Abstract:
In one embodiment of the invention, an enclosure for an electronic component and a plurality of lead traces that connect the electronic component to a circuit board is used. The enclosure has a flexible diaphragm on one side and a sealing flange supporting said diaphragm and providing an attaching surface to fix the enclosure to the circuit board. This enclosure surrounds the electronic component and creates a barrier resistant to the external environment.

Description:
TECHNICAL FIELD 
     The present invention relates generally to electronic component enclosures, and more particularly, to an enclosure for making a localized portion of a circuit board resistant to the surrounding environment. 
     BACKGROUND ART 
     It is well known in the electronic field that circuit boards may be sealed with potting materials or epoxy to secure the components to the circuit board. It is also well known that moisture may damage electronic components. 
     Sealing a circuit board with epoxy or potting materials or allowing moisture to contact electronic components has several shortcomings. Often when epoxy or potting materials are applied to a circuit board having an electronic component attached by lead traces, the lead traces tend to break. That is, when a potting agent or epoxy is applied, the electronic component is surrounded by the sealant, and, upon the sealant drying or upon exposure to temperature extremes, the electronic component has a tendency to be lifted from the circuit board. This lifting from the circuit board can cause the lead traces to break and result in a discontinuity in the circuit. Moreover, moisture has a tendency to cause electronic components to short-circuit. 
     Circuit board manufacturers have not substantially addressed the problem of component lift during and after sealing or moisture accumulation on electronic components. This has made it apparent that a technique for protecting localized electronic components on a circuit board from their environment is needed. The technique should be resistant to the external environment. The present invention is directed to this end. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the invention to provide reliable protection for localized electronic components on a circuit board from their environment. 
     In one embodiment of the invention, an enclosure for an electronic component having a plurality of lead traces that connect the electronic component to a circuit board is used. The enclosure includes a flexible diaphragm on one side and a sealing flange which is attached to the circuit board to surround the electronic component. 
     In a further embodiment of the invention, the enclosure is placed over at least a portion of one of the plurality of lead traces and the electronic component. The enclosure is then attached to the circuit board over the electronic component such that the electronic component is surrounded. Resultantly, a vacuum seal that is resistant to the surrounding environment is created. 
     The present invention thus achieves a reliable protection for localized electronic components on a circuit board. The present invention is advantageous in that it insures an environmentally resistive seal by creating a sealed environment between the electronic component on the circuit board and an enclosure for that electronic component. 
     Additional advantages and features of the present invention will become apparent from the description that follows and may be realized by the instrumentalities and combinations particularly pointed out in the appended claims, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the invention, there will now be described some embodiments thereof, given by way of example, reference being made to the accompanying drawings, in which: 
     FIG. 1 is a perspective view that illustrates a localized electronic component protection system according to one embodiment of the present invention. 
     FIG. 2 is a sectional view of FIG. 1 along line  2 — 2 . 
     FIG. 3 is a top view of an electronic component enclosure according to one embodiment of the present invention. 
     FIG. 4 is a side view of FIG.  3 . 
     FIG. 5 is a sectional view of FIG. 3 along line  5 — 5 . 
     FIG. 6 is a sectional view of FIG. 3 along line  5 — 5  in accordance with another embodiment of the present invention. 
     FIG. 7 is a top view of an electronic component enclosure in accordance with another embodiment of the present invention. 
     FIG. 8 is a top view of an electronic component enclosure in accordance with another embodiment of the present invention. 
     FIG. 9 is a top view of an electronic component enclosure in accordance with another embodiment of the present invention. 
     FIG. 10 is a top view of an electronic component enclosure in accordance with another embodiment of the present invention. 
     FIG. 11 is a sectional view of FIG. 10 along line  11 — 11 . 
    
    
     DETAILED DESCRIPTION 
     The present invention is illustrated with respect to a localized electronic component protector system, particularly suited for the electronics field. However, the present invention is applicable to various other uses that may require localized component protection. 
