EMI protective spring plate for motherboard

[0002] The present invention relates to an EMI protective spring plate for motherboard and, more particularly, to such an EMI protective spring plate, which has a lower dead point design that prevents permanent deformation.

[0003] In order to protect a motherboard against EMI (electromagnetic interference), spring plates may be installed in the border of the motherboard to support a plate shield. FIGS. From 1 through 3 show a spring plate constructed according to the prior art for this purpose. This structure of spring plate 10acomprises a flat top contact portion 11a, which supports a shielding cover plate 40a, a flat bottom soldering portion 15a, which is soldered to the motherboard 30awith tin soldering paste 20a, two side plate portions 14 vertically downwardly extended from two ends of the flat top contact portion 11a, an intermediate supporting portion 12aobliquely connected between the flat top contact portion 11aand the flat bottom soldering portion 15a, an upper turn R1aconnected between the flat top contact portion 11aand the intermediate supporting portion 12a, a second turn R2aconnected between the intermediate supporting portion 12aand the flat bottom soldering portion 15a, and two slots 13arespectively formed in the first turn R1aand the second turn R2a. This structure of spring plate 10ais still not satisfactory in function. Because the spring plate 10ahas a substantially S-shaped profile, it may hook other objects during its installation in the motherboard 30a, thereby causing a deformation. Because a stress is produced during the formation of the first turn R1aand the second turn R2a, the flat top contact portion 11aand the first turn R1aare forced downwards at different extents upon loading of the shielding cover plate 40a, thereby causing the shielding cover plate 40aunable to be stably supported on the flat top contact portion 11a. Unstable contact between the plate shield 40aand the flat top contact portion 11aaffects the EMI protective effect of the shielding cover plate 40a. Further, the spring plate 10amay be deformed permanently when received a high pressure.

[0004] The present invention has been accomplished to provide an EMI protective spring plate, which eliminates the aforesaid drawbacks. It is one object of the present invention to provide an EMI protective spring plate, which does not hook other objects during its installation. It is another object of the present invention to provide an EMI protective spring plate, which keeps the loaded EMI protective shielding cover plate stably in balance. It is still another object of the present invention to provide an EMI protective spring plate, which has a lower dead point design that prohibits the spring plate from being deformed excessively. To achieve these and other objects of the present invention, the EMI protective spring plate comprises a flat top contact portion, a flat bottom soldering portion, an oblique supporting portion diagonally connected between the flat top contact portion and the flat bottom soldering portion, a front sliding portion obliquely downwardly extended from one end of the flat top contact portion toward the flat bottom soldering portion and inserted through a lower slot in the oblique supporting portion, and a rear sliding portion obliquely upwardly extended from one end of the flat bottom soldering portion toward the flat top contact portion and inserted through an upper slot in the oblique supporting portion.

[0005] FIG. 1 is a perspective view of an EMI protective spring plate constructed according to the prior art.

[0006] FIG. 2 is a side view of the prior art EMI protective spring plate shown in FIG. 1.

[0007] FIG. 3 is a sectional view showing the prior art EMI protective spring plate installed.

[0008] FIG. 4 is a perspective view of an EMI protective spring plate constructed according to the present invention.

[0009] FIG. 5 is a sectional view of the EMI protective spring plate according to the present invention.

[0010] FIG. 6 is a front view of the EMI protective spring plate according to the present invention.

[0011] FIG. 7 is a sectional view showing the EMI protective spring plate installed according to the present invention.

[0012] FIG. 8 is similar 6 to FIG. 7 but showing a downward pressure given to the EMI protective spring plate according to the present invention.

