IC carrier or IC socket

Abstract: A latch arm 6 for engaging with a corner portion, etc. of an IC 3 being pivotably supported on a corner portion, etc. of a base member of an IC carrier or IC socket, a spring element 6b being extended from a rear end of the latch arm, the spring element 6b, when the latch arm 6 is pivoted upwardly to remove engagement, being bent to accumulate resilient force, so that the latch arm 6 is restored in the engaging direction by the reaction, in order to maintain the engagement with the IC 3.

Description: [Field of the Invention] This invention relates to an IC carrier for carrying thereon an IC for transportation or to be received in an IC socket. From another aspect, the present invention relates to an IC socket to be used for connection to an IC, and particularly to an IC holding construction which is common both to the IC carrier and the IC socket. [Brief Description of the Prior Art] USP4,881,639 owned by the present applicant discloses a one-piece type IC carrier comprising a base member and torsion bars each integrally formed on each corner of the base member, and latch arms integral with the torsion bars, respectively and adapted to engage with an edge portion of an IC placed on the base member. In this one-piece type IC carrier, each latch arm is pivoted upwardly about its corresponding torsion bar to remove its engagement with the IC. At this time, a twisting energy is accumulated in the torsion bar, and the latch arm is pivoted downwardly by this twisting energy so as to be brought into engagement its corresponding corner portion of the IC. The above carrier is operated to open and close the latch arms while exerting the twisting force to the torsion bars, so that the latch arms are engaged with and disengaged from the IC. Since the twisting force is repeatedly exerted to the torsion bars every time the IC is inserted and removed, the twisting stress is concentrated on connecting portions at both ends of the torsion bars which are integrally connected to the base member. As a result, the connecting portions gradually become fragile and unable to fully exhibit their function. Moreover, since the torsion bars are required to be extended across the corner portions of the base member which has only a limited space, it is difficult to obtain a sufficient length for each of the torsion bars. Therefore, the connecting portions of the torsion bars tend to be more fragile and are subjected to a danger of breakage. In addition, when the torsion bars and the latch arms are integrally formed in the base member, complicated narrow spaces or gaps for defining both of them must be formed therearound, and therefore, molding is not easy. As described above, in the IC carrier or IC socket of the type in which the above latch arms are elastically engaged with and disengaged from the IC, the latch arms are integrally formed on the base member such that the latch arms themselves are elastically shifted at the connecting portions, for example, at the above torsion bars, with respect to the base member. On the other hand, in the case where the latch arms are formed as separate parts from the base member to form a two-piece construction, the latch arms are pivotably supported relative to the base member through shafts or pins respectively, and the latch arms, when pivoted to positions for engagement with the IC, are brought into engagement with the base member through male and female engagement means in order to hold the IC. Such an IC engagement means as just mentioned can obviate such problems as deterioration in elasticity and breakage of the latch arms, the problems being inherent in the one-piece construction. However, the engagement between the male portion and the female portion is not reliable, and they are easily disengaged due to wear of the male and female portions. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an IC carrier or IC socket capable of effectively obviating the problems inherent in the conventional one-piece type and two-piece type IC carrier or IC socket. A specific object of the present invention is to provide an IC carrier or IC socket, in which latch arms can exhibit their wholesome function even after they are used repeatedly. According to one aspect of the present invention, there is essentially provided, in order to achieve the above objects, an IC carrier comprising a base member for carrying thereon an IC, latch arms each pivotably supported on said base member for pivoting between a first position for engaging with an edge portion of said IC and a second position for removing the engagement, and lock tabs each formed on an upper end of each of said latch arms and adapted to engage with and disengage from the edge portion of said IC, said IC carrier further comprising spring elements each projecting from a pivotal portion of each of said latch arms, said spring elements accumulating resilient force while said latch arms being pivoted in a direction for removing the engagement so as to urge said latch arms