JPH0736453U - Mounting structure for heat sink to IC package - Google Patents

Abstract

(57) [Abstract] [Purpose] Whether the package base material is plastic or ceramic, and whether the form is a dual in-line package or a pin grid array package, a heat radiation fin can be easily and easily installed. It can be detached and attached, thereby eliminating the need for derating in the circuit design and enabling the functions of the IC to be fully exerted. [Structure] The bottom surface of a heat radiation fin 4 is brought into close contact with the upper surface of an IC package 1 mounted on a printed circuit board 2 via a heat radiation sheet 3. These members have screw insertion holes 1a, 2
a, 3a, 4a are formed. The screw 5 is inserted into the screw insertion hole from the upper surface side of the heat radiation fin, the tip of the screw reaches the rear surface side of the printed board 2, and the nut 6 is screwed into the screw insertion hole. By tightening the screws, the heat radiation fins press and hold the IC package 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure for mounting a radiator on an IC package, and more particularly to a structure for mounting a radiator fin or a radiator plate on an electronic component such as an IC or an LSI.

[0002]

[Prior art]

 In recent years, ICs and LSIs have become multifunctional (highly functional) along with the multifunctionalization of devices incorporating electronic components. Along with this, the number of lead terminals in IC packages has tended to increase. ing. By the way, since the size of the IC itself does not change much even if the number of lead terminals increases, heat generation of the IC itself becomes a problem. Ceramics, plastics, etc. are used as the material for the IC package, but when the amount of heat generated by the IC is large, ceramics resistant to heat are used. When the amount of heat generated is particularly large, as shown in FIG. 10, the heat radiation fin 71 is integrally formed on the upper part of the ceramic package (pin grid array package) body 70, or as shown in FIG. As shown in the figure, a heat radiation fin 73 is integrally bonded to the upper part of the package body 70 to rapidly release the heat generated inside the IC.

Further, in the case of providing the heat radiation fins, the larger the surface area of the heat radiation fins, the higher the heat radiation effect becomes. However, in this case, since the substrate or the like exists in the height direction of the device, the heat radiation is performed. The fins cannot be raised in the height direction. Therefore, as shown in FIG. 12, a radiation fin 76 having a projected area larger than the projected area of the IC package 74 is adhered to the upper surface of the IC package 74.

[0004]

[Problems to be solved by the device]

 By the way, if the package is made of ceramic in consideration of the heat generation amount of the IC, there is a drawback that the manufacturing cost becomes high. Therefore, recently, from the viewpoint of low cost, plastic packages using resins such as epoxy resins and silicone resins are widely used.

However, unlike a ceramic package, the upper surface of the plastic package is not flat, and it has been difficult to bond the heat radiation fin to the upper surface of the package. Therefore, in the case of a plastic package that does not have heat dissipation fins, it is necessary to design the IC circuit design so that it does not have the maximum rating or by performing derating and designing the IC to maximize its capabilities. There was a problem that it could not be used to its full potential.

Further, when a heat radiation fin 74 larger than the projected area of the IC package 70 as shown in FIG. 12 is adhered, the heat radiation fin 74 interferes with the mounting work of other electronic components. Not only is there a problem, but there is also the inconvenience that the appearance of the IC hidden under the radiation fin 74 cannot be inspected. Also, because such a large heat dissipation fin has a large heat capacity, the soldering of electronic components in the vicinity does not occur when soldering all at once, and the heat supply is sufficient even when soldering each component individually. This was not possible, and soldering failure occurred in all cases.

Further, among the IC packages, the pin grid array package can generally have the heat radiation fins attached thereto, but in the case of the dual in-line package, it is difficult to attach the heat radiation fins due to the shape limitation. . For this reason, in particular, when designing the circuit of a dual in-line package IC that does not have a heat radiation fin, derating must be performed, and the ability of the IC cannot be maximized. It was

The present invention has been proposed in view of the above-mentioned problems of the prior art, and whether the package base material is plastic or ceramic, the package form is a dual in-line package or a pin grid array package. In either case, it is possible to easily and easily attach a radiator such as a radiator fin or a radiator plate, which eliminates the need for derating in the circuit design and ensures that the functions of the IC are sufficient. It is an object of the present invention to provide a heat dissipation structure for an IC package that can be fully utilized.