     Referring to FIGS. 1 and 2, a localized electronic component protector system  10  in accordance with one embodiment of the present invention is illustrated. The localized electronic component protector system  10  includes an enclosure  12  for an electronic component  28 . The enclosure has two sides. One side is a flexible diaphragm  14  which may be concave or convex with respect to a circuit board  20 . The other side contains a flange  16 . Preferably, the flange  16  is connected to the diaphragm  14  by a walled perimeter  13 . 
     One embodiment of the material that the enclosure  12  can be made of is moldable grade silicon rubber preferably having a hardness rating of approximately Shore A 40. The enclosure  12 , in addition, may be attached by an adhesive  27  like Dow Corning 6265 Silicon-based adhesive. The moldable grade silicon rubber and the Dow Corning 6265 Silicon-based adhesive work well because they are both resistant to moisture, potting materials and other adhesives as desired. 
     Furthermore, an example of the electronic component  28  is an integrated circuit that requires attachment to a circuit board by a plurality of lead traces  18  where those lead traces may be interfered with by potting materials, adhesives used to seal the circuit board  20  or moisture. However, the system  10  will protect various other electronic components, and the system will also protect multiple components under a single enclosure  12 . 
     To actuate the electronic component protector system  10 , adhesive is applied to the flange  16  and the enclosure  12  is placed over the electronic component  28 . Alternately, the adhesive  27  may be applied directly to the circuit board  20  around the electronic component  28  to be protected and the plurality of lead traces  18  by tracing the perimeter of the flange  16  of the enclosure  12  prior to the placement of the enclosure  12  on the circuit board  20 . Preferably, following application of adhesive  27  to the flange  16  or the circuit board  20 , the enclosure  12  is placed on the circuit board  20 . Thus an internal environment  25  is created which encloses the electronic component  28  and a portion of the plurality of lead traces  18  and is surrounded by the enclosure  12  that is resistant to the external environment. An example of how the enclosure  12  is attached is the compression of the diaphragm  14  to expel air from the internal environment  25  between the component  28  and the enclosure  12 . Thereby, a vacuum is created which aids in securing the enclosure  12 . Another example of attachment of the enclosure  12  is by creating a vacuum around the enclosure  12  on the circuit board  20 . This suctions the enclosure  12  onto the circuit board  20 . 
     Referring to FIG. 3, a top view of an electronic component enclosure  12  in accordance with one embodiment of the present invention is illustrated. Here, the enclosure  12  is represented as approximately square with a circular diaphragm  14 , but other possible options for the enclosure  12  design will be discussed later. 
     Referring to FIG. 4, a side view of the enclosure  12  of FIG. 3 is illustrated. FIG. 4 demonstrates that the flange  16  may be extended past the sides  13  of the enclosure  12  for a wide flange  16  for attachment of the enclosure  12  to the circuit board  20 . The wider flange  16  also provides a surface for the adhesive  27  to insure an adequate seal around the component  28 . 
     Referring to FIG. 5, a sectional view of FIG. 3 along line  5 — 5  is illustrated. An example of the diaphragm  14  is shown here to be concave  54 . However, the diaphragm  14  may also be convex  64  as shown in FIG. 6, which is an alternate sectional view of FIG. 3 along line  5 — 5 . 
     FIGS. 7,  8 ,  9 ,  10 , and  11  illustrate alternate embodiments of the present invention. For example, as shown in FIG. 7, the enclosure  72  is square with a square diaphragm  74 , square flange  76  and square sides  73 . Moreover, as shown in FIG. 8, the enclosure  82  is circular with a circular diaphragm  84 , circular sides  83  and a circular flange  86 . Furthermore, as shown in FIG. 9, the enclosure  92  has an octagonal flange  96  and sides  93  and a circular diaphragm  94 . Additionally, as shown in FIG. 10, the enclosure  102  is an embodiment without sides and merely as a diaphragm  104  and a flange  106 . FIG. 10 is further illustrated in FIG. 11, which is a sectional view of FIG. 10 along line  11 — 11 . 
     From the foregoing, it can be seen that there has been brought to the art a new localized electronic component protector system  10 . It is to be understood that the preceding description of the preferred embodiment is merely illustrative of some of the many specific embodiments that represent applications of the principles of the present invention. Numerous and other arrangements would be evident to those skilled in the art without departing from the scope of the invention as defined by the following claims: