JPH0896912A - Ic socket - Google Patents

Abstract

PURPOSE: To provide an IC socket suitable for BGA and LGA type ICs, capable of accommodating for high integration and increase in terminals and making thin, and having durability to repeated use. CONSTITUTION: An IC socket 1 has an electrical insulator, at least two contact terminals extruded from one surface of the electrical insulator, and at least two leads extruded from the other surface of the electrical insulator, for electrically connecting to an electric circuit. Each of the connecting terminals 2 consists of a member integrally formed with one or two or more conductive materials, and its head peak forms a point or a small area flat surface, and by pressing the electrode terminal of the IC to the head peak, the contact terminal 2 is electrically connected to the IC.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention can be used for mounting, but is particularly preferably used for continuity inspection, and BGA
(Ball grid array) type and LGA (land grid array) type integrated circuit (hereinafter IC)
IC socket that can be used for

[0002]

2. Description of the Related Art When an IC is installed on a substrate, the IC is generally mounted on the IC socket and then the IC socket is installed on the substrate. If you solder the IC directly to the board,
This is because it is inconvenient to replace the IC. The IC socket usually has a contact terminal for conducting with the IC on one side of the electric insulator, and has a lead for conducting with the electric circuit, which is fixed to the substrate by soldering on the opposite side. .

Conventionally, the PGA (pin grid array) type in which pin-shaped electrode terminals are arranged on the surface of the IC package has been the mainstream, and the contact terminal structure of the IC socket is a plate made of a conductive material. I for the spring structure
The contact pin method and the like in which the electrode terminal of C is inserted and fixed has been the mainstream (Japanese Patent Laid-Open No. 174923/1993). or,
The continuity check for quality control of IC is usually performed by I
With C attached to the IC socket installed on the board,
After a certain period of time under a high temperature of 85 to 200 ° C (Burn
-In test), by checking its continuity. Conventionally, an IC socket similar to that used for usual applications has been used for the IC continuity test.

[0004]

However, in recent years, with the demand for smaller ICs, higher integration and higher number of terminals of the ICs have progressed, and in PGA type ICs, the interval between the electrode terminals has become narrower and higher density. In addition to the pin-shaped electrode terminals, BGA type ICs in which hemispherical electrode terminals are arranged and LGA (land grid array) type ICs that have flat electrode terminals and have no protrusions appear. Came to.

Along with this, there has been a problem that the conventional contact pin method cannot be applied to BGA type and LGA type ICs. Further, in the contact pin type IC socket, in order to prevent the contact pins from contacting each other, it is necessary to provide an insulating means such as providing an insulating partition wall between the contact pins. There is a limit to the miniaturization of such a structure.

At present, a checker pin system is used in which a conductive spring is used for the contact terminal of the IC socket, and the IC package is fixed to the housing of the IC socket so that the electrode terminal of the IC is pressed against the spring. This method has the advantage that it can be applied to all types of ICs described above. However, the cost of the pin is high, and
Since the IC socket itself has a considerable thickness, in the Burn-in test in which many ICs are stacked in a state where they are mounted in the IC socket and left under high temperature, there is a problem that too much space is taken, and therefore there is a problem in continuity inspection. Not suitable.

Further, for the contact terminals of the IC socket used for the continuity test, it is preferable to use a material that is less likely to be worn by repeated contact with the electrode terminals of the IC and has durability that can repeatedly withstand a heat shock. is necessary.

[0008]

Means for Solving the Problems The present invention is suitably used for all types of ICs described above, can be used for high integration and multi-terminals of ICs, is thinner than conventional IC sockets, and can be used repeatedly. It is an object of the present invention to provide an IC socket having high durability.

That is, according to the present invention, the electrical insulator, the two or more contact terminals projecting on one surface of the electrical insulator, and the other contact surface projecting on the other surface of the electrical insulator are electrically connected to the electric circuit. An IC socket having two or more leads for use, wherein each of the contact terminals is formed of a member integrally formed of one or more conductive materials, and the top of the contact point is substantially a plane of a point or a small area. There is provided an IC socket that forms a portion and presses an electrode terminal of the IC against the top of the head to electrically connect the IC.

