Abstract:
A shock absorbing device for a notebook computer module. The device comprises of a notebook computer module, a cooling/protective plate, and two springs. A first spring is installed between the notebook computer module and the cooling/protective plate that provides a force trying to separate the cooling/protective plate and the module. The cooling/protective plate has a hole that permits a fastening insert to pass through. A first end of the fastening insert protrudes outside the cooling/protective plate while a second end of the fastening insert fastens onto the notebook computer module. There is a second spring between the first end of the fastening insert and the cooling/protective plate. The second spring provides a force trying to draw the cooling/protective plate closer to the module.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a shock-absorbing device. More particularly, the present invention relates to a shock-absorbing device for protecting a notebook computer module. 
     2. Description of Related Art 
     As the level of semiconductor integration continues to increase, size of various electronic devices inside a silicon chip becomes smaller. Therefore, the electronic devices need to be carefully protected from damage. In general, a component having a large number of devices is more vulnerable to physical damage than a component having few devices inside. Therefore, a compact component demands more protection. 
     Using the central processing unit (CPU) of a notebook computer as an example, the limited volume inside a notebook computer demands a CPU that is slightly different from a CPU installed inside a desktop computer. In addition, due to limited air space inside the notebook computer, airflow inside the notebook computer is also restricted. Therefore, heat dissipation is a problem for the CPU inside a notebook computer as well. 
     FIG. 1 is a schematic, cross-sectional view of a conventional shock-absorbing device around a notebook computer module. As shown in FIG. 1, a silicon chip  10  is mounted onto a printed circuit board (PCB)  12  via a connector (not shown). Alternatively, the silicon chip  10  is mounted directly onto the PCB  12 . In. general, a silicon chip installed inside a notebook computer has limited tolerance for temperature, pressure and bending. Because of the poor heat dissipating capability of the chip  10  alone and the vulnerability of the notebook computer to impact while being carried, a protective device is formed behind the printed circuit board  12  and above the chip  10 . 
     Corresponding in position to chip  10 , there is a backing plate  14  attached to the other side of the printed circuit board  12 . Because the silicon chip  10  usually has a large number of pins that need to be connected to the printed circuit board  12 , the printed circuit board  12  must have a certain degree of planarity to achieve connection. Since most printed circuit boards are not stiff enough, the supporting plate  14  serves as a stiff backing. In addition, the supporting plate  14  also provides some protection against bending to the PCB  12 , because any bending is likely to damage the chip  10 . 
     Due to the high level of integration on the silicon chip  10 , the amount of heat generated during operation is enormous. Hence, there is a cooling/protective plate  16  on top of the silicon chip  10 . The cooling/protective plate  16  is placed over the silicon chip  10  and fixed onto the printed circuit board  12  by a set of screws  18 . A protruding element  19  above the chip  10  presses against a surface of the cooling/protective plate  16  so that heat generated by the chip  10  can be conducted away quickly. The cooling/protective plate  16  further has an elastic portion  15  that permits the absorption of shock from external impact. However, how to make the cooling/protective plate  16  contact the chip  10  so that heat can be dissipated without exerting too much pressure on the chip  10  itself is a major design consideration. In general, the cooling/protective plate  16  can only absorb forces in one direction. For example, the cooling/protective plate  16  can absorb a force coming from the top of the chip  10 , but cannot withstand a force from the opposite direction. Therefore, the screws must be tightened very carefully so that the cooling/protective plate can exert a correct amount of pressure on the chip  10 . The maximum pressure a silicon chip such as a micro-pin grid array (μPGA) can tolerate is only about 689 kpa. Due to unevenness of the chip&#39;s surface, stress on the silicon chip may exceed the 689 kpa limit in some local areas. Yet, if insufficient torque is applied to the screws  18 , pressure exerted by the cooling/protective plate  16  on the protruding element  19  of the chip  10  is likely to be too low to provide a good contact for cooling. In addition, vibrations caused by physical impact of the notebook computer may loosen the grip of the cooling/protective plate. Even without any external impact, the pre-loaded pressure provided by the screws  18  just for holding the cooling/protective plate  16  onto the printed circuit board  12  is likely to bring down the shock buffering capacity of the cooling/protective plate  16 . 
