JP2008027773A - Ic socket and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IC socket of which the contact can contact by metal to a land on the IC package side, and which can cope with multiple pins, fine pitch, large current, and high speed with high productivity. <P>SOLUTION: One end part of contact piece 14 is formed by resin integrally at a through hole forming part 12 of a socket base body 10, and the portion other than the one end part of the contact piece 14 faces a through hole 21. A plating layer 20 is formed on the inner wall of the through hole 13 penetrating the through hole forming part 12 in front and rear direction, the surface and the rear face of the through hole forming part 12, and over the surface of the contact piece 14, to form a three-dimensional circuit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an IC socket used when mounting an IC package such as a CPU or LSI on, for example, a printed circuit board, and more specifically, for example, an IC socket in which a three-dimensional circuit is formed using a three-dimensional circuit forming technique and its manufacture It is about the method.

  Conventionally, techniques for mounting an IC package such as a CPU or LSI on a printed circuit board via an IC socket have been studied. Many motherboards of personal computers and servers are mounted with sockets for mounting CPUs of LGA (Land Grid array) packages and BGA (Ball Grid Array) packages.

  The number of pins and the speed of CPUs are increasing year by year in order to improve the functions and performance of CPUs, and measures are being taken by increasing the size of packages and making fine pitches. Along with this, it is necessary to cope with the increase in the number of pins of the IC socket, and it is also necessary to cope with an increase in the amount of bending accompanying an increase in the size of the package and a variation in the contact land of the package and the height variation of the ball. .

  Therefore, the IC socket is required to have a structure that can ensure a stroke in the bending direction in contact with the electrode portion of the IC package.

  Further, as a countermeasure to the fine pitch, it should be realized with a simple structure as much as possible, and a structure in which the connection from the package to the printed board is performed at a short distance is desirable.

  Furthermore, in order to cope with the high speed, it is important that the contact between the IC socket and the package has a low inductance, and the allowable current is required to be high in response to the increase in current consumption due to the high speed.

  The current mainstream of LGA package sockets is 400-800 pins with a pitch of about 1 mm. An IC socket having a structure in which a metal plate is bent in a complicated manner to form a predetermined contact piece and a contact is inserted into the socket housing. Is known (see, for example, Patent Documents 1 and 2). However, since these IC sockets are assembled by inserting contacts into the socket housing one pin at a time, as the number of pins increases, the contact insertion time required for manufacturing increases and productivity deteriorates.

As a countermeasure against such a problem, a structure using a column made of a conductive elastomer as a contact is known (for example, see Patent Document 3). However, when an elastomer is used as a contact in this way, the contact resistance is higher than that of metal contact, and there is a risk of heat generation and increase in voltage drop when the current is increased. Also, in the IC socket using elastomer, when the IC package is mounted, the contact portion made of elastomer does not wipe the metal surface of the land (electrode part) on the IC package side, so that the oxide film on the land is removed. There is a problem that cannot be expected. Furthermore, since this IC socket comes into contact with the land made of metal on the IC package side by pressure contact with the elastomer, there is a problem that the contact resistance changes with time.
JP 2004-158430 A JP-A-2005-19284 US Pat. No. 6,669,490

  SUMMARY OF THE INVENTION An object of the present invention is to provide an IC socket that can make metal contact with a land on the IC package side, has high productivity, and can cope with high pin count, fine pitch, large current, and high speed, and a manufacturing method thereof Is to provide.

  A first feature of the present invention is an IC socket, in which a plurality of contact housing holes penetrating in the front and back directions are formed, and through holes penetrating in the front and back directions are formed in the peripheral portion of the contact housing holes. A plate-like shape having a hole-forming portion, with the plate-shaped contact piece facing the contact receiving hole, and a base portion of the contact piece integrally provided on the side wall portion on the surface side of the through-hole forming portion And a plating layer formed to be continuous with the inner wall of the through hole, the front and back surfaces of the through hole forming portion, and the surface of the contact piece.

