JPH0734590U - IC socket - Google Patents

Abstract

(57) [Abstract] [Purpose] IC package 1 or IC chip lead 2
Alternatively, there is provided an IC socket that ensures the connection between the electrode and the fine electrode 4 or the electrode. [Structure] The fine electrodes 4 or electrodes are formed by composite plating of nickel with high hardness particles having a particle size of 15 μm or less, and then gold plating is performed thereon.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an IC socket used for mounting a multi-terminal IC package or a silicon IC chip, a burn-in test, etc., and is a socket for aging in both normal package state and chip state. is there.

[0002]

[Prior art]

 Currently, in the IC socket, the IC lead frame (material 42 alloy or copper alloy surface is solder-plated) and the contact pin punched by the press built into the socket (material BeCu surface is Ni-plated). 2 to 3 μm, and a gold plating on it to 0.2 to 0.3 μm) forms an electric path. On the other hand, the leads of IC packages or silicon chips tend to be higher in density. The contact pins of IC sockets for mounting or testing IC packages or silicon chips must also be densified accordingly. For example, as shown in FIG. 4, the electrodes 2a of the silicon IC chip 1a are based on aluminum, and the pitch is 0.2 mm or less, and the pitch of the fine electrodes 4 on the IC socket side is also reduced accordingly. I have to let you. Due to the fine pitch of the IC socket accompanying the tendency of the fine pitch of the IC package 1 or the IC chip 1a, good electrical connection between each lead 2, the electrode 2a and the 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, a film of aluminum oxide is formed on the surface thereof, so that contact failure is likely to occur.

[0003]

[Problems to be solved by the device]

 For this reason, it is conventionally known that diamond powder is used to break the oxide film on the surface, but since the particle size of the diamond powder is as large as 22 μm to 27 μm, the contact resistance value is large and the resistance value is large. Has a large variation and the contact pressure is also large.

[0004]

[Means for Solving the Problems]

 The present invention solves such a problem. In the IC socket body 10 of an IC socket for mounting an IC package or IC chip, the IC package or IC chip lead is provided below the portion where the IC package or IC chip is loaded. 2 or an elastic contact member 16 for connecting the electrode 2a and the external circuit 6 is provided, and the lead 2 of the contact member 16 or the electrode 4b in contact with the electrode 2a together with the high hardness particles 14 having a particle size of 15 μm or less It is formed by composite plating of nickel and then gold plating 15 is applied thereon. Further, in the IC socket body 10 of the IC socket in which the IC package or the IC chip is loaded, the elastic body 7 is provided below the portion in which the IC package 1 or the IC chip 1a is loaded, and the insulating film 5 is formed thereon. There is a circuit 6 having fine electrodes 4 and 4a in contact with the lead 2 or the electrode 2a of the IC package 1 or the IC chip 1a on the surface of the insulating film. This is an IC socket in which nickel is compound-plated together with high hardness particles 14 of 15 μm or less, and gold plating 15 is applied thereon. Further, in the IC socket body 10 of the IC socket in which the IC package or the IC chip is loaded, there is an elastic contact pin 16 below the portion in which the IC package 1 or the IC chip 1a is loaded. Has an electrode 4b in contact with the lead 2 of the IC package 1 or the IC chip 1a or the electrode 2a. The electrode 4b is composite-plated with nickel together with high hardness particles 14 having a particle size of 15 μm or less, and gold is deposited thereon. It is an IC socket formed by plating 15.

[0005]

[Work]

 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 securely connect the lead 2 or the electrode 2a to the circuit 6.

[0006]

[Embodiment] FIG. 1 is a vertical sectional view of a pressure type IC socket according to an embodiment of the present invention. Although an IC package 1 is used, it is also applicable when a silicon IC chip 1a is used. Of course, you can. The IC package 1 shown in this embodiment is an IC package in which the leads are gull-win shaped, and the leads 2 are 42 iron-nickel alloy or copper alloy solder-plated. The IC socket body 10 has a rectangular parallelepiped shape, and has an opening at the center of the upper surface for receiving the IC package 1. The cover 12 has a pressing portion 3 that presses the leads 2 of the IC package 1 downward. At a position below the opening in the IC socket body 10, there is an elastic body 7 made of a heat resistant silicone rubber material having a temperature of 150 ° C. or higher, and made of a polyimide resin or polyether sulfone or the like. There is a flexible insulating film 5, and a flexible circuit 6 made of copper foil or the like having fine electrodes 4 formed in high density in contact with the leads 2 is provided on the surface of the insulating film 5. ing. The circuit 6 is connected to the terminals 13, 13 ... Implanted in the bottom of the IC socket body 10.

