JP3476141B2 - Electronic package assembly support member, electronic package assembly, and method of assembling the assembly - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support member for assembling an electronic package for mounting a cooling device on an LSI, an assembling method of an electronic package assembly having the same, and an assembling method of the electronic package assembly having the same.

[0002]

2. Description of the Related Art High-density mounting, increasing the number of pins on LSI chips,
In order to meet the demand for higher transmission speed, the medium for transmitting electric signals is currently changing from pins to solder balls.

In recent years, the power consumption of LSI chips has been increasing, and cooling has become a very important factor.
Therefore, a huge cooling device (heat sink, liquid cooling module, etc.) is attached to the LSI chip.

A technique relating to a support member for mounting this cooling device is disclosed in Japanese Patent No. 26589667. FIG. 5 is a sectional view of an electronic package assembly in which a cooling device is attached by the supporting member. In FIG. 5, 11 is a lower leg, 12 is a heat sink, 13 is an upper leg, 40
Is an LSI chip, 42 is a substrate, 43 is a heat sink as a cooling device, 44 is an adhesive, and 45 is an adhesive.

In FIG. 5, the LSI chip 202 is cooled by the heat sink 43, and the support member is used to support the heat sink 43.

[0006]

However, in the technique disclosed in Japanese Patent No. 2658967, the load applied to the joint between the LSI chip and the substrate by the heat dissipation member is reduced by the support member. The structure did not strengthen the strength against the shearing force applied to the.

Further, in this technique, in order not to apply a load to the LSI chip, the heat radiating plate is fixed by a leg having a predetermined length to a height which does not contact the LSI chip.
The clearance depends on the mounting accuracy of the LSI chip, L
In consideration of the warp of the SI chip, the pad mounting accuracy, the leg processing accuracy, and the absorption of the warp gap of the supporting member bonding surface, about 0.3 mm was required.

The present invention has been made in view of the above points, and a support member for assembling an electronic package that reduces the load applied to the LSI chip joint portion and at the same time enhances the strength against the shearing force applied to the support member. Having
And to provide a method of assembling a child package assembly and the assembly.

Further, by shortening the clearance between the radiator plate and the LSI chip, more efficient electronic package assembly support member heat conduction for heat dissipation of the LSI chip, the electronic package assembly and the assembly with it It is also intended to provide an assembly method.

[0010]

In order to solve the above problems, an electronic package assembling support member according to the present invention is an electronic package assembling support member for mounting a cooling device on an LSI chip mounted on a substrate. In the above, there is provided a plate on which the cooling device is placed, and a leg provided in the plate for passing through a hole provided in the substrate, the plate being a mounting plate provided on the LSI chip.
It has a hole through which a screw for attaching the plate is attached .

An electronic package assembly according to the present invention
The body includes a support member for assembling the electronic package, an attachment plate for attaching the support member for assembling the electronic package to an LSI chip, and a substrate for passing legs of the support member for assembling the electronic package at the time of attachment. An electronic package assembly having a through hole
Then, the legs of the electronic package assembling support member are passed through the through holes of the substrate, and the electronic package assembling support member is attached to the attachment plate by the first joining means.

Further, in the method of assembling the electronic package assembly according to the present invention, the supporting member for assembling the electronic package, the mounting plate for mounting the supporting member for assembling the electronic package on the LSI, and the mounting plate at the time of mounting the mounting member. A method of assembling an electronic package assembly, comprising: a through hole of a substrate for passing a leg of a supporting member for assembling an electronic package; bonding the mounting plate to the LSI; and connecting the leg of the supporting member to the through hole. Passing the plate of the supporting member on the mounting plate adhered to the LSI while passing through, and soldering the leg of the mounted supporting member that is passed through the through hole, Screwing the plate of the placed support member to the mounting plate.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is an overall perspective view of a support member for assembling an electronic package according to an embodiment of the present invention. 101 is a leg of a support member for assembling an electronic package,
Reference numeral 102 is a plate of the electronic package assembly support member, 103 is a screw insertion hole for attaching the electronic package assembly support member, and 104 is a screw receiving hole for attaching the liquid cooling module to the electronic package assembly support member.

A hole is formed at a position corresponding to the leg of the electronic package assembly supporting member around the LSI chip of the substrate on which the LSI chip having the BGA (Ball Grid Array) structure is mounted, and the electronic package assembling supporting member leg 101 is formed. Insert into the hole. When the plate 102 of the support member for assembling the electronic package drops to the mounting plate mounted on the upper surface of the LSI chip by its own weight, the legs 101 are soldered. After soldering, the mounting plate and the electronic package assembly support member 100 are fastened with screws.

At the time of this screwing, it is necessary to take care not to apply stress to the joint between the LSI chip and the substrate. As a material of the support member 100 for assembling the electronic package, a metal having a high thermal conductivity such as copper or aluminum is used.

