JPH1126112A - Terminal for printed circuit board and ic socket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal for a printed circuit board which can be effectively used for developing time of the printed circuit board and an inspection of the printed circuit board or the like. SOLUTION: In this terminal a terminal 10 for a printed circuit board is mainly composed of an insulating plate-like contactor holding plate 1 in which stepped through holes 6 whose upper side becomes a small diameter part 6a and lower side becomes a large diameter part 6b are arranged in large numbers in specified arrangement in the thickness direction and locking means 1b to fix a prescribed cover-shaped body to a specified position are arranged outside the through hole groups 6, 6..., a contactor whose upper end projects in the through holes 6, a metallic coil spring 3 to impart springiness to the contactor and a sealing plate 5 having conductive pin groups 4, 4... fixed in close contact to an under surface of the contactor holding plate 1. An IC socket is composed of an IC pressing-down cover 20 having a cover side locking means 23 in this. A metallic part to short-circuit a part of a metallic coil in the lengthwise direction, may be arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board terminal and an IC socket mounted on a printed circuit board, and more particularly, to a surface mount IC (CSP [chip] having a BGA (ball grid array) type terminal. A terminal for a printed circuit board that can be engaged with a predetermined terminal relay socket or the like while containing a size package] type, and a lid (an IC holding cover) that engages with the terminal for a printed circuit board and clamps an IC. ).

[0002]

2. Description of the Related Art In recent years, with the rapid increase in the density of electronic circuits, the degree of component integration of ICs, resistor networks, and the like to be used has been further increased, and surface mounting has become popular, and withdrawal from one electronic component. The number of terminals to be connected is also increasing. Such a high-density component generally has a main portion integrated by molding, and a required terminal group is provided on a bottom surface or a side surface based on a predetermined standard.

Various shapes and arrangements of the terminals are employed in accordance with the degree of integration of the circuit. Particularly, in the case of IC parts having a high degree of integration and a large number of terminals, for example, a plan view of FIG. There is also a flat package type (QFP) that uses the four sides for terminal extraction as shown in the side view. In the illustrated example of the IC circuit (IC ′), 64 connection terminals (ICa, ICa,..., So-called “foot, gull wing”) of a predetermined standard size are arranged in a predetermined standard, and are densely arranged at a fine pitch in a line on each side surface. In general, the connection terminal group is soldered to a connection portion provided for the IC on a wiring pattern of a printed circuit board by using a reflow furnace or the like, and is surface-mounted.

[0004] However, since many surface-mounting ICs having a high degree of integration and being expensive and having an extremely large number of terminals have been used in many cases, such expensive ICs are not required during the manufacturing process of a printed circuit board. From the viewpoint of protecting from mechanical and electrical stress, even surface mount ICs may be mounted on a printed circuit board using an IC socket. The use of an IC socket is significant from the viewpoint of facilitating replacement of the IC when a failure occurs.

FIG. 5 shows an example of an IC socket for the (QFP) type described above.
No. 5-65736 (hereinafter also referred to as already proposed)). This figure is equivalent to the already proposed FIG. 7, and the reference numerals of the constituent parts are made to correspond by adding 100 to the already used reference numerals. The exemplified IC socket is composed of a main part of a printed circuit board terminal (10A) having a predetermined shape and an IC pressing lid (20A) engaged with the terminal (10A). FIG. 6 is a perspective view showing details of the printed circuit board terminal (10A) (corresponding to FIG. 1 already proposed, and the component code numbers are all added with 100).

The above-mentioned terminal (10A) for a printed circuit board mounted and used on a printed circuit board comprises a base (101) and a group of metal terminals (102, 102,...), And the base (101) has a substantially flat plate shape. A hole (101a) having a rectangular cross-section and a predetermined depth corresponding to a mold part of a predetermined surface mounting IC is provided in the center of the upper surface, and a lead terminal group of the surface mounting IC is formed. It has locking means (101c) for firmly fixing a predetermined terminal socket or IC holding lid (20A) described later having an equivalent terminal group, and the metal terminal group has an upper end (102b). The base (101) is elastically located on the upper surface, and the lower end (102a) is disposed below the base (101) in an appropriate arrangement and shape.

