JPH0158636B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to one of the components of an IC socket used when using a leadless chip carrier type IC package (herein referred to as an IC package). This invention relates to a lock cover for an IC socket used as a lock cover.

[Conventional technology]

Conventionally, as shown in FIGS. 11 and 12, a conductive contact pad 1 is formed on one surface and a conductive contact pad 1 is formed inside.
There is an IC package 3 made of ceramic with a built-in IC. This IC package 3 is used by being mounted on an IC socket, as shown in FIG.
The IC package 3 is prevented from falling off by the lock cover 5a. This lock cover 5a is fitted on the outside of a socket portion 7 mounted on a printed circuit board.

The socket part 7 includes an insulator 9 made to be able to receive the IC package 3 on its upper surface, and
The insulator 9 has a plurality of contacts 11 that are incorporated in the insulator 9 and make one-to-one contact with the contact pads 1 of the IC package 3. contact 11
has a protruding portion that penetrates the insulator 9 and protrudes downward. These protruding parts are for connection to circuit patterns on a printed circuit board.

A hole 17 into which the locking protrusion 13 of the insulator 9 fits is formed in the side surface of the lock cover 5a. Therefore, when the hole 17 is fitted into the locking protrusion 13 of the insulator 9, the lock cover 5a is locked and at the same time the contact 11 obtains an upward spring force.
The IC package 3 is held under pressure between the contacts 11 and the dowels 19 that protrude downward from the upper surface of the IC package 3a.

Lock cover 5a for such IC socket
Various other methods have also been devised. For example, in order to minimize the influence of thickness variations on contact force, the IC package 3 has an opening 21 formed in the center, as shown in FIGS. 14 and 15.
There is also a structure in which a spring piece 23 called a hold-down spring is attached to the socket lock cover 5b to push the IC package cage 3.

Another lock cover 5c, as shown in FIG. 16, has an opening 21 formed in the center so that the entire lock cover 5c is bent and deformed. This lock cover 5c is formed with pressing portions 25 on two sides around the opening 21 as spring means for pressing the IC package 3. Further, the four leg portions of the lock cover 5c have locking portions 27 that are locked to the locking protrusions 13 of the insulator 9 shown in FIG.

Such a lock cover 5c also has contact 11.
It is designed to have a small spring constant in the same way. Further, if the lock cover 5c is used with a sufficient displacement amount to obtain a high contact force, the amount of variation in the contact force will be small even if there are variations within tolerances in component dimensions and assembly dimensions.

Furthermore, the IC package 3 is equipped with a heat sink 30 as shown in FIGS. 17 and 18.
This may promote the radiation of heat generated from the package 3. The heat sink 30 has lock covers 5a, 5.
A flange portion 32 is provided to be attached to b and 5c. A heat sink 30 is attached to this IC package 3.
When installing the lock cover 5, the thickness of the lock cover 5 is equal to the thickness of the pressing flange portion 32 of the heat sink 30.
Efforts have been made to change the heights of the load points a, 5b, and 5c.

The heat sink 30 is inserted into the opening 21 from below the lock cover (eg 5c) as shown in FIG. In this state, the flange portion 32 is located inside the lock cover 5c.

[Problem that the invention seeks to solve]

However, in reality, the lock covers 5a, 5
Due to the restrictions imposed by the sizes of b and 5c, these spring means have to be short and hard springs, so there is a problem in that variations in various dimensions greatly affect the contact force.

In addition, when the heat sink 30 is attached to the IC package 3, the tolerance of the thickness of the IC package 3 and the tolerance of the thickness of the pressing flange portion 32 overlap and become the displacement tolerance, so the contact force The variation in this value also increases accordingly.

Further, the heat sink 30 includes lock covers 5a, 5b,
Since it is attached so as to penetrate through the opening 21 of 5c, the width in the lateral direction is limited to the dimensions of the opening 21. Therefore, in order to obtain sufficient heat dissipation performance, it is necessary to increase the height of the heat dissipation body 30.
There is a problem in that the mounting height is higher than other components on the printed circuit board.

