Patent Document

CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/817,306 filed on Apr. 29, 2013 and entitled “3D-Motion Gesture/Proximity Detection Module Sensor (MGPS)”, the contents of which are incorporated herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a motion sensing device, and more particularly, to a motion sensing device realized by a wafer level lens. 
     2. Description of the Prior Art 
     With the scientific and technological advancement, computer systems are viewed as necessities for ordinary people in their daily lives, from traditional functions, such as word processing and program executing, to modern multimedia processing, and computer games, etc. Thus, technology of the input apparatus also has improved. 
     A pointing device is utilized for transforming motions of a user into signals via a motion sensor capable of sensing a motion trace for an electronic device having computing capacity, so as to control the movement of graphical cursers or pointers on display screens, to select objects on display screens with a graphical user interface, and to perform control functions displayed on the screen, allowing the user direct interaction with the computer system. Thus, how to realize the motion sensor with high accuracy becomes a topic to be discussed. 
     SUMMARY OF THE INVENTION 
     In order to solve the above problem, the present invention provides a motion sensing device realized by a wafer level lens. 
     The present invention discloses a motion sensing device for sensing infrared rays, comprising a substrate; an optical module, comprising a first spacer layer, coupled to the substrate; a first glass layer, formed on the first spacer layer; a second spacer layer, formed on the first glass layer; a second glass layer, formed on the second spacer layer; a third spacer layer, formed on the second glass layer; a first lens, bonding on a first side of the second glass layer; and a second layer, bonding on a second side relative to the first side of the second glass layer; and a coating layer, covered on the optical layer for shielding the infrared rays, wherein the coating layer does not cover the first lens. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross section view of a motion sensing device according to an embodiment of the present invention. 
         FIG. 2  is a flow chart of a packaging method according to an embodiment of the present invention. 
         FIG. 3  is a flow chart of another packaging method according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Please refer to  FIG. 1 , which is across section view of a motion sensing device  10  according to an embodiment of the present invention. The motion sensing device  10  is utilized for sensing infrared rays, to detect the moving traces and the motions of external objects. As shown in  FIG. 1 , the motion sensing device  10  comprises a substrate  100 , an optical module  102  and a coating layer  104 . The substrate  100  comprises an optical sensing layer  106  and a transmission layer  108 , for sensing the light and accordingly outputting corresponded sensing signal. The optical layer  102  comprises spacer layers  110 - 114 , glass layers  116  and  118  and lens  120  and  122 , for filtering the light emitting to the substrate  100  such that the light emitting to the substrate  100  only comprises light with a specific wavelength (e.g. the wavelength of the infrared rays). For example, the optical module  102  may be a wafer level lens used for receiving the infrared rays. The coating layer  104  covers the optical layer  102 , for preventing additional infrared rays from emitting to the substrate  100 . Please note that, the coating layer  104  does not cover the lens  120  (i.e. does not cover the path of light emits to the substrate  100 ), for ensuring the motion sensing device  10  operates normally. As a result, the motion sensing device  10  for sensing the moving traces and the motions of the external objects can be realized by the wafer level lens. The motion sensing device  10  equipped with micro volume can be achieved. 
     In detail, the optical sensing layer  106  comprises a sensing unit SEN for sensing the light filter by the optical module  102  and outputting the corresponded sensing signal. According to different applications and design concepts, the method of configuring the sensing unit SEN on the substrate  100  can be appropriately changed. For example, the sensing unit SEN may be configured on the substrate  100  via a chip scale package (CSP) method, printed circuit board method or a lead frame method, and is not limited herein. In this embodiment, the transmission interface layer  108  comprises a ball grid array (BGA) (i.e. realized in the packaging technology of the ball grid array). Via a wafer-level chip scale packaging method with a through-silicon via technique, the sensing signal generated by optical sensing layer  106  can be transmitted to the external circuit through the transmission interface layer  108 , for performing corresponded calculating processes. 
     In addition, the optical module  102  is coupled (e.g. bonded) to the substrate  100  through the spacer layer  110 . For example, the spacer layer  110  may be glue or paint, and is not limited herein. The glass layer  116  is configured on the spacer layer  110 , for protecting the sensing unit SEN. The spacer  112  is configured between the glass layers  116  and  118 , for generating a space  124 . In this embodiment, the materials of the spacer layer  112  may comprise glass. The glass layer  118  is configured on the spacer layer  112  as the substrate of the lens  120  and  122 . The spacer layer  114  is configured on the glass layer  118  and forms an opening  126 . The lens  120  is configured in the opening  126  and is coupled (e.g. bonded) to a side of the glass layer  118  (e.g. the top side of the glass layer  118 ) via a translucent glue, such as a silicone, an Epoxy, and an Ultraviolet light (UV) Curable Adhesive. Similarly, the lens  122  is configured in the space  124  and is coupled (e.g. bonded) to another side of the glass layer  118  (e.g. the bottom side of the glass layer  118 ) via the translucent glue. 