The base (101) has a groove (101b) outside each side of the hole (101a) for accommodating the lead terminal group (ICa) of the surface mounting IC and individually accommodating them. The base (101) has four hills (1
01d), and a protruding portion (101e) having substantially the same length as the lower protruding portion of the metal terminal (102) near the center of the lower surface of the base (101), and a lower end of the metal terminal group (102). (102a) has the same arrangement and shape as the connection terminals (ICa) of the surface mounting IC and protrudes.

[0008] The corresponding IC holding lid (20A) is
A hole (130a) having an inner surface into which the outer surface of the hill (101d) is engaged is formed on the lower surface, and after a predetermined surface mounting IC is accommodated in the substrate (101), the substrate (101) The lead terminals (ICa) of the surface mounting IC are pressed into contact with the corresponding metal terminal groups (102).

In this publication, since the signal from the printed circuit board is connected to the same printed circuit board terminal (10A), the signal from the printed circuit board can be taken out by assembling appropriate components from the upper surface side and inspected. It describes that it can be used for applications and the like. By taking out each signal from above while the predetermined IC is connected, it is possible to inspect the IC and test-check the operation of the printed circuit board when the IC is mounted.

That is, in the field of manufacturing and supplying surface mount ICs, as described in the same proposed publication, I / O is required for current aging and performance inspection of manufactured ICs.
A power supply or a signal that is temporarily close to a use state is supplied to C or the like, or a predetermined voltage is applied to a predetermined connection terminal (pin) of the IC. FIG. 7 (corresponding to the already proposed FIG. 3) shows an example in which a step of inspecting the state of each terminal after inputting a specified signal to the pin and changing the operation state is required. The use of such a predetermined adapter to connect to a test circuit / device to enhance convenience is described in detail. The adapter can be used for testing or developing a printed circuit board without mounting an IC. Although a technical disclosure has been made for another type of adapter, it is omitted. The background art of the present invention has been described above.

By the way, high integration of components and high-density mounting of circuits have been further advanced, and the shape of terminal extraction and the miniaturization of the pitch between terminals have been advanced. The pitch of about 0.8 mm was adopted in the (QFP) exemplified above as the surface mounting terminal, but in the process of narrowing the pitch interval to 0.65 mm, 0.5 mm, 0.4 mm, the ball grid array (BGA) type Many terminal shapes are used. FIG. 8 is a side view and a bottom view showing an example of a ball grid array type IC.

In the IC (IC) shown in FIG. 8, metal terminals (BT, BT,...) Are provided in a matrix form using the entire central portion of the bottom surface (ICb) of the molded portion. The required connection from the integrated circuit part is achieved at the same time, and solder balls (BL) (bump: ball solder) are individually mounted on the lower flat part (Ts) of each metal terminal (BT) for mounting. It is something to keep. At the time of mounting, the I
Solder balls by placing C and heating using a reflow furnace etc.
(BL) is melted, and solder connection between each terminal and the board is performed.

By preparing a solder material for connection on the printed circuit board side, the IC package side may adopt a form in which a lower flat portion of each fine terminal is exposed, and is referred to as a row grid array (LGA). An IC package that adopts a ball grid array terminal shape and is formed slightly larger than the integrated portion may be referred to as a chip size package (CSP).

Such a ball grid array (BGA) (or row grid array (LGA))-shaped IC is also used for exactly the same reason as previously described in detail in connection with the already proposed proposal (Japanese Utility Model Laid-Open No. 7-30486). Using an IC socket is significant. In addition, it is also possible to take out a predetermined signal from a printed circuit board on which an actual ball grid array IC can be directly mounted for inspection of a printed circuit board circuit to which the IC is applied and for verification at design time, thereby shortening the inspection and development period. It is still very effective.

