Abstract:
A contact lead for engaging with an aperture lead of a circuit carrier, including a substrate contact portion electrically connected to a pad on a substrate a chip contact portion extending from the substrate contact portion and forming an angle with the substrate contact portion raising from the substrate. The contact lead chip contact portion may also be of a cylindrical shape vertically extending from the substrate contact portion. The present invention also provides a module including a printed circuit board having a plurality of pad thereon ,the contact lead electrically connected to the pad, an integrated circuit carrier having a plurality of aperture leads, the aperture leads passing through the contact lead and contacting respectively thereof, and a housing structure for housing the module and providing access for the user to assemble the integrated circuit carrier.

Description:
BACKGROUND 
   1. Field of Invention 
   The present invention relates to a contact lead. More particularly, the present invention relates to a contact lead for engaging with an aperture lead of an integrated circuit carrier. 
   2. Description of Related Art 
   The advancement in electronics products propels the integrated circuits industry to produce chips with smaller size, faster speed, and larger storage memory space. Therefore, products such as memory cards depreciate fast in value due to newer memory chips hitting the market at short time intervals. Memory cards with less memory are less likely to sell when cards with larger memory at a fair price are circulating in the market. The memory card manufacturer will have a hard time selling the outdated products and have no choice but to take a loss for the overstocked products. Furthermore, if the memory card manufacturer introduced a product, which is premature for the consumer market, the manufacturer will also take a loss for the unsold products. For example, if a memory card with a large memory capacity is introduced on the market but does not sell well as expected, the memory will have little use for the immediate future. 
   Therefore, the disadvantage is that memory cards such as secure digital (SD) cards and multi-media cards (MMC) does not possess upgrade or downgrade capabilities in memory size. This disadvantage leads to wasted products at both the manufacturer end and the consumer end. 
   Please refer to  FIG. 1 , an overview of the connection between an integrated circuit chip  102  and the contact leads  104 . The connection is a solder connection, wherein the leads  106  of the chip are soldered onto the contact leads  104  of the substrate  108 , respectively. The solder connection prevents the chip  104  from being replaced by a different memory chip without de-soldering. 
   For the forgoing reasons, there is a need for a circuit module such as memory cards, which allows for upgrades and downgrades of integrated circuit chips such as memory chips. The upgrading and downgrading may be done by a detachable structure allowing the memory chips to be detached from the circuit substrate rather than soldered onto the circuit substrate. 
   SUMMARY 
   The present invention is directed to a contact lead, that it satisfies this need of having a detachable structure on a circuit module. The contact lead comprises a substrate contact portion and a chip contact portion. The first end of the substrate contact portion is stamped onto the pads of the substrate and the second end is extended onto a tape, which serves as a support for the contact lead. The chip contact portion extending from the second end forms an angle with the substrate contact portion. The angle elevates from the substrate. In another embodiment of the present invention, the contact lead comprises a substrate contact portion and a chip contact portion. The substrate contact portion is electrically connected to the pads of the substrate. The chip contact portion has a cylindrical shape extending vertically from the substrate contact portion. In this embodiment, the contact lead further includes a spring coil looped around the contact lead. The chip contact portion is to be inserted and engaged with an aperture lead of an integrated circuit carrier. The engagement is a detachable engagement. 
   The detachable structure will allow the integrated circuit chips to be assembled onto the circuit substrate without the solder connection, and detached from the circuit substrate for replacement. The manufacturer may upgrade and downgrade memory cards according to the market demand and not let memory cards with undesirable memory size be wasted. On the consumer end, one may upgrade the memory card to a larger sized memory by replacing the memory chip rather than having to replace the entire memory card. 
   The memory card may also have multiple memory chips stacked on top of each other as long as the chip contact portion of the contact leads are of an adequate length to be able to securely engage with all the stacked chips. 
   Furthermore, to accommodate for the replaceable memory chips, a memory card housing is designed to provide access to the memory chips. 
