JPH01115145A - Resin sealed type integrated circuit - Google Patents

Abstract

PURPOSE:To prevent the generation of radio disturbance by a method wherein a metal film is formed on the surface of an integrated circuit package, and this metal film is earthed. CONSTITUTION:The metal thin film 11 used to shield electromagnetic waves is formed on the surface 5a which is in parallel with the surface 1a of the integrated circuit chip 1 in a package 5. As the direction of the high frequency electric line of force emitted from the surface 1a of the integrated circuit chip 1 is in the direction orthogonally intersecting with the surface 1a of the integrated circuit chip 1, the metal thin film 11 is formed in parallel with the surface 1a of the integrated circuit chip 1, and the high frequency waves emitted from the integrated circuit chip 1 are completely shielded by earthing through the intermediary of an earthing lead. As a result, the radio disturbance on the peripheral machines can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to high-speed operation monolithic ICs such as microcomputers and CPUs, and particularly to resin packages thereof.

[Conventional technology]

Conventionally, packages for 8-bit, 16-bit, and 32-bit CPUs and chip microcomputers have mainly been of the resin-sealed type as shown in FIGS. 3 and 4.

FIG. 3 is a perspective view showing a resin-sealed integrated circuit with a part of the package cut away, and FIG. 4 is a side view thereof. In these figures, 1 is an integrated circuit chip, 2 is a metal lead, and 3 is an integrated circuit chip.
Reference numeral 4 indicates a thin gold wire for connecting the surface electrode (not shown) of the integrated circuit chip 10 and the metal lead 2, and 4 indicates the integrated circuit chip 1. Metal lead 2. This is an epoxy resin that seals the thin gold wire 3 and forms the package 5.

The operating frequency of integrated circuits such as CPUs configured in this way has increased to 10
Devices that operate at high speeds of MHz to 20 MHz have been put into practical use.

[Problem that the invention seeks to solve]

However, as integrated circuits operate at higher speeds, high frequencies are generated from the surface of integrated circuit chips, and resin packages do not have the ability to shield electromagnetic waves, causing electromagnetic interference in peripheral devices.

[Means for solving problems]

The resin-sealed integrated circuit according to the present invention has a metal film formed on the surface of an integrated circuit pancake, and this metal film is grounded.

[Effect]

The electromagnetic waves emitted by the integrated circuit chip are shielded by the metal film.

〔Example〕

Hereinafter, its configuration and the like will be explained in detail with reference to embodiments shown in the drawings. FIG. 1 is a perspective view showing a resin-sealed integrated circuit on which a metal thin film according to the present invention is formed, with a part of the package cut away. In the figure, the same or equivalent members as those explained in the conventional example are given the same reference numerals, and detailed explanations will be omitted.

In the figure, 11 is a metal thin film for shielding electromagnetic waves, and this metal thin film 11 is formed by sputtering on a surface 5a parallel to the surface 1a of the integrated circuit chip 1 in the package 5, and b is formed by electroless plating. There is. 12
is a gold R-type film for connecting the metal thin film 11 and the grounding lead 13, and is formed on the side surface of the package 5 by sputtering or electroless plating like the metal thin film 11. That is, in order to form the metal thin film 11 on the package 50 surface 5, the metal leads 2 and the side surfaces of the package 5 are covered with a jig (not shown) after resin sealing, and sputtering or electroless plating is performed. It is done.

Therefore, since the direction of the high frequency electric lines of force of several tens of MHz to several hundreds of MHz emitted from the surface 1a of the integrated circuit chip 1 is perpendicular to the surface 1a of the integrated circuit chip 1, the metal thin film 11 is Integrated circuit chip 10 surface 1m
By forming the integrated circuit chip 1 in parallel with the integrated circuit chip 1 and grounding it through a grounding lead, the high frequency waves emitted from the integrated circuit chip 1 can be completely shielded.

Further, in this embodiment, the metal thin film 11 is grounded via the metal thin film 12 and the grounding lead 13, but the substrate on which this integrated circuit is mounted ( The same effect can be obtained by electrically connecting it to the ground (not shown). Furthermore, the shielding effect can be improved by forming the metal thin film 11 on the back surface of the package 5 and grounding it.

Although this embodiment has been described with reference to a dual in-line type integrated circuit in which metal leads 2 are arranged on all sides of the integrated circuit, the resin-sealed integrated circuit according to the present invention is not subject to such limitations. For example, it can be applied to an integrated circuit as shown in FIG. 2 without being limited. Figure 2 (
&), (b), and (C) are a front view, a side view, and a bottom view showing a single in-line type resin-sealed integrated circuit. In this figure, members that are the same as or equivalent to those shown in FIG. 1 are denoted by the same reference numerals, and detailed explanations are omitted here.

Furthermore, a package with a structure in which a metal cap is placed around the integrated circuit and the metal cap is grounded has the highest electromagnetic shielding effect, but the manufacturing cost of the package is high and assembly efficiency is poor. In contrast, in the resin-sealed integrated circuit according to the present invention, since the metal thin film is directly formed on the resin-sealed package, the manufacturing cost can be kept low, and it can be automated and easily mass-produced.

〔Effect of the invention〕

As explained above, according to the present invention, a metal film is formed on the surface of an integrated circuit package and this metal film is grounded.
The electromagnetic waves emitted by the integrated circuit chip are shielded by the metal film, so there is no interference with peripheral devices.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a resin-sealed integrated circuit according to the present invention with a part of the package cut away, Fig. 2 is a diagram showing another embodiment, and Fig. 3 is a conventional resin-sealed integrated circuit. FIG. 4 is a perspective view showing the circuit with a part of the back cage cut away, and FIG. 4 is a side view thereof. 50. fist, package, 110.11. Metal thin film.

Claims (1)

[Claims] A resin-sealed integrated circuit characterized by forming a metal film on the surface of an integrated circuit package and grounding the metal film.