However, a ball grid array (BG
A) Or, using only the lower surface of a flat IC package in a row grid array (LGA) IC, correspond to the terminal positions densely arranged in a matrix form, and securely connect between each terminal of the IC. In order to realize an IC socket or a terminal for a printed circuit board as described above, the above-mentioned structure cannot be applied at all as it is, and easy and reliable (BGA) terminal electrical connection can be obtained. A suitable connection structure has not yet been proposed. In addition, in the case of a digital IC operating at an extremely high frequency, an improper connection structure may cause a floating inductive component to be impractical, and such a careless connection structure is being sought. Was.

[0016]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a new structure suitable for a ball grid array type terminal particularly miniaturized in a surface mount IC. It is an object of the present invention to propose an IC socket and a terminal for a printed board for signal extraction. The present invention also proposes a structure in which the generation of the floating inductive component is suppressed.

[0017]

According to the present invention, there is provided a terminal for a printed circuit board.
A large number of stepped through holes (6) having a small diameter portion (6a) on the upper side and a large diameter portion (6b) on the lower side are provided in a prescribed arrangement in the thickness direction, and the outside of the through hole group (6, 6, ...). A contact holding plate (1) having an insulating property and having a locking means (1b) for fixing a predetermined lid-like body at a predetermined position; and a contact holding plate (1) in the through hole (6). A flange portion (2a) that abuts a step portion on the inner periphery of the through hole from below, and an upper pillar (2) extending above and protruding from the small diameter portion (6a).
b) and a metal tip contact pin (2) integrally formed with a lower pillar (2c) extending a predetermined length below the flange (2a), and a play around the outer periphery of the lower pillar (2c). The metal coil spring (3) fitted and accommodated in the large diameter portion (6b) in a biased state and the upper end of which is in contact with the collar portion (2a) from below, and is closely attached to the lower surface of the contactor holding plate (1). The bottom surface is provided with a bottom flat plate portion (4a) having a specified area on the lower surface and provided at the position corresponding to each of the through holes (6). Group of conductive pins in contact with the lower end of
(4, 4...).

Alternatively, a large number of stepped through-holes (7) having a large-diameter portion (7b) formed at the lower end of the small-diameter portion (7a) are provided in a predetermined arrangement in the thickness direction. Outside the group (7, 7,...), There is provided an insulating plate-like contact holding plate (1) having a locking means (1b) for fixing a predetermined lid-like body at a predetermined position. , The small diameter portion of the through hole (7)
The lower end of the diameter corresponding to (7a) is gradually formed to have a large diameter corresponding to the large diameter portion (7b), and is accommodated in the through hole (7), and the tip of the small diameter portion has a through hole (7). A metal coil spring (3A) of a predetermined length protruding by a predetermined amount from above the contact holding plate;
Each of the through-holes (7) is provided with a bottom flat plate portion (4a) having a specified area on the lower surface so as to be able to conduct electricity at a position corresponding to each of the through holes (7). A sealing plate (5) having conductive pin groups (4, 4,...) Insulated from each other and in contact with the lower end of the metal coil spring (3A) on the upper surface. In addition, the conductive pin (4B) extends to the inside of the metal coil spring (3A) and is located at a long shaft portion (4
It is preferable in terms of frequency characteristics if it is formed of an integral metal member consisting of c) and a bottom flat plate portion (4a) formed at the lower end.

The IC socket according to the present invention is composed of two parts, one of the terminals for a printed circuit board having the above-described configuration and the IC holding lid (20). Regarding (20), a ball grid array terminal provided with a lid side locking means (23) adapted to the locking means (1b) and placed at a specified position on the printed circuit board terminal (10). A predetermined IC provided with a (BT) group is covered from the upper side and is engaged and fixed to the printed circuit board terminal (10) by the lid side locking means (23), whereby the IC is connected to the metal coil spring (3). , 3A) in a compressed state so as to be sandwiched between the printed circuit board terminals (10). The operation and effect corresponding to each of the above-described configurations will be sequentially described in detail in respective corresponding portions in the following description.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiments] The present invention will be described below in detail based on embodiments shown in the accompanying drawings. Note that the same reference numerals in FIGS. 1 to 3 indicate equivalent parts.