  A second feature of the present invention is an IC socket composite, wherein the pair of IC sockets according to any one of claims 1 to 5 are brought into contact with each other in a state where the back surfaces are aligned with each other. In addition, the gist is that the plating layers on the back side of the through hole forming portion are soldered.

  A third feature of the present invention is a method of manufacturing an IC socket, wherein a plurality of contact storage holes penetrating in the front and back direction are formed, and a through hole penetrating in the front and back direction is formed in a peripheral portion of the contact storage hole. The base of the contact piece is integrally provided on the side wall portion on the surface side of the through-hole forming portion with the plate-like contact piece facing the contact receiving hole. A step of integrally molding the plate-shaped socket base with a synthetic resin, and a step of forming a plating layer so as to be continuous with the inner surface of the through hole, the front and back surfaces of the through hole forming portion, and the surface of the contact piece; The gist is to provide.

  According to the present invention, it is possible to provide an IC socket capable of making metal contact with a land on the IC package side, having high productivity, and capable of dealing with high pin count, fine pitch, high current, and high speed. .

  Hereinafter, an IC socket, an IC socket composite, and a method of manufacturing an IC socket according to the present invention will be described based on embodiments shown in the drawings.

[First Embodiment]
1 and 2 show an IC socket according to the present embodiment. 1 is a plan view of the main part of the IC socket, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

  The IC socket 1 according to the present embodiment is roughly constituted by a substantially plate-shaped socket base 10 integrally formed of a synthetic resin, and a plating layer 20 provided at an important point of the socket base 10. .

  The socket base 10 is formed with a plurality of through holes 11 as contact receiving holes in a predetermined arrangement. In the present embodiment, the planar shape of the through hole 11 is a rectangle.

  Further, a columnar through-hole forming portion 12 that protrudes toward the IC package (not shown) is formed in the vicinity of one peripheral portion in the longitudinal direction of the through hole 11 in the socket base 10. As shown in FIGS. 1 and 2, the through-hole forming portion 12 is formed in a columnar shape between the through holes 11 along the longitudinal direction of the through holes 11. A through hole 13 that penetrates the socket base 10 in the front and back direction is formed in the through hole forming portion 12.

  A plate-like contact piece 14 is formed in a cantilever shape on the upper side wall of the through hole forming portion 12 so as to face the opening on the surface side of the through hole 11. That is, the contact piece 14 is formed so as to protrude in parallel with the plate surface from one peripheral portion in the longitudinal direction of the through hole 11 toward the other peripheral portion. The contact piece 14 is set to have a predetermined thickness, and the plate-like front and back direction coincides with the front and back direction of the socket base 10. A hemispherical contact protrusion 14A is integrally formed at the center of the surface of the contact piece 14 on the free end side.

  A catalyst layer 21 is formed on the front and back surfaces of the through hole forming portion 12, the inner surface of the through hole 13, and the front surface side of the contact piece 14. A plating layer 20 is formed on the surface of the catalyst layer 21.

  In the IC socket 1 according to the present embodiment, since all the contact pieces 14 can be collectively formed by resin molding, it is possible to solve the problem that the manufacturing time is increased due to the increase in the number of pins of the IC socket 1.

  In the present embodiment, since the contact piece 10 can make metal contact with the land on the IC package side, the contact resistance can be set small, and there is no problem of voltage drop or heat generation of the contact portion. Furthermore, since there is a wiping function for rubbing between metals, an oxide film on the metal surface can be removed to achieve a fresh metal contact.

(Installation of IC package)
Next, the case where the IC package 40 is mounted on the IC socket 1 according to the present embodiment will be described with reference to FIGS.

