Abstract:
A housing for a radar sensor module has a back surface and a plurality of side surfaces connected to the back surface. A vent structure is connected to the back surface and at least one of the side surfaces. The vent structure includes an enclosure enclosing a chamber. A first opening in the vent structure penetrates the at least one of the side surfaces of the housing, such that the chamber is exposed to an exterior of the housing. A second opening in the vent structure penetrates the enclosure such that the chamber is exposed to an interior of the housing.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure is related to automotive radar systems and, in particular, to an automotive radar sensor module housing having a breather structure which substantially prevents moisture and debris from entering the module. 
     2. Discussion of Related Art 
     Breather structures or vent structures are commonly used in climate-proof sealing of many electronic devices and modules. In the automotive radar industry, breather structures are used to provide ventilation in radar sensor modules. 
     A conventional breather or vent is a structure which is coupled to the housing of an electronic module, such as an automotive radar sensor module. The structure typically includes several venting holes and an air-through but water-proof, i.e., semipermeable, material, which in many cases is heat-staked to the module housing. 
       FIGS. 1-3  illustrate a conventional automotive radar sensor module  10  with a conventional breather structure or vent structure  18 . Specifically,  FIG. 1  includes a schematic perspective view of a conventional assembled radar sensor module,  FIG. 2  includes a schematic perspective view of a portion of the interior of a housing of a conventional radar sensor module; and  FIG. 3  includes a schematic top view of the interior of a housing of a conventional radar sensor module. Referring to  FIGS. 1-3 , module  10  includes a housing  14 , which can contain all of the components of radar sensor module  10 . For example, housing  14  can contain one or more printed circuit boards (PCBs), cables, connectors, flexprints and/or other forms of interconnects, and/or other electronic devices as required to carry out the operations of radar sensor module  10 . Housing  14  can include an integral shelf  25  formed in side walls  20 ,  22  and back side  12  of housing  14  to support one or more electronic devices such as PCBs. These devices, e.g., PCBs, can be held stationary and in place by heat stake posts  26 . Housing  14  can also include connector shroud portion  16 , which allows electrical connections, i.e., wires, cables, etc., to penetrate housing  14  and make electrical connection with any of the electronic devices disposed within the interior of housing  14  of module  10 . 
     Conventional breather structure or vent structure  18  is formed in back side  12  of housing  14 . Breather structure  18  includes multiple through holes  24  which penetrate back side  12  of housing  14  to vent housing  14  to the external environment. This structure suffers some intrinsic disadvantages. For example, during inclement weather conditions or under poor road conditions, venting holes  24  can become plugged and/or blocked by dirt, salt, debris, water, snow, ice, and/or other foreign material, which can cause degradation in operation of radar sensor module  10 . 
     SUMMARY 
     According to one aspect, a housing for a radar sensor module is provided. The housing includes a back surface and a plurality of side surfaces connected to the back surface. A vent structure is connected to the back surface and at least one of the side surfaces. The vent structure includes an enclosure enclosing a chamber. A first opening of the vent structure penetrates the at least one of the side surfaces of the housing, such that the chamber is exposed to an exterior of the housing. A second opening of the vent structure penetrates the enclosure such that the chamber is exposed to an interior of the housing. 
     In some exemplary embodiments, the housing can include plastic, which, in some embodiments, is molded plastic. 
     In any of the embodiments, the vent structure can be at least partially molded integrally with the housing. 
     The vent structure can further include a semipermeable diaphragm over at least the second opening. 
     In some exemplary embodiments, the first opening has a first cross-sectional area in a first plane, the first cross-sectional area being larger than a second cross-sectional area of the chamber in a second plane parallel to the first plane, such that accumulation of foreign material in the chamber is reduced. 
     In some exemplary embodiments, the chamber can include a substantially trapezoidal shape in cross-section. 
     In some exemplary embodiments, the radar sensor module is an automotive radar sensor module. 
     In some exemplary embodiments, the back surface is substantially planar. 
