JPH10228969A - Ic socket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the generation of a contact failure by arranging a contact member in an IC package or an IC socket main body, and performing the compound plating of high hardness grains having a specified grain diameter or less and nickel to an electrode for connecting the contact member and an external circuit, and furthermore, performing the gold plating thereto. SOLUTION: An elastic contact pin 16 is arranged under a part to be loaded with an IC package or an IC chip 1a, and the contact pin 16 is provided with an electrode 4b. The electrode 4b is connected to a lead 2 or an electrode of the IC package 1 or the IC chip 1a. The electrode 4b is manufactured by performing the compound plating of the high hardness grains having grain diameter at 15μ or less and nickel, and performing the gold plating thereon. In this device, when the lead 2 or the electrode is pushed to the electrode 4b, the hard grains 14 of diamond bites the lead 2 or the electrode with gold of the gold plating so as to securely connect the lead 2 or the electrode to the circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC socket used for mounting a multi-terminal IC package or a silicon IC chip or for a burn-in test, and can be used in either a normal package state or a chip state. A socket for aging.

[0002]

2. Description of the Related Art At present, in an IC socket, an IC lead frame (a material of 42 alloy or copper alloy is solder-plated on the surface) and a contact pin punched by a press incorporated in the socket (a material of BeCu). Ni plating on the surface 2-3μm, gold plating on it 0.2-0.3μm
and m) make contact with each other to form an electric circuit. On the other hand, leads of IC packages or silicon chips tend to have higher densities. The contact pins of an IC socket for mounting or testing an IC package or a silicon chip must also be densified accordingly. For example, as shown in FIG. 4, a silicon IC chip 1a
The electrode 2a is based on aluminum, the pitch of which is 0.2 mm or less, and the pitch of the fine electrodes 4 on the IC socket side must be reduced accordingly. Due to the fine pitch of the IC socket accompanying the fine pitch of the IC package 1 or the IC chip 1a, good electrical connection between each lead 2, electrode 2a and fine electrode 4 becomes difficult. In particular, when the leads 2, electrodes 2a, and fine electrodes 4 of the IC chip 1a are made of aluminum, poor contact is liable to occur because the surface is coated with aluminum oxide.

[0003]

For this reason, conventionally, diamond powder is used to break the oxide film on the surface, but the particle diameter of the diamond powder is 22 μm.
Since it is as large as m to 27 μm, the contact resistance value is large, the resistance value varies greatly, and the contact pressure is large.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. In the present invention, an IC socket body 10 of an IC socket for mounting an IC package or an IC chip is provided with an IC socket.
An elastic contact member 16 for connecting the lead 2 or electrode 2a of the IC package or IC chip to the external circuit 6 is provided below the portion where the C package or the IC chip is loaded. 2 or the electrode 4b in contact with the electrode 2a has a particle size of 15 μm.
m and nickel with high hardness particles 14
Gold plating 15 is applied thereon. Also, I
In an IC socket body 10 of an IC socket for mounting a C package or an IC chip, an elastic body 7 is provided below a portion where the IC package 1 or the IC chip 1a is mounted, and an insulating film 5 is provided thereon. On the surface of the insulating film, the fine electrodes 4 and 4a which are in contact with the leads 2 or the electrodes 2a of the IC package 1 or the IC chip 1a.
The fine electrodes 4 and 4a have a particle size of 1
This is an IC socket formed by complex plating nickel with high hardness particles 14 of 5 μm or less and gold plating 15 thereon. Also, an IC package or an IC
In the IC socket main body 10 of the C socket, elastic contact pins 16 are provided below a portion where the IC package 1 or the IC chip 1a is loaded, and the contact pins 16 are attached to the IC package 1 or the IC chip 1a.
The electrode 4b is an IC socket formed by composite plating nickel with high hardness particles 14 having a particle size of 15 μm or less and nickel plating on the electrode 4b.

[0005]

[Operation] When the pressing portion 3 presses the lead 2 or the electrode 2a, the high hardness particles 14 bite into the lead 2 or the electrode 2a together with the gold of the gold plating 15, and connect the lead 2 or the electrode 2a to the circuit 6.
Connect securely.

[0006]

FIG. 1 is a longitudinal sectional view of a press-type IC socket according to an embodiment of the present invention. Although an IC package 1 is used, the present invention can be applied to a case where a silicon IC chip 1a is used. Of course. The IC package 1 shown in this embodiment is an IC package having gull-wing leads, and the leads 2 are formed by plating 42 iron nickel alloy or copper alloy with solder. The IC socket body 10 has a rectangular parallelepiped shape, and has an opening in the center of the upper surface thereof for receiving the IC package 1. The cover 12 has a pressing portion 3 for pressing the leads 2 of the IC package 1 downward. 150 ° C. below the opening in the IC socket body 10
There is an elastic body 7 made of the above heat-resistant silicon rubber material, on which a flexible insulating film 5 made of polyimide resin or polyethersulfone is provided. Is provided with a flexible circuit 6 made of copper foil or the like having fine electrodes 4 formed in high density and in contact with the leads 2. The circuit 6 includes terminals 13 implanted at the bottom of the IC socket body 10,
13...

