JP3727413B2 - Pin grid array socket - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a PGA socket used for connecting a semiconductor chip such as a CPU having a contact arrangement of a Pinglit Array (hereinafter abbreviated as PGA) type to other circuit components such as a printed wiring board.
[0002]
[Prior art]
FIG. 1 is a perspective view schematically showing a method of using a PGA socket.
[0003]
A PGA socket 1 shown in FIG. 1 is used to connect a semiconductor chip (for example, CPU) 12 to a printed wiring board 14. A plurality of contact pins 13 arranged in an array protrude from the back surface of the semiconductor chip 12. On the other hand, the fins 11 are typically provided on the upper surface of the semiconductor chip 12.
[0004]
A plurality of contact holes 2 are provided on the upper surface of the PGA socket 1 corresponding to the contact pins 13 of the semiconductor chip 12. On the other hand, from the back surface of the PGA socket 1, a plurality of contact pins 3 that are also arranged in an array protrude. Inner contact pieces (not shown in FIG. 1) are provided inside the respective contact holes 2 and are electrically connected to the corresponding contact pins 3. Thereby, between the component (semiconductor chip 12 in the configuration of FIG. 1) arranged on the upper surface side of the PGA socket 1 and the component (printed wiring board 14 in the configuration of FIG. 1) arranged on the lower surface side, An electrical connection is provided.
[0005]
The PGA socket 1 to which the semiconductor chip 12 is connected is connected to the printed wiring board 14 and further mounted on the mother board 19 through the socket 17. At this time, the contact pin 3 of the PGA socket 1, the contact hole 15 on the upper surface and the contact pin 16 on the lower surface of the printed wiring board 14 corresponding thereto, and the contact hole 18 provided in the socket 17, between these components. Electrical connection is ensured. On the printed wiring board 14, another IC chip 21, a changeover switch 22 for switching the operation clock of the semiconductor chip 12, and the like are provided as necessary.
[0006]
FIG. 2 is a diagram showing the configuration of the contact hole 2 and the contact pin 3 of the PGA socket 1. Specifically, FIG. 2A is a partial cross-sectional view of the PGA socket 1. FIG. 2B is a plan view of the PGA socket 1 viewed from the direction indicated by the arrow A in FIG. 2A and shows the arrangement of the contact pins 3.
[0007]
The contact pins of a conventional PGA type semiconductor chip are generally arranged at a pitch of 2.54 mm. In accordance with this, the contact holes 2 and the contact pins 3 of the conventional PGA socket 1 are also typically provided at a pitch of 2.54 mm. Further, the contact hole 2 and the contact pin 3 in this case are typically arranged at the apexes of the grid as shown in FIG.
[0008]
FIG. 3 is a diagram showing a configuration of contact pins 3 included in a conventional PGA socket. FIG. 3A is a view of the contact pin 3 as viewed from the side. Actually, as shown in FIG. 3B, a space 4 is provided in a part of the inside of the contact pin 3, and the inner contact piece 5 is inserted into the space 4 to contact the main body of the contact pin 3. are doing. Therefore, the actual cross-sectional shape of the contact pin 3 is as shown in FIG. When the contact pin 13 (see FIG. 1) of the semiconductor chip 12 mounted on the upper surface of the PGA socket 1 is inserted into the contact hole 2 of the PGA socket 1, it comes into contact with the inner contact piece 5 and further the main body of the contact pin 3 Is electrically conductive.
[0009]
FIG. 4 is a diagram schematically showing a configuration of a printed wiring board 14 which is a connection partner of the conventional PGA socket 1. Specifically, FIG. 4A is a partial cross-sectional view of the printed wiring board 14. FIG. 4B is a plan view of the printed wiring board 14 viewed from the direction indicated by the arrow B in FIG. 4A and shows the arrangement of the contact holes 15.
[0010]
As shown in FIG. 4B, the contact hole 15 of the printed wiring board 14 is arranged at each vertex of a grid with a pitch of 2.54 mm and further arranged at the face center position. Contact pins 16 are inserted into the contact holes 15 at positions corresponding to the apexes of the 2.54 mm pitch grid from the side opposite to the surface shown in FIG. Therefore, the contact pins of the printed wiring board 16 are also provided at a 2.54 mm pitch as a result.
[0011]
FIG. 5 is a view showing a state in which the conventional PGA socket 1 is connected to the printed wiring board 14. Specifically, FIG. 5A is a partial cross-sectional view of the PGA socket 1 and the printed wiring board 14 in a connected state. FIG. 5B is a plan view of the printed wiring board 14 viewed from the direction indicated by the arrow C in FIG.
