JPH0425055A - Lead frame for ic - Google Patents

Abstract

PURPOSE:To prepare a lead frame for IC without necessitating the work of removing resin molded in the gate section from the lead frame by forming the contact surface between the place facing the gate section of a resin molding die and the resin molded in the gate section into an irregular shape. CONSTITUTION:In a mold product taken out from a resin molding die after resin molding is completed, on a lead frame 1 connected to a resin-sealed IC 2 molded resin 3 is formed at the gate section thereof and molded resin 4 at the runner section thereof, and when a triangular groove is prepared on the contact surface between the lead frame 1 and the resin 3 molded in the gate section, the adhesion between the lead frame 1 and the resin molded at the gate section is degraded, thereby being able to make the resin molded on the gate section hard to be resident at the surface of lead frame 1. As a result, the work of removing the resin molded at the gate section from the lead frame is unnecessitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC lead frame, and more particularly to an IC lead frame used in the assembly and manufacture of a resin-sealed IC device using a transfer molding method.

[Conventional technology]

A conventional IC lead frame (hereinafter referred to as lead frame) has a smooth surface on its entire surface including a portion corresponding to a gate portion of a resin molding die.

[Problem to be solved by the invention]

In the resin encapsulation process for ICs using the transfer molding method, the molded product is removed from the resin molding mold after resin molding, and the resin molded in the pot, runner, and gate parts of the resin molding mold and the resin-sealed IC are separated. However, at this time, it is desirable that the IC is broken and separated from the boundary between the resin-sealed IC and the resin molded in the gate portion.

The resin molded in the goo parts 1 to 1 has a structure in which it is in contact with the lead frame surface, but when a conventional lead frame is used, as shown in Fig. 4 (a) and (b), the lead Since the surface of the frame 1 is smooth, the adhesive force between the resin 3 molded in the goo 1~ part and the lead frame 1 is high, so that the border between the resin 3 molded in the gate part and the resin-sealed IC 2 is strong. The lead frame 1 does not break, but breaks from the boundary between the resin 3 molded in the gate part and the resin molded in the runner part, and the resin 3 molded in the gate part remains on the lead frame 1.

If the resin 3 molded on the goo parts 1 to 1 remains on the lead frame 1''2, a problem will occur in which additional work will be required to remove the resin 3 molded on the goo parts from the lead frame 1. There's a problem.

An object of the present invention is to provide an IC lead frame that does not require the work of removing the resin molded in the goo parts 1 to 1 from the lead frame.

[Means to solve the problem]

According to the present invention, in an IC lead frame used in a resin-sealed IC device, irregularities are provided on the contact surface with the resin at a portion corresponding to a portion of the goo 1 of the resin molding die.

〔Example〕

Figures 1 (a) and (b) are a partial plan view and a partial sectional view of the first embodiment of the present invention, and Figures 2 (a) and (b) are molded products taken out from the resin molding die after resin molding. FIG. 2 is a partial plan view and a partial sectional view of FIG.

In the first embodiment, as shown in FIG. 1 (a>, (b)),
A triangular groove 5 is formed in a horizontally elongated manner on the contact surface with the resin corresponding to the goo parts 1 to 1 of the resin molding die of the lead frame 1, thereby providing unevenness.

The molded product taken out from the resin molding mold after resin molding is a resin-sealed IC, as shown in FIGS. 2(a) and (b).
2 is connected to the lead frame 1'' 2. Resin 3 molded on the runner part and resin 4 molded on the runner part are formed, but the resin-sealed IC 2 and the gate part are formed. It is desirable that the rupture occurs at the boundary of the resin 3.

By providing a triangular groove 5 on the contact surface with the resin 3 molded on the gate part of the lead frame]
- and the adhesive force between the resin 3 molded on the gate portion decreases. This makes it difficult for the resin 3 molded on the gate portion to remain on the surface of the lead frame.

1 - Regarding the adhesive strength between an epoxy resin for base molding and a metal such as a lead frame, the adhesive strength in the mutual peeling direction is relatively lower when the metal surface is uneven than when it is smooth. It is something. This development is considered to be related to molding shrinkage of the resin.

FIGS. 3(a) and 3(b) are a partial plan view and a partial sectional view of a second embodiment of the present invention.

The second embodiment, as shown in FIGS. 3(a) and (b),
This is an example in which a hemispherical depression 6 is formed on the contact surface with the resin 3 molded on the gate portion of the lead frame to provide unevenness.

This embodiment also provides the same effects as the first embodiment.

〔Effect of the invention〕

As explained above, the present invention provides unevenness on the surface of the lead frame at a location corresponding to the goo I part, thereby reducing the adhesive force between the resin molded in the goo 1~ part and the lead frame, and It is possible to prevent molded resin from remaining on the lead frame.

This has the effect of making it unnecessary to remove the resin molded on the cage part from the gate frame.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are a partial plan view and a partial sectional view of the first embodiment of the present invention, and Figures 2 (a) and (b) are molded products taken out from the resin molding die after resin molding. FIGS. 3(a) and 3(b) are a partial plan view and a partial sectional view of the second embodiment of the present invention, and FIGS. 4(a) and (b).
) are a partial plan view and a partial sectional view showing an example of a state in which resin molded in a gate portion remains adhered to a conventional lead frame. 1...Lead frame, 2...Resin-sealed IC
l3... Resin molded on the gate portion, 4... Resin molded on the runner portion, 5... Triangular groove, 6... Hemispherical depression.

Claims (1)

[Claims] An IC lead frame for use in a resin-sealed IC device, characterized in that a contact surface with a resin at a portion corresponding to a gate portion of a resin molding mold is provided with irregularities.