FIG. 2 is a view showing an example of an assembly in which the support member for assembling the electronic package shown in FIG. 1 is attached to an LSI chip. 2 (a) is a sectional view thereof, and FIG. 2 (b).
Is a perspective view thereof. 201 is a substrate, 202 is an LSI chip, and 203 is a support member 10 for assembling an electronic package.
Mounting plate provided on the LSI chip 202 for mounting 0 on the LSI chip 203, 204 is a through hole provided at a position corresponding to a leg of the supporting member for assembling the electronic package, and 205 is a supporting member for assembling the electronic package. A screw for joining a plate, 206
Is a screw receiving hole for the screw.

Through holes 204 are provided in the substrate 201 at positions corresponding to the legs 101 of the electronic package assembly support member, and the electronic package assembly support member legs 1 are formed.
01 is passed through this through hole 204. Also,
The support member 100 for assembling the electronic package is mounted on the mounting plate 20.
It is screwed to 3.

As described above, the through-hole is provided in the substrate and the legs of the supporting member for assembling the electronic package are passed therethrough to be soldered to reduce the load applied to the joint between the LSI chip and the substrate. At the same time, the strength against the shearing force of the support member for assembling the electronic package is enhanced. Furthermore, since it is structured to be stopped with screws,
The bonding strength between the LSI chip and the supporting member becomes even stronger.

A method of mounting a liquid cooling module as a cooling device on an LSI chip using a support member for assembling an electronic package will be described below. FIG. 3 is a diagram showing an outline thereof. In FIG. 3, 300 is a liquid cooling module,
Reference numeral 301 denotes a screw insertion hole into which a screw for attaching the liquid cooling module 300 to the electronic package assembling support member 100 is inserted, and 105 denotes the screw. Mounting plate 203
(Material: aluminum) is fixed to the central portion of the upper surface of the LSI chip 202 with an adhesive.

An electronic package assembly support member 100 (material: copper) is placed over the LSI chip 202 and the mounting plate 203 to cover the electronic package assembly support member 100.
The four legs 101 are inserted into the holes provided in the substrate around the LSI chip 202, respectively. When the leg 101 of the electronic package assembly support member is inserted and dropped to the mounting plate, the leg 101 of the electronic package assembly support member is soldered and screwed from the upper surface of the electronic package assembly support member 100 to the mounting plate 203. Fix it.

At this time, due to an error in the mounting positions of the electronic package assembling support member 100 and the LSI chip 202, stress may occur at the joint (solder ball) between the LSI chip and the substrate due to the mounting.
The mounting screw insertion port 103 of the support member 100 for assembling the electronic package needs a gap enough to absorb the error.

Further, between the electronic package assembling support member plate 102 and the mounting plate 203, a compound for filling a gap caused by the warp or surface roughness of the electronic package assembling support member plate 102 and the mounting plate 203. A medium such as a heat radiation sheet is used.

After the electronic package assembly support member 100 is attached, the electronic package assembly support member 10 is attached.
A cooling device such as a heat sink or a liquid cooling module (indicated by a liquid cooling module in FIG. 3) is attached to the upper part. A compound or the like is similarly used between the support member 100 for assembling the electronic package and the cooling device 300, and they are fixed to each other by screwing. The number of screws and the fixing position can be changed according to the cooling device.

Hereinafter, an electronic package assembly in which the cooling device 300 is mounted by using the above-mentioned mounting method using the supporting member for assembling the electronic package will be described. FIG. 4 shows a sectional view thereof. The heat generated at the joint between the LSI chip and the substrate is released from the LSI chip as shown in the figure, and heat is exchanged in the liquid cooling module.

When the liquid cooling module is vertically mounted on the LSI chip 202 without using the electronic package assembling support member, the stress due to the weight of the liquid cooling module itself and the stress due to the external force such as an operation error or an unexpected shock are caused by the solder. Often exerts a shearing force on a ball, but LSI
Since the electronic package assembly support member is installed so as to cover the chip 202, the electronic package assembly support member absorbs the stress. Therefore, it is possible to prevent the solder ball from peeling off due to the shearing force and disconnection of the signal.

Further, since a material having a very high thermal conductivity such as copper or aluminum is used for the support member for assembling the electronic package, the effect of cooling the solder balls is very good.
This is because when the liquid cooling module is mounted using the electronic package assembly support member made of a material with low thermal conductivity,
Since the heat conductivity of the support member for assembling the electronic package is low, heat is likely to be accumulated around the high temperature portion, and the heat transfer area to the liquid cooling module is not so large.

However, when a support member for electronic package assembly having a high thermal conductivity is used, heat easily diffuses in the support member for electronic package assembly, and the heat is attached without using the support member for electronic package assembly, or The heat transfer area to the liquid cooling module is expanded compared to when it is mounted using a support member for electronic package assembly with poor thermal conductivity,
The cooling effect of the LSI chip is further improved.

