 6
The dam lead 7 and the outer lead 2 may be cut first, and the auxiliary lead 8 and the outer lead 2 may be cut later. Alternatively, the tie bar cut punch 6 may have an inclined shape.

〔Effect of the invention〕

As described above, according to the present invention, by bringing the dam lead close to the package and providing the auxiliary lead connected to the dam lead, the dam lead and the auxiliary lead can be cut without the tie bar cut punch coming into contact with the gap between the leads. As a semiconductor device, it can be used as a semiconductor device without the adhesion of Paris dust.
A high quality product with no package cracks can be obtained. Furthermore, wear of the tie bar cut punch can be prevented, resulting in a long service life.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a resin-sealed semiconductor lead frame and a tie bar cut punch in a tie bar cutting process according to an embodiment of the present invention, and FIG. 2 is a sectional view thereof. FIG. 3 is a plan view showing a tie bar cut punch in a conventional resin-sealed semiconductor lead frame and tie bar cutting process, and FIG. 4 is a sectional view thereof. 1. Package, 2. Outer lead, 3. Tie bar, 4. Paris between leads, 5. Lead frame, 6. Tie bar cut punch, 7. Dam lead, 8
- Auxiliary lead, 9... Protrusion, 10 - Cutting part. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (3)

[Claims] (1) A lead frame used in a resin-sealed semiconductor device has a dam lead that minimizes the intrusion of resin between the outer leads during the resin-sealing process;
A resin-sealed semiconductor lead frame characterized in that an auxiliary lead is provided that can be cut without contacting resin that has entered between the outer leads in a post-process of cutting the dam lead portion. (2) The resin-sealed semiconductor lead frame according to claim 1, wherein the dam lead and the auxiliary lead are connected to the outer lead, and the dam lead and the auxiliary lead are also connected. (3) The resin-sealed semiconductor lead frame according to claim 1, wherein the connection between the dam lead and the outer lead is minimized in each connection portion of the dam lead, the auxiliary lead, and the outer lead.