JPH01241848A - Ic device - Google Patents

Abstract

PURPOSE:To attenuate radiation noise from an IC chip by a shielding effect, by sealing the chip with a package formed of a magnetic material and by making it operate as an inductor against conduction noise transferred through the leads of the IC to attenuate the noise. CONSTITUTION:A package 20 formed fo an upper package section 21 and a lower package section 22 is formed of a magnetic material made of ferrite or the like. Since the lead pins 13 of an IC chip 12 are surrounded with ferrite, they operate as inductors against a high frequency signal and a conduction noise. Since the IC 12 of an IC chip 11 is enclosed wholly with a magnetic material, its radiation noise is shielded. Thus, the IC package is composed of ferrite thereby to remove or suppress all the conduction noise, radiation noise by the mounted IC package itself.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to integrated circuits (hereinafter referred to as integrated circuits).
It is called r-ault-IC-. ) The present invention relates to an IC device which is made of a magnetic material to reduce electromagnetic interference noise to the chip and which takes measures against electromagnetic interference.

2. Description of the Related Art In general, IC devices are often used, which are constructed by integrating analog, digital, or a combination of both volatile electrical circuits mainly using materials such as semiconductors. This IC device is
Various circuits are formed on a substrate (wafer) and then cut into small pieces to form IC chips. The function of the IC device itself is this 121\.

This can be achieved with a C chip, but for practical convenience, this I
An IC device is produced by packaging a C chip in a package made of plastic, ceramic, or the like.

This IC device can be divided into several types depending on its intended use9 function.

For example, a so-called DIP (dual-In-11n) has leads arranged in two rows on both sides of the package.
apackage) or one lead on one side of the package.
The so-called S I P (single
-In -Package) and various other products have been put into practical use.

At present, packages in which the above-mentioned IC chips and leads are mounted are made of materials such as plastic or ceramic. By the way, ordinary plastics, ceramics, etc. do not have the effect of preventing electromagnetic interference waves such as noise generated from electromagnetic equipment.

This electromagnetic interference consists of conduction noise radiated from the lead pins of the IC, noise radiated from the 10 chips, and the like. The concept of radiation refers to the fact that noise and the like are radiated from one point around the Ic lead pin or chip. Therefore, the electromagnetic interference waves emitted from IC chips, leads, etc. are prevented and removed using ferrite beads and the like.

FIG. 6 is an equivalent circuit diagram showing an example of conventional electromagnetic interference prevention measures. In the figure, 1 is an IC device, 2 is an I
The IC chip 3 constituting the C device 1 is a ferrite bead provided within the IC device 1 and between the IC chip 2 and the leads. The ferrite beads 3 provide impedance against high frequency noise and prevent electromagnetic interference waves radiated from the lead pins.

In addition to using the above-mentioned ferrite beads, a low-pass filter (LPF) 5 made of a CR circuit is inserted between the IC chip 2 and the output terminal of the IC device 1 as shown in FIG. There are also ways to attenuate it.

Furthermore, as shown in FIG. 8, the radiation noise due to the radiation of the electromagnetic interference waves described above is attenuated by shielding the entire IC with a sheet metal or the like. In FIG. 8, a shield case 6 made of sheet metal or the like is viewed from the upper side of the IC device 1 on which an IC chip (not shown) is mounted.
This shield case 6 is grounded by covering it. Note that the reference numeral 7 is a lead pin protruding from both sides of the pan cage of the IC device 1, and the reference numeral 8 is a plurality of fixing claws provided at the lower end of the shield case 6.

Problems to be Solved by the Invention However, according to conventional IC devices, electromagnetic interference cannot be suppressed or eliminated simply by connecting lead pins to IC chips and mounting these IC chips in a package made of ordinary plastic or ceramic. The problem was that it could not be done.

In addition, in order to suppress conduction noise emitted from each pin of the IC chip, it is necessary to attach ferrite beads or the like to the signal line from the IC chip, or to install an LPF consisting of a CR circuit, etc. In order to suppress the radiated noise from the ICC10 cage, the entire ICC10 cage must be shielded5/7, and there is also the problem that countermeasure components other than the IC package are required.

The present invention is intended to solve such conventional problems, and aims to reduce electromagnetic interference waves generated from the IC chip itself or lead pins without making any changes to the circuit of the IC chip.