Since the legs of the support member for assembling the electronic package are dropped into the through holes, L
It is possible to install the plate of the support member for assembling the electronic package in a position in contact with the LSI chip without imposing a load on the SI chip. In addition, several tens of μ are required because screws are attached between the electronic package assembly support member and the mounting plate.
It can be mounted in the order of m. Also in the present embodiment, the gap between the plate of the electronic package assembly support member and the LSI chip is filled with the adhesive, and the gap is 4 when compared with the example disclosed in Japanese Patent No. 2658967.
~ 5 times shorter.

Since the distance between the electronic package assembly support member plate, which is a holding member of the liquid cooling module, and the LSI chip is shortened, the heat conduction between the electronic package assembly support member plate and the mounting plate is more efficient. It came to be done.

[0030]

As described above, according to the present invention,
The load applied to the joint between the LSI chip and the substrate was reduced, and at the same time, the strength against the shearing force of the support member for assembling the electronic package was enhanced. Furthermore, since the structure is fixed by screws, the bonding strength between the LSI chip and the supporting member is further increased.

Further, since the legs of the supporting member for assembling the electronic package are dropped into the through holes provided in the substrate, the distance between the plate of the supporting member for assembling the electronic package and the LSI chip can be further reduced, and the LSI can be made closer. The heat conduction efficiency to the plate of the electronic package assembly support member for heat dissipation of the chip is improved.

Further, if the cooling device is mounted by using the supporting member for assembling the electronic package having a material having a high thermal conductivity, the heat is diffused to the supporting member for assembling the electronic package and the heat is transferred to the cooling device. Since the area is expanded, LS
The cooling effect of the I-chip is further improved.

[Brief description of drawings]

FIG. 1 is an overall perspective view of an electronic package assembling support member according to an embodiment of the present invention.

FIG. 2 is a sectional view and a perspective view when an electronic package assembling support member is attached.

FIG. 3 shows a liquid cooling module 300 using the support member 100.
It is a figure used for description of the outline of the method of attaching.

FIG. 4 is a diagram illustrating an electronic package assembly according to an exemplary embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a conventional electronic package assembly.

[Explanation of symbols]

100 Electronic package assembly support member 101 Supporting member legs for electronic package assembly 102 Support plate for electronic package assembly 103 screw insertion port 104 screw receiving hole 105 screws 201 substrate 202 LSI chip 203 Mounting plate 204 Holes in the board 205 screw 206 screw receiving hole 300 liquid cooling module 301 screw insertion port

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Claims (10)

(57) [Claims] 1. A support member for assembling an electronic package for mounting a cooling device on an LSI chip mounted on a substrate, wherein a plate on which the cooling device is placed, and a plate provided on the plate,
And a leg for passing into a hole provided in said substrate, said
The board is in front of the mounting board provided on the LSI chip.
A support member for assembling an electronic package, which has a hole through which a screw for attaching a writing plate is inserted . 2. The support member for assembling an electronic package according to claim 1, wherein the plate is made of a material having thermal conductivity. 3. The supporting member for assembling an electronic package according to claim 2, wherein the material having thermal conductivity is copper or aluminum. 4. An electronic package assembling support member according to claim 1, an attachment plate for attaching the electronic package assembling support member to an LSI chip, and an electronic package assembling support member at the time of attachment. electrodeposition having a through-hole of the substrate for passing a leg
In the child package assembly, the legs of the electronic package assembling support member are passed through the through holes of the substrate, and the electronic package assembling support member is attached to the attachment plate by the first joining means. Electronic package assembly
body. 5. A cooling device is attached to the surface of the supporting member for assembling the electronic package opposite to the surface on the LSI chip side by the second joining means.
The electronic package assembly according to claim 4. 6. The electronic package assembly according to claim 1.
Support member and the support member for assembling the electronic package into an LSI chip
Mounting plate for mounting, and support part for assembling the electronic package at the time of mounting
Board through holes for the legs of the material to pass through.
In the child package assembly, the electronic package is assembled in the through hole of the board.
The leg of the support member is passed through the screw, which is the first joining means.
Therefore, the support member for assembling the electronic package is
Electronic package characterized by being attached to a mounting plate
Cage assembly. 7. A cooling device is attached to a surface of the support member for assembling the electronic package opposite to the surface on the LSI chip side by the second joining means.
The electronic package assembly according to claim 6. 8. The electronic package assembly according to claim 7, wherein the second joining means is a screw . 9. An electronic package assembling support member according to claim 1, an attachment plate for attaching the electronic package assembling support member to an LSI, and legs of the electronic package assembling support member at the time of attachment. In a method of assembling an electronic package assembly having a through hole of a substrate for passing through, a step of adhering the mounting plate to the LSI, and a step of passing the legs of the supporting member through the through hole, Mounting the plate on the mounting plate adhered to the LSI; soldering the legs of the mounted supporting member that are passed through the through holes; and mounting the supporting member on the mounting member. A step of screwing a plate to the mounting plate, and assembling the electronic package assembly. 10. The method further comprises the steps of placing a cooling device on the plate of the screwed support member, and screwing the placed cooling device to the plate of the support member. The method of assembling an electronic package assembly according to claim 9.