FIG. 2 is an enlarged view of the fine electrode 4. The fine electrode 4 is obtained by complex plating nickel with diamond particles 14 and gold plating 15 thereon. The diameter of the diamond grains 14 is 15 μm or less. The thickness of the gold plating 15 is such that the nickel plating is not oxidized. Next, the operation of this device will be described. When the IC package 1 is loaded into the opening at the center of the upper surface of the IC socket main body 10, and the cover 12 is covered and pressed downward from above, the pressing portion 3 presses the lead 2 downward as shown by the arrow in FIG. As a result, the diamond grains 14 bite into the lead 2 together with the gold of the gold plating 15, and connect the lead 2 to the fine electrode 4, the circuit 6, and the terminal 13. It is believed that the depth of penetration of the diamond particles is on the order of about 5 to 10 microns. When the IC chip 1a is used, the diamond particles 14 penetrate into the aluminum inside while breaking the aluminum oxide film of the electrode 2a, and the connection becomes good.

FIG. 3 is a longitudinal sectional view of a rotary press type IC socket according to another embodiment of the present invention, and the same parts as those in the above embodiment will be described using the same reference numerals. In the figure, 1 is I
C package body, 2 is a lead of the IC package, 3 is a pressing portion for pressing the lead 2, 4a is a fine electrode on which a large number of contacts for connecting to the lead 2 are formed at high density, and 5 is a fine electrode 4a. An insulating film 6 made of a flexible polyimide or the like provided on the surface thereof, and a copper foil 6 electrically connected to the fine electrode 4 a provided on the surface of the insulating film 5. A flexible circuit 7 is provided over the entire lower portion of the fine electrode 4a, an elastic body such as rubber contacting the insulating film 5 from below, and 8 is an IC socket body 10
A block attached to be able to swing up and down with respect to 1
1 is a spring having one end attached to the IC socket main body 10 and the other end attached to the block 8; 12 is a cover having a pressing portion 3 attached rotatably to the IC socket; 13 is connected to the circuit 6; These terminals are attached to the IC socket main body 10 in accordance with the pitch of the connection portion of the circuit board in order to connect to a circuit board for performing an IC package mounting test or the like.

Thus, when mounting the IC package, the cover 12 is opened and the IC package 1 is loaded into the IC socket body 10, and the leads 2 are placed on the fine electrodes 4a. The fine electrodes 4a are provided on the surface of the insulating film 5 at the same pitch as the pitch of the leads 2 of the IC package. The block 8 is formed by the elastic force of the spring 11.
An upward force is applied to the IC socket body 10. When the cover 12 is closed, the pressing portion 3 connects the lead 2 to the IC.
The socket body 10 is pressed downward. Then
First, the elastic body 7 starts to be elastically deformed, and then the block 8 turns left around the rotation shaft 9 to deform the spring 11. At this time, the fine electrode 4a also rotates about the rotation axis 9, and the lead 2
To perform a wiping action. And lead 2
And the circuit 6 are securely connected, and further connected to a circuit board (not shown) through the terminal 13.

The distance between the lead 2 and the fine electrode 4a rubbing is determined by the amount of rotation of the block 8 when the lead 2 is pressed by the pressing portion 3. Therefore, by increasing the amount of rotation, the wiping effect between the lead 2 and the fine electrode 4a can be obtained more reliably. However,
The rotatable range of the block 8 must be a range where there is no danger of bending the lead 2. In the above-described embodiment, an example in which nickel is composite-plated together with diamond particles on the fine electrode has been described. Any hardness particles may be used.

[Experimental Examples] (Purpose of Measurement) What are the contact characteristics between the deposited film based on aluminum and various contact materials which are expected to be used for sockets in the future and the deposited film? A test (actual) test was performed to determine which of the contact materials can provide the best contact characteristics. (Test method) Using a contact characteristic test jig designed and manufactured by our company, test the relationship between contact pressure and contact resistance on an Al-based evaporated film on a Si chip (experiment)
I do. As shown in FIG. 5, various contact materials 20 are brought into contact with an aluminum-based deposition film 22 deposited on a silicon chip 21 and a spring 23 is applied from the back of the contact material.
The distal end 25 is pushed by a pin 24 commonly called a pogo pin via the. Then, the pushing force is gradually and strongly pushed. The force is measured by the load cell 26 (P / E sensor). Then, a change in resistance value is measured from one end of each of the aluminum-based vapor-deposited films 22 of the contact substance 2 according to a four-terminal measurement method (a commercially available “LowOhm Meter”).
And the measured current is 50 μA). The tip of the pogo pin 24 was measured for two types, round and flat. FIG. 6 shows the relationship between the resistance value and the pressure. The resistance values of two conventionally known materials and the two materials of the present invention are shown in Table 1, the contact pressure is shown in Table 2, and the overall evaluation is shown in Table 3. According to this, it can be seen that the contact resistance was reduced at a light contact pressure, and good results were obtained overall. This is a light contact pressure
It is considered that the contact area between the gold plating and the lead was kept large because the amount of penetration into the oxide film was small.