[0012]
The PGA socket 1 and the printed wiring board 14 are positioned so that the respective contact pins 3 and 16 are shifted from each other by a half pitch (1.27 mm), and the contact pin 3 of the PGA socket 1 defines a contact hole of the printed wiring board 14. It is mounted so as to penetrate through and protrude from the opposite side. The protruding contact pin 3 of the PGA socket 1 and the contact pin 16 of the printed wiring board 14 are electrically connected by a wiring 23 provided on the surface of the printed wiring board 14.
[0013]
Further, an appropriate wiring pattern (not shown) is provided on the surface of the printed wiring board 14, and the contact pins 3 or 16 are connected to other circuit elements mounted on the printed wiring board 14. As a result, the signal of the semiconductor chip 12 mounted on the PGA socket 1 is subjected to necessary signal processing on the printed wiring board 14 and then transmitted to the mother board 19 via the socket 17.
[0014]
In the PGA socket 1 having the above-described configuration, wiring may be formed on the housing surface. However, in the PGA socket 1 according to the prior art, the contact hole 2 and the contact pin 3 are generally arranged at each vertex position of the grid of 2.54 mm pitch, and the space margin for forming the wiring is compared on the housing surface. Exist.
[0015]
[Problems to be solved by the invention]
In order to cope with the trend toward pinching pitches in recent PGA type semiconductor device structures, the contact pins 3 of the PGA socket 1 also need to be arranged at pinching pitches (eg, 1.27 mm pitch). In such a PGA socket corresponding to the pinching pitch, the contact hole and the contact pin are arranged at the face center position in addition to the apex of the grid. Therefore, the contact holes and the contact pins are consequently arranged at a 1.27 mm pitch. Therefore, there is not much room for providing wiring on the surface of the housing. In this case, a sufficient distance cannot be ensured between the contact pin or the contact hole and the wiring, and the withstand voltage between them is lowered.
[0016]
The present invention has been made in order to solve the above-mentioned problems, and the object thereof is to reduce the insulation pitch so that a necessary wiring pattern can be easily formed on the surface of the housing without deteriorating the withstand voltage. To provide a corresponding PGA socket.
[0017]
[Means for Solving the Problems]
A pin grid array socket according to the present invention includes a housing in which a plurality of through holes are provided in an array, and a plurality of contact members respectively inserted into the plurality of through holes, and a wiring pattern on a surface of the housing The diameter of the first through hole located in the vicinity of the wiring pattern among the plurality of through holes is set to a value smaller than the diameters of the other second through holes. This achieves the above object.
[0018]
In one embodiment, the housing is configured by combining a first housing member and a second housing member, and each of the plurality of contact members includes the first housing member and the second housing member. And is held in a swingable state.
[0019]
In one embodiment, each of the plurality of contact members is a contact pin with one end protruding to the outside of the housing, and an inner contact piece is inserted inside the other end of the contact pin, Electrical continuity is ensured between the contact pin and the inner contact piece.
[0020]
Alternatively, each of the plurality of contact members is a contact sleeve provided on an inner wall of the through hole, and inner contact pieces are inserted into both ends of the contact sleeve, respectively, and the contact sleeve and the respective contact sleeves Electrical conduction between the inner contact piece is ensured.
[0021]
Preferably, the wiring pattern is formed by MID technology.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 6 is a perspective view schematically showing a method of using the PGA socket 100 according to the present invention.
[0023]
A PGA socket 100 shown in FIG. 6 is used for mounting a semiconductor chip (for example, CPU) 112 on a socket 117 mounted on a motherboard 119. Furthermore, the PGA socket 100 has a function as a CPU accelerator for increasing the internal clock frequency of the semiconductor chip (CPU) 112, and a changeover switch 122 is provided for this purpose. However, the application of the present invention is not limited to such a PGA socket having a CPU accelerator function. For example, as described in the prior art, a PGA socket used for connecting a semiconductor chip to a printed wiring board. Needless to say, it can also be applied to.
[0024]
A plurality of contact pins 113 arranged in an array protrude from the back surface of the semiconductor chip 112. On the other hand, typically, the heat radiation fins 111 and the heat radiation fan 110 (or only one of them) are provided on the upper surface of the semiconductor chip 112.
