JPS6217832B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for mounting an IC, an LSI, a printed circuit board, or the like on a printed circuit board.

Traditionally, when mounting a flat circuit board (hereinafter referred to as a flat board) such as an IC, LSI, or printed circuit board on another printed circuit board, there are methods of directly connecting and fixing the two by soldering, etc., as well as methods of using connectors or sockets. There is. For example, in an IC or LSI having lead-type or pin-type connection terminals, a socket 3 equipped with a socket contact 2 that fits each terminal 1 is fixed in advance on a printed circuit board 4, as shown in FIG. Mounting is carried out by fitting the terminals 1 of the flat plate 5 to be mounted into each socket contact and pushing the flat plate into the socket. However, with this method, as the number of terminals on the flat plate increases, the clamping force of the entire socket contact increases, so a large force is required when inserting or removing the flat plate from the socket, and there is a risk of accidentally damaging the terminals or the flat plate itself. In addition to the possibility of serious accidents, since the terminal and socket contact are connected in series, the conductive path from the flat plate to the printed circuit board becomes long, which has an adverse effect on high frequency characteristics. Furthermore, there are mounting methods as shown in FIGS. 2 and 3 for devices having connection terminals that are directly attached to a flat plate called a pad. For example, Figure 2a
Reference numeral 6 denotes a flat plate to be mounted, which has a pad 7 on its periphery. A housing 9 is mounted on the printed circuit board 8 in advance, and elastic metal contacts 11 corresponding to the pads 7 are arranged in a recess 10 in the housing, and one end of the contact protrudes from the lower surface of the housing 9 and is mounted on the printed circuit board. Since it is connected to the conductor pattern 12 of
is stored in the recess 10, then a cover 13 is placed from above, the four corners are screwed together with the housing 9 to the printed circuit board, and the flat plate 6 is pressed.
As shown in FIG. 2B (A-A' sectional view in FIG. 2A), the contact 11 comes into elastic contact with the pad 7, thereby connecting the flat plate and the conductive pattern of the printed circuit board. Further, in the method shown in FIG. 3, no contact is provided in the recess 10' of the housing 9' mounted on the printed circuit board 8', and instead, the end 14 of the conductor pattern 12' corresponds to the pad 7 of the flat plate 6. arranged in position. It is a plate-shaped elastic insulator that is approximately the same size as the flat plate, and around its periphery, there is conductive metal foil or the like in a U-shape that faces the pad 7 and the conductor pattern end 14 and short-circuits them. First, the relay elastomer 16 on which the terminals 15 are arranged is placed in the recess 10'.
By placing the flat plate 6 on top of the flat plate 6, covering it with the cover 13 and screwing it onto the printed circuit board as in the case of FIG. 2, the flat plate is pressed by the cover and the flat plate presses the elastomer 16. Due to the elasticity of the elastomer, the terminal 15 comes into sufficient contact with the pad 7 and the conductor pattern end 14, thereby achieving connection between the flat plate and the conductor pattern. In either of the methods shown in FIG. 2 or 3, by sufficiently pressing the flat plate 6 with the cover 13, the contact 11 or the elastomer 1
6 has its own elasticity and comes into contact with the pad of the flat plate with sufficient contact pressure, and by simply attaching and removing the cover, the flat plate can be attached to or removed from the printed circuit board without the need to apply any particular force to the flat plate, thus preventing damage. In addition to being easy to carry out without fear, this method has the advantage that the conductive path can be made shorter than in the case of FIG. 1, so that high frequency characteristics can be improved. However, as the flat plate becomes larger and the number of pads increases, the elasticity of the contacts or elastomer causes the intermediate portions of the housings 9, 9' to become weaker in areas away from the screws that fix the cover, as shown in Figure 4. At most, the cover 13 and the printed circuit boards 8, 8' may be bent as shown by X and X', and as a result, sufficient contact pressure cannot be obtained at the contact area between each pad and the contact or terminal, resulting in electrical contact. There was a risk that it would cause instability. Furthermore, in the above mounting method, the area of the housing on the printed circuit board and the volume including the cover are larger than that of the flat plate body. Increasing the thickness of the cover or increasing the number of fixing screws on the cover not only increases the area occupied by the housing, but also increases the number of screw holes provided on the printed circuit board, which creates disadvantages in terms of printed circuit board circuit design. .