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

[Table 3]

(Results) As a result of the comprehensive evaluation, it was found that the contact characteristics of "free cut" in which nickel was plated with diamond were good. Among them, those plated with gold are preferred. It has been found that the size of the diamond particles is preferably in the range of about 3 to 15 μm for the aluminum vapor-deposited film.

FIG. 7 shows still another embodiment of the present invention, and the same portions as those in the above-described embodiment will be described using the same reference numerals. Elastic contact pins 16 are provided below the portion where the IC package 1 or the IC chip 1a is loaded.
Electrode 4b in contact with lead 2 or electrode 2a of C chip 1a
This electrode 4b is composite-plated with nickel together with high-hardness particles 14 having a particle size of 15 μm or less, and a gold plating 15 is formed thereon.
Is applied. In the drawing, reference numeral 17 denotes a partition wall provided on the socket body 10 for separating the contact pins 16 from each other, and reference numeral 18 denotes a curved portion for easily bending the contact pins 16 up and down. In this apparatus, when the lead 2 or the electrode 2a is pressed toward the electrode 4b, the diamond grains 14 are formed together with the gold of the gold plating 15 by the lead 2 or the electrode 2a.
And lead 2 or electrode 2a is securely connected to the circuit.

[0017]

As described above, according to the present invention, the fine electrodes 4, 4a or 4b are nickel-plated together with the high-hardness particles 14 and gold-plated 15 thereon. Is pressed when the electrode 2a is pressed.
Is to bite into the lead 2 or the electrode 2a together with the gold of the gold plating 15 and securely connect the lead 2 or the electrode 2a to the circuit 6, but since the particle size of the high hardness particles 14 is as small as 15 μm or less, The contact resistance value is small, the variation in the resistance value is small, and the contact pressure is small.

[Brief description of the drawings]

FIG. 1 shows an outline of an embodiment of the present invention;
It is a longitudinal section of a C socket.

FIG. 2 is an enlarged view of a main part thereof.

FIG. 3 is a longitudinal sectional view of a rotary pressing type IC socket according to another embodiment of the present invention.

FIG. 4 is a rear view showing the leads of the silicon chip.

FIG. 5 is an explanatory diagram of an experimental example.

FIG. 6 is a graph showing a relationship between a resistance value and a pressure.

FIG. 7 is a perspective view of a main part of still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC package 1a IC chip 2 Lead 2a electrode 4 Fine electrode 4a Fine electrode 4b electrode 5 Insulating film 6 Circuit 7 Elastic body 10 IC socket main body 14 High hardness particle 15 Gold plating 16 Contact pin

Claims (4)

[Claims] In an IC socket body (10) of an IC socket for mounting an IC package or an IC chip, a lead (2) of an IC package or an IC chip or an electrode ( An elastic contact member (16) for connecting the external circuit (6a) to the external circuit (6a) is provided, and the electrode (4b) of the contact member (16) in contact with the lead (2) or the electrode (2a) is granular. An IC socket in which nickel is composite-plated together with high-hardness particles (14) having a diameter of 15 μm or less, and gold plating (15) is performed thereon. 2. An IC socket main body (10) of an IC socket for mounting an IC package or an IC chip,
An elastic body (7) is provided below a portion where the IC package (1) or the IC chip (1a) is loaded, and an insulating film (5) is provided thereon. The fine electrodes (4, 4) in contact with the leads (2) or the electrodes (2a) of the IC package (1) or the IC chip (1a)
There is a circuit (6) having the fine electrode (4, 4a).
4a) is an IC socket formed by complex plating nickel with high-hardness particles (14) having a particle size of 15 μm or less, and then performing gold plating (15) thereon. 3. An IC socket body (10) of an IC socket for mounting an IC package or an IC chip,
An elastic contact pin (16) is provided below a portion where the IC package (1) or the IC chip (1a) is loaded, and the contact pin (16) is attached to the IC package (1) or the IC chip (1). 1a) has an electrode (4b) in contact with the lead (2) or the electrode (2a), and this electrode (4b) is composite-plated with nickel together with high-hardness particles (14) having a particle size of 15 μm or less, and is further plated thereon. IC socket with gold plating (15). 4. The high-hardness particles (14) are made of any one of diamond, silicon carbide, silica, titanium whiskers, and ceramics, or those containing a plurality of these. The IC socket according to claim 1, 2 or 3, wherein