in a direction for realizing the engagement. From another aspect of the present invention, there is also provided an IC socket, comprising a base member for carrying thereon an IC, latch arms each pivotably supported on said base member for pivoting between a first position for engaging with an edge portion of said IC and a second position for removing the engagement, and lock tabs each formed on an upper end of each of said latch arms and adapted to engage with and disengage from the edge portion of said IC, said IC carrier further comprising spring elements each projecting from a pivotal portion of each of said latch arms, said spring elements accumulating resilient force while said latch arms being pivoted in a direction for removing the engagement so as to urge said latch arms in a direction for realizing the engagement. According to the present invention, when each latch arm is pivoted upwardly while bending the spring element, the arm is disengaged from the IC in order to allow the IC to be removed. On the other hand, resilient force is accumulated in each spring element when the latch arm is pivoted in the direction for removing the engagement, and this resilient force causes each latch arm to be pivoted in the direction for realizing its engagement with the IC. As described above, according to the present invention, there can be obviated such problems that the latch arms are subjected to resilient deterioration, breakage, etc. due to repeated use thereof as often experienced in the conventional one-piece type IC carrier or IC socket which is integral with the base member. In addition, there can also be obviated such problems that the latch arms are subjected to insufficient engagement, erroneous engagement, etc. due to wear of the engaging portions because of repeated use, as often experienced in the two-piece type IC carrier in which the latch arms are pivotably supported on the base member. Even if the IC is repeatedly inserted into and removed from the base member of the IC carrier or IC socket, the latch arms can still exhibit their wholesome function. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of an IC carrier showing one embodiment of the present invention; Fig. 2 is a bottom view of the above; Fig. 3 is a sectional view of the above; Fig. 4 is a side view, showing a latch arm now in engagement with an IC; Fig. 5 is a sectional view of an important portion showing a steady state of the latch arm; Fig. 6 is a sectional view of an important portion showing a released state of the latch arm; Fig. 7 is a sectional view of an important portion showing an engaging state of the latch arm; and Fig. 8 is an enlarged sectional view of a pivotal shaft portion of the latch arm. DETAILED DESCRIPTION OF THE EMBODIMENT One preferred embodiment of the present invention will now be described in detail with reference to Figs. 1 through 8 inclusive. The numeral 1 denotes a base member which forms a carrier body made of synthetic resin. The base member 1 is of a generally square configuration and has an IC accommodation portion 2 formed in and opening at a generally central portion thereof. The IC accommodation portion 2 is of a generally square configuration and accommodates therein an IC 3 such that each side of the IC 3 is in parallel relation with each side of the IC accommodation portion 2. As shown in Fig. 1, seat members 4 for supporting each row of a group of leads 7 arranged along and extending sidewards from each side of the IC 3, are formed on opposing two or four sides of the IC accommodation portion 2. The IC accommodation portion 2 is defined at an inner area of each seat member 4. Each corner portion of the base member 1 is provided with a latch arm 6. The latch arm 6 is received in a through-chamber 8 which is opened at both upper and lower surfaces of each corner portion, and pivotably supported on an inner surface of the through-chamber 8 through a shaft portion 5. Each latch arm 6 is disposed at angles along a diagonal line of the IC accommodation chamber 2, such that the axis of the shaft portion 5 is perpendicular to the diagonal line. Therefore, each latch arm 6 is pivoted upwardly and downwardly on the diagonal line about the shaft portion 5. When latch arm 6 is pivoted downwardly, it is engaged with the corresponding corner portion of the IC 3 received in the IC accommodation portion 2, and when the latch arm 6 is pivoted upwardly, it is disengaged from the corresponding corner portion of the IC. Each latch arm 6 is provided at an inner end, i.e., upper end, with a lock tab 6a which is removably engaged with the IC 3. As shown in Fig. 8, the shaft portion 5 is pushed into a lower opening portion 8b of the through-chamber 8 so that both ends of the shaft are press-fitted to a bearing portion 8a formed in an inner side wall opposite the lower opening portion. On the other hand, the latch arm 6, as shown in Fig. 5, etc., is raised from the shaft portion 5 disposed at a lower surface side of the base member 1 towards an upper opening portion 