KR100293940B1 - Structure of the emi shield can for rf system - Google Patents

Abstract

PURPOSE: An electromagnetic wave-shield can structure for an RF system is provided to prevent other circuit parts from being affected by a noise by covering a circuit device with a can. CONSTITUTION: An EMI noise generation circuit device(Ns) is mounted on a PBA(43). A can body(41) and a can cover(42) surround the EMI noise generation circuit device(Ns) for shielding. The can body(41) passes short and long legs through a hole(44) of the PBA(43), and bends the long leg and solders the same on a rear surface of the PBA(43). A rectangular through hole(41a) is formed on upper right and left sides of the can body(41). A stopper(42a) is installed on inner left and right sides of the can cover(42) to be inserted into the through hole(41a). A projection(42b) is formed on front and rear insides to press the can body(41). The projection(42b) of the can cover(42) is formed in a manner that a small projection is made through a press embossing process and continuously compresses a side wall of the can body(41). The leg passing through the PBA(43) is bent on a rear surface of the PBA and soldered so as not to form a gap between the can body and an upper surface(43a) of the PBA.

Description

Electromagnetic shielding can structure for RF system {STRUCTURE OF THE EMI SHIELD CAN FOR RF SYSTEM}

The present invention relates to an electromagnetic shielding can structure for an RF (radio frequency) system, and in particular, excellent assembly productivity due to low cost input for improving the EMC (electromagnetic compatibility) and EMI (electromagnetic interference) capability of PCS systems and other RF equipment. The present invention relates to an electromagnetic shielding can structure for RF (RF) systems that has strengths in terms of maintenance and maintenance and has an excellent shielding effect.

Typically, today, PCS systems and other RF equipment must use shielding cans in some form to improve their EMC (electromagnetic compatibility) and EMI (electromagnetic interference) capabilities.

In the related art, as shown in FIG. 1, a can body 11 and a can cover 12 include an EMI noise generating circuit element Ns mounted on a PBA 13. ) Is a shielded structure. The can body 11 is soldered (SOLDERING 15) on the back of the PBA 13 through the through hole (THROUGH HOLE) 14 of the PBA (13), is installed on the PBA (13) A can body 11 and a can cover 12 are provided on the upper surface of the PBA 13 to surround the EMI noise generating circuit element Ns.

The can body 11 and the can cover 12 are formed in the upper front circumference of the can body 11 so as to be engaged with each other, the engaging projection 11a protruding outward is formed, the can cover 12a is also a can body ( The engaging jaw 12a is formed to protrude inward to the lower front circumference of the can cover 12 to be engaged with 11).

As described above, the EMI is shielded using the can body 11 and the can cover 12 to shield the EMI noise generating circuit elements Ns provided on the PBA 13.

As described above, the locking jaws are coupled to detach the can cover installed on the can body, and thus, a strong press is required, and a press mold for manufacturing a can (CAN) according to forming a locking jaw at the front circumference of the can body and the can cover is provided. This is complicated and mold manufacturing costs are increased. As a result, there is a problem in that the manufacturing cost of the can is also increased.

FIG. 2 is another example of the prior art, in which the wall thickness of the can body 21 is thickened to shield the EMI noise generating circuit elements Ns provided on the PBA 23, so that the lower part of the can body 21 is made of PBA ( 23 and the screw 24, and the can cover 22 is assembled to the upper portion of the can body 21 by a screw 25.

As described above, the EMI is shielded by the can body 21 and the can cover 22 coupled with the PBA and the screw to shield the EMI noise generating circuit device Ns installed on the PBA 23.

However, due to the thickness of the screw coupled to the can body 22 for shielding the EMI noise generating circuit elements Ns installed on the PBA 23, the thickness t of the can must be thickened so that the mounting space of the circuit components is reduced. There is a disadvantage, there is a problem in terms of productivity and the future maintenance in accordance with the screw assembly is very inconvenient.

FIG. 3 illustrates a case in which a center inner wall can 32 is mounted in the prior art, and circuit elements of bands 33 and 34 having different frequency domains mounted on the same PBA 31 (FIG. The inner wall can 32 is provided in order to shield EMI noise between Ns1, Ns2, Ns3, and Ns4. As shown in FIG. 4, the inner wall can 32 is usually made of a nickel plate or a copper alloy plate having a thickness of less than 1 mm 32a. Even a slight impact in the left and right F directions of the inner wall can 32 is inclined as shown by the dotted line 32b, and thus, a disadvantage that the portion of the PBA 31 rear soldering 32c is very likely to be damaged is generated. will be. In addition, due to the inclination of the inner wall can, there is a problem that the automatic soldering process cannot be performed in the mass production process.