FIG. 2 shows an enlarged view of the fine electrode 4. The fine electrode 4 is obtained by compound plating nickel with diamond grains 14 and then gold plating 15 thereon. The diamond grains 14 have a grain size of 15 μm or less. The thickness of the gold plating 15 is set so that the nickel plating does not oxidize. 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 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. The depth at which the diamond particles dig is thought to be about 5 micron to 10 microns. When the IC chip 1a is used, the diamond grains 14 pierce the aluminum oxide inside the electrode 2a while breaking the aluminum oxide film, and the connection is good.

FIG. 3 is a longitudinal sectional view of a rotary pressing type IC socket according to another embodiment of the present invention. The same parts as those in the above embodiment will be described using the same reference numerals. In the figure, 1 is an IC package main body, 2 is an IC package lead, 3 is a pressing portion for pressing the lead 2, 4a is a fine electrode in which a large number of contacts for connecting with the lead 2 are formed with high density, 5 is an insulating film made of flexible polyimide or the like having a fine electrode 4a provided on its surface, and 6 is a state capable of being electrically connected to the fine electrode 4a provided on the surface of the insulating film 5. A flexible circuit made of copper foil, etc., 7 is disposed over the entire lower part of the fine electrode 4a, and is made of an elastic body such as rubber that contacts the insulating film 5 from below, and 8 is a rotating shaft. A block attached to the IC socket body 10 by 9 so as to be able to swing up and down, 11 is a spring attached to the IC socket body 10 at one end and another end is attached to the block 8, and 12 is an IC socket. A cover having a pressing portion 3 that is movably attached, 13 is adjusted to the pitch of the connection portion of the circuit board in order to connect with the circuit board that is in the connection state with the circuit 6 and for the mounting test of the IC package. Terminal attached to the IC socket body 10.

Thus, when the IC package is mounted, the cover 12 is opened, and the IC package 1 is loaded into the IC socket body 10. Then, 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 receives an upward force against the IC socket body 10 due to the elastic force of the spring 11. When the cover 12 is closed, the pressing portion 3 presses the lead 2 downward against the IC socket body 10. Then, the elastic body 7 begins to elastically deform, and then the block 8 rotates counterclockwise about the rotation shaft 9 to deform the spring 11. At this time, the fine electrode 4a also rotates around the rotating shaft 9 and rubs the lead 2 to perform a wiping action. Then, the lead 2 and the circuit 6 are securely connected, and further connected to a circuit board (not shown) through the terminal 13.

Therefore, the distance at which the lead 2 and the fine electrode 4 a rub each other is determined by the rotation amount 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 of the lead 2 and the fine electrode 4a can be more reliably obtained. However, the rotatable range of the block 8 must be a range where there is no risk of bending the lead 2. In the above examples, an example in which nickel is compound-plated together with diamond grains on the fine electrode has been shown, but instead of diamond grains, a high-grade metal oxide film such as silicon carbide, silica, titanium whiskers, or ceramics that can destroy metal oxide coatings. Any hard particles are acceptable.

[Experimental Example] (Purpose of measurement) What is the contact property between the vapor-deposited film made of aluminum and various contact substances that will be used in the socket in the future and the vapor-deposited film? A trial (actual) test was conducted to find out which of the various contact substances has the best contact characteristics. (Test method) Using a contact property test jig designed and manufactured by our company, test (experiment) what is the relationship between contact pressure and contact resistance for an Al-based evaporated film on a Si chip. As shown in FIG. 5, various contact substances 20 are brought into contact with the vapor deposition film 22 based on aluminum vapor-deposited on the silicon chip 21, and a pin 24, which is commonly called a pogo pin, is formed from the back face of the contact substance through a spring 23. Push the tip 25 with. Then, the pushing force is gradually and strongly pushed. The force is measured by the load cell 26 (P / E sensor). Then, the change in the resistance value between each end of the vapor deposition film 22 based on aluminum of the contact substance 2 is measured according to the four-terminal measurement method (a commercially available "Low Ohm Meter" is used, and the measured current is 50 μA). The pogo pin 24 was measured for both round and flat types at the tip. The relationship between resistance and pressure is shown in FIG. The resistance values of two conventionally known materials and two materials of the present invention are shown in Table 1, the contact pressure is shown in Table 2, and the comprehensive evaluation is shown in Table 3. According to this, it can be seen that the contact resistance was reduced with a light contact pressure, and that good results were obtained overall. It is considered that this is because the contact area between the gold plating and the leads is kept large because the contact pressure is light and the amount of bite into the oxide film is 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 plating was sprinkled with diamond was good. Among them, the one with gold plating on it is preferable. 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 deposition film.