     SUMMARY OF THE INVENTION 
     Accordingly, the purpose of the present invention is to provide a shock-absorbing device for a notebook computer module. The module is capable of buffering the module against impact forces in both directions and providing a correct amount of contact pressure between the device and a cooling/protective plate. 
     To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a shock absorbing device. The device comprises a notebook computer module, a cooling/protective plate, and two springs. There is a first spring between the notebook computer module and the cooling/protective plate, and the notebook computer module and the cooling/protective plate are in contact with each other. The first spring provides a force that tries to separate the cooling/protective plate and the module. The first spring is slid over the body of a balancing rod. A first end of the balancing rod passes through a hole in the cooling/protective plate and a second end of the balancing rod touches the module. There is a fastening insert on the cooling/protective plate as well. The fastening insert passes through another hole in the cooling/protective plate and then fastens onto the module. A second spring is slid between one end of the fastening insert and the cooling/protective plate. The second spring provides a force that tries to bring the cooling/protective plate and a printed circuit board of the module. When the cooling/protective plate that holds the module is fastened onto a substratum, the amount of pressure on the module such as a chip can be adjusted by increasing or decreasing the spring loading. In the meantime, when an external force is exerted on the cooling/protective plate or the entire module is forced to vibrate, the stored potential in the springs can counteract a portion of the external force or vibrations. Hence, the force or the vibration is dampened and so the module inside the notebook computer is saved. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings, 
     FIG. 1 is a schematic, cross-sectional view of a conventional shock-absorbing device round a notebook computer module; 
     FIG. 2 is a perspective view of a shock-absorbing device for a notebook computer module according to a first embodiment of this invention; 
     FIG. 3 is an exploded, perspective diagram showing all the components necessary for assembling the shock-absorbing device according to the first embodiment of this invention; 
     FIG. 4 is a schematic, bottom view of the shock-absorbing device according to the first embodiment of this invention; 
     FIG. 5 is a schematic, cross-sectional view along line I—I of FIG. 4; 
     FIG. 6 is a schematic, cross-sectional view along line II—II of FIG. 4; and 
     FIG. 7 is an exploded, perspective diagram showing all the components necessary for assembling a shock-absorbing device for a notebook computer module according to a second embodiment of this invention. 
    
    
     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. 
     FIG. 2 is a schematic, perspective view of a shock-absorbing device for a notebook computer module according to a first embodiment of this invention. FIG. 3 is an exploded, perspective diagram showing all the components necessary for assembling the shock-absorbing: device according to the first embodiment of this invention. In general, the central processing unit (CPU) of a notebook computer requires greater protection. Therefore, the CPU inside a notebook computer must be surrounded by a good shock-absorbing device such as the one in FIG. 2. A micro-pin grid array type of microprocessor chip  20  is generally used inside a notebook computer. Due to the generation of a large amount of heat and the limited tolerance of any stress, the silicon chip  20  needs to be protected by a cooling/protective plate  40  and a backing plate  30 . 
     As shown in FIG. 3, there is a chip-mounting region  23  on a printed circuit board  22  for mounting the chip  20 . In fact, the chip  20  is mounted on a front surface  24  and the backing plate  30  is mounted on a back surface  25  of the chip-mounting region  23 . The backing plate  30  is a flat and thin panel that can be mounted onto the printed circuit board  22  by glue or with screws. The surface area of the backing plate  30  is roughly the same as the chip-mounting region  23 . In other words, the footprint of the backing plate  30  on the PCB  22  is larger than the footprint of the silicon chip  20  on the PCB  22 . Since the silicon chip  20  is mounted onto the chip-mounting region  23 , the backing plate  30  is able to provide a high degree of planarity for the chip on the printed circuit board  22 . The backing plate  30  is also able to provide additional resistance against an external bending moment. Since the area on the printed circuit board  22  for mounting the chip  20  can still maintain a high degree of planarity despite bending, the chip  20  is protected. Furthermore, strength of the backing plate  30  can be further increased by adding one more backing plate  30 ′ at the back of the backing plate  30 . 