8a through an elbow portion 6c facing the lower opening portion 8b, and further extended inwardly on the diagonal line along the upper opening portion. A foremost or upper end of the latch arm 6 is provided with the lock tab 6a. A spring element 6b extends backwardly from the pivotal support portion of each latch arm 6 pivotably supported by the shaft. The latch arm body and the spring element are integrally formed of synthetic resin material. The spring element 6b extends on the diagonal line in a direction opposite to the lock tab 6a (i.e., in the extending direction of the latch arm 6). A free end 6d of the spring element 6 contacts a spring bearing portion 9 formed of an inclination surface formed on a rear inner wall of the through-chamber 8, or the free end 6d may contact the spring bearing portion 9 when the latch arm 6 is pivoted upwardly. As shown in Fig. 6, when the latch arm 6 is pivoted upwardly, the free end portion 6d of the spring element 6b contacts the spring bearing portion 9 thereby preventing a further pivotal movement. As a result, the spring element 6b is bent to accumulate resilient force. As means for preventing an excessive downward pivotal movement of the latch arm 6, for example, a stop 10 for restricting an upward pivotal movement of the spring element 6b is integrally formed on an inner wall of the through-chamber 8. As one example, as shown in Fig. 7, the stop 10 is disposed such that when the latch arm 6 is in an engagement position, the stop 10 is in abutment with an upper surface of the spring element 6b and the free end 6d of the spring element 6b is abutted with the spring bearing portion 9. A basal portion of each latch arm 6 is connected to a central portion of each shaft portion 5, while a basal portion of each spring element 6b is connected to both end portions of the shaft portion 5. The spring element 6b is gradually reduced in width as it goes away from the connecting portion towards the free end portion 6d and also gradually reduced in thickness. The narrowest and thinnest free end portion 6d is operated to contact the spring bearing portion 9. As shown in Figs. 5 and 6, when the latch arm 6 is pivoted upwardly about the shaft portion 5, the spring element 6b is prevented its pivotal movement by the spring bearing portion 9 and bent to accumulate resilient force, and the lock tab 6a is pivoted into a position where the lock tab 6a is not interfered with the IC (i.e. position where the engagement is removed). As mentioned above, the basal portion of each latch arm 6 is provided with an elbow portion 6c facing the lower opening portion 8b of the through-chamber 8. A curved outer surface of this elbow portion 6c is formed in an arc form, and this arcuately curved portion is served as a pressure receiving portion 6e for a jig, and the portion 6e is served as shutter means for the latch arm 6. The numeral 11 denotes a jig which is operated by a robot. The jig 11, as shown in Fig. 6, is vertically movable. When the jig 11 is moved upwardly, one end of the jig 11 is inserted into the through-chamber 8 through the lower opening portion 8b in order to push up the pressure bearing portion 6e, and as a result, the latch arm 6 is caused to be pivoted upwardly so as to be disengaged from the IC 3. In that state (i.e., the latch arm 6 is in a released state), the IC 3 is inserted into and removed from the IC accommodation portion 2. When the pushing-up force of the jig 11 to the latch arm 6 is removed, the latch arm 6 is automatically pivoted downwardly due to restoring force of the spring element 6b so as to be engaged with an upper surface of the corner portion of the IC 3. As a result, the IC 3 is held on the base member 1. As shown in Fig. 7, when the lock tab 6a of each latch arm 6 is in engagement with the corner portion of the IC 3, a small amount of resilient force still remains in the spring element 6b, and the lock tab 6a is lightly abutted with the corner portion by this resilient force, so that the engagement is maintained. In the engagement state shown in Fig. 7, since the upward pivotal movement of the latch arm 6 is prevented by the spring bearing portion 9 even if the resilient force of the spring element 6b is zero, the engagement between the IC 3 and the lock tab 6a can be maintained. When the lock tab 6a of the latch arm 6 is in engagement with the IC, the upper end face 6f of the latch arm 6 is abutted with a side surface (for example, side surface of the corner portion), and the IC is correctly positioned and held by and between the upper end faces 6f of the opposing latch arms 6. Therefore, the upper end face 6f of each latch arm 6 forms a positioning surface for the IC. The lock tab 6a is brought into engagement with the IC which is correctly positioned and held by and between the upper end faces 6f of the opposing latch arms 6. In Fig. 4, the latch arms 6 are in engagement with the opposing corner portions of the IC 3 so that the IC 3 is held on the base member 1. As understood from Fig. 4, the latch members 