FIG. 7 shows still another embodiment of the present invention. The same parts as those of the above-mentioned embodiment will be described using the same reference numerals. An elastic contact pin 16 is provided below the portion where the IC package 1 or the IC chip 1a is loaded, and the contact pin 16 has an electrode in contact with the lead 2 or the electrode 2a of the IC package 1 or the IC chip 1a. This electrode 4b is formed by composite plating of nickel with high hardness particles 14 having a particle diameter of 15 μm or less, and then gold plating 15 is applied thereon. In the figure, reference numeral 17 denotes a partition wall provided between the contact pins 16 provided in the socket body 10, and reference numeral 18 denotes a curved portion for facilitating the contact pins 16 to be vertically bent. In this device, when the lead 2 or the electrode 2a is pressed toward the electrode 4b, the diamond grain 14 bites into the lead 2 or the electrode 2a together with the gold of the gold plating 15 and securely connects the lead 2 or the electrode 2a to the circuit. To do.

[0017]

[Effect of device]

 As described above, in the present invention, the fine electrodes 4, 4a or the electrodes 4b are nickel-plated together with the high hardness particles 14, and the gold plating 15 is applied on the fine electrodes 4, 4a, so that the pressing portion 3 forms the lead 2 or the electrode 2a. When pressed, the high hardness particles 14 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. Since it 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 drawings]

FIG. 1 shows an outline of an embodiment of the present invention in which a wall pressing type I is used.
It is a longitudinal cross-sectional view of a C socket.

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

FIG. 3 is a vertical 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 resistance value and pressure.

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

[Explanation of symbols]

 1 IC Package 1a IC Chip 2 Lead 2a Electrode 4 Micro Electrode 4a Micro Electrode 4b Electrode 5 Insulating Film 6 Circuit 7 Elastic Body 10 IC Socket Body 14 High Hardness Particle 15 Gold Plating 16 Contact Pin

Claims (4)

[Scope of utility model registration request] 1. In an IC socket main body (10) of an IC socket in which an IC package or IC chip is loaded, a lead (2) or an electrode (of the IC package or IC chip is provided below a portion where the IC package or IC chip is loaded. The contact member (16) having elasticity for connecting the external circuit (6) to the electrode (2a) is arranged, and the electrode (4b) in contact with the lead (2) or the electrode (2a) of the contact member (16) is a particle. An IC socket obtained by compound-plating nickel with high-hardness particles (14) having a diameter of 15 μm or less, and then plating with gold (15). 2. An IC socket body (10) of an IC socket in which an IC package or an IC chip is loaded,
An elastic body (7) is provided below the IC package (1) or the portion where the IC chip (1a) is loaded, and an insulating film (5) is provided on the elastic body (7). Fine electrodes (4) in contact with leads (2) or electrodes (2a) of the IC package (1) or IC chip (1a)
There is a circuit (6) with 4a) and this fine electrode (4,
4a) is an IC socket formed by composite plating nickel together with high hardness particles (14) having a particle diameter of 15 μm or less, and gold plating (15) on the composite plating. 3. An IC socket main body (10) of an IC socket in which an IC package or an IC chip is loaded,
An elastic contact pin (16) is provided below the portion where the IC package (1) or the IC chip (1a) is loaded, and the contact pin (16) has the above-mentioned IC package (1) or IC chip ( 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 An IC socket that is plated with gold (15). 4. The high-hardness particles (14) are made of any one of diamond, silicon carbide, silica, titanium whiskers, and ceramics, or one containing a plurality of these. The IC socket according to claim 1, 2, or 3.