Abstract:
A light receiving module includes a substrate, a light receiving element mounted on the substrate, a resin package covering the light receiving element, and a shield cover into which the resin package is inserted in an insertion direction. The shield cover includes first and second press plates configured to press the resin package in two different directions that are perpendicular to the insertion direction. The first press plate and the second press plate include a first end and a second end, respectively, which are adjacent but different in position in the insertion direction.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a light receiving module used as a remote control receiving means of e.g. a television. 
   2. Description of the Related Art 
     FIG. 8  shows an example of conventional light receiving module (see JP-A-2004-335881, for example). The illustrated light receiving module X includes a substrate  91 , a light receiving element  92 , an IC chip  93 , a resin package  94  and a shield cover  95 . The light receiving element  92  and the IC chip  93  are mounted on the substrate  1 . The light receiving element  92  generates electromotive force corresponding to the amount of infrared rays received. The IC chip  93  transmits a signal or an electric current flowing through the light receiving element  92  to the outside of the light receiving module X. The resin package  94  covers the light receiving element  92  and the IC chip  93 . The resin package  94  includes a lens  94   a  facing the light receiving element  92 . The shield cover  95  covers the resin package  94  while allowing the lens  94   a  to be exposed. The shield cover  95  is provided with a grounding terminal  95   a . The shield cover  95  serves as an electromagnetic shield by converting incoming electromagnetic waves into weak electric currents and releasing the currents to an external ground line through the ground terminal  95   a . The shield cover  95  may be formed by press working a metal plate. 
   To manufacture the light receiving module X, care should be taken in mounting the shield cover  95  properly to the resin package  94  on the substrate  91 . However, if the inner dimension of the shield cover  95  is too large or too small for the resin package  94 , the shield cover  95  fails to be properly positioned relative to the resin package  94 , or even the mounting of the shield cover  95  maybe very difficult. Further, in mass-producing the light receiving module X, a large number of shield covers  95  are handled collectively. In such a process, shield covers  95  may get entangled with each other, which deteriorates the manufacturing efficiency of the light receiving module X. 
   SUMMARY OF THE INVENTION 
   An object of the present invention, which is proposed under the circumstances described above, is to provide a light receiving module having a structure that facilitates proper mounting of a shield cover. 
   According to the present invention, there is provided a light receiving module comprising: a substrate; a light receiving element mounted on the substrate; a resin package covering the light receiving element; and a shield cover into which the resin package is inserted in an insertion direction. The shield cover includes a first press plate and a second press plate, where the first press plate is configured to press the resin package in a first direction perpendicular to the insertion direction, and the second press plate is configured to press the resin package in a second direction perpendicular to the insertion direction and different from the first direction. The first press plate and the second press plate include a first end and a second end, respectively, which are adjacent to each other in the insertion direction and different in position from each other in the insertion direction. 
   With the above arrangement, due to the pressing force of the two press plates, the resin package and the shield cover are properly positioned two-dimensionally as viewed in the insertion direction. Moreover, the space between the ends of the two press plates is reduced. Therefore, in collectively handling a large number of shield covers to manufacture the light receiving modules, the shield covers are prevented from being entangled. 
   Preferably, the first end and the second end may overlap each other as viewed in the insertion direction when the resin package is separated from the shield cover. 
   Preferably, the shield cover may include an edge connected to one of the first end and the second end, where the edge is inclined with respect to the insertion direction. 
   Other features and advantages of the present invention will become more apparent from detailed description given below with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view showing a light receiving module according to the present invention; 
       FIG. 2  is a plan view showing the light receiving module of the present invention; 
       FIG. 3  is a sectional view taken along lines III-III in  FIG. 2 ; 
       FIG. 4  is a bottom view showing the light receiving module of the present invention; 
       FIG. 5  is a rear view showing the light receiving module of the present invention; 
       FIG. 6  is a side view showing the light receiving module of the present invention; 
       FIG. 7  is a plan view showing a shield cover of the light receiving module of the present invention; and 
       FIG. 8  is a front view showing a conventional light receiving module. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. 