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the conventional method, to make it easy to attach or remove a flat plate to a printed circuit board, and to have good high frequency characteristics because the conductive path from the flat plate to the printed circuit board is short.
A flat circuit board that provides reliable contact with circuit patterns even when the flat board is large and the number of connection terminals increases, without increasing the area and volume of the printed circuit board required for flat board mounting. The purpose is to provide an implementation method.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

First, in FIG. 5 showing the structure of a flat plate such as an IC, LSI, or printed circuit board used in the circuit flat board mounting method according to the present invention, a plurality of pin terminals 30 are erected on the bottom surface of a flat plate 20. Electrical connection between the flat plate and the printed circuit board is established by bringing the terminals into contact with the conductive pattern of the printed circuit board facing each other via a conductor.

The portion of the pin terminal 30 in contact with the bottom of the flat plate is the seat 31.
A flange 33 having a larger diameter than the stem 32 is provided near the tip of the pin terminal, and a locking step 34 is formed on the side of the flange near the flat plate. It functions to engage with a locking hole for locking. The elastomer 40 is made of a conductive material, has a through hole in its center, is inserted into the pin terminal, and is always in close contact with the pin terminal due to its own elasticity, with one end surface in contact with the seat 31. . The outer diameter of the seat 3 should be as large as possible so that adjacent elastomers do not come into contact with each other when the elastomer is pressed and deformed as described later.
This is desirable in order to increase the contact area with 1 and the conductor pattern described later. FIG. 6 shows a state in which the flat plate 20 is placed on a printed circuit board 50 to be mounted, and the printed circuit board 50 is provided with through holes 51 having a diameter that allows the flanges 33 to pass through them at positions corresponding to each pin terminal 30. . A conductor pattern is provided on the printed circuit board surface to connect to each through hole and configure the required circuit, but especially around the through hole opening on the flat plate side, a conductor pattern is provided to form a contact surface with the elastomer 40. A conductive pattern 52 is typically provided on the elastomer having an outer diameter approximately equal to the end of the elastomer. The locking plate 60 connects the flat plate 20 to the printed circuit board 50.
It is used to fix the plate to the substrate and to establish electrical connection between the flat plate and the conductor pattern of the printed circuit board, and its outline is shown in FIG. The locking plate has approximately the same planar dimensions as the flat plate to be mounted, and its thickness is equal to the height difference 34 for locking the pin terminal that protrudes from the printed circuit board surface when the flat plate is placed on the printed circuit board and the printed circuit board surface. A dimension Y is slightly larger than the distance between the flat plate pin terminals 30, and a locking hole 61 having a keyhole-like outer shape and the same number of pin terminals as the pin terminals is penetrated on the surface thereof. It is set up. The locking hole consists of a circular hole portion 62 and a long hole-shaped narrow portion 63 connected thereto.The circular hole portion 62 has a diameter that allows the flange 33 of the pin terminal 30 to pass through, but the width of the narrow portion 63 is smaller than the diameter of the flange and larger than the diameter of the stem 32, and the length of the narrow portion is such that the stem can sufficiently engage the locking step of the flange when the stem passes through the end thereof. must be at least the radius of the flange. (See Figure 10) In order to completely mount the flat plate from the state shown in Figure 6 where the flat plate is placed on the printed circuit board, press the flat plate 20, printed circuit board 50, and locking plate 60 together as shown in Figure 7. A pushing jig 70 and a receiving jig 80 are required. Each jig is made of a highly rigid material in order to prevent bending or local force from being applied to each part during pressing. Note that FIG. 11 shows the structure of the receiving jig 80. The receiving jig 80 has projecting walls 81 parallel to each other on both sides of one surface, and a concave plane 82 is formed between the projecting walls in which the locking plate 60 is accommodated when the jig is used. Also, the height of the projecting wall from the concave plane is slightly larger than the thickness of the locking plate. The concave plane 82 has a flat plate 2
The flange 3 of the pin terminal corresponds to the pin terminal 30 of 0.
An escape hole 83 having a diameter that allows the passage of 3 is bored. A circuit board mounting method using the above configuration is as follows.

