1. Field of the Invention
The present invention relates to an electronic part and a circuit substrate.
2. Description of the Related Art
With the recent improvement in the performance of computer systems, numerous electronic parts having various functions are mounted on a single circuit substrate and when an electronic part requires replacement due to failure or the like, or when a new electronic part is added to expand function, replacement work or addition work of the electronic part on the circuit substrate is necessary. In such a case, a hot plug (hot swap) mechanism is required when a desirable part must be replaced or added in a state in which a part of the circuit substrate is kept alive while another part of the circuit substrate is not.
When the connecting terminals 400 and 500 thus arranged are connected, upon plugging the plug-type connection terminal 400 into the plug portion 510 of the receptacle-type connecting terminal 500, the wirings 402 that are arranged at both ends in a direction perpendicular to the direction of the electrical connection and the wirings 502 are connected first, the wirings 403 and the wirings 502 are connected next, and the wirings 404 and the wirings 502 are connected finally. When the plug-type connecting terminal 400 is unplugged from the plug portion 510, the wirings are disconnected in the opposite order. Such a structure is referred to as card-edge connection.
On the other hand, in an electronic part 600, a plurality of electrical connecting terminals 601 to 603 that are different in height (having different lengths) from a main surface 604 in an inserting direction (direction indicated by outlined arrows in
In other words, in the hot swap mechanism of conventional connecting structures such as the card-edge connection shown in
There still are some problems with the hot swap mechanism described above. For example, in the card-edge connection, the wirings 402 to 404 can only be formed on the main surface 401, which is on only one of the two sides of the plug-type connection terminal 400. In PGA, to maintain strength, the electrical connecting terminals 601 to 603 cannot be formed at intervals smaller than certain intervals in the electronic part 600, in other words, there is a limit in terms of high density mounting.
Therefore, to achieve further high density mounting, mounting techniques such as a ball grid array (BGA) and a land grid array (LGA) have been developed, which enable electrical connection between an electronic part and a circuit substrate with electrodes formed at 0.5 millimeter (mm) intervals. However, in BGA and LGA, once electrical connection with the circuit substrate is established, connectors such as an electrode bump and an electrode land are mechanically connected to each other permanently. Therefore, this mounting technique is not suitable for part replacement or the like (For example, Japanese Patent Laid-Open Publication Nos. 2000-340709 and 2001-68594).
Therefore, electrical connection of an electronic part and a circuit substrate in which part replacement or the like can be easily done has been achieved by arranging deformable spiral contactors on the circuit substrate while maintaining correspondence with the electrode shape in BGA and the like.
As shown in
Furthermore, as shown in
In the electrical connection of the electronic part and the circuit substrate shown in
In addition, for high integration and high density, it is difficult to implement both the attaching/detaching mechanism of the electronic parts and the hot swap mechanism at the same time in a chip size package (CSP) technique, such as BGA and LGA. The techniques disclosed in the patent documents mentioned above do not provide a technique that achieves the attaching/detaching mechanism of the electronic parts and the hot swap mechanism at the same time, either.
It is an object of the present invention to at least solve the above problems in the conventional technologies.
An electronic part according to one aspect of the present invention is mounted on a circuit substrate having a plurality of elastic electrical contactors, and includes a plurality of electrical connecting terminals enabling to establish electrical connection with the circuit substrate by contacting the electrical contactors. The electrical connecting terminals are formed to be different in height from each other relative to a surface on which the electrical connecting terminals are formed.
A circuit substrate according to another aspect of the present invention includes a plurality of electrical contactors that enable to establish electrical connection with an electronic part that is mounted on the circuit substrate and that includes a plurality of electrical connecting terminals, by contacting the electrical connecting terminals. The electrical contactors are elastic, and are different from each other in height relative to a surface on which the electrical contactors are formed, in a state in which no external force is applied.
The other objects, features, and advantages of the present invention are specifically set forth in or will become apparent from the following detailed description of the invention when read in conjunction with the accompanying drawings.
Exemplary embodiments according to the present invention are explained in detail with reference to the accompanying drawings.
In electrical connection of an electronic part and a circuit substrate according to a first embodiment of the present invention, spherical connecting terminals (solder bumps) having different sizes (diameters) are used as the electrical connecting terminals of the electronic part, and planar spiral contactors having different sizes (diameters) are used as the electrical contactors of the circuit substrate.