It is another object of the present invention to provide a heat dissipation structure for an IC package, which is excellent in solderability and inspectability of parts even if the heat dissipation fin is large.

[0010]

[Means for Solving the Problems]

 The present invention is characterized in that a radiator such as a radiator fin or a radiator plate is detachably attached to the IC package while being pressed and biased.

Further, according to the present invention, the bottom surface of the heat radiation fin is brought into close contact with the upper surface of the IC package mounted on the board, and the heat radiation fin is fixed to the printed circuit board in a state of pressing the IC package with a screw. It is characterized by being

In addition, the present invention is a dual in-line package in which an IC package is mounted on a printed circuit board through an IC socket, and is located between the IC socket and the IC package and adheres to the bottom surface of the IC package. A first heat radiating plate having a horizontal plate portion and upright portions provided on both ends of the horizontal plate portion in the longitudinal direction of the package, a horizontal plate portion in close contact with the upper surface side of the IC package, and a package of the horizontal plate portion A second heat radiating plate having upright portions provided on both ends in the longitudinal direction, and the first heat radiating plate is sandwiched between the IC package and the IC socket when the IC package is loaded into the IC socket. The second heat dissipation plate is detachably fastened to and held by the first heat dissipation plate while sandwiching the IC package.

Further, according to the present invention, in a dual in-line package in which an IC package is mounted on a printed circuit board through an IC socket, a horizontal plate portion located between the IC socket and the bottom surface of the IC socket is closely attached. And a first heat dissipation plate having upright portions provided on both ends of the horizontal plate in the longitudinal direction of the package, and heat dissipation fins having a surface in close contact with the upper surface of the IC package. The package is fixed and held by being loaded in the IC socket, and the heat radiation fin is detachably fixed and held by the heat radiation plate in a state of being pressure-bonded to the upper surface of the IC socket.

[0014]

[Action]

 According to the present invention, regardless of whether the package is made of ceramic or plastic, a radiator such as a radiator fin or a radiator plate is attached in a pressed state to the IC package, so that the heat generated inside the IC is released to the outside. It becomes possible. Further, since this heat dissipating body is detachable, it is possible to change it to a heat dissipating body of any size and shape after the fact and to adjust the heat radiation amount.

Further, since the heat radiator is configured to be detachable in this way, even when the heat radiator has a projected area larger than the projected area of the IC package, at the time of soldering or inspection, You can work after removing the radiator in advance.

Further, according to the present invention, even when the IC package is a dual in-line package mounted on a printed circuit board through an IC socket, a radiator such as a radiator fin or a radiator plate is sandwiched between the dual in-line packages. The dual in-line package can effectively dissipate the heat inside the IC even if the dual in-line package is made of plastic that is difficult to bond the heat radiation fin. Also in this case, since the heat radiator is removable, it is possible to adjust the heat radiation amount after the fact by using a heat radiator whose size and shape are appropriately changed.

[0017]

【Example】

 Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention, which relates to a case where the IC package is a dual in-line package. As can be seen from the plan view of (a), the front view of (b), the side view of (c), and the perspective view of (d), the lead terminals 1b of the IC package 1 are soldered to the printed circuit board 2. There is. A heat radiation sheet 3 made of, for example, a material such as silicon or mica is provided on the upper surface of the IC package 1, and a heat radiation fin 4 made of a material such as aluminum or iron is placed on the heat radiation sheet 3. Has been done.