[0025]
A plurality of contact holes 102 are provided on the upper surface of the PGA socket 100 so as to correspond to the contact pins 113 of the semiconductor chip 112. On the other hand, from the back surface of the PGA socket 100, a plurality of contact pins 103 that are also arranged in an array protrude. Inner contact pieces (not shown in FIG. 6) are provided in the respective contact holes 102 and are electrically connected to the corresponding contact pins 103. As a result, there is an electrical connection between the components disposed on the upper surface side of the PGA socket 100 (semiconductor chip 112 in the configuration of FIG. 6) and the components disposed on the lower surface side (the socket 117 in the configuration of FIG. 6). A connection is provided.
[0026]
The PGA socket 100 to which the semiconductor chip 112 is connected is mounted on the motherboard 119 via the socket 117 as described above. At this time, the electrical connection between these components is ensured by the contact pin 103 of the PGA socket 100 and the corresponding contact hole 118 provided in the socket 117.
[0027]
FIG. 7 is a plan view of the PGA socket 100 and shows the arrangement of the contact holes 102.
[0028]
The contact hole 102 and the contact pin 103 of the PGA socket 100 are arranged at positions corresponding to the vertexes of the grid of 2.54 mm pitch and the face center of the grid in accordance with the contact arrangement of the recent PGA type semiconductor chip. Has been. As a result, in the PGA socket 100 of the present invention, the contact holes 102 and the contact pins 103 are arranged at a pitch of 1.27 mm, which is half the conventional pitch.
[0029]
In the PGA socket 100 of the present invention, the wiring 120 is formed on the surface of the housing. This wiring 120 is, for example, a wiring pattern to the mounting portion 124 on which the changeover switch 122 for switching the internal clock of the semiconductor chip (CPU) mounted in the PGA socket 100 is mounted. The wiring 120 is formed by a MID (Molded Interconnection Device) technique in which a resin surface constituting the housing of the PGA socket 100 is plated, and a predetermined wiring 120 is further formed in that portion.
[0030]
Further, in the PGA socket 100, the shape of the contact hole 102 is different in the vicinity of the place where the wiring 120 is formed and in other places. This will be further described below with reference to FIGS. 8 (a) and 8 (b). FIG. 8A is an enlarged plan view of a portion indicated by “D” in FIG. FIG. 8B is a cross-sectional view taken along line XX shown in FIG.
[0031]
Specifically, the diameter of the contact hole 102b located in the vicinity of the location where the wiring 120 is formed is made smaller than the diameter of the contact hole 102a in other locations. However, the diameter of the contact hole 102c where the wiring 120 and the contact pin 103 are electrically connected by the solder 140 is set to a value between the diameter of the contact hole 102a and the diameter of the contact hole 102b.
[0032]
In this way, by selectively changing the diameter of the contact hole 102, in the PGA socket 100 of the present invention, it is easy to form the wiring 120 on the housing surface. Furthermore, since the distance between the contact portion (contact hole 102 and contact pin 103) and the wiring 120 can be increased, the withstand voltage is improved even though the PGA pattern has a narrow pitch.
[0033]
In order to form wiring on the surface by MID technology, it is desirable to use liquid crystal polymer (LCP) as a resin material constituting the housing.
[0034]
By the way, the contact pin of the PGA socket is generally attached by being press-fitted into the housing. On the other hand, the contact pin can be attached to the housing without performing such a press-fitting process.
[0035]
FIG. 9 is a diagram showing a configuration of the contact pin 103 included in the PGA socket that enables the above. FIG. 9A shows the contact pin 103 as viewed from the side. Actually, as shown in FIG. 9B, a space 104 is provided in a part of the inside of the contact pin 103, and the inner contact piece 105 is inserted into this space 104 to contact the main body of the contact pin 103. are doing. Therefore, the actual cross-sectional shape of the contact pin 103 is as shown in FIG. When the contact pin 113 (see FIG. 6) of the semiconductor chip 112 mounted on the upper surface of the PGA socket 100 is inserted into the contact hole 102 of the PGA socket 100, it comes into contact with the inner contact piece 105 and further the main body of the contact pin 103. Is electrically conductive.
[0036]
Further, the contact pin 103 shown in FIG. 9 has a portion 130 processed so as to have a “collar shape” on its side surface. The contact pin 103 is held by the housing using the collar portion 130, but in the present invention, the press-fitting process as in the prior art is not performed at that time. A method for holding the contact pin 103 in the present invention will be described below.
[0037]
FIG. 10 is an exploded cross-sectional view illustrating the configuration of the PGA socket 100 in more detail.
[0038]
As shown, the housing of the PGA socket is broken down into two parts. Hereinafter, for convenience, these will be referred to as a first housing member 132 and a second housing member 134, respectively. Each of the first housing member 132 and the second housing member 134 is provided with a plurality of through holes 133 and 135 in a grid pattern with a 1.27 mm pitch as described above with reference to FIG. Yes. As described above with reference to FIG. 9 and as shown again in FIG. 10, the contact pin 103 having the inner contact piece 105 therein is inserted into the through holes 133 and 135. .