FIG. 1 is a diagram showing an embodiment of a printed circuit board terminal and an IC socket according to the present invention. FIG. 1A is a side sectional view of a printed circuit board terminal (10) of one embodiment. This is shown together with the substrate (PB), and FIG. 1 (b)
1 is a side sectional view of an IC socket using the printed circuit board terminal (10), and FIG. 1 (c), FIG. 1 (b), and FIG.
(e) is an enlarged sectional side view showing a main part structure of the printed circuit board terminal according to the present invention.

The terminal (10) for a printed circuit board shown in the figure is mounted on a printed circuit board or the like, and can take out a signal from the printed circuit board in combination with an appropriate terminal socket. As shown in (1), an IC socket of the present application can be constructed in combination with an IC holding lid, and a suitable IC can be mounted on a printed circuit board. Although this was possible in the existing proposal, it cannot be used for the purpose of extracting a signal with a compatible IC mounted.

The printed circuit board terminal (10) of the embodiment is roughly fixed to a contact holding plate (1) made of an insulator (synthetic resin or the like) and having a rectangular plate shape with a predetermined thickness and a lower surface thereof. It comprises a sealing plate (5) and a plurality of contact mechanisms (2, 3; see FIG. 1 (c)) accommodated in the contact holding plate (1) in a large number with a predetermined distribution.

The contact holding plate (1) has a large number of stepped through holes (6) in a predetermined arrangement in the thickness direction corresponding to the arrangement of all the terminals of a compatible IC (for example, see FIG. 8). Is provided. Each through-hole (6) has a small-diameter portion (6a) on the upper side and a large-diameter portion (6b) on the lower side. In addition, these through-hole groups (6,6 ...)
In order to fix a predetermined lid-like body at a specified position on the upper surface side as described later, for example, at four apex portions outside the
b) is formed (in the embodiment, a stepped hole for receiving a nut). It should be noted that, from an appropriate position on the lower surface of the contact holding plate (1), 2
The above positioning protrusion (1e) protrudes downward by a certain length. By fitting the positioning protrusion (1e) into a through hole provided in the printed circuit board (PB), the relative position can be accurately adjusted.

The contact portions are individually accommodated in the through holes (6) and are sealed with a sealing plate (5) fixed from below, and the upper end protrudes from the through holes (6) with a spring property. In this embodiment, the contact portion is constituted by an upper end contact pin (2) and a metal coil spring (3). The tip contact pin (2)
It has a substantially cylindrical shape of a predetermined length slightly smaller in diameter than the small diameter portion (6a), but has a thin collar portion (2a) slightly smaller in diameter than the large diameter portion (6b) in the center. That is, the tip contact pin (2)
A flange portion (2a) abutting from below on a step portion on the inner periphery of the through hole in the through hole (6) and the small-diameter portion (6a) extending above the flange portion (2a).
The lower pillar (2c) extending a predetermined length is formed integrally below the upper pillar (2b) and the brim portion (2a) projecting from, and is made of, for example, gold plated brass material and used. .

The metal coil spring (3) has a predetermined length with a diameter smaller than the outer diameter of the lower pillar (2c) and smaller than the inner diameter of the large diameter portion (6b). It is wound and the surface is plated with gold. This metal coil spring
(3) is loosely fitted on the outer periphery of the lower column (2c) and
(6b), it is housed in a biased state in which the lower end portion abuts against the lower sealing plate (5) and the upper end abuts against the collar portion (2a) from below.

The sealing plate (5), which is fixed in close contact with the lower surface of the contact holding plate (1), seals each contact and carries out a conductive connection from each contact downward, is made of, for example, a synthetic resin. A conductive pin group (4, 4,...) That allows current to flow between the front and back surfaces is provided at all positions respectively corresponding to the through holes (6) in the inner portion. The conductive pin (4) may be prepared as an appropriate metal member formed in a predetermined shape and incorporated into the sealing plate, or may be realized as a through-hole portion (and a pad portion) of a printed board. That is, a metal circular pad portion is formed at a predetermined position on each of the front and back surfaces of the synthetic resin sealing plate, a through hole is opened at each position, and the circular pad portions at the upper and lower ends of the hole portion are formed by a well-known through hole technology. Conductive connection is made inside the hole. If necessary, the remaining openings are sealed.