     The cooling/protective plate  40  is in contact with the silicon chip  20  so that heat generated by the chip can be carried away as quickly as possible. The surface area of the cooling/protective plate  40  is greater than that of the chip  20  but is almost identical to that of the chip-mounting region  23 . Only the protruding element  42 , which has a similar surface area as the silicon chip  20 , is in direct contact with the chip  20 . The cooling/protective plate  40  is fastened to the printed circuit board  22  by means of a screw  49  that passes through each of a pair of fastening inserts  44  on the cooling/protective plate  40 . A pair of balancing rods  32  are positioned between the printed circuit board  22  and the cooling/protective plate  40 . A fixed end  32 ′ of each balancing rod  32  is in contact with the printed circuit board  22 . The fixed end  32 ′ of each balancing rod  32  is either pushed against the surface of the printed circuit board  22  or glued directly onto the surface of the printed circuit board  22 . A movable end  32 ″ of each balancing rod  32  passes through a hole  38  in the cooling/protective plate  40 . There is a hole  35  near the movable end  32 ″ of each balancing rod  32  for inserting a pin  36 . The pin  36  is parallel to the cooling/protective plate  40  so that the positions of the balancing rods  32  are fixed. Furthermore, there is a compression spring  34  around each balancing rod  32 . Since the balancing rods  32  are perpendicular to both the cooling/protective plate  40  and the printed circuit board  22 , the balancing rod  32  can only move in an up or down direction, either compressing or relaxing the spring  34 . Due to spring compression, a force of magnitude F 1  is exerted on the printed circuit board  22  and a force of magnitude F 2  is exerted on the cooling/protective plate  40 . The forces F 1  and F 2  are of the same magnitude but act in opposite directions, and they try to separate the cooling/protective plate  40  and the printed circuit board  22 . The furthest distance of separation between the cooling/protective plate  40  and the printed circuit board  22  is reached when the pins  36  touch the cooling/protective plate  40 . When an external force acts on the cooling/protective plate  40  such that the cooling/protective plate  40  moves towards the printed circuit board  22 , the silicon chip  20  is compressed. However, due to additional compression of the spring  34 , forces F 1  and F 2  increasingly counteracts a portion of the external force so that the ultimate additional pressure on the chip  20  is greatly reduced. 
     A pair of fastening inserts  44  is also installed on the cooling/protective plate  40 . A first end  44 ′ of each fastening insert  44  passes through a protruding element  39  on the cooling/protective plate  40  and reaches the printed circuit board  22 . A screw  49  that passes through the hollow center of the fastening insert  44 , a C-clip  48  and a nut  45  finally sinks into a protruding element  31  on the backing plate  30 . The backing plate  30 , the printed circuit board  22  and the cooling/protective plate  40  are all parallel to each other but perpendicular to the fastening inserts  44 . The nut  45  is used to support the protruding element  31  on the backing plate  30  so that the backing plate  30  is fastened onto the printed circuit board  22 . The C-clip is one of the components in an assembly that also includes the fastening insert  44 , a compression spring  46  and the screw  49 . 
     A second end  44 ″ of the fastening insert  44  has a large diameter than the body of the insert  44  so that the compression spring  46  can remain in position after sliding onto the fastening insert  44 . The spring  46  is capable of providing a force F 3  to the cooling/protective plate  40  and a force F 4  to the fastening insert  44 . Forces F 3  and F 4  are of the same magnitude but act in opposite directions. Forces F 3  and F 4  try to push the cooling/protective plate  40  away from the fastening insert  44 . Since the fastening insert  44  is already fixed onto the printed circuit board  22 , the cooling/protective plate  40  can chip  20 . 