  FIG. 3 shows a state immediately before the IC package 30 is aligned with the IC socket 1. The IC package 30 is an LGA package, and a plurality of land portions 31 are arranged on the lower surface. The contact protrusions 14 </ b> A protruding from the other end of the contact piece 14 on the IC socket 1 side are provided in the same manner as the arrangement of the land portions 31 of the IC package 30. As shown in FIG. 3, the position in the land portion 31 that first contacts the contact protrusion 14A is the position indicated by the alternate long and short dash line L1 in the figure.

  FIG. 4 shows a state in which the land portion 31 of the IC package 30 is pressed against the contact protrusion 14 </ b> A of the IC socket 1 and then pressed. At this time, as shown in FIG. 4, the contact protrusion 14 </ b> A and the land portion 31 abut at a position indicated by a one-dot chain line L <b> 2 in the drawing. Therefore, the plating layer 20 and the land portion 31 on the surface of the contact protrusion 14A are rubbed while being displaced from each other at the position of the alternate long and short dash line L1 to L2.

  FIG. 5 shows a state where the land portion 31 of the IC package 30 is further pressed against the contact protrusion 14 </ b> A of the IC socket 1. At this time, as shown in FIG. 5, the contact protrusion 14 </ b> A and the land portion 31 abut at a position indicated by a one-dot chain line L <b> 3 in the drawing. Accordingly, the plating layer 20 on the contact protrusion 14A and the land portion 31 are rubbed and moved from the position where they first contact each other while being displaced from each other by a distance d. Eventually, a retention lock mechanism (not shown) may be held so that the IC package 30 does not come off.

  As described above, the contact is displaced while being rubbed, thereby having a wiping action for removing the oxide film on the contact. Therefore, the plating layer 20 and the land portion 31 can ensure a connection with a small contact resistance.

  When the contact piece 14 bends downward, the contact point between the plating layer 20 and the land portion 31 can be moved and the contact can be ensured because the contact protrusion 14A is hemispherical, and the contact protrusion 14A is inclined. This is because the hemispherical curved surface is always in contact with the land portion 31 even if the posture is inclined.

(IC socket mounting)
As a method for mounting the IC socket 1 according to the present embodiment, solder balls can be used. Hereinafter, a method for forming solder balls will be described with reference to FIGS.

  This mounting method can be used, for example, when the IC socket 1 is mounted on a motherboard (main printed circuit board) of a personal computer. As shown in FIGS. 6A and 6B, the solder paste 40 is screen-printed on the land 20A on the back surface side formed in the through hole 13 of the IC socket 1.

  Next, as shown in FIG. 6C, the printed solder paste 40 may be changed to solder balls 41 by heating by a method such as reflow.

  In order to mount the manufactured IC socket 1 on the mother board, the IC socket 1 is positioned and placed on the mother board, and soldering by reflow is performed at the same time when other components are mounted. .

(IC socket complex)
For server sockets that require IC socket maintenance, it is convenient to use an IC socket complex 1A as shown in FIG.

  As shown in FIG. 7, the IC socket complex 1 </ b> A manufacturing method prepares a pair of IC sockets 1 provided so that the lands 20 </ b> A on the back surface side of the through-hole forming portion 12 are vertically symmetrical. A solder paste (not shown) is printed on one land 20 </ b> A of the IC socket 1. Then, as shown in FIG. 7, the pair of IC sockets 1 are aligned and joined so that the lands 20A correspond to each other. At this time, the solder paste is interposed between the lands 20A corresponding to each other.

  Next, while maintaining this state, heating such as reflow is performed to solder the lands 20A of the pair of upper and lower IC sockets 1 with the solder 42, thereby completing the IC socket complex 1A.

  Since this IC socket complex 1A has contacts on the front and back surfaces, a socket structure that can be exchanged on the front and back surfaces can be realized.

(IC socket manufacturing method)
Next, a method for manufacturing the IC socket 1 according to the present embodiment will be described by applying MID (Molded Interconection Device) technology.

  First, primary injection molding for forming the socket base 10 as shown in FIG. Surface treatment is performed by etching the surface of the socket base 10 thus formed.