Each conductive pin (4) or the through-hole portion and the pad portion of the printed circuit board has a solder ball (B
(L), a conductive bottom flat plate portion (4a) is formed in a prescribed area corresponding to the specified area, and a similar flat plate portion (4b) is formed on the upper surface so as to contact the lower end of the metal coil spring (3). It has become. Therefore, in the printed circuit board terminal (10), a conductive path from the bottom flat plate portion (4a) to the tip contact pin (2) is ensured, and the tip of the tip contact pin (2) has a spring property in the axial direction. Becomes

To assemble the printed circuit board terminal (10), the contact holding plate (1) is simply turned upside down, the tip contact pins (2) are inserted into all the through holes in a predetermined direction, and the metal coil spring (3) After that, the sealing plate (5) is fixed to the contact holding plate (1), so that it can be easily and easily performed. The printed circuit board terminal (10) is surface-mounted at a predetermined position on an arbitrary printed circuit board (PB) in which an arbitrary electronic circuit or the like is incorporated.
The symbol (BL ′) indicates a solder connection portion that has been solidified after the solder ball was melted by heating.

A component having a ball grid array type terminal on the upper surface side of the printed circuit board terminal (10);
The members are engaged and used. For example, an IC mounted as shown in FIG. 1 (b) is sandwiched in combination with an IC holding lid (20) to be used as an IC socket, or a ball grid attached to the tip of a flexible cable as shown in FIG. ICE probe with array equivalent terminals (20
C) and the printed circuit board (PB) and the ICE device (In Cir
ICE equipped with a ball grid array equivalent terminal group for connecting terminals or for changing the shape and arrangement of terminals so that a general ICE probe can be easily attached and detached as shown in FIG. Can be used in combination with the attachment (20D). This point is described in detail in the above-mentioned proposal, and the description is omitted here.

When the above-mentioned parts are engaged with the upper surface of the printed circuit board terminal (10) in a pressed state, the metal springs (3) at the respective terminal positions are in a compressed state, and the restoring force of the metal spring (3) causes the contact portion to be in contact. A secure electrical connection is ensured. Also,
When the metal coil spring (3) is compressed, it is eccentric and inevitably comes into contact with the outer side surface of the lower column (2c) of the tip contact pin (2), correspondingly corresponding to the portion of the metal coil spring (3). The length is electrically shorted. This means that the current flows by bypassing the coil part, which has a wound shape and has a large inductive component electrically, and in circuits handling high-frequency signals, the effect of the floating inductive component is greatly reduced. This contributes to the stabilization of the circuit operation.

In the above-described embodiment, the contact portion uses a tip contact pin. However, another structure may be adopted only in the contact portion and the corresponding through hole of the contact holding plate. it can. FIG. 1 (d) is an enlarged sectional view of a main part showing an embodiment of a different contactor partial structure. In this example,
The metal coil spring alone constitutes the contact and has a simpler structure. That is, in forming a printed circuit board terminal having a structure substantially similar to that described above, the contact holding plate (1) is provided with a large number of steps corresponding to the arrangement of all the terminals of a suitable IC as in the previous embodiment. A large number of through-holes are provided in a prescribed arrangement in the thickness direction, but each through-hole (7) is a stepped through-hole with a large-diameter portion (7b) formed at the lower end of the small-diameter portion (7a). I have. Other parts of the contact holding plate, for example, the locking means (1b) and the positioning protrusion (1e) may be exactly the same as in the previous embodiment.

Correspondingly, the contact portions individually accommodated in the through hole (7) have a diameter corresponding to the small diameter portion (7a) of the through hole (7) and a lower end portion having a large diameter portion (7). A metal coil spring (3A) having a predetermined length gradually formed to have a large diameter corresponding to 7b) and housed in the through-hole (7) and having a small-diameter portion tip projecting a predetermined amount from above the through-hole (7). ) Is used. That is, the metal coil spring (3A) is a metal wire of beryllium copper or the like, and most of its length, including the upper end portion, in the length direction including the small diameter portion (7) of the through hole (7).
It is wound with a diameter corresponding to a) and gradually expands toward the lower end corresponding to the length of the large diameter portion (7b) to a large diameter slightly smaller than the diameter of the large diameter portion (7b). It is formed to have a diameter. The material and surface treatment may be the same as those described above.