     FIGS. 1-6  show an example of light receiving module according to the present invention. The light receiving module A of this embodiment includes a substrate  1 , a light receiving element  2 , an IC chip  3 , a resin package  9  and a shield cover  5 . The light receiving module A is an electronic device which may be incorporated in a television set for receiving-signals (e.g. infrared rays) transmitted from a remote controller. 
   The substrate  1  is made of resin such as glass-fiber-reinforced epoxy resin and formed into an elongated rectangle as viewed in plan. The obverse surface of the substrate  1  is formed with a wiring pattern (not shown) As shown in  FIGS. 1 and 4 , a plurality of main terminals  11  are provided on a side surface of the substrate  1 . Each of the main terminals  11  is provided by forming a conductor layer on an inner surface of a groove extending in the thickness direction of the substrate  1 . The main terminals  11  are provided for mounting the light receiving module A on e.g. a circuit board (not shown). 
   The light receiving element  2  may comprise a PIN photodiode. Upon receiving infrared light from an external remote controller, the light receiving element  2  generates photo electromotive force and hence electric current corresponding to the received light. Though not shown, the light receiving element  2  has a PAN junction structure comprising a p-type semiconductor layer as an upper layer and an n-type semiconductor layer as a lower layer. The light receiving element  2  is wire-bonded to the wiring pattern on the substrate  1 . 
   The IC chip  3  converts the current flowing through the light receiving element  2  into signals and outputs the signals to an external controller. The IC chip  3  may include a current/voltage conversion circuit, an amplifying circuit, a limiter circuit and a detector circuit. The IC chip  3  is wire-bonded to the wiring pattern on the substrate  1 . 
   The resin package  4  may be made of an epoxy resin containing a colorant, so that it allows the passage of infrared rays but blocks visible light completely or to a required degree. The resin package  4  encloses the light receiving element  2  and the IC chip  3  for protection. As shown in  FIG. 3 , the resin package  4  is formed with a convex lens  4   a  facing the light receiving element  2 . The lens  4   a  refracts the infrared rays from the remote controller to cause the infrared rays to converge on the light receiving element  2 . 
   The shield cover  5  shields the IC chip  3  from electromagnetic waves and light. The shield cover  5  covers the resin package  4  in a manner such that the lens  4   a  is exposed. The shield cover  5 , which may be made by bending a metal plate, includes a top plate  50 , a rear plate  51 , two press plates  52 ,  53 , and a side plate  54 . As shown in  FIG. 4 , a lower opening  5   a  is defined by the rear plate  51 , two press plates  52 ,  53  and the side plate  54 . Through the opening  5   a , the resin package  4  is inserted into the shield cover  5  in the direction x shown in  FIGS. 1 and 3 . As shown in  FIGS. 3 and 6 , the side plate  54  is formed with an inclined portion  54   a . The inclined portion  54   a  facilitates the insertion of the resin package  4  into the shield cover  5 . 
   The top plate  50  covers a portion of the resin package  4  that is adjacent to the lens  4   a . The top plate  50  is formed integral with the rear plate  51 , the press plate  53  and the side plate  54 . The rear plate  51  covers a rear side surface of the resin package  4 . The rear plate  51  is formed with a ground terminal  55 . The ground terminal  55  is to be connected to a ground line which is a part of the wiring pattern of the substrate  1 . The ground terminal  55  conducts the unwanted electric current (converted from the electromagnetic wave received by the shield cover  5 ) to the ground line. The press plate  52  extends from the rear plate  51 . 
   As shown in  FIGS. 1 and 4 , the press plate  52  presses the resin package  4  in a direction perpendicular to the insertion direction x. With this arrangement, the resin package  4  is held by the press plate  52  and the side plate  54 . The press plate  52  is formed with an embossed portion  52   e  projecting toward the resin package  4 . The side plate  54  is formed with an embossed portion.  54   e  projecting toward the resin package  4 . By holding the resin package  4  between the embossed portions  52   e  and  54   e , the resin package  4  is positioned properly relative to the shield cover  5  in the direction in which the press plate  52  and the side plate  54  are spaced from each other. 