First, as shown in FIG.
Place the pin terminal 30 on top of the printed circuit board and make it protrude from the bottom surface of the printed circuit board through the through hole 51, and then place the locking plate 60 in close contact with the bottom surface of the printed circuit board with the pin terminal passing through the locking hole 61. However, in this case, due to the thickness of the locking plate as described above, the locking step 34 of the flange of the pin terminal is at a position slightly recessed into the hole by a distance Y from the lower surface of the locking plate. In this state, as shown in FIG. 10a, the flange 33 is located at the circular hole 62 of the locking hole, so the locking plate cannot slide in the horizontal direction. Next, as shown in FIG. 7, when pressing force F is applied from above and below using the pushing jig 70 and the receiving jig 80, the flat plate 20, the printed circuit board 50, and the locking plate 60 are pressed together, and the receiving jig 80 is pressed as shown in FIG. Since the tool 80 presses the printed circuit board 50 with its projecting wall 81 and the elastomer 40 is compressed between the printed circuit board and the flat plate 20, the protrusion length of the pin terminal 30 from the lower surface of the printed circuit board increases accordingly. Therefore, if a pressing force F is applied such that the amount of compression of the elastomer becomes larger than the above-mentioned dimension Y, the locking step 34 of the flange will protrude beyond the lower surface of the locking plate 61. In this state, only the stem portion 32 with a small diameter has penetrated into the locking hole, and the locking plate is not directly receiving the force from the receiving jig as described above. It becomes possible to easily slide in the direction a shown in Figure a or Figure 9. Then, when the locking plate is slid in the direction a and the narrow part 63 of the locking hole is moved to the position of the stem 32 as shown in FIG. 10b, the pushing jig and the receiving jig are removed. The terminal pin 30 tries to increase the distance between the flat plate and the printed circuit board due to the repulsion from the state.
The terminal pin tries to be pulled into the locking hole again from the protruding state when compressed, but the narrow part 63 of the locking hole of the terminal pin
Since the locking step 34 of the flange is located at this position, the locking step 34 of the flange is locked by the narrow portion and does not return any further into the locking hole. Therefore, the elastomer still remains compressed by the dimension Y shown in FIG.
With its own residual elasticity, both end surfaces are brought into close contact with the pin terminal seat 31 and the conductive pattern 52 of the printed circuit board, thereby maintaining a mutually reliable electrical contact state. This is the state shown in FIG. 8, which means that the flat plate has been reliably mounted on the printed circuit board. Furthermore, if it is necessary to remove the mounted flat plate from the printed circuit board, this can be easily done by using the reverse method to the above. In addition, if the dimensions of the flat plate to be mounted in the above method become large,
When the printed circuit board 50 is pressed by the receiving jig 80, the rebound of the elastomer causes the printed circuit board to warp in the middle part of the projecting wall 81 toward the side opposite to the flat plate, and the pin terminal protrudes from the printed circuit board surface by that amount. There is a risk that the locking plate will not be able to slide due to insufficient amount. In that case, as shown in FIG. 11, one or more anti-warping stands 8 are installed on the concave surface 82 of the receiving jig, which has the same height as the projecting wall 81 and serves to support the printed circuit board at the middle part of the projecting wall.
4 will be erected. In this case, as shown in FIG. 9, the locking plate 60 also needs a long hole 64 through which the anti-warp stand passes. The length of this elongated hole in the major diameter direction must be such that it does not come into contact with the anti-warping stand when the locking plate is slid. Other than that, the method of engaging the pin terminal and the locking plate is exactly the same as described above. Another way to check that the elastomer is compressed when a pressing force is applied with a jig and that the flange protrudes beyond the surface of the locking plate to the extent that it does not interfere with the sliding of the locking plate is as shown in Figure 7. The escape hole 83 of the receiving jig may be made deep enough so that the tip of the terminal pin 30 just hits the bottom of the hole when the elastomer is compressed by the required amount, or a predetermined hole 83 may be provided between the flat plate and the printed circuit board. It is also possible to take measures to sandwich the gauge 90 having a thickness of .