6 may be engaged with four corners or they may be engaged with two opposing corners of the IC. The latch arms 6 may be engaged with those edge portions of the IC 3 which include the corner portions, respectively. In the above embodiment, the latch arms 6, the spring elements 6b, and the shaft portions 6 are integrally formed of synthetic resin. As a modified embodiment, the spring elements 6b may be made of metal and integrally formed with the latch portions 6. The shaft portions 5 may be metal pins, respectively. In the drawings, the present invention is applied to an IC carrier. However, the present invention may be applied to an IC socket. Although not shown, an IC socket is formed by implanting a plurality of contacts into the base member 1 such that the contacts can be brought into contact with leads 7 of the IC 3, respectively. The contacts are arranged around the IC accommodation portion, for example, the area corresponding to the seat members 4, so that they are readily brought into contact with the IC leads 7, respectively. In this case, the latch arm 6 is engaged with the edge portion of the IC 3 and served as means for maintaining the foregoing contacting relation. In the above embodiment, the base member is formed in a regular square configuration, and the latch arms are disposed on the diagonal lines. When the base member takes, for example, a rectangular configuration, the latch arms are disposed on the diagonal lines, or at angles or parallel with each side of the base member, respectively. According to the present invention, resilient force is accumulated owing to the spring elements had by the latch arms themselves. By this resilient force, the latch arms are automatically returned into the engaging direction so as to maintain the engagement with the IC by their own function. A similar function as in the one-piece type IC carrier can be realized by a two-piece construction. As described above, according to the present invention, there can be obviated such problems that the latch arms are subjected to resilient deterioration due to repeated use thereof and molding is difficult as often experienced in the conventional one-piece type IC carrier or IC socket. In addition, there can also be obviated such problems that the latch arms are subjected to insufficient engagement, erroneous engagement, etc. due to wear of the engaging portions because of repeated use, as often experienced in the two-piece type IC carrier or IC socket in which the latch arms are pivotably supported on the base member. According to the present invention, even if the IC is repeatedly inserted into and removed from the base member of the IC carrier or IC socket, the latch arms can still exhibit their wholesome function.

Claims: An IC carrier comprising a base member for carrying thereon an IC, latch arms each pivotably supported on said base member for pivoting between a first position for engaging with an edge portion of said IC and a second position for removing the engagement, and lock tabs each formed on an upper end of each of said latch arms and adapted to engage with and disengage from the edge portion of said IC, said IC carrier further comprising spring elements each projecting from a pivotal portion of each of said latch arms, said spring elements accumulating resilient force while said latch arms being pivoted in a direction for removing the engagement so as to urge said latch arms in a direction for realizing the engagement. An IC carrier as claimed in claim 1, wherein each spring element being integrally formed of synthetic resin, together with each latch arm and extending in a direction opposite to said lock tab. An IC carrier as claimed in claim 2, wherein a free end of each spring element being abutted with an inclination surface so as to be bent. An IC socket, comprising a base member for carrying thereon an IC, latch arms each pivotably supported on said base member for pivoting between a first position for engaging with an edge portion of said IC and a second position for removing the engagement, and lock tabs each formed on an upper end of each of said latch arms and adapted to engage with and disengage from the edge portion of said IC, said IC socket further comprising spring elements each projecting from a pivotal portion of each of said latch arms, said spring elements accumulating resilient force while said latch arms being pivoted in a direction for removing the engagement so as to urge said latch arms in a direction for realizing the engagement. An IC socket as claimed in claim 4, wherein each spring element being integrally formed of synthetic resin, together with each latch arm and extending in a direction opposite to said lock tab. An IC socket as claimed in claim 4, wherein a free end of each spring element being abutted with an inclination surface so as to be bent.

Inventors: KUBO MASAAKI, KUBO, MASAAKI
Applicants: YAMAICHI ELECTRONICS CO LTD, YAMAICHI ELECTRONICS CO., LTD.
Application year: 1992
Main classification: H05K7
IPC codes: B65D85, H05K7