The solder bumps 101 to 103 are formed in such relation as the solder bump 101>the solder bump 102>the solder bump 103 in diameter, and are arranged in order of the solder bump 103, the solder bump 102, and the solder bump 101 toward the end of the main surface 116 of the connecting substrate 117 so that the diameter of the solder bumps gradually increases. The spiral contactors 151 to 153 are formed in such relation as the spiral contactor 151>the spiral contactor 152>the spiral contactor 153 in diameter so as to correspond to the solder bumps 101 to 103, respectively.
Electrode lands 111 to 113 formed with Cu and the like in desirable sizes are formed on the conductor pattern 119, and the rest of the main surface 116 is covered with a resist 118. The solder bumps 101 to 103 are formed by plating on the electrode lands 111 to 113, for example, by putting the connecting substrate 117 in liquid obtained by heating solder to be melted in a deoxygenated atmosphere. At this time, if the electrode lands 111 to 113 are formed in such relation as the electrode land 111>the electrode land 112>the electrode land 113 in size (diameter), the amount of the solder to be plated differs depending on the size of the electrode lands 111 to 113 due to surface tension of the melted solder, thereby obtaining the solder bumps 101 to 103 of different sizes.
Subsequently, as shown in
When the electronic part 100 in which the solder bumps 101 to 103 are thus formed is mounted on the circuit substrate 150, each of the solder bumps 101 to 103 and each of the spiral contactors 151 to 153 come into contact as follows to establish electrical connection.
Then, as shown in
With such electrical connection, when the electronic part 100 is connected to the circuit substrate 150, it is possible to bring the solder bump 101 and the spiral contactor 151 into contact to be alive first, to bring the solder bump 102 and the spiral contactor 152 into contact to be alive next, and to bring the solder bump 103 and the spiral contactor 153 to be alive finally. Moreover, since each of the solder bumps 101 to 103 and each of the spiral contactors 151 to 153 are not mechanically connected, when the electronic part 100 is separated from the circuit substrate 150, it is possible to disconnect the solder bump 103 and the spiral contactor 153 first, the solder bump 102 and the spiral contactor 152 next, and the solder bump 101 and the spiral contactor 151 finally, in reverse order.
With this arrangement, a hot swap mechanism can be implemented, for example, by a configuration in which a power source circuit is energized by contact of the solder bump 101 and the spiral contactor 151, and other circuits such as a program circuit are energized by contact of the solder bumps 102 and 103 and the spiral contactors 152 and 153. Therefore, in addition to the hot swap mechanism, in which an arbitrary circuit in the electronic part 100 is energized first, and other circuits are energized later, the attaching/detaching mechanism of the electronic part 100 with respect to the circuit substrate 150 can also be implemented. In the first embodiment, the solder bumps 101 to 103 are arranged so that the height in the direction of contact gradually increases toward the edge of the main surface 116. This arrangement is suitable for the following cases.
Arrangement of the solder bumps 101 to 103 is not limited to the arrangement described above, and can be modified according to a desired connecting mode and the like. As described above, according to the electronic part and the circuit substrate according to the first embodiment, the size (height) of the solder bumps 101 to 103 of the electronic part 100 are varied in the direction of contact with the circuit substrate 150 relative to the main surface 116 of the connecting substrate 117. Therefore, the contact/separation timing of the respective solder bumps 101 to 103 and the respective spiral contactors 151 to 153 are varied, thereby implementing the hot swap mechanism of the electronic part 100 with respect to the circuit substrate 150. Moreover, since the electrical connection is achieved by bringing each of the solder bumps 101 to 103 and each of the spiral contactors 151 to 153 into contact, the attaching/detaching mechanism of the electronic part 100 with respect to the circuit substrate 150 can be achieved. Therefore, for example, at the time of maintenance or replacement of parts, attachment and detachment of the electronic part 100 is possible while achieving the hot swap mechanism. Furthermore, since this electrical connection of the electronic part and the circuit substrate is applicable to BGA and LGA, high density mounting of the electronic part 100 becomes possible.
