JPH0312230Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a contact structure used in a card attachment/detachment device having electronic functions. More specifically, the present invention relates to an improved contact structure suitable for use in a device for attaching and detaching a circuit board such as a so-called electronic card incorporating an integrated circuit (hereinafter referred to as an IC).

With the recent development of IC technology, it has become possible to realize large-scale ICs on small chips.
A wide variety of products with advanced functions have been developed, and their uses have further expanded.

For example, read-only memory (ROM), in which programs such as microprocessors are written, and random access memory (RAM), which can read and write data, are embedded in thin cards. Summer.

Furthermore, electronic devices incorporating microprocessors and the like are becoming smaller and more pocket-sized, and there is a growing demand for the use of cards incorporating ICs and the like in these devices.

To give one example of its use, so-called credit cards and cash cards, which are often used in financial matters, are also becoming increasingly integrated into ICs.
Devices that use such electronic cards are also required to be pocket-sized.

[Prior Art] When using such an electronic card, the connection point between the card and electronic equipment is a printed circuit board (hereinafter referred to as
Abbreviated as PCB. ), but since the handling of electronic cards is usually very rough, the edges are particularly prone to damage and are unreliable. Additionally, many leads had to be drawn out from the many terminals of the IC to the edges of the card, which was not always easy to manufacture and caused an increase in price.

To solve this problem, the IC terminals buried in the middle of the card or their vicinity are used as terminals to connect to electronic equipment, without extending the terminals to the ends of the card.

The number of these terminals increases as electronic devices improve their functionality and
With the increase in the functionality of IC cards, these terminals have increased in number and come to be arranged in a limited area.

When such an electronic card having a terminal in the middle is inserted into or removed from an electronic device, the contact pins of the electronic device and the terminal surface of the electronic card may rub against each other.
Because the contact pins were damaged, it was not possible to achieve reliability over one million connection and disconnection cycles, for example.

In addition, to prevent the contact pins of the electronic device from rubbing against the terminal surface of the electronic card, some devices retract the contact pins before inserting the electronic card, and then push the contact pins out to make contact.
The mechanism was complicated, the shape was large, and the operability was poor, leading to an increase in costs. Furthermore, in electronic cards in which many terminals are arranged at finer pitches, there is a problem in that the electronic cards cannot be accurately positioned when mounted, resulting in a lack of contact reliability.

Therefore, the applicant of the present application filed Utility Application No. 1983-055007, Japanese Patent Application No. 60-175405, and Utility Application No. 128971-1983 in order to solve the problems of the prior art. On February 7th, we filed a patent application for ``electronic card attachment/detachment device 1, 2, 3''.

In these applications, after the electronic card is completely inserted into the device, a contact terminal board having many contact terminals is brought close to the inserted surface of the electronic card, so that many contact terminals are connected to the terminal surface of the electronic card. The contact was made with a constant pressure. When taking out the electronic card, the contact terminal board moves away from the surface of the electronic card, and many of the contact terminals are completely removed from the terminal surface of the electronic card before the electronic card is ejected.

Here, the structure of a contact terminal board and a contact terminal in the prior art is shown in FIG. 6 and will be described.

5a to 5h are terminal surfaces of an electronic card, for example. 6 and 7 are contact terminal boards, respectively, a large number of 11 and 21 are contact terminals attached to the contact terminal boards 6 and 7, respectively, and 12 and 2.
2 is at each tip of the contact terminals 11 and 21,
A contact portion for contacting each terminal surface 5a to 5h, 1
3 and 23 are lead portions that are lead wires of the contact terminals 11 and 21. When the electronic card is inserted, the two integrated contact terminal boards 6 and 7 are lowered in the direction of arrow 51, and each contact portion 12 and 22 comes into contact with the corresponding terminal surface 5a to 5h. When the electronic card is to be removed, the contact terminal boards 6 and 7 are moved in the direction opposite to the arrow 51 and the electronic card is then removed.

The terminal surface 5e is a ground terminal surface and serves as a ground terminal of the electronic card. Therefore, in order to ensure contact, the two contact portions 22 are designed to contact the terminal surface 5e at the same time.

[Problems to be solved by the invention] Although the prior art illustrated above solves many problems, it has the following problems.

