JPH06223936A - Ic socket - Google Patents

Abstract

PURPOSE:To improve the productivity and characteristic by securing the reliable connection between socket terminals and pads regardless of the number of the pads in the structure of an IC socket. CONSTITUTION:An IC socket fitted or removed with ICs having pads arranged into a matrix is constituted of socket terminals 41 each formed into a terminal for a board at one end, offset-bent in the direction of the thickness exceeding the plate thickness at the other end after passing through a fixed section to an insulator, extended in the width direction on the same plane, formed into a contact extended diagonally upward in an acute angle, and planted in nearly the diagonal direction of the pad matrix so that the junctions at contact tips correspond to the pads, an insulator 51 having the peripheral wall inner face surrounding the contact existence area as the outer shape guide face at the time of plantation, an IC pressing plate 52 having the shape pressing the surface peripheral area of an IC positioned by the insulator 51, and a means pressing or releasing the IC pressing plate 52 in the insulator 51 in the IC direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an IC socket for attaching and detaching an IC such as an LSI in which a plurality of external connection electrodes (hereinafter referred to as pads) are arranged and formed in a matrix of fine pitch, and particularly, the number of pads. The present invention relates to an IC socket (hereinafter simply referred to as a socket) for ensuring a reliable electrical connection between a socket terminal and a pad to improve productivity and characteristics even when the number increases.

Among various ICs, there is a recent LSI or the like in which several tens to several hundreds of pads are arranged in a matrix with a fine interval such as a pitch of 1.27 mm.

When such ICs are individually tested or mounted on a circuit board or the like, a dedicated socket is often used to facilitate the attachment / detachment. However, the number of pads is further increased or the pads are increased as the degree of integration is improved. -Since it is becoming difficult to secure a reliable electrical connection between the socket terminal and the pad due to dimensional variation of the socket terminal and the like, it is desired to cope with it.

[0004]

2. Description of the Related Art FIG. 5 exemplifies a case where a test IC is an LSI. FIG. 5 is a schematic view for explaining an example of the configuration of a conventional socket. (5-1) shows the configuration and (5-2) shows It shows the state when assembled in the socket.

As shown in Fig. (5-1), the LSI1 as a test IC is
A plurality of pads 13 connected to each pattern element of the chip 12 are arranged and formed in a matrix pattern of a pitch p (for example, p = 1.27 mm) around the chip on the surface of the substrate 11 on which the LSI chip 12 is formed. Is.

On the other hand, a plurality of LSI sockets 3 are mounted and fixed at predetermined positions on a circuit board 2 which constitutes a tester for the LSI 1 (or where the LSI 1 is mounted), and which are patterned on the circuit board 2. A connection plate 31 for realizing a connection between a connection electrode (not shown) and the pad 13;
It comprises a housing substrate 32 for positioning and fixing the SI 1 with respect to the connection plate 31, and a housing lid plate 33 for positioning and pressing the LSI 1 on the connection plate 31 for setting.

Among these, the connecting plate 31 having a "B" shape in plan view which is almost equal to the pad forming area of the LSI 1 is formed by the insulating elastic plate 311 made of silicon rubber or the like.
The contact pins 312 are formed in a "V" shape at positions corresponding to 13 so that both ends of the contact pins 312 are exposed on both sides of the elastic plate 311. The contact pins 312 are enlarged. As shown in the extraction diagram (a), the elastic plate 311
When is thinned by pressing from both sides thereof, it can be curved at the curved portion 312a according to the thickness variation.

Therefore, one end of each contact pin 312 of the elastic plate 311 is aligned with each connection electrode on the circuit board 2 formed as a connection electrode (not shown) at each position corresponding to the pad 13. After mounting on
By placing the LSI 1 on the other surface of the elastic plate 311 so that the pads of the elastic plate 311 and the other ends of the contact pins 312 are aligned with each other, the pads and the circuit of the LSI 1 are irrespective of the thickness of the elastic plate 311. The connection electrodes of the substrate 2 can be electrically connected via the contact pins 312.

Further, the housing substrate 32, which has a "B" shape in plan view, in which the elastic plate 311 can be positioned in the region of the square hole 32a provided in the central portion, has a thickness that is a natural state of the elastic plate 311. The case substrate 32 is formed thinner than the original thickness, and the housing substrate 32 is positioned at a predetermined position of the circuit substrate 2 by a jig or the like (not shown), and the both are fixed by means such as screwing, and then the square hole is formed. By positioning the elastic plate 311 in the region 32a, the elastic plate 311 can be positioned with respect to the substrate 2.