   It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
       FIG. 1  is an overview of the connection between an integrated circuit chip and the contact leads; 
       FIG. 2   a  is an illustration of a row of contact leads connected to a printed circuit board according to a first embodiment of the present invention according to one preferred embodiment of this invention; 
       FIG. 2   b  is a side view of the contact lead according to the first embodiment of the present invention; 
       FIG. 3   a  is an illustration of a row of contact leads connected to a printed circuit board according to a second embodiment of the present invention; 
       FIG. 3   b  is a side view of the contact lead  302  according to the second embodiment of the present invention; 
       FIG. 4   a  is an illustration of an integrated circuit carrier engaging with the contact leads of the first embodiment of the present invention; 
       FIG. 4   b  is a cross section view along the line AB in  FIG. 4   a;    
       FIG. 4   c  is a cross section view a cross section view along the line AB in  FIG. 3   a  with an extra integrated circuit carrier; 
       FIG. 5   a  is a cross section view of an integrated circuit carrier engaging with the contact leads of the second embodiment of the present invention; 
       FIG. 5   b  is a cross section view of an integrated circuit carrier engaging with the contact leads of the second embodiment of the present invention with an extra integrated circuit carrier; 
       FIG. 6  is an exploded view of a memory card according to the second embodiment of the present invention; 
       FIG. 7   a  is a top view of the assembled memory card without the clamping structure; and 
       FIG. 7   b  is a top view of the assembled memory card with the clamping structure clipped onto the opening. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
   Please refer to  FIG. 2   a , and  2   b  simultaneously.  FIG. 2   a  illustrating a row of contact leads connected to a printed circuit board according to a first embodiment of the present invention. The contact lead  202  is electrically connected to the pad  204  on the printed circuit board  206 . The contact lead  202  is supported by a tape  208 . In  FIG. 2   b , a side view of the contact lead  202  according to the first embodiment of the present invention, the structure of the contact lead is divided into a substrate contact portion  210  and a chip contact portion  212 . The substrate contact portion  210  may be further divided into a first end  210   a  and a second end  210   b . The first end  210   a  is stamped onto the pad  204  and is electrically connected to the pad  204 . The second end  210   b  is extended from the first end onto the tape  208 . The chip contact portion  212  is an extension from the second end  210   b . The chip contact portion  212  forms an angle  214  with the substrate contact portion  210 . The degree of elevation may vary for different applications. 
   Please refer to  FIGS. 3   a  and  3   b  simultaneously.  FIG. 3   a  illustrating a row of contact leads connected to a printed circuit board according to a second embodiment of the present invention. The contact lead  302  is electrically connected to the pad  304  on the printed circuit board  306 . The contact lead  302  also includes a spring coil  308  looped around the contact lead providing support for engaging with the aperture leads. In  FIG. 3   b , a side view of the contact lead  302  according to the second embodiment of the present invention. The structure of the contact lead  302  is divided into a substrate contact portion  310  and a chip contact portion  312 . The substrate contact portion  310  may be soldered onto the pads  304  of the printed circuit board  306 . The chip contact portion  312  has a cylindrical shape providing a fitting shape for engaging with the aperture leads. The chip contact portion  312  extends vertically from the substrate contact portion  310 . 
   Please refer to  FIGS. 4   a ,  4   b , and  4   c  simultaneously.  FIG. 4   a  illustrating an integrated circuit carrier  402  engaging with the contact leads  202  of the first embodiment of the present invention. The integrate circuit carrier  402  may be a leadframe packaged integrate circuit, a semiconductor die packaged onto a transfer substrate, or an integrated circuit package connected onto a transfer carrier via a flip-chip method. The integrated circuit carrier  402  has aperture leads  404  which allows the contact leads  202  to be inserted into the aperture leads  404  and establish electrical connection with the aperture leads  404 . In  FIG. 4   b , a cross section view along the line AB in  FIG. 4   a , the contact lead  202  engages with the aperture lead  404 . The structure of the aperture leads  404  forces the chip contact portion  212  to be bended in the direction of the arrow  306  from its previous position  408 . The bending of the chip contact portion  212  provides a force pressing the chip contact portion  212  against the aperture lead  404 . The bending force therefore provides a secure engagement between the contact lead  202  and the aperture lead  404 . In  FIG. 4   c , a cross section view a cross section view along the line AB in  FIG. 4   a  with an extra integrated circuit carrier  410  stacked on top of the integrated circuit carrier  302 . The stacking structure allows the integrated circuit carriers to be electrically connected with each other and also with the substrate  412 . The stacking structure also provides the flexibility of stacking multiple integrated circuit carriers to adjust the memory size of the memory card. In order to stack multiple integrated circuit carriers, the chip contact portion  212  will need to be extended in length to securely engage with all the stacked integrated circuit carriers. 