The metal coil spring (3A) is also enclosed by a sealing plate (5) fixed from below, the large diameter portion at the lower end is housed in a biased state, and the upper end protrudes by a predetermined amount from the through hole (7). It is in a state and naturally has an original spring property. The sealing plate (5) may be exactly the same as described above. A printed circuit board terminal employing such a contact structure is simpler even with less components and assembling. This printed circuit board terminal can, of course, be used for connecting to an IC socket or ICE device as in the previous embodiment. However, there is no improvement in the high-frequency characteristics, and there is an electric coil property.

FIG. 1 (e) is an enlarged side sectional view of a main part showing another embodiment of a contact structure according to the printed circuit board terminal of the present invention. This embodiment is intended to improve the high frequency characteristics in the above embodiment. In this contact structure, only the shape of the conductive pin is different from that of FIG. 1 (d) described above, and the other portions are completely the same. That is, the conductive pin (4B) is an integrated metal member including a long shaft portion (4c) having a predetermined diameter and extending to the inside of the metal coil spring (3A) and a bottom flat plate (4a) formed at the lower end. It is comprised including. Note that a flat plate portion is provided on the top surface of the sealing plate (5).
It is preferable to form (4b) (it can be omitted by setting the outer diameter of the long shaft (4c) and the diameter of the metal coil spring (3A)).

In the printed circuit board terminal (10) having the structure shown in FIG. 1 (e), a reliable electric connection is ensured at each terminal contact portion where a component is appropriately pressed and engaged with the upper surface. The metal coil spring (3A) is compressed and eccentric (bent), and comes into contact with the outer peripheral side surface of the long shaft portion (4c), and a substantial portion of the metal coil spring (3A) is electrically short-circuited to bypass the coil portion. Current flows, and the effect of the floating induction component on the high frequency signal is reduced, and the operation of the circuit is stabilized.

The printed circuit board terminal (1
0) is a metal terminal group on the lower surface on the minute land at the position corresponding to the ball grid array terminal provided on the predetermined printed circuit board.
Surface mounting is performed by using a reflow furnace with the same (BT). For positioning, the positioning protrusion (1e) is fitted into a guide hole provided in the printed circuit board, so that accurate mounting can be easily performed and workability is good.

In the same manner as in the case of the above-mentioned proposal, the connection parts of the printed circuit board can be connected to the external circuit by combining the printed circuit board terminal with appropriately formed auxiliary parts, and various signals and the like can be connected. Input and output are possible. Thus, the state of the printed circuit board can be known from the outside, and the inspection of the printed circuit board and the like can be easily performed.

Further, by using the printed circuit board terminal (10), a predetermined surface mounting IC can be accommodated, and the IC can be connected and fixed by appropriately using an IC pressing portion, which is used for energizing aging of the IC. be able to. In addition, an appropriate adapter is prepared and the arrangement of the terminal group protruding above the adapter is
It is also possible to perform terminal arrangement conversion or terminal shape conversion such as dispersing them in a staggered manner so as to facilitate connection of lead wires or the like differently from the lower surface side.

In addition to taking out the lead wire, the conductive portion guided to the upper surface of the terminal socket is appropriately led to the connector portion by using the relay board, and the connector is connected to another board (combination of a press-connecting connector and a ribbon cable). Electronic circuit), or connect predetermined parts with flexible printed circuit board and reinforcing plate from the upper surface of the terminal socket to input / output signals and the like with the outside. It can be used for establishing a connection, etc., in exactly the same manner as already proposed.
In addition, since the lower surface terminal group is a ball grid array terminal, it is possible to connect a predetermined portion of the printed circuit board to the outside where the IC for surface mounting is directly mounted and the outside,
It is easy to test the board before mounting the IC,
The situation is the same, for example, when the C and the substrate are simultaneously developed, they can be used for shortening the development period.