[0013] Referring to FIGS. From 4 through 7, an EMI protective spring plate 1 is shown comprising a flat top contact portion 11, which supports a shielding cover plate 4 (see FIG. 7), a flat bottom soldering portion 18, which is soldered to a motherboard 3, an oblique supporting portion 12 diagonally connected between one end, namely, the rear end of the flat top contact portion 11 and one end, namely, the front end of the flat bottom soldering portion 18, a first turn R1 connected between the rear end of the flat top contact portion 11 and one end, namely, the top end of the oblique supporting portion 12, an upper slot 131 and a lower slot 132 respectively formed in the oblique supporting portion 12 at different elevations, a front sliding portion 14 obliquely downwardly extended from one end, namely, the front end of the flat top contact portion 11 toward the flat bottom soldering portion 18 and inserted through the lower slot 132, a second turn R2 connected between the front end of the flat top contact portion 11 and one end of the front sliding portion 14, a rear sliding portion 15 obliquely upwardly extended from one end, namely, the rear end of the flat bottom soldering portion 16 toward the flat top contact portion 11 and inserted through the upper slot 131, a third turn R3 connected between the rear end of the flat bottom soldering portion 18 and one end of the rear sliding portion 15, a fourth turn R4 connected between one end, namely, the bottom end of the oblique supporting portion 12 and one end, namely, the front end of the flat bottom soldering portion 18, a first slope 16 formed in the connection area between the fourth turn R4 and the front end of the flat bottom soldering portion 18, and a second slope 17 formed in the connection area between the third turn R3 and the rear end of the flat bottom soldering portion 18. The first slope 16 and the second slope 17 distribute accumulated stress of the tin soldering paste 2, the third turn R3, and the fourth turn R4 in different directions upon a downward applied to the flat top contact portion 11. Preferably, the free end (bottom end) of the front sliding portion 14 and the free end (top end) of the rear sliding portion 15 are respectively rolled up. The front sliding portion 14 has a width gradually reducing from its top end toward its bottom end (i.e., gradually reducing in direction from the flat top contact portion 11 toward the flat bottom soldering portion 18). The rear sliding portion 15 has a width gradually reducing from its bottom end toward its top end (i.e., gradually reducing in direction from the flat bottom soldering portion 18 toward the flat top contact portion 11). The free end (top end) of the rear sliding portion 15 is disposed in contact with the bottom surface of the flat top contact portion 11. The free end (bottom end) of the front sliding portion 14 is spaced above the flat bottom soldering portion 18. The spring plate 1 further comprises two upright baffles 19 formed integral with two opposite lateral sides of the flat bottom soldering portion 18, which stops tin soldering paste 2 from falling to the top surface of the flat bottom soldering portion 18 when soldering the flat bottom soldering portion 18 to the motherboard 3.

[0014] Referring to FIG. 8 when loading the shielding cover plate 4 on the flat top contact portion 11 of the spring plate 1 after the flat bottom soldering portion 18 of the spring plate 1 has been soldered to the motherboard 3, the rear sliding portion 15 is forced to turn inwards and to move its free end forwards along the bottom surface of the flat top contact portion 11, and the front sliding portion 14 is forced to move downwards and then to turn inwards, causing the free end of the front sliding portion 14 to be moved backwards along the top surface of the flat bottom soldering portion 18. The slot 131 or 132 has a width wider than the free end of the sliding portion 14 or 15 but narrower than the fixed end of the sliding portion 14 or 15. Therefore, the slots 131;132 limit the sliding distance of the sliding portions 14;15, preventing the spring plate 1 from being excessively deformed. This is the so-called lower dead point design. Because the spring plate 1 has an enclosed structure (the free end of the front sliding portion and the free end of the rear sliding portion are kept from touching external objects), the spring plate 1 does not hook external objects during its installation. Because two turns are provided at the two ends of the flat top contact portion 11, the flat top contact portion 11 is maintained in balance and prohibited from sloping in one direction upon loading of the shielding plate 4. Therefore, the shielding plate 4 can be stably supported on the flat top contact portion 11. Further, the lower dead point design prevents protects the spring plate 1 from being deformed excessively.

[0015] A prototype of EMI protective spring plate has been constructed with the features of FIGS. from 4 through 8. The EMI protective spring plate functions smoothly to provide all of the features discussed earlier.

[0016] Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.