In the above embodiment, separate elastomers were used, but as shown in Fig. 12, this elastomer consists of a conductive part 101 that contacts the outer periphery of the pin terminal and another insulating part 102, and both are integrally formed. Alternatively, instead of the elastomer, a contact 200 made of an elastic metal plate having a curved portion as shown in FIG. 13 may be used. Furthermore, as shown in FIG.
A plate-shaped elastomer 100' similar to the plate-shaped elastomer 100 in the figure is placed on the printed circuit board 50 instead of on the flat plate side.
It may also be fixed to the side by adhesive or the like. Further, in this embodiment, the locking hole has a specific shape, but it may be triangular or any other shape as long as it has a narrow portion that can lock the shoulder of the flange. Naturally, various design changes are included within the scope of the invention.

As is clear from the above explanation, according to the circuit flat board mounting method of the present invention, when mounting on a circuit flat printed circuit board such as an IC, LSI or printed circuit board, the flange of the pin terminal is used as a method for fixing the flat board. Since it is engaged with the stop plate and pressed against it by the rebound elasticity of the elastomer, the fixed state is not only stable, but also the flat plate can be easily attached to and removed from the printed circuit board by using a jig.
In addition, the electrical connection between the flat plate and the printed circuit board is made by the compressed conductive elastomer coming into close contact with both, so the contact is reliable and the conductive path can be made shorter than when using connectors, etc. In addition to having good high-frequency characteristics, the use of a locking plate reduces the area and volume required on the printed circuit board for flat board mounting, and there is no need to provide screw holes for fixing screws on the printed circuit board. It is extremely advantageous in terms of printed circuit board circuit design, and has many features such as being able to maintain high reliability of contact between the terminal and the circuit pattern of the printed circuit board even when the flat plate becomes large. When applied to the device, the reliability can be improved, the device can be made smaller, and the flat plate can be easily attached and detached, which is an extremely significant effect.

[Brief explanation of the drawing]

FIG. 1 shows a conventional example of a mounting method using a socket. FIGS. 2, 3, and 4 show conventional examples of a method for mounting a flat plate having pads. FIG. 5 is a side view and a plan view of an example of a flat plate used in the present invention. FIG. 6, FIG. 7, and FIG. 8 are diagrams showing a flat plate mounting method according to the present invention. FIG. 9 is a plan view of an example of a locking plate used in the present invention. 1st
Figure 0 is a diagram showing the positional relationship between the locking hole and the pin terminal. FIG. 11 is a perspective view showing an example of a receiving jig used in the present invention. FIGS. 12, 13, and 14 show other embodiments of the present invention. 20... Circuit flat plate (flat plate), 30... Pin terminal, 40... Elastomer, 50... Printed circuit board, 52... Circuit pattern, 60... Locking plate, 7
0...Pushing jig, 80...Receiving jig.

Claims (1)

[Claims] 1 A method in which one of two circuit boards having an electric circuit is mounted on the other circuit board while making mutual electrical connections, and one circuit board has pin terminals planted on one side. The pin terminal has a flange portion having a locking step near the tip, a stem portion that is connected to the flange portion and has a smaller diameter than the flange portion, and is integral with the pin terminal at a point where it contacts one of the circuit flat plates. a seat, and an elastic conductor is arranged around the pin terminal in contact with the seat,
In addition, a hole through which the pin terminal can pass is provided in the other circuit plate, and a conductor portion is provided around the opening on one circuit plate side of the hole, and one circuit plate is connected to the other circuit plate. After passing the pin terminal through the hole and protruding the flange portion to the opposite surface, the locking portion is placed between the locking step of the flange portion and the surface of the other circuit flat plate. By inserting a locking plate having a narrow portion that can engage with the step, the second
At the same time, the elastic conductor is compressed and the elastic conductor itself is brought into pressure contact with the seat and the conductor portion due to its repulsion, thereby causing the two circuit plates to be in contact with each other. A method for mounting a circuit on a flat board, characterized in that the circuit is configured so as to obtain an electrical connection.