As described above, the terminal for a printed circuit board of the present application makes it possible to easily guide a signal from the printed circuit board to the outside or to apply a signal or the like from the outside by using a terminal socket or the like in combination. . In addition, the IC socket of the present application can be configured together with the IC holding cover, and can be used for mounting a surface mounting IC.

That is, the printed circuit board terminal of the present invention can be used in combination with a lid member (IC holding lid) to constitute a ball grid array type IC socket for a predetermined IC. In this case, any of the printed circuit board terminals described above can be used as the printed circuit board terminal.

That is, the IC socket of the present invention is, for example, shown in FIG.
(b) As shown in an embodiment of the present invention, any one of the printed circuit board terminals having the above-described structure and an IC press cover are provided, and the IC press cover is engaged with the printed circuit board terminal side. Lid locking means (23) adapted to means (1b)
And covers the predetermined IC provided with the ball grid array terminal (BT) group placed at a predetermined position on the printed circuit board terminal (10) from the upper side and covers the lid side locking means (2
According to 3), the terminal is engaged with and fixed to the terminal (10) for a printed circuit board. When both are engaged,
C. In this state, the metal coil springs (3, 3A) are individually kept in a compressed state, and the restoring force of the metal coil springs (3, 3A) securely contacts the ball grid array terminals (BT) on the back surface of the IC. Establish and maintain electrical connections.

As described above, the IC socket of the present application is composed of the printed circuit board terminal (10) and the IC holding cover (20), and since the IC for surface mounting can be mounted by the socket, the protection and replacement of the IC can be achieved. Is advantageous.

[0045]

As described in detail above, the printed circuit board terminal of the present invention is surface-mounted on a predetermined IC substrate employing a ball grid array terminal by the above-described structure, and has the same ball grid array terminal shape. Signals from the printed circuit board can be easily extracted to the outside by combining with a terminal socket having a terminal group, etc.
Therefore, the board can be easily tested before mounting the IC,
When C and a substrate are developed at the same time, the development period can be shortened. Further, since the surface mounting IC itself can be accommodated, it can be used as an IC socket as it is in combination with the IC holding cover. Moreover, it is easy to assemble with a simple configuration and can be provided at low cost.

The IC socket according to the present invention comprises a printed circuit board terminal as described above and an IC pressing cover which engages with the terminal. The IC pressing cover moves a predetermined IC at a predetermined position on the printed circuit board terminal. After being mounted on the terminal, the ball grid array terminal of the IC is securely and individually pressed into contact with the projecting portion of the upper surface of the printed circuit board terminal so that the IC can be electrically connected to a predetermined portion of the printed circuit board. Array terminal shape surface mount IC
Can be used as an IC socket. In particular, a metal coil spring having a structure having a long shaft portion that comes into contact with the inner peripheral side when the metal coil spring is deformed by compression has an advantage that high frequency characteristics are good.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of a printed circuit board terminal and an IC socket of the present invention. FIG. 1 (a) is a side sectional view showing an embodiment of a printed circuit board terminal, and FIG.
FIG. 1 (c) is a side sectional view showing one embodiment of a C socket;
1 (d) and 1 (e) are enlarged side sectional views of a through hole and a contact portion of the contact holding plate according to the present invention.

FIG. 2 is a side sectional view illustrating an example of a use state of the printed circuit board terminal of the present invention.

FIG. 3 is a side sectional view illustrating another example of use of the printed circuit board terminal of the present invention.

FIG. 4 is an external view (a plan view and a side view) showing an example of an IC having a known flat package terminal shape.

5 is a side sectional view showing an example of a conventional IC socket compatible with the IC of FIG.

FIG. 6 is an external perspective view showing a known printed circuit board terminal.

FIG. 7 is a side sectional view illustrating an example of use of the known printed circuit board terminal of FIG. 6;

FIG. 8 is an external view (side view and bottom view) showing an example of an IC employing a ball grid array terminal according to the present invention.

