JPH11186470A - Combination of ic socket and ic package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mount an IC package at a high density. SOLUTION: An IC package 10 provided with at least two leads 14 per one pin 12, and another IC socket 20 provided with at least two conductors 28 and 30 per one pin fitting 22, are combinedly used. On the socket 20, side leads 38 are arranged in addition to a plurality of longitudinal leads 34 which are protruded downward from the bottom face of the socket 20. One conductor 28 of each pin fitting 22 is connected to one of the longitudinal leads 34 and the other conductor 30 of the fitting 22 is connected to one of the side leads 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an integrated circuit (IC).
IC used to mount packages on printed wiring boards
The present invention relates to a socket and a combination of an IC package and an IC socket.

[0002]

2. Description of the Related Art In mounting an integrated circuit (IC) package on a printed wiring board, there is a method of mounting an IC socket on the printed wiring board and inserting the IC package into the IC socket. This is because the IC package can be easily replaced.

For example, a PGA (Pin Grid Arra) shown in FIG.
In the y) type IC package, a large number of leads 2 are arranged on the bottom surface of the package 1 like a sword. I
The IC socket 3 has a number of pin fittings 4 as shown in FIG. 7 corresponding to the leads 2 of the C package.
Each lead 2 of the C package 1 is inserted into a lead insertion opening 5 of a pin fitting 4 of the socket 3. Socket 3
The pin fitting 4 is connected to an integral lead 6 projecting from the bottom of the socket 3 like a sword, and the lead 6 of the socket 3 is soldered to the printed wiring board.

In the conventional PGA type IC package and IC socket, each lead 2 is connected to one electrode (pat) of an integrated circuit by a thin metal wire, and a set of a lead 2, a pin fitting 4, and a lead are provided. 6 transmits one signal.

A DIP (Dual In-line Packag) shown in FIG.
In the e) type IC package and IC socket, a corresponding pair of leads 2 and 6 transmit one signal.

[0006]

SUMMARY OF THE INVENTION IC package and IC
The problem with the conventional mounting method combining sockets is that high-density mounting is not possible. The reason is that only one signal can be handled by one set of leads, so to mount an IC package with many electrodes
Many leads need to be placed on the bottom of the socket,
As a result, the size of the IC socket increases.

An object of the present invention is to enable high-density mounting of an IC package.

[0008]

In the combination of the IC package and the IC socket according to the present invention, the IC package includes a plurality of pins projecting downward from the bottom surface thereof.
Each pin has a plurality of longitudinal leads electrically connected to one another in the circumferential direction and connected to the electrodes of the integrated circuit. On the other hand, the IC socket has the same number of pin fittings for receiving the pins of the IC package respectively, and each pin fitting has an I
It has a plurality of conductors that are electrically insulated from each other in the circumferential direction and that respectively contact the longitudinal leads of the C package. One of the plurality of conductors of each pin fitting is connected to a longitudinal lead projecting downward from the bottom surface of the socket, and the other conductor is connected to a side lead disposed on the side of the socket. .

As described above, by using an IC package having a plurality of leads for each pin and an IC socket having a plurality of leads for each pin fitting in combination,
By allowing multiple signals to be transmitted with a single pin and pin fittings, arranging the longitudinal leads on the bottom of the socket like a sword and placing the side leads on the sides of the socket, Since a large number of leads are drawn from both the side and the side, high-density mounting of the IC package is possible.

In a preferred embodiment, the lower end of the longitudinal lead of the socket is formed of a low melting point metal such as solder, and the lower end of the longitudinal lead of the socket and the lower end of the side lead are substantially flush with each other. It is.

With this arrangement, the lower ends of the longitudinal leads protruding downward from the bottom surface of the socket can be soldered to the upper surface of the printed wiring board. If the socket is soldered in this way, it is not necessary to penetrate the printed wiring board by penetrating the inner layer pattern of the printed wiring board in order to insert the lead, so that the printed wiring board can be designed at high density.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 1 shows an embodiment of a PGA type IC package used in the combination of the present invention. Referring to FIG. 1, a large number of pins 12 project from the bottom of the IC package 10 like a sword, and these pins 12 are arranged at regular intervals in front, rear, left and right.

As shown in FIGS. 1B and 1C,
In this embodiment, each pin 12 comprises two longitudinal leads 14, which are circumferentially insulated from each other by an electrical insulator 16 extending along a vertical center plane. Therefore, in the illustrated embodiment, one pin 12 can transmit two signals. Each lead 14 is connected to a separate electrode (pat) of an IC chip 18 embedded in a package by a thin metal wire in a known manner.