     According to another aspect, a vented radar sensor module is provided. The module includes a housing having a back surface and a plurality of side surfaces connected to the back surface. The module also includes a vent structure connected to the back surface and at least one of the side surfaces of the housing. The vent structure includes an enclosure enclosing a chamber. A first opening of the vent structure penetrates the at least one of the side surfaces of the housing, such that the chamber is exposed to an exterior of the housing. A second opening of the vent structure penetrates the enclosure such that the chamber is exposed to an interior of the housing. 
     In some exemplary embodiments, the housing can include plastic, which, in some embodiments, is molded plastic. 
     In any of the embodiments, the vent structure can be at least partially molded integrally with the housing. 
     The vent structure can further include a semipermeable diaphragm over at least the second opening. 
     In some exemplary embodiments, the first opening has a first cross-sectional area in a first plane, the first cross-sectional area being larger than a second cross-sectional area of the chamber in a second plane parallel to the first plane, such that accumulation of foreign material in the chamber is reduced. 
     In some exemplary embodiments, the chamber can include a substantially trapezoidal shape in cross-section. 
     In some exemplary embodiments, the radar sensor module is an automotive radar sensor module. 
     In some exemplary embodiments, the back surface of the housing is substantially planar. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of embodiments of the present disclosure, in which like reference numerals represent similar parts throughout the several views of the drawings. 
         FIG. 1  includes a schematic perspective view of a conventional radar sensor module. 
         FIG. 2  includes a schematic perspective view of a portion of the interior of a housing of a conventional radar sensor module. 
         FIG. 3  includes a schematic top view of the interior of a housing of a conventional radar sensor module. 
         FIG. 4  includes a schematic perspective view of a portion of the interior of a housing of a radar sensor module having a channelized breather structure, according to some exemplary embodiments. 
         FIG. 5A  includes a schematic perspective view of a portion of the interior of a housing of a radar sensor module having a channelized breather structure, according to some exemplary embodiments. 
         FIG. 5B  includes a schematic perspective view of the portion of the interior of a housing of a radar sensor module having a channelized breather structure illustrated in  FIG. 5A , including an installed semipermeable diaphragm or screen element in the breather structure, according to some exemplary embodiments. 
         FIG. 6  includes a schematic top view of a portion of the interior of a housing of a radar sensor module having a channelized breather structure, according to some exemplary embodiments. 
         FIG. 7  includes a schematic perspective view of a radar sensor module having a channelized breather structure, according to some exemplary embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     As noted above, the conventional breather or venting structure  18  illustrated in  FIGS. 1-3  suffers some intrinsic disadvantages. For example, during inclement weather conditions or under poor road conditions, venting holes  24  can become plugged and/or blocked by dirt, salt, debris, water, snow, ice, and/or other foreign material, which can cause degradation in operation of radar sensor module  10 . According to the exemplary embodiments described in detail herein, a channelized breather structure is provided such that these drawbacks of the conventional structures are substantially reduced or eliminated. 
       FIGS. 4, 5A, 5B, 6 and 7  illustrate an automotive radar sensor module  110  with a channelized breather structure or vent structure, according to some exemplary embodiments. Specifically,  FIG. 4  includes a schematic perspective view of a portion of the interior of a housing of a radar sensor module having a channelized breather structure, according to some exemplary embodiments.  FIG. 5A  includes a schematic perspective view of a portion of the interior of a housing of a radar sensor module having a channelized breather structure, according to some exemplary embodiments.  FIG. 5B  includes a schematic perspective view of the portion of the interior of a housing of a radar sensor module having a channelized breather structure illustrated in  FIG. 5A , including an installed semipermeable diaphragm or screen element in the breather structure, according to some exemplary embodiments.  FIG. 6  includes a schematic top view of a portion of the interior of a housing of a radar sensor module having a channelized breather structure, according to some exemplary embodiments.  FIG. 7  includes a schematic perspective view of a radar sensor module having a channelized breather structure, according to some exemplary embodiments. 