[Explanation of symbols]

 (1) Contact holding plate, (1b) Locking means, (2) Tip contact pin, (2a) Collar, (2b) Upper column, (2c) Lower column, ( 3)… Metal coil spring, (3A)… Metal coil spring, (4)… Conductive pin (group): (Through hole), (4a)… Bottom flat plate, (4c)… Long shaft, (5)… Sealing plate, (6a) ... small diameter part, (6b) ... large diameter part, (6) ... through hole (with step), (7a) ... small diameter part, (7b) ... large diameter part, (7) ... ( (10) ... PCB terminal, (20) ... IC holding lid, (23) ... Lid locking means, (BT) ... Ball grid array terminal (metal terminal), (IC) ... IC.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor ▲ Masayoshi Yoshi ▼ 3-10 Akihabara, Taito-ku, Tokyo Inside Tokyo Eletech Corporation

Claims (4)

[Claims] An upper part has a small diameter part (6a) and a lower part has a large diameter part (6a).
A large number of stepped through-holes (6), which have become b), are provided in a prescribed arrangement in the thickness direction, and a predetermined lid is fixed at a prescribed position outside the through-hole group (6, 6,...). A plate-like contact holding plate (1) having an insulating property, provided with a locking means (1b) for engaging the same; and a flange contacting a step portion of the inner periphery of the through hole from below in the through hole (6). Part (2a), an upper column (2b) extending above and projecting from the small diameter part (6a), and a lower column (2c) extending a predetermined length below the flange (2a) are integrally formed. Metal contact pin
(2) a metal coil spring that is loosely fitted to the outer periphery of the lower pillar (2c), is accommodated in the large diameter portion (6b) in a biased state, and has an upper end abutting against the collar portion (2a) from below. (3) is provided so as to be able to conduct electricity between the front and back surfaces at positions individually corresponding to the through holes (6), which are fixed in close contact with the lower surface of the contact holding plate (1), and have a specified area on the lower surface. A sealing plate (5) provided with a group of conductive pins (4, 4,...) Insulated from each other and having a bottom flat plate portion (4a) and being in contact with the lower end of the metal coil spring (3) on the upper surface. A terminal for a printed circuit board. 2. A large number of stepped through holes (7) having a large diameter portion (7b) formed at the lower end of a small diameter portion (7a) are provided in a predetermined arrangement in a thickness direction, and the through hole group (7, 7,...) Is provided. Outside the plate-shaped contact holding plate (1) having an insulating property provided with locking means (1b) for fixing a predetermined lid-like body at a predetermined position, and the through hole (7) The lower end has a diameter corresponding to the small diameter portion (7a) and is gradually formed to have a large diameter corresponding to the large diameter portion (7b), and is accommodated in the through hole (7), and the tip of the small diameter portion has a through hole. (7) A metal coil spring (3A) of a predetermined length protruding by a predetermined amount from above
And a bottom flat plate portion having a specified area on the lower surface, which is provided so as to be able to conduct electricity between the front and back surfaces at positions respectively corresponding to the through holes (7), which are fixed in close contact with the lower surface of the contact holding plate (1). (4a) and a sealing plate (5) having conductive pin groups (4, 4,...) Insulated from each other and in contact with the lower end of the metal coil spring (3A) on the upper surface. A terminal for a printed circuit board. 3. An elongated shaft portion (4) having a predetermined diameter, wherein the conductive pin (4B) extends to the inside of the metal coil spring (3A).
3. The printed circuit board terminal according to claim 2, wherein the terminal is a one-piece metal member comprising c) and a bottom flat plate formed at a lower end. 4. The printed circuit comprising a terminal (10) for a printed circuit board according to claim 1, and a lid-side locking means (23) adapted to the locking means (1b). A predetermined IC provided with a ball grid array terminal (BT) group placed at a predetermined position on the board terminal (10) is covered from above and the printed board terminal (10 )
Thus, an IC socket comprising an IC holding lid (20) for holding the IC between the printed circuit board terminal (10) and the metal coil spring (3, 3A) in a compressed state.