Therefore, it is an object of the present invention to provide a lock cover for an IC socket that lowers the spring constant of the spring piece, reduces variation in contact force when using a heat sink, and does not limit the size of the heat sink. There is a particular thing.

[Means for solving problems]

According to the present invention, the IC package is fitted into the socket portion that receives the IC package, and is engaged with the socket portion.
A lock cover for an IC socket that presses an IC package against the socket has two parallel main spring pieces spaced apart from each other, and a lock cover that is bent inward from the outer end near the center of the two main spring pieces. a secondary spring facing the surface opposite to the socket part, the main spring having a connecting part rotatably connected to the socket part at one end;
and has an engaging portion that engages with the socket portion at the other end, and holds a flange portion of a heat sink for promoting heat radiation of the IC package between the main spring and the sub spring. A lock cover for an IC socket is obtained, which is characterized by the following features.

〔Example〕

1 to 4 show an IC socket using a lock cover according to an embodiment of the present invention.

The illustrated IC socket is used to connect a ceramic IC package 3 (see FIG. 11) having a conductive contact pad 1 formed on one surface and containing an IC. This IC socket includes a lock cover 40 and a socket portion 41.

The lock cover 40 is fitted onto the outside of a socket portion 41 that is mounted on the printed circuit board. The socket portion 41 has an insulator 43 and contacts 45 that make one-to-one contact with the contact pads 1 of the IC package 1 on the inner surface of the insulator 43. The contact 45 has a protruding portion that protrudes below the insulator 43. This protruding portion is a portion connected to a circuit pattern on a printed circuit board. A pressing force is applied to the IC package 3 disposed on the contacts 45 from above by the lock cover 40.

Referring also to FIG.
Auxiliary members 55 and 57 connected with each other (see Figure 1)
It has Thus, an opening 60 is formed in the lock cover 40 by the main spring 47 and the auxiliary members 55, 57. The opening 60 is the locking portion 52
It extends to the vicinity of. The entire main spring acts as a hold-down spring.

Note that a connecting portion 63 having a hole 61 for rotatably connecting to the hinge portion 50 is integrally provided at both ends of one of the auxiliary members 55.

The main spring 47 is warped in an unloaded state as shown in FIG. 6, but when in use it is locked against this warpage. In the center part of the main spring 47
Main dowel 62 for pressing IC package 3
is formed.

Further, near the center of the main springs 47, a sub spring 65 is formed by bending the outer ends of the main springs 47 inward. The secondary spring 65 is the main spring 4
It is facing 7. This sub spring 65 has a sub dowel 6.
7 is formed. A flange portion 71 of the heat radiator 69 is sandwiched between the main spring 47 and the sub spring 65, which is indicated by a two-dot chain line in the figure. The mounting state of this heat sink 69 is also shown in FIGS. 7 and 8.

Now, when the IC package 3 is assembled inside the insulator 43 of the socket part 41, the contact pad 1 of the IC package 3 comes into contact with the contact 45 inside the insulator 43. Further, as shown in FIG. 6, the lock cover 40 is rotated toward the IC package 3 using the hinge portion 50 as a fulcrum. Then, the rotating end of the lock cover 40 is pushed down, and the auxiliary member 57 of the lock cover 40 is opposed to the side surface of the insulator 43.
7 is engaged with the locking portion 52. That is, the auxiliary member 57
acts as an engaging portion that engages with the socket portion 41. As a result, contact pad 1 of IC package 3
comes into pressure contact with the contact 45, ensuring electrical connection.