     FIG. 4 is a schematic, bottom view of the shock-absorbing device according to the first embodiment of this invention. As shown in FIG. 4 the cooling/protective plate  40  is in the shape of a square. The movable end  32 ″ of the balancing rods  32  for carrying the spring  34  and the second end  44 ″ of the fastening inserts  44  for carrying the spring  46  are arranged to be on opposite corners. Therefore, the force F 2  exerted by the spring  34  and the force F 3  exerted by the spring  46  on the cooling/protective plate  40  can balance. When an external force acts on the cooling/protective plate  40  pushing the cooling/protective plate  40  towards the chip  20  or away from the chip  20 , the compression springs  34  or the compression springs  46  can provide a counteractive force. Hence, the chip  20  is protected. Obviously, the number of fastening inserts  44  and the number of balancing rods  32  can be variables as long as a stable configuration is possible. 
     FIG. 5 is a schematic, cross-sectional view along line I—I of FIG.  4 . FIG. 6 is a schematic, cross-sectional view along line II—II of FIG.  4 . As shown in FIGS. 5 and 6, the protruding part  39  of the cooling/protective plate  40  actually has an internal cavity  39 ′ having a diameter only slightly bigger than the compression spring  46 . Consequently, when the spring  46  is pushed inside the internal cavity  39 ′, the spring  46  does not move sideways and thus does not produce an unbalanced distribution of forces. 
     In this invention, forces exerted by the set of compression springs  46  and  34  on the cooling/protective plate  40  permit the cooling/protective plate  40  to contact the chip  20  without exerting too much pressure. In addition, the set of springs  46  and  34  each exerts a force on a corner of the chip-mounting region  23 . Therefore, even a bending moment can be balanced. In other words, even if the edge of the cooling/protective plate  40  is under pressure, the springs  34  and  46  can still act concertedly to redistribute and counteract the external forces in order to protect the chip  20 . 
     FIG. 7 is an exploded, perspective diagram showing all the components necessary for assembling a shock-absorbing device for a notebook computer module according to a second embodiment of this invention. As shown in FIG. 7, the shock-absorbing device is used to prevent the vibration of a hard disk  60  because the hard disk  60  is another easily damaged component inside a notebook computer. The hard disk  60  is mounted onto a support plate  70 . Aside from supporting the hard disk  60 , the support plate  70  also serves to protect the hard disk  60  against external impact. There is a pair of balancing rods  62  between a mounting surface  61  on the hard disk  60  and the support plate  70 . A fixed end  62 ′ of the balancing rod  62  directly contacts the mounting surface  61 . The fixed end  62 ′ is glued onto the mounting surface  61  or is simply pushed against the mounting surface  61 . A movable end  62 ″ of the balancing rod  62  passes through a hole  68  on the support plate  70 . There is a hole  65  near the movable end  62 ″ of the balancing rod  62  such that a pin  66  can be inserted after the movable end of the rod passes through the support plate  70 . The inserted pin  66  is parallel to the mounting surface  61  so that there is a maximum travel distance for the balancing rod  62  with respect to the support plate  70 . A compression spring  64  is slid over each balancing rod  62 . Since the balancing rod  62  is perpendicular to the support plate  70 , the compression spring  64  can only move up and down relative to the support plate  70 . Due to the compression of the springs  64 , a force of the same magnitude but opposite in direction acts on the mounting surface  61  and the support plate  70 , respectively. The forces try to separate the mounting surface  61  from the support plate  70 . 
     A pair of hollow-center fastening inserts  74  is also installed on the support plate  70 . A first end  74 ′ of the fastening insert  74  passes through a protruding element  69  on the support plate  70  and contacts the mounting surface  61 . A screw  79  that passes through the fastening insert  74 , a C-clip  78  and the mounting surface, and sinks into the hard disk  60 . Hence, the fastening inserts  74  are fixed onto the mounting surface  61 . A second end  74 ″ of the fastening insert  74  has a larger diameter so that a compression spring  76  slid onto the fastening insert  74  can remain in position. Due to the compression of the springs  76 , a force of the same magnitude but opposite in direction acts on the second end  74 ″ of the fastening inserts  74  and the support plate  70 , respectively. The forces try to draw the support plate  70  closer to the mounting surface  61 . 
     The second embodiment of this invention is very similar to the first embodiment. Both embodiments make use of two sets of compression springs to provide forces acting from different positions. Hence, a notebook computer module surrounding by the shock-absorbing device is buffered against external forces caused by unwanted impact. 
     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.