     Finally, since the operations of the sensing unit SEN senses the motions of the objects is achieved via detecting the infrared rays, the sensing unit SEN is sensitive to the variations of infrared rays in the surrounding environment. In such a condition, the coating layer equipped with the function of shielding the infrared rays is needed to cover the optical module  102 , for shielding the infrared rays of the specific wavelength range, so as to avoid affecting the sensing result of the sensing unit SEN. Please note that, the coating layer  104  does not cover the lens  120 , for ensuring the path of the infrared rays emits to the sensing unit SEN. In addition, the motion sensing device  10  may further comprise an infrared ray emitting unit (not shown in  FIG. 1 ), for emitting the infrared rays capable of passing through the lens  120  and  122  and being sensed by the sensing unit SEN. As a result, via the coating layer  104  absorbing the additional infrared rays, the motion sensing device  10  can receive the infrared rays emitted by the infrared ray emitting unit by the optical module  102  (e.g. the wafer level lens. The functions of sensing the moving traces and motions of the objects can be accordingly achieved, therefore. 
     Noticeably, the above embodiments provide a motion sensing device realized by the wafer level lens, so as to reduce the manufacture cost and increase the production efficiency via the wafer level manufacturing technology. According to different applications and design concepts, those with ordinary skill in the art may observe appropriate alternations and modifications. For example, the wavelength of the light received by the sensing unit SEN for performing the operations of sensing the moving traces and motions of the objects can be altered to different wavelength ranges, such as the wavelength ranges of the UV and the visible light. Note that, when the wavelength range of the light received by the sensing unit SEN changes, the wavelength range of the light shielded by the coating layer  104  needs to be accordingly altered for avoiding affecting the sensing result of the sensing unit SEN. 
     In the above embodiments, the single motion device is described for illustrating the structure and the packaging method. In general, when producing the packages of the motion sensing device, the entire packaging materials are configured layer by layer for generating multiple packages at the same time. Then, the multiple packages are sawed for acquiring multiple separate packages. According to different applications, the motion sensing device can be packaged by different packaging methods. For example, the substrate  100  and the optical module  102  can be realized in different wafers. Via wafer bonding, the substrate  100  and the plurality of optical module  102  configured on different wafers can be bonded. Next, the coating layer  104  is formed on each optical module  102  via the package coating. Finally, the single motion sensing device  10  can be acquired after the package sawing process. 
     On the other hand, the step of bonding the substrate  100  and the plurality of optical modules  102  configured on different wafer can be appropriately modified according to different applications. In an embodiment, the plurality of optical modules  102  configured on the wafer is cut for acquiring the plurality of separate optical modules  102 . Each of the optical modules  102  is bonded to the substrate  100  configured on the wafer, and then performing the follow-up processes, such as the coating process and the sawing process. According to the above steps, the single motion sensing device  10  also can be acquired. 
     The packaging method of the motion sensing device abovementioned can be summarized into a packaging method  20 , as shown in  FIG. 2 . The packaging method  20  comprises the following steps: 
     Step  200 : Start. 
     Step  202 : Perform a wafer bonding process, for bonding a plurality of optical modules on a first wafer and a substrate on a second wafer. 
     Step  204 : Perform a package coating process, for forming a coating layer, used for absorbing infrared rays, on the plurality of optical modules. 
     Step  206 : Perform a package sawing process. 
     Step  208 : End. 
     According to the packaging method  20 , a plurality of optical modules on a first wafer can be bonded to a substrate on a second wafer. Next, a coating layer can be formed on each optical module for absorbing the infrared rays, via performing a package coating process. After performing a package sawing process, the single motion sensing device can be acquired. 
     The packaging method of the motion sensing device abovementioned can be further summarized into another packaging method  30 , as shown in  FIG. 3 . The packaging method  30  comprises the following steps: 
     Step  300 : Start. 
     Step  302 : Perform a package sawing process on a plurality of optical modules configured on a first wafer, for acquiring separate optical modules. 
     Step  304 : Bond the separate optical modules to a substrate configured on a second wafer. 
     Step  306 : Perform a package coating process, for forming a coating layer, used for absorbing infrared rays, on the plurality of optical modules. 
     Step  308 : Perform a package sawing process. 
     Step  310 : End. 
     According to the packaging method  30 , the plurality of optical modules configured on the first wafer is sawed into separate optical modules (e.g. wafer level lens) and then the separate optical modules are bonded to the substrate configured on the second wafer. Similar to the steps  204  and  206  of the packaging method  20 , after performing the package coating process and the package sawing process, the single motion sensing device is therefore acquired. 
     To sum up, the above embodiments utilize the wafer level lens to realize motion sensing device. The manufacture cost can be reduced and the production efficiency can be improved via the wafer level manufacturing technology. Moreover, the motion sensing device of the above embodiments can be packaged via different packaging methods according to different applications and design concepts. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.

Technology Category: 4