The IC package 10 shown in FIG. 1 is used in combination with the PGA type IC socket shown in FIG. Referring to FIG. 2, the socket 20 has a large number of cylindrical pin fittings 22 arranged at positions corresponding to the pins 12 of the IC package 10. Each pin fitting 22 receives a corresponding pin 12 of the package 10 through a pin insertion port 24.

As shown in FIG. 2B, in this embodiment, each of the pin fittings 22 has a substantially longitudinal slit 25.
Are divided into two conductors 28 and 30, which are circumferentially insulated by an electrical insulator 26 filled in a longitudinal slit 25. In order to improve the electrical connection between the corresponding pins 12 and the respective leads 14, the conductors 28 and 30 are formed with elastic metal contact pieces 32, respectively.

One of the two conductors 28 and 30 of each pin fitting 22 is integrally connected to a longitudinal lead 34 projecting downward from the bottom surface of the socket 20 like a sword.

On the side of the socket 20, the same number of side leads 38 as the pin fittings 22 are arranged. As can be clearly seen from FIG. 2 (c), in the illustrated embodiment, the side leads 3
Reference numerals 8 are arranged at predetermined intervals along four sides of the socket 20. The other conductor 30 of each pin fitting 22 is connected to each side lead 38 by a conductor pattern 36 formed in the socket. As can be clearly seen from FIG. 2B, each side lead 38 has a horizontally extending portion 38a, a vertically extending portion 38b, and a horizontal leg 3a.
8c.

At the time of mounting the IC package 10, first, as shown in FIG. 2A, the IC socket 20 is printed while the longitudinal leads 34 of the IC socket 20 are passed through holes formed in the printed wiring board 40. It is placed on the upper surface of the wiring board 40. Next, the lower ends of the longitudinal leads 34 are soldered to the terminals of the circuit formed on the back surface of the printed wiring board 40, and the legs of the side leads 38 are connected to the terminals of the circuit formed on the upper surface of the printed wiring board 40. The parts 38c are soldered respectively.
Then, the IC package 10 is inserted into the socket 20 thus fixed.

Each of the pins 12 of the IC package 10
Since the longitudinal leads 14 are insulated by the electrical insulator 16, the signals of the respective electrodes of the IC chip 18 are individually transmitted to the longitudinal leads 14 when the package 10 is inserted into the socket 20. In addition, socket 20
Since the conductors 28 and 30 and the contact pieces 32 of each pin fitting 22 are insulated by the electrical insulator 26, the signal transmitted to each lead 14 of the package 10 is
It is individually transmitted to the longitudinal lead 34 or the lateral lead 38 via one of the two contact pieces 32 and the conductor 28 or 30. This signal is transmitted to the connection destination via the corresponding pattern of the printed wiring board 40.

In the embodiment shown in FIGS. 1 and 2, the socket 20 has the same number of lateral leads 38 as the longitudinal leads 34.
Therefore, signals can be handled twice as compared with the conventional system shown in FIG. 6, and the mounting density can be doubled.

FIG. 3 shows a variation of the socket shown in FIG. The same elements as those shown in FIG. 2 are denoted by the same reference numerals, and only the differences will be described. In this variation, the lower end of the longitudinal lead 34 of each pin fitting 22 has a lower end such as solder. Spherical end 4 made of melting point metal
2 are provided. The lower end of the spherical end 42 is the side lead 38
Are arranged at substantially the same level as the leg portion 38c, preferably at a slightly lower level.

Since the lower ends of the longitudinal leads 34 are formed by soldering in this manner, the socket 20 according to this variation is placed on the upper surface of the printed wiring board 40, and the spherical end 42 is heated to melt the solder. Accordingly, the longitudinal leads 34 can be easily soldered to the circuit formed on the upper surface of the printed wiring board 40. According to this variation, it is not necessary to drill a hole for inserting the longitudinal lead 34 of the socket into the printed wiring board, so that the degree of freedom in designing the circuit pattern (especially the inner layer pattern) of the printed wiring board is increased, Printed wiring boards can be designed with high density.

FIGS. 4 and 5 show an embodiment in which the present invention is applied to a DIP type IC package and IC socket. The same elements as those of the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description will be omitted.
Mainly explaining the difference, in this embodiment,
The pins 12 of the IC package 10 are arranged along the long side of the package and extend vertically to the bottom surface. FIG.
(B) and FIG. 4 (c), each pin 1
2 has two longitudinal leads 14 insulated by an electrical insulator 16 as in the previous embodiment, each lead 14 being connected to a separate electrode of the IC chip.