When the heat sink 69 is in use, the sub spring 65 also presses the flange portion 71 of the heat sink 69 downward. Therefore, the combined spring force of the secondary spring 65 and the main spring 47 acts as a pressing force between the heat sink 69 and the IC package 3, so that the spring constant becomes low. At this time,
As shown in FIG. 8, the main dowel 62 of the main spring 47 is
Move away from IC package 3. The IC package 3 is then pressed downward via the heat sink 69. Although not shown in the figure, while the main dowel 62 of the main spring 47 presses the IC package 3, the sub dowel 67 of the sub spring 65 also presses the IC via the heat sink 69.
It may also be in a state where the package 3 is pressed. Which state will occur depends on the thickness of the flange portion 71 of the heat sink 69 and the thickness of the IC package 3.

Referring to FIGS. 1 and 5, since the opening 60 extends close to the locking member 52, the heat sink 60
9 is the conventional lock cover 5a shown in FIG.
Rather than attaching it from below as in the case of
It can be installed by sliding it from the side as shown by the arrow in the figure. Therefore, as shown in FIG. 10, the dimension b' of the heat sink 69 is not limited to the dimension a' of the opening 60. Further, it is possible to design the height of the heat sink 69 to be low.

〔Effect of the invention〕

As explained above with the examples, the present invention
According to the lock cover for IC socket, it is now possible to design a spring with a low spring constant by using most parts of the lock cover as a spring.
Even if there are variations within tolerances in component dimensions or assembly dimensions, it is now possible to reduce the effect on contact force.

In addition, when using a heat sink, even if the tolerance of the thickness of the heat sink's flange part is added as an undefined element of displacement, the secondary spring joins the main spring as a spring element, and the two springs act together, resulting in a composite spring. Since the constant is smaller, it has become possible to suppress fluctuations in contact force.

Furthermore, since the heat dissipation element is installed by sliding into the groove, the size of the heat dissipation part is not limited to the size of the opening, and therefore the heat dissipation part can be enlarged in the lateral direction, resulting in high heat dissipation performance. It becomes possible to design a heat sink with a lower height.

[Brief explanation of drawings]

FIG. 1 is a partially sectional plan view of an IC socket using a lock cover according to an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a front view of FIG. 1, and FIG. 3 is a partial sectional view, FIG. 5 is a perspective view of the lock cover in FIG. 1, FIG. 6 is a side view showing the lock cover in the released state, FIG. 7 is a plan view showing the lock cover in the pressed state, and FIG. 8 is - in Figure 7
9 is a side view showing how to attach the heat radiator, FIG. 10 is an explanatory diagram showing the dimensional relationship between the heat radiator and the main spring and sub spring, and FIG. 11 is a plan view showing a general IC package. 12 is a side view of FIG. 11, FIG. 13 is an explanatory cross-sectional view of the state in which an IC package is attached to a conventional IC socket, and FIG. 14 is another example of a lock cover used in a conventional IC socket. 15 is a cross-sectional view of FIG. 14, FIG. 16 is a perspective view showing still another example of a lock cover used in a conventional IC socket, and FIGS. 17 and 18 are views of a heat sink. FIG. 19, a perspective view showing a conventional example, is an explanatory diagram illustrating the relationship between a conventional lock cover and a heat radiator. 3; IC package, 40; Lock cover, 4
1; Socket part, 45; Contact, 47; Main spring, 50; Hinge part, 52; Locking part, 57; Auxiliary member acting as an engaging part, 60; Opening part, 6
1; Hole, 62; Main dowel, 63; Connection part, 65;
Sub-spring, 67; sub-dowel, 69; heat sink.

Claims (1)

[Claims] 1. In an IC socket lock cover that is fitted to a socket portion that receives an IC package and that engages with the socket portion and presses the IC package against the socket portion, two main spring pieces parallel to each other and spaced apart from each other; a secondary spring bent inward from an outer end near the center of the main spring and facing a surface of the main spring opposite to the socket part, the main spring having one end pivoted to the socket part; The IC package has a connecting part that can be connected to the IC package, and has an engaging part on the other end that engages with the socket part, and promotes heat dissipation of the IC package between the main spring and the sub spring. A lock cover for an IC socket, characterized in that it holds a flange part of a heat dissipating body.