Further, the case lid plate 33 having the same size as the case substrate 32 and having a square hole 33a having substantially the same size as the square hole 32a at the center is provided on the back surface (lower surface in the figure) of the case lid plate 33. In the center of the side, a concave step surface 33b is formed at a depth slightly shallower than the thickness of the substrate 11 so that the substrate 11 of the LSI 1 described above can be positioned in the periphery thereof. The board 32 can be positioned by fitting with a plurality of (four peripheral points in the figure) guide pins 32b provided so as to project on the upper surface of the peripheral wall.

Therefore, after mounting the inverted LSI 1 on the connection plate 31 on the circuit board 2 as shown by the arrow A, the housing cover plate 33
While the LSI 1 is positioned on the periphery of the substrate while covering the casing substrate 32 with the guide of the guide pins 32b and pressed down, the LSI 1 positioned by the casing cover plate 33 can be pressed against the elastic plate 311. , (4-2) of Figure 4
As shown in FIG. 7, each pad 13 of the LSI 1 and each connection electrode (not shown) of the circuit board 2 can be electrically connected via the contact pin 312.

In the socket 2, the LSI 1 can be attached / detached by simply removing the housing cover plate 33. Therefore, in the test / inspection process of the LSI 1, the process can be efficiently performed, and in the mounting process on the circuit board, replacement work with a defective product is performed. Etc. has the advantage that it can be done easily.

It should be noted that the same effect can be obtained even in the case of an LSI having a radiation fin 14 as shown by a broken line.

[0014]

However, in the socket having the conventional structure, the insulating elastic plate and the contact pin are included as the number of pads increases as the integration degree of the LSI increases and the pad formation area increases due to the increase. Since it is difficult to form a uniform structure over the entire surface, it is difficult to secure reliable conduction with respect to the circuit board connection electrodes of all pads. Since there is no change, there is a problem that if a minute foreign substance or the like is present in the contact area, the connection between the two becomes unstable and the connection reliability may be reduced.

[0015]

The above object is to mount an IC having external connection electrodes arranged in a matrix on the back surface side of a chip mounting board on a circuit board, or to release the mounting. The one end is formed on the external connection terminal connected to the corresponding connection electrode of the circuit board, and the other end after passing through the fixing part to the insulator is larger than the plate thickness on one side in the width direction of the fixing part. A socket terminal formed in a tongue-shaped contact extending in the width direction and obliquely upward at an acute angle on the same surface after being offset-bent in the thickness direction, and a plurality of the socket terminals The contact portion located at the tip of the contact can be implanted and fixed substantially in the diagonal direction of the matrix of the external connection electrodes so that they correspond to the external connection electrodes of the IC. Has a shape that can press only the insulator formed so that the inner surface of the peripheral wall surrounding the tongue-shaped contact existence area serves as the outer shape guide surface of the IC, and the peripheral area of the surface of the IC positioned by the insulator. IC holding plate and the I
And a means capable of releasing the C-pressing plate toward or away from the IC guided by the insulator.

[0016]

[Function] A tongue capable of moving a socket terminal (hereinafter, simply referred to as a terminal) in contact with each pad of an LSI while changing the contact position with the pad according to the pressing movement amount when the pad is pressed. If the pad-shaped contact is provided, it is possible to make a sliding contact between the pad and the contact, so that it is possible to suppress the contact failure due to the inclusion of foreign matter and to slide according to the pad to which each individual contact comes in contact. Therefore, it is possible to secure reliable conduction between the two regardless of the number of pads and the size.

Further, when terminals arranged corresponding to pads arranged in a matrix of equal pitch are arranged in a diagonal direction of the matrix and the tongue-shaped contacts described above are arranged between the rows. The length of the tongue-shaped contact can be set regardless of the pitch.

Therefore, according to the present invention, a cantilever shape having a free end tip portion as a contact portion with a pad is formed in a region in which a terminal made of a plate material is offset and bent in a thickness direction from a fixed portion to an insulator by an amount exceeding the plate thickness. The pad is constructed with a tongue piece, and the terminal is planted in an insulator in a matrix diagonal direction of the pad so that the tongue-shaped contacts are parallel to each other at a position where a contact portion to the pad corresponds to the pad. To configure the socket.