   The press plate  53  presses the resin package  4  in a direction perpendicular to both of the insertion direction x and the pressing direction of the press plate  52 . Thus, the resin package  4  is held not only by the press plate  52  and the side plate  54  but also by the press plate  53  and the rear plate  51 . The press plate  53  is formed with an embossed portion  53   e . By holding the resin package  4  between the inner surface of the rear plate  51  and the embossed portion  53   e , the resin package  4  is properly positioned relative to the shield cover  5  in the direction in which the press plate  53  and the rear plate  51  are spaced from each other. 
   As shown in  FIG. 1 , the press plates  52  and  53  include ends  52   a  and  53   a . When the resin package  4  is inserted into the shield cover  5 , the ends  52   a  and  53   a  are positioned adjacent to each other as viewed in the insertion direction x, as shown in  FIGS. 1 ,  2  and  4 . Further, as shown in  FIG. 1 , the positions of the ends  52   a  and  53   a  in the insertion direction x differ from each other.  FIG. 7  shows the shield cover  5  in the state before the resin package  4  is inserted. In this state, as viewed in the insertion direction x, the ends  52   a  and  53   a  overlap each other. This is because the press plates  52  and  53  are bent in advance in the direction in which the resin package  4  is to be held. When the resin package  4  is inserted into the shield cover  5 , the press plates  52  and  53  are warped outward by the resin package  4 . The elastic force generated in this way at the press plates  52  and  53  works as the pressing force to press the resin package  4 . As shown in  FIG. 1 , the press plate  52  includes an inclined edge  52   b  connected to the end  52   a . As shown in  FIG. 6 , the side plate  54  includes an inclined edge  54   b . The angle of inclination of the inclined edges  52   b  and  54   b  with respect to the insertion direction x is about 45 degrees. 
   The advantages of the light receiving module A will be described below. 
   According to the above-described embodiment, in manufacturing the light receiving module A, the resin package  4  and the shield cover  5  are precisely positioned relative to each other just by inserting the resin package  4  into the shield cover  5 . Particularly, the two press plates  52  and  53  press the resin package  4  in the directions which are perpendicular to each other. Therefore, the two-dimensional positioning of the resin package  4  and the shield cover  5  as viewed in the insertion direction x is performed properly. 
   In mass-producing light receiving modules A, a large number of shield covers  5  may be stored in e.g. a part feeder. In each of the shield covers  5 , the end  52   a  of the press plate  52  and the end  53   a  of the press plate  53  differ from each other in position in the insertion direction x, so that the ends  52   a  and  53   a  completely overlap each other as viewed in the insertion direction x. Therefore, it is possible to avoid a situation where part of a shield cover  5  is caught between the press plates  52  and  53  of another shield cover  5 . Therefore, in collectively handling a large number of shield covers  5 , the shield covers  5  are prevented from getting entangled. 
   The provision of the inclined edges  52   b  and  54   b  at the shield cover  5  is advantageous for preventing the tangling of the shield covers  5 . If a corner portion having an interior angle of 90 degrees or smaller is provided instead of the inclined edge  52   b ,  54   b , the corner portion may be caught between the press plates  52  and  53  of another shield cover  5  due to wedge effect. According to the present invention, such tangling of the shield covers  5  is prevented from occurring. 
   To bond the resin package  4  and the shield cover  5  together, an adhesive may be used. The adhesive may be applied between the top plate  50  and the resin package  4 . When the resin package  4  is inserted into the shield cover  5 , the adhesive may be pushed out from between the top plate  50  and the resin package  4 . If the adhesive pushed out adheres to the lens  4   a , the reception of infrared rays by the light receiving element  2  may be hindered. In this embodiment, however, due to the provision of the embossed portions  53   e  and  54   e  at the press plate  53  and the side plate  54 , a relatively large space is defined between the resin package  4  and the press plate  53  or the side plate  54 . Therefore, the adhesive pushed out by the insertion of the resin package  4  is held in the space. Therefore, the adhesive is prevented from adhering to the lens  4   a.    
   The present invention being thus described, it is obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to those skilled in the art are intended to be included within the scope of the following claims.