As electronic cards become more popular, they tend to be handled extremely roughly, and the terminal surface of the electronic card that comes into contact with the contact terminals of the electronic card attachment/detachment device is not necessarily flat and may be distorted, such as warping or twisting. The contact terminal may not make complete contact with the terminal surface of the electronic card.
If the spring pressure of the spring 31 is increased in order to prevent this, the terminal surface and contact terminals of the electronic card will be damaged, making it impossible to achieve high reliability, such as the ability to withstand 1,000,000 attachment/detachment cycles. In particular, for devices with a large number of terminals and narrow terminal spacing, it has been difficult to obtain such highly reliable contacts in a flat and compact shape.

Furthermore, advances in IC technology have enabled large-capacity ROM and
LSIs such as RAM have come into widespread use, but these LSIs are extremely vulnerable to abnormal application of power supply voltage and static electricity, which can cause not only damage to the memory contents but also irreversible destruction of the elements themselves. It happened that I arrived.

[Means for Solving the Problems] A contact that is attached with a number of contact terminals each having a contact portion at its tip, is substantially parallel to the surface of the electronic card, and can change the distance from the surface of the electronic card. In the terminal board, in order to contact the ground terminal surface of the electronic card, at least one contact terminal has a longer length from the attachment part to the contact terminal board to the contact part at the tip than the other contact terminals;
Moreover, the contact portion is arranged closer to the surface of the electronic card than the contact portions of other contact terminals.

[Function] When the electronic card is inserted, the contact terminal board moves away from the electronic card, approaches the electronic card after insertion, and the contact portion at the tip of the longest contact terminal first contacts the ground terminal surface of the electronic card, The contact portions at the tips of the other contact terminals then contact other terminal surfaces of the electronic card, and each contact portion can obtain good contact. This avoids abnormal application of power supply voltage, and even if the device side or the electronic card side is charged, the grounding terminal surface of the electronic card is grounded first, which prevents problems due to static electricity. do not have. The longest contact terminal has a larger displacement of its contact part than the other terminals, but because it is correspondingly longer, its springiness does not get fatigued, and the contact pressure of the contact part is also equal to that of other contact parts. Since it is made substantially equal to the ground terminal surface of the electronic card, sufficient reliability can be obtained without damaging the ground terminal surface of the electronic card. In addition, if multiple rows of contact terminals are required, this can be done by stacking multiple contact terminal boards on the board, and the planar structure allows for a flat and compact shape. I was able to do that.

[Example] An example of the present invention is shown in FIG. 1, FIG. 2, FIG. 3, and FIG. 4, and will be described below.

In these figures, components corresponding to those shown in FIG. 6 are given the same numbers and symbols.

In FIG. 1, 7A is a contact terminal board;
In addition to the contact terminal 21, long contact terminals 31A and 31B are provided with cuts 35. 32A,B
are the contact parts of the long contact terminals 31A and 31B, and 33
A and B are their lead parts. When the contact substrates 6 and 7A are lowered in the direction of the arrow 51,
Since the contact portions 33A and 33B are located lower than the other contact portions 12 and 22, the terminal surface 5
Contact e. This terminal surface 5e serves as a ground terminal surface of the electronic card.

The contact portions 32A and 32B are connected to the other contact portions 12 and 22.
Although the amount of displacement is larger than that of the contact terminal 31A,
Since B is made long, its contact pressure is substantially equal to the contact pressure of the other contact portions 12, 22.

FIG. 2 is a diagram showing another embodiment of the present invention, in which notches 45A and 45B are provided in one contact terminal board 6A, and long contact terminals 41A and 41B are provided in addition to the contact terminal 11. This corresponds to an electronic card in which the terminal surfaces 5a to 5h are lined up in a row.

Since the contact portions 42A and 42B located at the tips of the long contact terminals 41A and B are lower than the other contact portions 12, when the contact terminal board 6A is lowered in the direction of the arrow 51, the terminal surface 5c first and 5g
come into contact with. In this case, terminal surfaces 5c and 5g serve as ground terminal surfaces of the electronic card. The functions and effects of these long contact terminals 41A and 41B are the same as those of the long contact terminals 31A and 31B shown in FIG.