Therefore, a sliding contact can be made between each pad and the corresponding tongue-shaped contact, so that a socket can be constructed which can realize a reliable connection regardless of the number of pads and the dimensional variation of each part.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining a terminal according to the present invention together with a method of implanting it in an insulator. (1-1) shows a state before implanting the terminal, and (1-2) shows implanting of the terminal. It is the figure which showed the state at the time.

FIG. 2 is a diagram showing the displacement and action of the terminal according to the present invention, FIG. 3 is a diagram showing an example of the structure of the socket according to the present invention, and FIG. 4 is a diagram illustrating the completed state of the socket. .

In each of the figures, the case where the IC is the LSI described in FIG. 5 is taken as an example. Therefore, the same target members and parts as those in FIG. Is omitted.

In FIG. 1 (1-1), a terminal 41 made of a metal plate for spring such as phosphor bronze has a bulge protruding on both sides in the width direction.
An external connection terminal 41 to be connected to a circuit board or the like (not shown) is provided on one side in the longitudinal direction of the fixing portion 41b to the insulator 42 including the 41a.
c is formed, and on the other side, an acute-angled slant is formed on the same surface after offset bending from one side in the width direction of the wide portion 41d serving as a positioning portion for the insulator 42 by a step amount that exceeds at least the plate thickness. A tongue-shaped contact 41e extending upward is formed by punching, and a semicircular contact portion 41f is formed at the tip of the free end side of the contact 41e so as to project upward. .

On the other hand, the insulator 42 for locating and implanting the terminal 41 fixes the terminal 41 to the terminal implantation area 42a having a thickness about the length of the fixing portion of the terminal 41 by the fixing portion 41b. The possible square holes 42b are formed by being aligned in the diagonal direction of the matrix at the respective positions corresponding to the matrix intersections of the same pitch P as the pads 13 of the LSI 1 described with reference to FIG.

Therefore, as shown by the arrow B, the terminal 41 is connected from the external connection terminal 41c side to the above-mentioned square holes 42 of the insulator 42.
Tongue-shaped contact 41e
The terminals 41 can be implanted and fixed to the insulator 42 as shown in (1-2) in which the terminals are arranged in parallel.

In this case, since the connecting portion 41f of each terminal 41 is located in a matrix shape having the same pitch P as each pad 13 of the LSI 1 described with reference to FIG. 5, the square hole 42 formed in the insulator 42 is formed.
By appropriately setting the arrangement area of b according to the length and shape of the tongue-shaped contact 41e, the connecting portion 41f of the contact 41e can be perfectly matched with each pad 13 of the LSI 1.

2A and 2B for explaining the displacement of the terminals and the action thereof, (2-1) shows a state before the LSI is mounted, and (2-2) shows the LSI.
It is a figure showing the state at the time of wearing. In (2-1) of the drawing, a plurality of pads 13 are formed on one surface (lower surface in the drawing) of the substrate 11 of the LSI 1 described in FIG.

On the other hand, in the insulator 42 described in FIG. 1, the terminals described in FIG. 1 are provided at respective positions corresponding to the pads 13.
The connection portion 41f of 41 is planted and fixed so as to be positioned, but in this case, each terminal 41 is left-right symmetric with respect to a chip (12 in FIG. 5) not shown in the center of the LSI1. It is planted and fixed to the insulator 42 in such an arrangement.

Therefore, if the above-mentioned LSI 1 located above the terminal 41 is lowered as indicated by the arrow C, when it is lowered to the position indicated by the alternate long and short dash line C ₁ , the connecting portion 41f of the terminal 41 and the LS are connected.
The pad 13 of I1 contacts at point P ₁ .

Then, when the LSI 1 is lowered as it is, the connecting portion 41f of the terminal 41 is pressed and the tongue-like contact is formed.
Since the region 41e is displaced in the direction of arrow D, the contact position with the connecting portion 41f on the pad 13 moves.

Then, place the LSI 1 at a predetermined position, that is, (2-
When lowered to the position shown in 2), the connection part 41 of the terminal 41
Since f and the pad 13 of the LSI 1 are in contact with each other at the point P ₂ , as a result, the contact point P ₁ at the initial contact of (2-1)
Distance between contact point P ₂ at the end of descent in (2-2) δ
Only the connecting portion 41f and the pad 13 of the LSI 1 slide.