  Next, secondary injection molding is performed leaving a portion to be plated. As shown in FIG. 8B, the secondary injection mold 50 is a simple mask for forming a circuit. And as shown in FIG.8 (c), the catalyst layer 21 is made to adhere to the part exposed from the type | mold 50 for secondary injection molding.

  Thereafter, as shown in FIG. 9A, after removing the secondary injection molding die 50, if a plating process is performed, a three-dimensional circuit is formed with the plating layer 20 as shown in FIG. 9B. be able to. In this plating step, the plating layer 20 is formed on the catalyst layer 21. As the plating treatment, either electroless plating or electrolytic plating may be performed.

  Further, as shown in FIGS. 6A to 6C, solder balls 41 may be formed on the lands 20A of the plating layer 20 on the back surface of the through-hole forming portion 12, and then a retention lock mechanism component is provided. Also good.

  Here, an example of a specific specification of the IC socket 1 will be described.

Circuit width 0.2mm ~
Circuit interval 0.2mm ~
Contact piece thickness 0.3mm ~
Through hole diameter φ0.2mm
Plating base Cu: 4 to 10 μm
Plating intermediate layer Ni: 6 to 20 μm
Plating finish layer Au: 0.1 to 0.3 μm
Applicable resin LCP, SPS, PA, PPA, PPS, PC-ABS, PEI
In the above specification example, examples of the base (Cu), intermediate (Ni), and finish (Au) are shown as plating. However, depending on the specification environment, the intermediate is eliminated and Au is plated directly on Cu. May be.

  The applied resin may be selected depending on the required characteristics. However, when electric characteristics are important, a liquid crystal polymer (LCP) having a low dielectric constant is an effective material. In the case of using LCP, there is an advantage that heat resistance is easily increased, a reflow resistance is sufficient, and that strength is high. On the other hand, the mechanical strength is anisotropic and the weld strength is low. However, in recent years, engineering plastics technology has advanced dramatically, and materials called super engineering plastics, which have been compatible with each other, have been developed one after another. Since any material that can be used for injection molding can be applied, it is considered that the possibility of selecting a resin that meets the purpose will be increased.

  In the IC socket 1 according to the present embodiment, by using the MID technology, productivity is remarkably higher than that of the conventional IC socket, and it is possible to cope with an increase in the number of pins, a fine pitch, a large current, and a high speed. .

  In particular, in the present embodiment, since the plurality of contact housing holes formed in the socket base 10 are the through holes 11, when the socket base 10 is resin-molded, the mold structure is simple and easy to mold. In addition, there is an advantage that it can be performed at a low cost.

[Second Embodiment]
10 and 11 show an IC socket 2 according to a second embodiment of the present invention. FIG. 10 is a plan view of the main part of the IC socket, and FIG. 11 is a cross-sectional view taken along the line BB of FIG.

  The IC socket 2 of the present embodiment has a configuration in which the later-described elastomer 60 is provided in the IC socket 1 according to the first embodiment, and other configurations are the same as those of the first embodiment. Accordingly, in the IC socket 2, the same parts as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 10 and FIG. 11, elasticity for suppressing contact pressure adjustment of the contact piece 14 and reduction of contact pressure due to deformation of the contact piece 14 in the through hole 11 of the IC socket 2 according to the present embodiment. An elastomer 60 is disposed as a material having properties (rebound properties). In addition, as a material having resilience, heat resistance, chemical resistance, and creep resistance are good like a fluorine-based elastomer. For example, a material having heat resistance of 230 ° C. or more can withstand reflow. Because it can.

  Also in the IC socket 2 according to the present embodiment, the same operations and effects as those of the first embodiment described above can be achieved. Further, the manufacturing method of the IC socket 2 according to the present embodiment is the same as the manufacturing method of the IC socket 1 according to the first embodiment described above. After the socket base (socket housing) 10 is molded, the IC socket 2 is penetrated. A step of forming the elastomer 60 in the hole 11 is incorporated.