In the first embodiment, a case where spherical contacting terminal (solder bumps) as the electrical connecting terminal of an electronic part and planar spiral contactors as the electrical contactors of a circuit substrate are respectively used has been explained.
On the other hand, in electrical connection of an electronic part and a circuit substrate according to a second embodiment of the present invention, disk-shaped connecting terminals (electrode lands) are used as the electrical connecting terminals of the electronic part, and convex spiral contactors are used as the electrical contactors of the circuit substrate. In the second embodiment, the same reference characters are used for the parts that have been explained, and duplicate explanation is omitted.
The electrode lands 201 to 203 are formed such that the size (diameter) thereof along the main surface 216 is identical. Similarly, the spiral contactors 251 to 253 are formed such that the size (diameter) thereof along a main surface 256 of an insulating substrate 257 is identical corresponding to the electrode lands 201 to 203, but the height thereof in the direction of contact with the electronic part 200 gradually increases toward the edge of the main surface 256.
Subsequently, as shown in
When the electronic part 200 is mounted on the circuit substrate 250 in which the spiral contactors 251 to 253 are thus formed, each of the electrode lands 201 to 203 and each of the spiral contactors 251 to 253 come into contact as follows to establish electrical connection.
Then, as shown in
With such electrical connection, when the electronic part 200 is connected to the circuit substrate 250, it is possible to bring the spiral contactor 251 and the electrode land 201 into contact to be alive first, to bring the spiral contactor 252 and the electrode land 202 into contact to be alive next, and to bring the spiral contactor 253 and the electrode land 203 into contact to be alive finally. Moreover, when the electronic part 200 is separated from the circuit substrate 250, it is possible to disconnect the electrode land 203 and the spiral contactor 253 first, the electrode land 202 and the spiral contactor 252 next, and the electrode land 201 and the spiral contactor 251 finally, in reverse order of the order in the case of connection.
With this arrangement, in addition to the hot swap mechanism, in which an arbitrary circuit in the electronic part 200 is energized first and other circuits are energized later, the attaching/detaching mechanism of the electronic part 200 with respect to the circuit substrate 250 can also be implemented. As described above, according to the electrical connection of the electronic part and the circuit substrate according to the second embodiment, the height of each of the spiral contactors 251 to 253 of the circuit substrate 250 is varied in the direction of contact with the electronic part 200 relative to the main surface 256 of the insulating substrate 257. Therefore, the contact/separation timing of the respective electrode lands 201 to 203 and the respective spiral contactors 251 to 253 are varied, thereby implementing the hot swap mechanism of the electronic part 200 with respect to the circuit substrate 250. Moreover, similarly to the first embodiment, since the electrical connection is achieved by bringing each of the electrode lands 201 to 203 and each of the spiral contactors 251 to 253 into contact, the attaching/detaching mechanism of the electronic part 200 with respect to the circuit substrate 250 can be achieved. Therefore, for example, at the time of maintenance or replacement of parts, attachment and detachment of the electronic part 200 is possible while achieving the hot swap mechanism. Furthermore, since this electrical connection of the electronic part and the circuit substrate is applicable to BGA and LGA, high density mounting of the electronic part 200 becomes possible. The electrode lands 201 to 203 and the spiral contactors 251 to 253 can be formed such that the sizes thereof along the main surface 216 and the main surface 256 are different from each other as described in the first embodiment.
In the second embodiment, a case where disk-shaped connecting terminals (electrode lands) as the electrical connecting terminal of an electronic part and convex spiral contactors as the electrical contactors of a circuit substrate are respectively used has been explained.
On the other hand, in electrical connection of an electronic part and a circuit substrate according to a third embodiment of the present invention, disk-shaped (cylindrical) connecting terminals (electrodes) having different heights are used as the electrical connecting terminals of the electronic part, and convex spiral contactors having different heights are used as the electrical contactors of the circuit substrate. In the third embodiment, the same reference characters are used for the parts that have been explained, and duplicate explanation is omitted.
The electrodes 301 to 303 are formed such that the size (diameter) thereof along the main surface 316 is identical, and the height thereof in the direction of contact with the circuit substrate 350 gradually increases toward the edge of the main surface 316. Furthermore, the spiral contactors 351 to 353 are formed at positions corresponding to positions of the electrodes 301 to 303 on the main surface 356, such that the size (diameter) thereof along a main surface 356 is identical, and the height thereof in the direction of contact with the electrode part 300 gradually increases toward the edge of the main surface 356.