     Referring to  FIGS. 4, 5A, 5B, 6 and 7 , radar sensor module  110  according to some exemplary embodiments includes a housing  114 , which can contain all of the components of radar sensor module  110 . For example, housing  114  can contain one or more PCBs, cables, connectors, flexprints and/or other forms of interconnects, and/or other electronic devices as required to carry out the operations of radar sensor module  110 . Housing  114  can include an integral shelf  125  formed in side walls  120 ,  122  and back side  112  of housing  114  to support one or more electronic devices such as PCBs. These devices, e.g., PCBs, can be held stationary and in place by heat stake posts  126 . Housing  114  can also include connector shroud portion  116 , which allows electrical connections, i.e., wires, cables, etc., to penetrate housing  114  and make electrical connection with any of the electronic devices disposed within the interior of housing  114  of module  110 . 
     Housing  114  also includes a channelized breather structure or vent structure  118 , according to some exemplary embodiments, which provides the breathing/venting functions to module  110 . In contrast to conventional breather structures, such as breather structure  18  illustrated in  FIGS. 1-3 , breather structure  118  of the present disclosure is not formed to penetrate back side  112  of housing  114  to the exterior of module  110 . Instead, breather structure  118  is formed with side walls  121  and a top surface  131  above the surface of back side  112 . The interior of channelized breather structure  118  includes a channel or chamber  119  defined by the volume of space disposed between and enclosed by side walls  121  and top surface  131  of breather structure  118 , as well as the portion of back side  112  within the region defined by side walls  121  of breather structure  118  and side wall  120  of housing  114 . 
     Channelized breather structure  118  includes multiple through holes  124  which penetrate top surface  131  of breather structure  118  to vent housing  114  into chamber or channel  119 . As illustrated in  FIG. 5B , a breathing element in the form of semipermeable diaphragm or screen member  125  can be installed in place over through holes  124  as a protection against the entry of small particles of debris into the interior of housing  114 . Semipermeable diaphragm  125  can be installed by some known process, such as heat staking. An opening  123  penetrating side wall  120  opens chamber or channel  119  to the external environment, thus venting housing  114  and assembled module  110 . As illustrated most clearly in  FIG. 6 , chamber or channel  119  has a shape such that opening  123  is relatively large in cross-sectional area, compared with other cross-sections of chamber or channel  119  parallel to opening  123 . In some exemplary embodiments, as illustrated in  FIG. 6 , chamber or channel  119  can have tapered side walls  127 , such that chamber or channel  119  can have a substantially trapezoidal shape. 
     In some exemplary embodiments, because of the substantially larger opening  123  and sloped or tapered chamber side walls  127 , the likelihood of any debris, moisture, or other foreign matter being trapped in chamber  119  is substantially reduced or eliminated. In fact, any such debris, moisture, excess water or other foreign matter that may enter chamber  119  would tend to flow out of chamber  119  to the exterior of housing  114 . Also, since no vent holes for breather structure  118  are exposed to the exterior of housing  114 , and, in particular, to the exposed back side  112  of housing  114 , any hit of water, salt, dirt, mud or other undesirable foreign material, will not result in any such material directly entering housing  114 . This greatly enhances the operational reliability of radar sensor module  110 . 
     In some exemplary embodiments, housing  114  can be made of an insulating plastic material. The plastic material can be formed by a known process such as plastic molding. Various features of housing  114  can be molded integrally with housing  114 . For example, shelf  125 , heat stake posts  126  and breather structure  118 , which includes side walls  121 , top surface  131  and through holes  124 , can be formed integrally with housing  114  in a single molding process. As noted above, semipermeable diaphragm  125  can be formed as a separate element and can be installed on top of breather structure  118  by some known process such as heat staking. It will be understood that these materials and fabrication processes are exemplary only. The present disclosure is applicable to other housing materials and other manufacturing processes. 
     Whereas many alterations and modifications of the disclosure will no doubt become apparent to a person of ordinary skill in the art after having read the foregoing description, it is to be understood that the particular embodiments shown and described by way of illustration are in no way intended to be considered limiting. Further, the subject matter has been described with reference to particular embodiments, but variations within the spirit and scope of the disclosure will occur to those skilled in the art. It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present disclosure. 
     While the present inventive concept has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present inventive concept as defined by the following claims.