[Other embodiments]
It should not be understood that the descriptions and drawings which form part of the disclosure of the above-described embodiments limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, each of the above embodiments is an example in which the catalyst layer is formed under the plating layer, but it is needless to say that the plating layer may be formed without forming the catalyst layer.

It is a principal part top view of the IC socket which concerns on the 1st Embodiment of this invention. It is AA sectional drawing of FIG. It is principal part sectional drawing which shows the state before mounting | wearing with an IC package to the IC socket which concerns on 1st Embodiment. It is principal part sectional drawing which shows the state in the middle of mounting | wearing with the IC package to the IC socket which concerns on 1st Embodiment. It is principal part sectional drawing which shows the state which mounted | wore the IC package to the IC socket which concerns on 1st Embodiment. (A)-(c) is principal part sectional drawing which shows the process of forming a solder ball in the land of the back surface of an IC socket. It is principal part sectional drawing of the IC socket composite_body | complex which manufactured the pair of IC socket which concerns on 1st Embodiment, and made the back side land contact each other via a solder paste, and performed reflow. (A)-(c) is sectional drawing which shows the manufacturing process of the IC socket which concerns on 1st Embodiment. (A) And (b) is sectional drawing which shows the manufacturing process of the IC socket which concerns on 1st Embodiment. It is a principal part top view which shows the IC socket which concerns on 2nd Embodiment. It is BB sectional drawing of FIG.

Explanation of symbols

1, 2
DESCRIPTION OF SYMBOLS 1A IC socket complex 10 Socket base | substrate 11 Through-hole 12 Through-hole formation part 13 Through-hole 14 Contact piece 14A Contact protrusion 20 Plating layer 20A Land 21 Catalyst layer 30 IC package 31 Land part 40 Solder paste 41 Solder ball 42 Solder 60 Elastomer

Claims (8)

A plurality of contact housing holes penetrating in the front and back directions are formed, and a through hole forming portion in which a through hole penetrating in the front and back directions is formed in a peripheral portion of the contact housing hole, and the plate-shaped contact piece is the contact A plate-shaped socket base body in which the base portion of the contact piece is integrally provided on the side wall portion on the surface side of the through-hole forming portion in a state facing the storage hole;
A plating layer formed so as to be continuous with the inner surface of the through hole and the front and back surfaces of the through hole forming portion and the surface of the contact piece;
An IC socket comprising:   2. The IC socket according to claim 1, wherein the socket base is integrally formed of a synthetic resin having electrical insulation.   3. The IC socket according to claim 1, wherein a bulging contact protrusion is formed on a surface of the free end portion of the contact piece.   The IC socket according to claim 1, wherein a member having resilience is accommodated in the contact accommodation hole.   The IC socket according to claim 4, wherein the repulsive member is made of a material having durability against reflow.   6. The IC according to claim 1, wherein a solder ball is provided on a plating layer formed so as to be exposed on a back surface side of the through hole forming portion. socket.   The pair of IC sockets according to any one of claims 1 to 6, wherein the pair of IC sockets are in contact with each other in a back surface state, and the plating layers on the back surface side of the through hole forming portion are soldered together. An IC socket composite characterized by the above. A plurality of contact housing holes penetrating in the front and back directions are formed, and a through hole forming portion in which a through hole penetrating in the front and back directions is formed in a peripheral portion of the contact housing hole, and the plate-shaped contact piece is the contact A step of integrally molding a plate-shaped socket base body with a synthetic resin in which the base portion of the contact piece is integrally provided on the side wall portion on the surface side of the through-hole forming portion in a state facing the storage hole; ,
Forming a plating layer so as to be continuous with the inner surface of the through hole and the front and back surfaces of the through hole forming portion and the surface of the contact piece;
A method for manufacturing an IC socket, comprising:

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