A side view of the one shown in Fig. 1 is shown in Fig. 3;
FIG. 4 is a side sectional view of the notch 45A shown in the figure, and the contact terminals 11, 21, 3
1, 41 is shown in FIG. 5a, the contact portions 12, 2
A graph showing the relationship between the displacement amount and the contact pressure at 2, 32, and 42 is shown in FIG. 5b, and will be explained.

The lengths of the contact terminals 31 and 41 are both l ₂ , the amount of displacement of the contact parts 12 and 22 when they contact the terminal surface 5 of the electronic card is Δ ₁ , and the contact parts 32 and 4
2 is the displacement amount of ₂ , δ is the difference between Δ ₂ and Δ ₁ , w is the width of the cross section of the contact terminals 11, 21, 31, 41, t is the thickness, I is the moment of inertia of the area, and longitudinal property is If the coefficient is E and the contact pressure of each contact part 12, 22, 32, 42 is P, then I=bt ³ /12 (1) Δ ₁ = Pl ₁ ³ /3EI (2) Δ ₂ = Pl ₂ ³ /3EI (3), and if the contact pressure P, longitudinal elastic modulus E, and moment of inertia I are constant, then from the relationships l ₁ < l ₂ and Δ ₁ < Δ ₂ , the displacement Δ is on the As shown in FIG. 5b, where the contact pressure P is taken, at a specific value of the contact pressure P _c , the relationship between the spring constants is P _c /Δ ₁ >P _c /Δ ₂ (4).

That is, which contact portions 12, 22, 32, 42
The contact pressure of can also be the same value, P _c .

The contact structure according to the present invention described above is disclosed in Utility Application No. 60-055007, Japanese Patent Application No. 60-175405,
128971 and the February 7, 1986 patent application for "Electronic card attachment/detachment device 1, 2, 3", if used as a contact terminal, it will realize an extremely reliable and easy-to-use compact electronic card attachment/detachment device. be able to.

[Effects of the invention] As is clear from the above explanation, in the present invention, a long contact portion contacts the contact terminal surface of the electronic card before other contact portions and leaves the ground terminal surface after other contact portions. By providing a contact terminal and making the contact pressure substantially equal to that of other contact parts, even if there is an abnormal application or disconnection of the power supply voltage, this can be prevented, and it can be protected from destruction due to static electricity. This prevents wear and tear on each terminal. Furthermore, since each contact terminal is independently flexible, it is possible to obtain sufficiently good contact even if the terminal surface of an electronic card, etc. is warped or otherwise distorted. The present invention provides a highly reliable contact structure in which the contact terminal boards can be overlapped according to the terminal rows, and the contact terminals are subjected to very little stress.
The effect is extremely large.

Furthermore, if used in combination with the prior art pending by the present applicant, due to the effect of the prior art, there will be no damage caused by rubbing the contact terminals when an electronic card or the like is inserted, resulting in poor contact. Such malfunctions do not occur, and the effects of the present invention are extremely large.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is a perspective view showing another embodiment, FIG. 3 is a side view of the one shown in FIG. 1, FIG. 4 is a side sectional view of the one shown in FIG. 2, and FIG. 5 explains contact pressure. FIG. 6 is a perspective view showing the prior art. 5... Terminal surface, 6, 7... Contact terminal board, 1
1, 21, 31, 41...contact terminal, 12, 2
2, 32, 42...contact part, 13, 23, 33,
43...Lead part, 35, 45...Notch.

Claims (1)

[Claims for Utility Model Registration] (1) Substantially parallel to the plane of a circuit board having a plurality of terminal surfaces including at least one grounding terminal surface, to which a plurality of contact terminal means having contact portions at the tips are attached; In the contact terminal board, the plurality of contact terminal means are arranged in such a manner that the plurality of contact terminal means are brought into contact with the plurality of terminal surfaces by changing the distance from the surface of the circuit board, A contact structure comprising at least one contact terminal means having said contact portion located closer to said ground terminal surface than said contact portion. (2) The at least one contact terminal means is longer than the other contact terminal means, and the contact pressure at the contact portion of the tip of the at least one contact terminal is substantially equal to the contact pressure at the other contact portion. A contact structure according to claim 1 of the utility model registration claim, which is equivalent. (3) At least one contact terminal means including the contact portion located close to the ground terminal surface is
at least one contact point at the same time.
The contact structure according to claim 1, which is a contact structure that contacts one of the ground planes.