As shown in FIG. 2, screw insertion holes 1 a that vertically penetrate are formed on both ends of the IC package 1 in the longitudinal direction. As shown in FIG. 1, screw insertion holes 2a, 3a, 4a are formed in the printed circuit board 2, the heat dissipation sheet 3, and the heat dissipation fin 4 at positions corresponding to the screw insertion holes 1a of the IC package 1, respectively. . These screw insertion holes 1a, 2a, 3a, 4a are on the coaxial line, and the screw 5 is inserted from the side of the radiation fin 4. The tip of the screw 5 projects through the back surface side of the printed circuit board 2, and by screwing a nut 6, the substrate 2, the IC package 1, the heat dissipation sheet 3, and the heat dissipation fin 4 are fastened and held to each other. That is, the IC package 1 and the heat dissipation sheet 3 are sandwiched by the print substrate 2 and the heat dissipation fins 4.

In the above description, the radiation fin 4 is pressed against the IC package 1 side by the fastening force of the screw 5 and the nut 6, but the head of the screw 5 is separated from the radiation fin 4. A compression coil spring (not shown) may be interposed here, and the radiating fin 4 may be urged to contact the IC package side by the urging force of the spring.

FIG. 3 shows a second embodiment, and relates to the case where the IC package 8 is a pin grid array package. Screw insertion holes 8a are formed in the four corners of the IC package 8 where the pin terminals 8b do not exist so as to extend vertically. Further, spacers 8c are formed on the surfaces of the four corners facing the printed circuit board so as to prevent the package from sticking to the printed circuit board 2 when the IC package 8 is connected to the printed circuit board. ing.

As shown in FIG. 4, the IC package 8 is connected to the printed circuit board 2, and the heat dissipation sheet 3 and the heat dissipation fins 9 are placed on the upper surface side of the IC package 8. Similar to the first embodiment, the printed circuit board 2, the heat dissipation sheet 3 and the heat dissipation fin 9 are provided with screw insertion holes 2a, 3a, 9a at positions corresponding to the screw insertion holes 8a formed in the IC package 8, respectively. Has been formed. These screw insertion holes 2a, 8a, 3a, 9a are on the coaxial line, and the screw 5 is inserted from the side of the radiation fin 9. The tip of the screw 5 penetrates and projects to the back surface side of the printed circuit board 2, and by screwing a nut 6 onto this, the substrate 2, the IC package 8, the heat dissipation sheet 3, and the heat dissipation fin 4 are fastened and held to each other. It

In the first and second embodiments described above, the heat dissipation sheet 3 is interposed between the IC packages 1 and 8 and the heat dissipation fins 4 and 9. 8 and the heat radiation fins 4 and 9 are in close contact with each other to improve the heat conduction efficiency and serve as a cushioning material at the time of fastening to prevent damage to the IC packages 1 and 8. Therefore, the heat dissipation sheet 3 is not an essential requirement of the first device.

FIG. 5 shows a third embodiment, which is proposed in order to eliminate the drawbacks of the prior art shown in FIG. 12, and shows the IC package 12 mounted on the printed circuit board 11. This relates to the case where the projected area of the radiation fin 15 is larger than the projected area. That is, also in the third embodiment, the bottom surface of the heat radiation fin 13 is brought into close contact with the upper surface of the IC package 12, and in this state, the printed board 11 and the heat radiation fin 13 are fastened and held to each other by the screw 15 and the nut 16. A heat radiation fin 13 is fixed on the IC package 12. A compression coil spring 18 is interposed between the head of the screw 15 and the heat radiation fin 13 to bias the heat radiation fin 13 to the upper surface of the IC package 12. Needless to say, the heat dissipation sheet described above may be interposed between the IC package 12 and the heat dissipation fins 13 in the third embodiment. Further, in this embodiment, the heat radiation fin 13 is urged into contact with the IC package 12 by using the compression coil spring 18, but without using such a blade, the heat radiation fin 13 is tightened by the fastening force of the screw 15. May be pressed against the IC package 12.