When the electronic part 300 in which the electrodes 301 to 303 are formed is mounted on the circuit substrate 350 in which the spiral contactors 351 to 353 are thus formed, each of the electrodes 301 to 303 and each of the spiral contactors 351 to 353 come into contact as follows to establish electrical connection.
Then, as shown in
With such electrical connection, when the electronic part 300 is connected to the circuit substrate 350, it is possible to bring the electrode 301 and the spiral contactor 351 into contact to be alive first, the electrode 302 and the spiral contactor 352 into contact to be alive next, and the electrode 303 and the spiral contactor 353 into contact to be alive finally. Moreover, when the electronic part 300 is separated from the circuit substrate 350, it is possible to disconnect the electrode 303 and the spiral contactor 353 first, the electrode 302 and the spiral contactor 352 next, and the electrode 301 and the spiral contactor 351 finally, in reverse order to the order in the case of connection.
With this arrangement, the hot swap mechanism, in which an arbitrary circuit in the electronic part 200 is energized first and other circuits are energized later, can be implemented. As described above, according to the electrical connection of the electronic part and the circuit substrate according to the third embodiment, the height of the electrodes 301 to 303 and the height of the spiral contactors 351 to 353 of the circuit substrate 350 are varied so as to increase toward the edge of the main surface 316 and the edge of the main surface 356 in the direction of contact with each other.
Therefore, the contact/separation timing of the respective electrodes 301 to 303 and the respective spiral contactors 351 to 353 are varied further certainly, thereby implementing the hot swap mechanism. Moreover, similarly to the first embodiment and the second embodiment, since the electrical connection is achieved by bringing each of the electrodes 301 to 303 and each of the spiral contactors 351 to 353 into contact, the attaching/detaching mechanism of the electronic part 300 with respect to the circuit substrate 350 can also be achieved. Therefore, for example, at the time of maintenance or replacement of parts, attachment and detachment of the electronic part 300 is possible while achieving the hot swap mechanism. Furthermore, since this electrical connection of the electronic part and the circuit substrate is applicable to BGA and LGA, high density mounting of the electronic part 300 becomes possible. The electrodes 301 to 303 and the spiral contactors 351 to 353 can be formed such that the sizes thereof along the main surface 316 and the main surface 356 are different from each other as described in the first embodiment.
Moreover, although illustration and explanation are omitted, besides usage of the deformable spiral contactors described above as the electrical contactors of the circuit substrate, the electrical connection of the electronic part and the circuit substrate according to the present invention can be implemented, for example, by forming regular electrode lands in the circuit substrate, and using deformable conductive rubber or anisotropically conductive rubber having different sizes as the electrodes of the electronic part. With such a configuration also, the contact/separation timing of the electronic part and the circuit substrate can be varied, thereby implementing the hot swap mechanism at the same time with implementation of the attaching/detaching mechanism.
As described above, according to the electrical connection of the electronic part and the circuit substrate of the first to the third embodiments of the present invention, an attaching/detaching mechanism and a hot swap mechanism of an electronic part in high density mounting can be implemented at the same time.
The present invention is not limited to the first to the third embodiments described above, and various modifications can be applied within a scope not departing from the points of the present invention. For example, instead of the electronic part 100 to be mounted on the circuit substrate 150, a connector having electrical connecting terminals can be used to achieve the electrical connection in which the contact/separation timing is varied. Moreover, while in the first embodiment, for example, a case where the spiral contactors 151 to 153 are flat in the initial state as shown in
According to the embodiments of the present invention described above, an attaching/detaching mechanism and a hot swap mechanism of an electronic part and a circuit substrate can be implemented at the same time. Moreover, order of electrical connection with a circuit substrate can be controlled even for electrical connecting terminals of an electronic part of surface-mounting type.
Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth.
This is a continuation application of International Application Number PCT/JP2005/005030, which was filed on Mar. 18, 2005.
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Number | Date | Country | |
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Parent | PCT/JP2005/005030 | Mar 2005 | US |
Child | 11898713 | US |