[0039]
In the actual assembly process, first, as shown in FIG. 11, the contact pins 103 are respectively inserted into the through holes 135 of the second housing member 134. Next, the first housing member 132 is combined with the second housing member 134 with the contact pin 103 inserted in this manner, and the contact pins 103 are respectively inserted into the through holes 133 of the first housing member 132. To do. Thereby, the shape shown in FIG. 12 is obtained. At this time, each contact pin 103 is held by the housing by pressing the flange-shaped portion 130 on the side surface of each contact pin 103 against the second housing member 134 by the first housing member 132.
[0040]
By adopting such a holding mechanism, it is not necessary to perform a press-fitting process in the manufacturing process of the PGA socket. As a result, even if the PGA sockets have a narrow pitch, it is possible to avoid the occurrence of cracks in the housing, which is a problem in the prior art, as the press-fitting process is performed. Therefore, according to the present invention, for example, a PGA socket having a pinching pitch such as a 1.27 mm pitch can be manufactured with a high yield.
[0041]
Further, in such a holding mechanism, the contact pin 103 is not firmly fixed to the housing, unlike the case of holding by the press-fitting process in the prior art. Rather, each contact pin 103 can change its orientation between the first and second housing members 132 and 134 with some degree of freedom. That is, each contact pin 103 is held by the housing in a swingable state. Below, the holding structure of the contact pin 103 of the present invention having such characteristics is referred to as a “floating structure”.
[0042]
FIG. 13 is a partial cross-sectional view schematically showing the holding state of the contact pin 103 with such a floating structure. The contact pin 103 indicated as (II) in the drawing is held without being inclined with respect to the center line of the contact hole 102 indicated by a one-dot chain line. On the other hand, the contact pin 103 indicated by (I) in the drawing is held slightly tilted with respect to the center line of the contact hole 102 indicated by a one-dot chain line.
[0043]
According to such a floating structure, other circuit components connected to the PGA socket 100, for example, in the configuration of FIG. When the contact pin 103 is inclined to some extent, the pitch deviation can be absorbed and engaged. Therefore, even if there is some variation in pitch accuracy between the samples of the semiconductor chip 112, the variation is absorbed. As a result, the utilization efficiency of the semiconductor chip sample is improved.
[0044]
Further, even if the pitch of the contact pins 103 of the PGA socket 100 itself is shifted to some extent, the contact pins 103 themselves are inclined to some extent by the floating structure, thereby enabling connection. Therefore, the level of pitch accuracy of the contact pins 103 required when manufacturing the PGA socket 100 itself can be reduced.
[0045]
Further, in the PGA socket 100 described above, contact pins 103 having inner contact pieces 105 therein are inserted into the plurality of contact holes 102, respectively. On the other hand, if the inner contact pieces 105 are provided at both ends of each contact hole 102 instead of providing the contact pin 103, the contact pin of the external circuit component is bidirectionally connected to the contact hole of the PGA socket. It becomes the structure which can be inserted.
[0046]
FIG. 14 is a cross-sectional view showing the shape of the contact hole 102 that enables the above-described configuration.
[0047]
Specifically, a contact sleeve 106 for ensuring electrical conduction is inserted into each contact hole 102, and inner contact pieces 105 are inserted from both sides so as to be in contact therewith. At this time, by holding the contact sleeve 106 in the floating structure described in the first embodiment, the same effect as described above can be obtained. The shape of the contact sleeve 106 is not limited to a specific shape, and various shapes as shown in FIGS. 14A to 14D are possible.
[0048]
FIG. 15 is a cross-sectional view schematically showing how the semiconductor chip 210 and the printed wiring board 220 are mounted on the PGA socket 200 of the present embodiment having the inner contact pieces from both directions as described above. As shown in the drawing, the contact pin of the semiconductor chip 210 is inserted from one side of the PGA socket 200, and the contact pin of the printed wiring board 220 is inserted from the other side.
[0049]
In the above description, the contact holes and contact pins of the PGA socket of the present invention are arranged at positions corresponding to the apexes and face centers of the grid of 2.54 mm pitch, and as a result, arranged at a pitch of 1.27 mm. Yes. Or even if it is the structure where a contact hole and a contact pin are arrange | positioned at each vertex of a 1.27 mm pitch grid, it cannot be overemphasized that this invention can be applied and there exists an effect similar to the above-mentioned.