FIG. 6 is an explanatory view showing the fourth embodiment, in which the IC package 22 is a dual in-line package mounted on the printed circuit board 20 via the IC socket 23, and the heat sink 24, 25 is detachably attached to the IC package 22. That is, the heat radiating plates 24 and 25 here are made of aluminum, iron, or the like, and the shapes thereof are horizontal plate portions 24a and 25a that extend in the horizontal direction together, as best understood from FIG. The horizontal plate portions 24a, 25a have upright portions 24b, 25b bent at right angles from both ends in the longitudinal direction. The distance between the upright portions 24b, 24b of the lower heat radiation plate 24 is larger than the distance between the upright portions 25b, 25b of the upper heat radiation plate 25 by the plate thickness so that the upper heat radiation plate 25 can be housed inside. There is. The upright portions 24b and 25b of the heat radiating plates 24 and 25 are provided with screw holes 24c and 25c for fixing and holding the heat radiating plates 24 and 25, which will be described later, to each other. The heat sink 24 on the lower side has its horizontal plate portion 24a in close contact with the bottom surface of the IC package 22 and the upright portions 24b facing upward from both outsides of the lead terminals 22a of the IC package 22. It is fixed in a sandwiched state between the IC package 22 and the IC socket 23. The upper heat radiating plate 25 is positioned such that the upright portions 25b are fitted between the upright portions 24b of the lower heat radiating plate 24 and the horizontal plate portions 25a are in close contact with the upper surface of the IC package 22. It is arranged so as to be parallel to the heat radiation plate 24. At this time, the screw holes 24c and 25c formed in both the upright portions 24b and 25b are aligned with each other, and the screw 26 is screwed into the holes so that the heat radiation plates 24 and 25 are fixed and held to each other.

FIG. 8 shows a radiator in the fifth embodiment, and the lower radiator plate 24 is a horizontal plate as in the fourth embodiment shown in FIGS. 6 and 7 above. It has a portion 24a, an upright portion, and a screw hole 24c. In this embodiment, the heat radiation fin 31 is used instead of the upper heat radiation plate 25 used in the fourth embodiment. The heat dissipating fin 31 has a longitudinal dimension set so as to fit between the upright portions 24b, 24b of the heat dissipating plate 24, and screw holes 31a are formed on both longitudinal end faces thereof. It is being touched. As shown in FIG. 9, the heat radiation fin 31 is fixed to the heat radiation plate 24 with its bottom surface in close contact with the upper surface of the IC package 22.

Also in the fourth and fifth embodiments described above, the heat radiation sheet 3 used in the first embodiment is provided between the IC package 22 and the heat radiation plates 24 and 25 and / or the heat radiation fins 31. It may be interposed.

Also in the fourth and fifth embodiments, it is possible to properly set the heat radiation amount by changing the size and shape of the heat radiation plates 24 and 25 and the heat radiation fin 31.

[0029]

[Effect of device]

 As described above, according to the present invention, since the radiator such as the radiator fin or the radiator plate is attached to the IC package in a crimped state, even if the IC package is made of plastic that cannot be adhered to the radiator, Even if the ceramic package does not have a heat sink, the heat sink can be freely and easily attached. Therefore, if such a radiator is attached, the circuit design can be designed with the maximum rating of the IC, and the derating in the circuit design becomes unnecessary. Moreover, if such a heat radiator is attached to the IC package, the heat generated from the IC is released to the outside, and the temperature rise of the IC itself can be reduced, and the functional reliability thereof can be improved. .

Further, according to the present invention, since the radiator is removably attached to the IC package, even if the projected area of the radiator is larger than the projected area of the IC package, the radiator can be removed. In addition, it will not hinder the soldering work of the electronic components in the surroundings, and it will be possible to effectively prevent the occurrence of defective soldering and obtain a highly reliable product.

Further, according to the present invention, even if it is difficult to provide a heat radiator as in an IC package such as a dual in-line package, the heat radiator can be easily attached. In this case, the circuit design can be performed with the maximum rating, the temperature rise of the IC itself can be reduced, and the functional reliability of I C can be significantly improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a first embodiment of the present invention, in which (a) is a plan view, (b) is a front view, (c) is a side view, and (d) is an external perspective view.