In the above-mentioned IC socket, it is preferable that the contact terminal has a spring property and retains contact with the electrode terminal of the IC by elastic deformation. As a means for imparting a spring property to the contact terminal, the contact terminal is beryllium. It may be made of copper. Further, in the above IC socket, it is preferable that each of the contact terminals has a single crown.
When the contact terminal is cut in a plane parallel to the surface of the electric insulator on which it is arranged, it is preferable that the cross-sectional area becomes smaller as it goes away from the surface. The shape of the portion of the contact terminal that protrudes from the surface of the electrical insulator may be a hemisphere, a semielliptic sphere, a cone, an elliptical cone, or a polygonal pyramid. Further, in the above IC socket, when the IC is mounted on the IC socket, it is preferable that the surface of the electrode terminal of the IC and the surface of the contact terminal of the IC socket slide in a state where they are in contact with each other.

[0011]

[Operation] The IC socket of the present invention will be described with reference to FIG. FIG. 1a has a pin-shaped lead 5, FIG. 1b
Indicates a hemispherical lead 5. In the IC socket 1 for continuity inspection of the present invention, each of the contact terminals 2 is made of a member integrally formed of one or two or more conductive materials, and the crown portion substantially forms a flat surface of a point or a small area. To do. The conduction with the IC is performed by pressing the electrode terminal of the IC against the crown. The top of the head means the part of the surface of the contact terminal 2 that is farthest from the surface of the electrical insulator on which it is provided.

By using the contact terminal 2 having such characteristics, it can be applied to BGA type and LGA type ICs, and the lead spacing of the IC can be made smaller than that of the conventional contact pin type and checker pin type IC sockets. It becomes possible to easily deal with narrowing and high density. Although it is difficult to make a contact pin or the like having a complicated structure finer, in the IC socket of the present invention, since the contact terminal 2 is integrally formed and the structure and shape are simple, its diameter is small. Need only be adjusted according to the spacing of the contact terminals of the IC.

Further, compared to the method using pins, IC
Since the thickness of the socket can be reduced, Bur
In n-in test or the like, it becomes possible to process a large number of ICs at one time. Specifically, in the conventional contact pin type and checker pin type IC sockets,
When IC is installed, the total thickness is 15mm-40mm
However, with the IC socket of the present invention, 5 mm to 15 m
m.

As long as the above conditions are satisfied, the shape of the contact terminal is not particularly limited, and various polyhedrons, rotating bodies such as gourd-shaped bodies or those having a plurality of protrusions on the surface of a hemisphere can be used. , Among them, those having a single crown are preferable, and a shape in which the cross-sectional area when the contact terminals are cut by a plane parallel to the surface on which they are arranged becomes smaller as the distance from the surface becomes smaller, preferable. As such a shape, the shape of the part protruding from the surface is
For example, a hemisphere, a semi-elliptical sphere, a cone, an elliptical cone or a polygonal cone, a truncated cone, or a truncated pyramid can be considered.

As shown in FIG. 2, when the IC is mounted on the IC socket of the present invention, the surface of the electrode terminal 3 of the IC and the surface of the contact terminal 2 of the IC socket slide in a state where they are in contact with each other. . When mounting the IC in the IC socket, by rubbing the surface of the electrode terminal 3 of the IC with the surface of the contact terminal 2 of the IC socket, the oxide film, dust, etc. coated on both surfaces can be stripped off to ensure the conduction. You can do it (wiping). Therefore, the contact stability between the contact terminal 2 of the IC socket and the electrode terminal 3 of the IC can be ensured with a low load. When wiping is not performed, if there is dust or the like on the surface of the contact terminal 2 of the IC socket or the electrode terminal 3 of the IC, a large load is required to secure the contact stability, and the substrate may be deformed. growing.

In the IC socket of the present invention, the area of the flat portion of the small region is preferably 25% or less of the bottom area of the electrode terminal of the IC, more preferably 15% or less, and 5% or less. It is more preferable that there is. 25
If it is more than%, it is difficult to maintain contact stability and the force required for wiping becomes large, especially when used in an LGA type IC.