[0050]
Further, the numerical value of the pitch of the contact arrangement is not limited to the specific value mentioned in the above description.
[0051]
【The invention's effect】
As described above, in the PGA socket of the present invention, the formation of wiring on the surface of the housing is facilitated by selectively changing the diameter of the through hole (contact hole) provided in the housing. Further, since the distance between the contact portion (contact hole and contact pin) and the wiring can be increased, the withstand voltage is improved even though the PGA pattern has a narrow pitch.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a method of using a PGA socket.
2A is a partial cross-sectional view of a conventional PGA socket, and FIG. 2B is a plan view as viewed from the direction indicated by an arrow A in FIG.
3A is a side view of a contact pin included in a conventional PGA socket, and FIG. 3B is a cross-sectional view of the contact pin shown in FIG. 3A and an inner contact piece inserted therein. It is a figure and (c) is sectional drawing which shows the state in which the inner contact piece was inserted in the contact pin.
4A is a partial cross-sectional view of a printed wiring board, and FIG. 4B is a plan view of the printed wiring board as viewed from the direction indicated by arrow B in FIG.
5A is a partial cross-sectional view showing a state in which the PGA socket shown in FIG. 2 is attached to the printed wiring board shown in FIG. 4, and FIG. It is the top view seen from the direction shown by.
FIG. 6 is a perspective view schematically showing a method of using a PGA socket.
FIG. 7 is a plan view of the PGA socket of the present invention.
8A is a partially enlarged plan view of a part of FIG. 7, and FIG. 8B is a cross-sectional view taken along line XX shown in FIG.
9A is a side view of a contact pin that can be included in the PGA socket of the present invention, and FIG. 9B is a cross-sectional view of the contact pin shown in FIG. (C) is sectional drawing which shows the state in which the inner contact piece was inserted in the contact pin.
FIG. 10 is a cross-sectional view showing a configuration of a housing that can be included in the PGA socket of the present invention.
FIG. 11 is a cross-sectional view showing a process of attaching a contact pin to a housing that can be included in the PGA socket of the present invention.
FIG. 12 is a cross-sectional view of a contact pin mounted on a housing that can be included in the PGA socket of the present invention.
FIG. 13 is a partially enlarged cross-sectional view showing a state in which a contact pin is attached to a housing that can be included in the PGA socket of the present invention.
14A to 14D are cross-sectional views showing various shapes that can be taken by a contact sleeve that can be provided in the PGA socket of the present invention.
15 is a cross-sectional view showing a state in which contact pins of a semiconductor chip and a printed wiring board are inserted into the contact sleeve shown in FIG. 14;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 PGA socket 2 Contact hole 3 Contact pin 5 Inner contact piece 11 Radiation fin 12 Semiconductor chip 14 Printed wiring board 17 Socket 19 Mother board 21 IC chip 22 Changeover switch 100 PGA socket 102, 102a, 102b, 102c Contact hole 103 Contact pin 105 Inner Contact piece 106 Contact sleeve 110 Radiation fan 111 Radiation fin 112 Semiconductor chip 117 Socket 119 Motherboard 120 Wiring 122 Changeover switch 124 Changeover switch mounting part 132 First housing member 134 Second housing member 200 PGA socket 210 Semiconductor chip 220 Printed wiring board

Claims (5)

A housing having a plurality of through holes are provided in a grid shape, a pin grid array socket includes a plurality of contact members which are respectively inserted into the through hole of the plurality of the wiring pattern is provided on the surface of the housing A pin having a diameter of a first through hole located in the vicinity of the wiring pattern among the plurality of through holes set to a value smaller than a diameter of the other second through hole. Grid array socket.   The housing is configured by combining a first housing member and a second housing member, and each of the plurality of contact members is sandwiched between the first housing member and the second housing member. The pin grid array socket according to claim 1, wherein the pin grid array socket is held in a swingable state.   Each of the plurality of contact members is a contact pin whose one end protrudes to the outside of the housing, and an inner contact piece is inserted inside the other end of the contact pin. The pin grid array socket according to claim 1, wherein electrical continuity between the contact pieces is ensured.   Each of the plurality of contact members is a contact sleeve provided on an inner wall of the through hole, and inner contact pieces are inserted into both ends of the contact sleeve, respectively, and the contact sleeve and the respective inner contacts The pin grid array socket according to claim 1 or 2, wherein electrical conduction between the pieces is ensured.   The pin grid array socket according to any one of claims 1 to 4, wherein the wiring pattern is formed by MID technology.

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