Therefore, even if a foreign matter or the like is present between the pad surface and the connecting portion 41f, the foreign matter is automatically removed and a reliable connection can be secured. L
When the pressing of SI1 is released, the displaced terminals 41 can be pushed back to the initial state by pushing up the LSI1 by the springback.

Therefore, the LSI 1 having any number of pads can be obtained by placing or pressing the LSI 1 on a socket in which the terminals 41 are aligned and planted as shown in the drawing or by removing the LSI 1.
However, a reliable connection can be secured.

Particularly, when the terminals 41 are implanted and fixed so as to be symmetrical with respect to the LSI chip as shown in the drawing, the sliding force from the terminals 41 applied to the pads 13 of the LSI 1 becomes equal to the left and right, so that the LSI 1 is positioned with respect to the socket. It can be facilitated.

In FIG. 3 showing a configuration example as a socket, the LSI 1 as a test IC is the one described in FIG.
Then, the socket 5 according to the present invention for attaching and detaching the LSI 1
Is an insulator mounted and fixed on the circuit board 2 described in FIG.
It is composed of an IC holding plate 52 made of non-rust steel and the like and two locators 53 made of the same material.

The inner insulator 51 has, for example, a rectangular shape in plan view, and a concave step surface 51a into which the LSI 1 can be guided and dropped by the outer shape of the substrate 11 in the central portion and the LSI in the central portion.
The LSI chip 12 of No. 1 is formed concentrically with the square hole 51b of a size capable of being dropped in, and the thickness of the concave step surface 51a region is the thickness of the insulator 42 in FIG. Is formed equal to.

Further, the LSI 1 in the area of the concave step surface 51a
At the respective positions corresponding to the pads 13 arranged in the matrix of the pitch p, the terminals 41 described in FIG. 1 are arranged so as to be aligned in the diagonal direction of the matrix as shown in the enlarged view of extraction (b). It is constructed by being planted and fixed by a square hole 42b equal to 1.

It should be noted that the depth d from the upper surface of the concave step surface 51a is the same as when the terminal 41 is implanted in the step surface 51a.
The height from the 51a to the upper end of the connection portion of the terminal 41 (the height from the board surface to the alternate long and short dash line C ₁ in FIG. 3) h, the thickness t ₁ of the substrate 11 of the LSI ₁ and the thickness t of the IC suppressing plate 52 and ₂ obtained by adding _{"h + t 1 + t 2} " is set to be slightly smaller than the.

The IC restraining plate 52 has a "B" shape in plan view having an outer shape that allows the side wall forming the concave step surface 51a of the insulator 51 to be dropped as a guide, and the square hole 52a in the center thereof. Are formed to be larger than the square holes 51b of the insulator 51.

Further, the two locators 53, which are "L" -shaped in plan view and have substantially the same size as the two adjacent surfaces of the upper surface of the peripheral wall of the insulator 51, have inner sides 53a and 53b slanted in the thickness direction. Elliptical holes 53d, which are formed on the cut slope 53c and have a major axis in the terminal arrangement direction when placed on the upper surface of the peripheral wall of the insulator 51, are formed at a plurality of locations (four locations in the figure) on both pieces. Has been done.

In each locator 53, a screw 54 passing through the elliptical hole 53d is screwed into a screw hole 51c provided at a corresponding position on the upper surface of the insulating peripheral wall to contact the upper surface of the peripheral wall. It can slide in the direction of arrow E in the drawing.

Therefore, as described with reference to FIG. 1, the insulator 51 in which the terminal 41 is implanted is connected to the external connection terminal 41 of the terminal 41.
After connecting and fixing to the circuit board 2 at the c part, the LSI 1 is shown in FIG.
As shown by arrow A, turn the inside out and place it on the terminal 41.
The mounting plate 52 is mounted on the back surface side of the LSI 1 and then the two locators 53 are mounted on the upper surface of the peripheral wall of the insulator 51 with the screws 54, so that the required socket 5 on which the LSI 1 is mounted can be mounted.
It can be configured as in (4-1).

At this point, the LSI 1 is mounted on the position of the alternate long and short dash line C ₁ in (2-1) of FIG. 2, that is, on the connecting portion 41f of each terminal 41. The upper surface 52b of 52 is in a state of protruding from the upper surface of the peripheral wall of the insulator 51.