In the IC socket of the present invention, it is preferable that the contact terminal has a spring property and elastically deforms to hold the contact with the electrode terminal of the IC. By providing the contact terminals with spring properties, when the IC is mounted, as shown in FIG. 3, the surfaces of the contact terminals and the electrode terminals of the IC are slightly dented, and the force required for wiping can be reduced. , If the top of the head is a point, the contact becomes larger and conduction can be made more reliable. In order to give the contact terminal elasticity, it is conceivable to use a material having an elasticity for the contact terminal or to make the inside of the contact terminal hollow.

As a material having a spring property suitable for the IC socket of the present invention, horizontal copper, phosphor bronze or other conductive copper alloy or clad material is used, but beryllium copper is preferably used. Further, in order to improve the contact stability, the contact terminal may be treated by plating, sputtering, vapor deposition or the like, or a contact terminal may be formed by integrally forming two or more conductive materials by forming a clad. IC for continuity test
The socket is repeatedly used at a high temperature of 85 to 200 ° C., and a large number of ICs are repeatedly attached and detached. Therefore, it is necessary to use, for the contact terminals of the IC socket for the continuity test, a material having durability that repeatedly withstands wear due to heat shock and wiping operation. On the other hand, regarding the conductivity, the level of conductivity can be checked, that is, pure copper is 10
When it is 0%, it is sufficient if it has a conductivity of 10% or more.

Beryllium copper is preferably used for the IC socket of the present invention as a material having the above characteristics. The conductivity of beryllium copper is 20 to 60% with respect to pure copper, depending on its composition, and it has sufficient conductivity for conduction inspection. Further, it can be seen that the pickers hardness of copper is 80 to 100, whereas that of beryllium copper is 250 to 400, which is excellent in wear resistance. Furthermore, since beryllium copper is excellent in flexibility, it can be satisfactorily contacted with the electrode terminal of the IC when used as a terminal. The contact terminals made of beryllium copper may be hollow inside in order to further increase the spring property.

As the composition of beryllium copper used in the present invention, the amount of beryllium in the total amount containing copper as a main component is 0.1%.
2 to 6.0% by weight, nickel and cobalt combined to 0.
1 to 3.0 wt%, one or more elements selected from the group consisting of aluminum, silicon, iron, titanium, tin, magnesium, manganese, zinc or indium in total of 0.
It is preferable to contain 0.05 to 3.0% by weight, respectively, 1.6 to 2.0% by weight, 0.2 to 1.0% by weight,
It is more preferable to contain 0.05 to 1.0% by weight,
1.6-2.0 wt%, 0.2-0.6 wt%, 0.0
It is more preferable to contain 5 to 1.0% by weight.

When the beryllium content is more than 6.0% by weight, the conductivity is lowered, which is not preferable. Further, even if the beryllium content is more than 2.0% by weight, the increase in strength corresponding to the beryllium content cannot be obtained, which is uneconomical. On the other hand, 0.
If it is less than 2% by weight, the strength of the contact terminal is insufficient.
Further, if the total amount of nickel and cobalt is more than 3.0% by weight, the conductivity is lowered, and if less than 0.2% by weight, the increase in strength due to the addition of beryllium is suppressed, and the addition amount of beryllium is further increased. Must. Further, when the total amount of aluminum and other elements is more than 3.0% by weight, the conductivity is lowered, and when the total amount is less than 0.05% by weight, the strength at high temperature is particularly insufficient.

Next, a method for manufacturing the IC socket of the present invention will be described. The material such as beryllium copper used for the contact terminal is made into particles by the rotating electrode method or the like. The rotating electrode method is a method in which a fixed electrode, an electron beam, an arc plasma, etc. are opposed to a metal consumable electrode, and the end face of the consumable electrode is melted and rotated at a high speed to disperse the resulting melt by centrifugal force. This is a method of producing a metal powder. The metal powder produced in this manner is filled into the holes provided on the electric insulator at positions corresponding to the positions where the terminals are provided, and the shape of the protruding portion is formed by using an inversion mold or the like. By heating the metal powder to melt it and then solidifying it, a contact terminal having a desired shape can be obtained.