FIG. 2 is an explanatory view showing an IC package (dual inline package) used in the first embodiment of the present invention, (a) is a plan view, (b) is a front view, and (c) is a side view. .

FIG. 3 is an explanatory view showing an IC package (pin grid array package) used in a second embodiment of the present invention, (a) is a plan view, (b) is a side view, and (c) is an external view. Perspective view.

FIG. 4 is an explanatory view showing a second embodiment of the present invention, (a) is a plan view and (b) is a front view.

5A and 5B are explanatory views showing a third embodiment of the present invention, in which FIG. 5A is a plan view and FIG. 5B is a front view.

6A and 6B are explanatory views showing a fourth embodiment of the present invention, wherein FIG. 6A is a front view, FIG. 6B is a side view, and FIG.

FIG. 7 is an external perspective view showing a radiator (a radiator plate) used in a fourth embodiment of the present invention.

FIG. 8 is an external perspective view showing a radiator (a radiator plate and a radiator fin) used in a fifth embodiment of the present invention.

FIG. 9 is an explanatory view showing a fifth embodiment of the present invention, (a) is a front view, (b) is a side view, and (c) is an external perspective view.

10A and 10B are explanatory views showing a conventional pin grid array package with heat dissipation fins, FIG. 10A is an external perspective view, and FIG. 10B is a front view.

FIG. 11 is an external perspective view showing a conventional radiation fin bonded to a pin grid array package.

FIG. 12 is an external perspective view showing a heat radiation fin having a projected area larger than the projected area of the IC package bonded to the IC package.

[Explanation of symbols]

1 IC Package (Dual Inline Package) 2 Printed Circuit Board 3 Heat Dissipation Sheet 4 Heat Dissipation Fin 5 Screw 11 Printed Circuit Board 12 IC Package 13 Heat Dissipation Fin 15 Screw 16 Nut 20 Printed Circuit Board 22 IC Package (Dual Inline Package) 23 IC Socket 24 Heat Sink 25 Heat sink 26 Screw 31 Heat sink fin

Claims (4)

[Scope of utility model registration request] 1. A structure for attaching a radiator to an IC package, wherein a radiator such as a radiator fin or a radiator plate is detachably attached to the IC package in a pressed state. 2. The bottom surface of the heat radiation fin is in close contact with the upper surface of the IC package mounted on the board, and the heat radiation fin is fixedly held on the printed board while pressing the IC package. The structure to attach the heat sink to the IC package. 3. An IC package is a dual in-line package that is mounted on a printed circuit board via an IC socket, and a horizontal plate portion that is located between the IC socket and the IC package and is in close contact with the bottom surface portion of the IC package. A first heat radiating plate having upright portions provided on both ends of the horizontal plate portion in the package longitudinal direction; a horizontal plate portion closely attached to an upper surface side of the IC package; and both end sides of the horizontal plate portion in the package longitudinal direction And a second heat radiating plate having an upright portion provided in the IC package. The first heat radiating plate is fixed while being sandwiched between the IC package and the IC socket when the IC package is loaded in the IC socket. The second radiator plate is detachably fastened to and held by the first radiator plate while sandwiching the IC package, and the radiator is attached to the IC package. Structure. 4. A dual in-line package in which an IC package is mounted on a printed circuit board via an IC socket, a horizontal plate portion located between the IC socket and closely contacting a bottom portion of the IC socket, and the horizontal plate portion. The heat dissipation plate has upright portions provided on both ends of the plate in the package longitudinal direction, and the heat dissipation fin has a surface that is in close contact with the upper surface of the IC package. The heat dissipation plate mounts the IC package in an IC socket. In some cases, the heat sink is fixed in a state of being sandwiched between the IC package and the IC socket, and the heat radiation fin is detachably fixed and held by the heat sink in a state of being crimped to the upper surface of the IC socket. A structure to attach a heat radiator to an IC package.