   Please refer to  FIG. 5   a , and  5   b  simultaneously.  FIG. 5   a  illustrating an a cross section view of an integrated circuit carrier  502  engaging with the contact leads  302  of the second embodiment of the present invention. The integrate circuit carrier  502  may be a leadframe packaged integrate circuit, a semiconductor die packaged onto a transfer substrate, or an integrated circuit package connected onto a transfer carrier via a flip-chip method. The integrated circuit carrier  502  has aperture leads  504  which allows the contact leads  302  to be inserted into the aperture leads  504  and establish electrical connection with the aperture leads  504 . The inner surface of the aperture leads  504  makes contact with the outer surface of the chip contact portion  312 . The friction force between the surfaces may induce a detachable grip between the aperture leads  504  and the chip contact portion  312 . Furthermore, the spring coil  308  supports the integrated circuit carrier  502  and may force the integrated circuit carrier  502  against the a clamping structure (not shown), such as a cap to fix the integrated circuit carrier  502 . In  FIG. 5   b , a cross section view of an integrated circuit carrier  502  engaging with the contact leads  302  of the second embodiment of the present invention with an extra integrated circuit carrier  510  stacked on top of the integrated circuit carrier  502 . The stacking structure allows the integrated circuit carriers to be electrically connected with each other and also with the substrate  512 . The stacking structure also provides the flexibility of stacking multiple integrated circuit carriers to adjust the memory size of the memory card. In order to stack multiple integrated circuit carriers, the chip contact portion  312  will need to be extended in length to securely engage with all the stacked integrated circuit carriers. 
   Please refer to  FIG. 6 , an exploded view of a module according to the third embodiment of the present invention. The module may be a memory card such as a SD card or a MMC. The memory card  600  includes a detachable module  602 , and a housing structure  604 . The detachable module  602  includes a printed circuit board  606  having the contact leads of either the first embodiment, the second embodiment or the combination thereon, a integrated circuit carrier  608  with aperture leads  610  is electrically connected to the contact leads via the connection described above. There may be more than one integrated circuit carrier electrically connected to the contact leads. Multiple integrated circuit carriers may be stacked on top of each other and be kept in the same housing structure  604 . The housing structure  604  includes a card housing  612 , a socket housing  614 , and a clamp housing  616 . The card housing  612  engages with the printed circuit board  606  and shields the surface of the printed circuit board  606 , which has the contact leads of either the first embodiment, the second embodiment or the combination thereon. The card housing  612  has an opening  618  located on top of the integrated circuit carrier  608 . The socket housing  614  is assembled inside the opening  618  and engages securely with the opening  618 . The socket housing  614  also has an opening  620  located on top of the integrated circuit carrier  608  exposing the integrated circuit carrier  608  thus providing the channel for integrated circuit carrier  608  attachment and detachment. Lastly, the clamping structure  616  acts as a cap to seal the enclosure of the memory card. The clamping structure may click onto the sides of the opening  620  and be removed when replacing the integrated circuit carrier  608 . 
   Please refer to  FIG. 7   a , and  FIG. 7   b  simultaneously.  FIG. 7   a  is a top view of the assembled memory card  600  without the clamping structure  616 . The opening  620  is of a suitable size to ensure the integrated circuit carrier  408  may be attached and detached with relative ease.  FIG. 7   b  is a top view of the assembled memory card  600  with the clamping structure  616  clipped onto the opening  620 . By removing the clamping structure, one may replace the memory chip on the printed circuit board with a different memory size chip, and/or stack multiple chips onto the printed circuit board. 
   The present invention is a contact lead for engaging with an aperture lead of an integrated circuit carrier. The contact lead provides a detachable connection between the printed circuit board and the integrate circuit carrier. The detachable connection may be applied to memory cards such as SD cards and MMC. Therefore when one desires to upgrade or downgrade the memory size of a memory card, it is not necessary for one to discard the entire memory but may choose to replace the memory chips on the memory card. 
   It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.