Referring to FIG. 5, a socket 20 has pin fittings 22 arranged along its long side. As in the embodiment of FIG. 2, each pin fitting 22 is
Is divided into two conductors 28 and 30, the conductors 28 and 30 being respectively connected to the longitudinal lead 34 and the side lead 3.
8 is connected.

The combination of the IC package shown in FIG. 4 and the IC socket shown in FIG. 5 has the same effect as that described above for the combination shown in FIG. 1 and FIG.

Although specific embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made. For example, the pins 12 of the IC package 10 and the pin fittings 22 of the socket 20 have been described as having two leads or conductors, respectively.
Each pin 12 and pin fitting 22 may be divided into three or more leads or conductors arranged at equal circumferential intervals by an insulator. In that case, additional side leads 38 can be provided, one conductor of each pin fitting connected to the longitudinal lead 34 and the other conductor connected to the side lead 38.

[0027]

According to the present invention, a plurality of signals are handled by each pin of the IC package and each pin fitting of the IC socket, and a large number of leads are drawn from both the bottom and side surfaces of the socket. Therefore, high-density mounting of the IC package becomes possible.

According to a preferred embodiment, when the lower end of the longitudinal lead of the socket is formed of a low melting point metal such as solder, and the lower end of the longitudinal lead of the socket and the lower end of the side lead are substantially flush with each other. Since it is not necessary to pierce the printed wiring board to insert the longitudinal leads, the printed wiring board can be designed at a high density.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of an IC package constituting a combination of the present invention, and FIG. 1 (a) is a perspective view, FIG.
FIG. 1B is a longitudinal sectional view of the pin, and FIG.
FIG. 4 is a cross-sectional view of the pin taken along line -I.

FIG. 2 is an explanatory view of a first embodiment of an IC socket constituting a combination of the present invention. FIG. 2 (a) is an II-II of FIG. 2 (c).
2B is a cross-sectional view of the pin fitting and the side lead, FIG. 2C is a plan view of the socket, and FIG. 2C is a side view for simplification. The number of leads has been reduced.

FIG. 3 is a view similar to FIG. 2, showing a variant of the IC socket;

FIG. 4 is a view similar to FIG. 1, showing another embodiment of the IC package.

FIG. 5 is a view similar to FIG. 2, showing another embodiment of the IC socket.

FIG. 6 is a perspective view of a conventional IC package and IC socket.

FIG. 7 is a longitudinal sectional view of a pin fitting of the IC socket shown in FIG. 6;

FIG. 8 is a perspective view of another IC package and IC socket of the related art.

[Explanation of symbols]

 10: IC package 12: IC package pin 14: IC package pin longitudinal lead 18: IC (integrated circuit) chip 20: IC socket 22: IC socket pin fitting 28, 30: IC socket pin fitting conductor 34: longitudinal lead of IC socket 38: lateral lead of IC socket

Claims (3)

[Claims] 1. A combination of an IC package in which an integrated circuit is embedded and an IC socket into which the IC package is inserted, wherein the IC package includes a plurality of pins protruding downward from a bottom surface thereof, and each of the pins includes a plurality of pins. Comprises a plurality of longitudinal leads electrically insulated from one another in a circumferential direction respectively connected to the electrodes of the integrated circuit; and wherein said IC socket comprises an equal number of pin fittings for respectively receiving pins of said IC package, and each of said pin fittings Is IC
A plurality of conductors electrically insulated from each other in a circumferential direction, each of the plurality of conductors being in contact with a longitudinal lead of the package, and one of the plurality of conductors of each pin fitting protrudes downward from a bottom surface of the socket; Combination characterized in that it is connected to the directional lead and the other conductor is connected to a side lead arranged on the side of the socket. 2. The lower end of the longitudinal lead of the socket is formed of a low melting point metal, and the lower end of the longitudinal lead and the lower end of the side lead are located substantially on the same plane. Combination based on. 3. An IC socket for use in mounting an IC package, comprising a plurality of pin fittings for respectively receiving pins of the IC package, each of the plurality of pin fittings being electrically insulated from each other in a circumferential direction. One of the plurality of conductors of each pin fitting is connected to a longitudinal lead projecting downward from a bottom surface of the socket, and the other conductor is a lateral lead disposed on a side of the socket. Wherein the lower end of the longitudinal lead is formed of a low melting point metal, and the lower end of the longitudinal lead and the lower end of the side lead are disposed on substantially the same plane.