Then, when the two locators 53 are equally moved in the approaching directions as indicated by arrows E ₁ and E ₂ by a jig or the like (not shown), the IC restraint plate 52 is pushed down by the slope 53c and the LSI 1 descends. Therefore, the state shown in (4-2), in other words, the state shown in (2-2) in FIG. 2 can be obtained.

Therefore, each pad 13 and terminal 41 of the LSI 1
As a result, the connection electrode (not shown) of the circuit board 2 can be surely connected. Socket 5 having such a configuration
Then, since each terminal 41 operates independently, the LSI 1
The dimensional variation of each pad 13 of the
Since it can be absorbed in the region of the tongue-like contact 41e of 41, and the terminal 41 and the pad 13 are in sliding contact with each other, even in an IC having any number of pads, each pad and the connection terminal, and thus the circuit board. It is possible to realize a socket that can be reliably connected to the connection electrode.

When the locator 53 is moved in the reverse direction, the LSI 1 is pushed up by the spring back of the terminal 41 itself as described with reference to FIG. 2, so the initial state shown in (4-1) of FIG. 4 should be restored. You can

Further, the rising angle α (FIG. 2) in the natural state of the tongue-shaped contact portion of the terminal 41 described above is, for example, 0.25 mm × 0.4 mm in cross section of the contact region,
It has been experimentally confirmed that a good result can be obtained by setting it to about 30 degrees when the radius of the curved portion is 3.5 mm and the radius is about 1.5 mm.

[0048]

As described above, according to the present invention, even when the number of pads is increased, an IC which secures a reliable electrical connection of all pads to the socket terminals and improves the productivity and characteristics.
Can provide a socket for use.

In the description of the present invention, the case of an LSI is taken as an example, but a circuit board or the like having a plurality of circuit chips or the like mounted on one surface and a plurality of pads connected to them on the other surface has the same effect. It is clear that

[Brief description of drawings]

FIG. 1 is a diagram for explaining a terminal according to the present invention together with a method of implanting it in an insulator.

FIG. 2 is a diagram showing the displacement and action of the terminal according to the present invention.

FIG. 3 is a diagram showing a configuration example of a socket according to the present invention.

FIG. 4 is a diagram illustrating a completed state as a socket.

FIG. 5 is a schematic diagram illustrating a configuration example of a conventional socket.

[Explanation of symbols]

1 LSI (IC) 2 Circuit board 5 IC socket 11 Board 12 LSI chip 13 External connection electrode (pad) 41 Socket terminal 41a Bulge 41b Fixed part 41c External connection terminal 41d Wide part 41e Tongue-shaped contact 41f Contact part 42 Insulator 42a Terminal installation area 42b Square hole 51 Insulator 51a Concave step surface 51b Square hole 51c Screw hole 52 IC restraint plate 52a Square hole 52b Top surface 53 Locator 53a, 53b Inner part 53c Slope surface 53d Elliptical hole 54 Screw

Claims (2)

[Claims] 1. An IC socket for mounting or unmounting an IC having external connection electrodes arranged in a matrix on a back surface side of a chip mounting board on a circuit board, wherein one end of the circuit is the circuit. The other end after passing through the fixed part (41b) to the insulator (42) formed on the external connection terminal (41c) connected to the corresponding connection electrode of the board has a plate thickness on one side in the width direction of the fixed part (41b). Socket terminal (41) formed on the tongue-shaped contact (41e) that extends obliquely upward at an acute angle after extending in the width direction on the same surface after being offset-bent in the thickness direction
And a plurality of the socket terminals (41) with their tongue-shaped contacts (4
The connecting portion (41f) located at the tip of 1e) can be implanted and fixed substantially in the diagonal direction of the matrix of the external connection electrodes so as to correspond to the external connection electrodes of the IC, and at the time of the implantation and fixing, An insulator (51) formed so that the inner surface of the peripheral wall surrounding the tongue-shaped contact existence area of the socket terminal (41) serves as the outer shape guide surface of the IC; and an IC positioned on the insulator (51). An IC holding plate (52) having a shape capable of pressing only the peripheral area of the surface, and an IC in which the IC holding plate (52) is guided by the insulator (51).
Means (53) capable of pressing in the direction of or releasing the pressing,
An IC socket characterized by comprising at least and. 2. The socket terminal (41) according to claim 1, wherein the tongue-shaped contacts (41e) are arranged and planted in an insulator (51) so that the tongue-shaped contacts (41e) of the socket terminals are the center of the IC. An IC socket characterized by that.