Means for Solving the Problems In order to achieve the above object, the present invention is such that the IC package itself is made of a magnetic material such as ferrite, and the IC chip is mounted within this magnetic IC package.

Function: By configuring the present invention as described above, the IC package made of magnetic material acts as an inductance component against conducted noise, and the package itself acts as a shielding material against radiated noise. .

Therefore, both conduction noise and radiation noise can be attenuated, and electromagnetic interference waves can be reduced or eliminated.

61\7 Embodiments Hereinafter, embodiments of the present invention will be described using FIGS. 1 to 5. FIG. 1 is an exploded perspective view showing one embodiment of the present invention. In the figure, an IC device 10 is shown with an IC chip 12 sandwiched between an upper package part 21 and a lower package part 22 by adhesive or the like. It is integrated. The electrodes of this IC chip 12 are connected to lead pins 13 via bonding wires 14.

In FIG. 2, the lower surface 21a of the upper package part 21
A recess 23 capable of accommodating the IC chip 12 and the like, and a plurality of parallel grooves 24 formed from the recess 23 in correspondence with the width and number of the lead pins 13 are formed on the side. The peripheral edge of the upper surface 22a of the lower package portion 22 forms an adhesive-applied surface 22a corresponding to the IC chip 12 and the like. The peripheral edge of the lower surface 21a of the upper package part 21 and the upper surface 22a (peripheral edge) of the lower package part 22 are joint surfaces that can be brought into close contact with each other. The package part 20 extending from the lower package part 22 to the structure 7 is made of a magnetic material such as ferrite.

Based on the above configuration, the assembly operation of the IC package will be explained. The electrodes of the IC chip 12 are bonded to the lead pins 13 whose tips have not yet been cut using wires 14 . By placing the IC chip 12 and the like on the lower package part 22 whose upper surface 22a is coated with an adhesive (not shown), and by covering the recessed part 23 with the upper package part 21 coated with adhesive and pressing it from above and below. IC
The device 1o is integrated and completed. At this time, the joint surfaces 21a and 22a of the upper and lower pancage parts 21, 22 are processed to be flat in advance, so that they come into surface contact with each other. The IC device 10 bonded in this way is assembled into a completed IC package 10 by bending the lead pins 13 downward in a predetermined process and cutting them to the same length. becomes. At this time, the lead pins 13 of the Ic chip 11 are surrounded by the package portion 2° made of ferrite, as shown in FIG.

Next, the electrical operation of this embodiment will be explained using FIG. 5. As described above, since the lead pins 13 of the IC chip 12 are surrounded by ferrite, they act as an inductor against high frequency signals and conduction noise. Furthermore, since the IC 12 of the IC chip 11 is entirely surrounded by a magnetic material, radiation noise is shielded.

By configuring the IC pancake with ferrite in this way, both conduction noise and radiation noise can be removed or suppressed by the mounted IC package itself.

Effects of the Invention As is clear from the above examples, the present invention has the following effects.

By making the IC package from magnetic material, the IC leads and chip are surrounded by magnetic material. Therefore, (1) To act as an inductor and attenuate the conduction noise transmitted through the IC leads9-・-/
゛ can be done.

(2) Radiation noise from the Ic chip can be attenuated by shielding.

In this way, electromagnetic interference waves can be reduced by using a magnetic material as the material of the IC package without changing the circuit of the IC chip.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing one embodiment of the electromagnetic interference countermeasure 1c device according to the present invention, FIG. 2 is a partially exploded perspective view showing the pan cage part of FIG. 1, and FIG. FIG. 4 is a plan view showing the shielded state of the Ic device shown in FIG. 4, FIG. 5 is an equivalent circuit diagram illustrating the electrical operation of the present invention, and FIG. Fig. 7 is an equivalent circuit diagram showing a conventional IC device using beads, Fig. 7 is an equivalent circuit diagram showing a conventional IC device using a CR circuit, and Fig. 8 is a conventional IC device using a shield case. FIG. 10-=・IC device, 12-・-IC chip, 13
...Lead pin, 2o...Magnetic package part, 101\-No21...Top package part, 22...Lower package part, 21a, 22b...Bonding surface . Name of agent: Patent attorney Toshio Nakao (1 person)
Q l , j O/ dQ℃ 1-11-1 zu return-L-I Tongsheng

Claims (1)

[Claims] An IC device characterized in that an IC chip is sealed in a package made of a magnetic material.