The contact terminals arranged on the surface of the electric insulator are 85-2 used in the Burn-in test.
It is fixed to the electrical insulator and the leads of the IC socket by a conductive material that does not soften even at a high temperature of 00 ° C. Solder, silver solder, or the like is used as such a material. The leads of the IC socket may be pin-shaped or hemispherical. In the case of the pin shape, one end thereof is directly or indirectly fixed to the contact terminal and the other end is soldered to the substrate or inserted into a hole provided in the substrate to connect to the electric circuit. In the case of a hemisphere, a part of a spherical conductor is embedded in an electrical insulator, a part of the embedded part is directly or indirectly fixed to a contact terminal, and the other end is soldered to a board to provide electrical conductivity. Make connections to the circuit.

The IC socket of the present invention can be mounted on a general substrate for use, and the IC socket and the substrate can be integrated by directly disposing a conductive material on the substrate. By doing so, the thickness becomes smaller as compared with the case where the IC socket is mounted on the substrate, so that more I
C can be tested at the same time.

[0025]

EXAMPLES The IC socket of the present invention will be described in more detail with reference to the illustrated examples, but the present invention is not limited to these examples. IC socket 1 shown in FIG.
At the upper surface of the electrical insulator 4, the hemispherical contact terminal 2
And a lead 5 is provided on the lower surface for conducting with the circuit. FIG. 4a shows a pin-shaped lead 5 and FIG. 4b shows a hemispherical lead 5. A movable portion 6 is provided above the electrical insulator 4, and the movable portion 6 has a through hole 7 arranged corresponding to the contact terminal 2.

When mounting the IC 8 on the IC socket 1, first, as shown in FIG. 5, the movable portion 6 is displaced to the right, and the through hole 7 is displaced to the right of the corresponding contact terminal 2. Be located at. Next, the electrode terminal 9 of the BGA type IC 8 is fitted into the through hole 7. Finally, the movable part 6 is slid to the left and fixed. The movable portion 6 may be slid directly by hand, or may be slid by operating a lever or the like provided on the IC socket.

[0027]

The IC socket of the present invention is suitable for use in BGA and LGA type ICs, can be used for high integration and multi-terminal ICs, and is thinner than conventional IC sockets for repeated use. Since it has durability, it is used not only for mounting but also for continuity inspection.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an IC socket of the present invention.

FIG. 2 is a schematic diagram showing a wiping process.

FIG. 3 is a schematic view showing a contact state between a contact terminal of the IC socket of the present invention and an electrode terminal of the IC.

FIG. 4 is a perspective view showing another embodiment of the IC socket of the present invention.

FIG. 5 is a schematic view showing a method of mounting an IC on the IC socket of the present invention.

[Explanation of symbols]

1 ... IC socket, 2 ... Contact terminal, 3 ... IC electrode terminal, 4 ... Electrical insulator, 5 ... IC socket lead,
6 ... Movable part, 7 ... Through hole, 8 ... IC, 9 ... IC electrode terminal

Claims (7)

[Claims] 1. An electrical insulator, two or more contact terminals projecting on one surface of the electrical insulator, and two projecting contacts on the other surface of the electrical insulator for electrically connecting to an electric circuit.
An IC socket having the above leads, wherein each of the contact terminals is made of a member integrally formed of one or two or more conductive materials, and the top portion of the contact terminal substantially forms a flat portion of a point or a small area. An IC socket, which is formed and is electrically connected to an IC by pressing an electrode terminal of the IC against the crown. 2. The IC socket according to claim 1, wherein the contact terminal has a spring property and retains contact with the electrode terminal of the IC by elastic deformation. 3. The IC socket according to claim 2, wherein the contact terminal is made of beryllium copper. 4. The IC socket according to claim 1, 2 or 3, wherein each of the contact terminals has a single crown. 5. The IC socket according to claim 1, wherein a cross-sectional area when the contact terminal is cut by a plane parallel to the surface is smaller as the contact terminal is farther from the surface in a protruding direction of the contact terminal. . 6. The IC socket according to claim 1, wherein the shape of the portion of the contact terminal protruding from the surface is a hemisphere, a semielliptic sphere, a cone, an elliptical cone or a polygonal cone. 7. When mounting an IC in an IC socket, I
The IC socket according to claim 1, wherein the surface of the electrode terminal of C and the surface of the contact terminal slide while both are in contact with each other.