Accordingly, an object of the present invention is to improve the electromagnetic shielding of an RF system in order to cover the circuit elements generating EMI noise in a unit used in the RF system so as not to affect other circuit components that may be affected by the noise. In providing cans.

The present invention for achieving the above object is an electromagnetic shielding device for separating and shielding the frequency of the other area of the circuit elements installed in the PBA in the unit used in the RF system, the inner wall can for separating and shielding the circuit elements of the PBA Is a plate bent along the shielding length to separate and shield the bands in the angular frequency region, and a plurality of legs are formed at regular intervals, and the legs of the inner wall can are inserted into the holes formed in the PBA, and the legs are bent at the back of the PBA. Electromagnetic shielding can structure for RF system characterized by automatic soldering.

1 is a conventional electromagnetic shielding can structure for RF system,

2 is an electromagnetic shielding can structure for RF system of another conventional embodiment

3 is a configuration diagram in which a conventional electromagnetic shielding inner wall can for an RF system is mounted;

4 is a state diagram that the inner wall can is installed in a conventional PBA,

5 is an electromagnetic shielding can structure for RF system of the present invention,

6 is a right side view of the electromagnetic shielding can for an RF system of the present invention;

7 is a cross-sectional view of the can body and can cover of the present invention.

8 is a configuration diagram in which the electromagnetic shielding inner wall can for RF system of the present invention is mounted;

9 is a state diagram that the inner wall can is installed in the PBA of the present invention,

10 is a perspective view of an inner wall can of the present invention;

<Description of the symbols for the main parts of the drawings>

41: can body 41a: through hole

42: can cover 42a: locking jaw

42b: Protrusion 43: PBA

44: hole 45: soldering

51: inner wall can 51a: leg

52, 53: band Ns: circuit element

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used for the same components, even if displayed on different drawings. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

5 is a cross-sectional configuration diagram of the electromagnetic shielding can for RF system of the present invention is combined, Figure 6 is a right side view of the electromagnetic shielding can for RF system of the present invention, Figure 7 is the can body and can cover of the present invention Is a cross-sectional view of. 8 is a configuration diagram in which the electromagnetic shielding inner wall can for RF system of the present invention is mounted, FIG. 9 is a state diagram in which an inner wall can is installed in the PBA of the present invention, and FIG. 10 is a perspective view of the inner wall can of the present invention. Referring to the configuration and operation of the present invention with reference to it.

The can body 41 is short and long in order to surround and shield the EMI noise generating circuit element Ns mounted on the PBA 43 by the can body 41 and the can cover 42. The leg is penetrated through the hole 44 of the PBA 43, and the leg is bent and soldered 45 from the rear side of the PBA 43. A rectangular through hole 41a is formed at the upper left and right sides of the can body 41. The locking jaw 42a and the projection 42b for pressing and pressing the can body 41 on the inner and left and right sides of the can cover 42 to be fitted into the through holes 41a. Formed. The projection 42b of the can cover 42 forms a small projection by press embossing so that the wall surface of the can body 41 is always pressed. The leg passing through the PBA 43 in the can body 41 is bent (45) by bending at the back of the PBA 43 in order to prevent a gap between the PBA upper surface 43a and the can body 41.

In order to shield the EMI noise generated by the circuit element Ns mounted on the PBA 43, the solder body 45 is inserted into the hole 44 formed in the PBA 43 by soldering 45. The can cover 42 is covered on the can body 41 so that the can cover 42 is covered on the can body 41. At this time, the locking jaw 42a formed on the inner left and right sides of the can cover 42 is inserted into the through hole 41a of the can body 41 as shown in FIG. The formed protrusion 42b presses the can body 41 and is coupled as shown in FIG. 6. In the above state, EMI noise of the circuit element Ns provided in the PBA 43 can be shielded by the can body 41 and the can cover 42.

As described above, the through-hole 41a of the can body 41 is not formed in the entire can body 41 but is formed only in a part 42at of the left and right surfaces, and the locking jaw 42a of the can cover 42 is formed. The detachable force can be adjusted according to the length. In addition, small projections 42b are formed on the front and rear surfaces where the locking projections 42a are not formed by press embossing, so that the wall surface of the can body 41 is always pressed.

As shown in FIG. 8, the inner wall can 51 used separately from the can body and can cover mentioned above is a band of each frequency region in the same PBA 43 that mounts circuit elements Ns using different frequencies. Used to separate and shield (52,53). The inner wall can 51 is a plate bent along the shielding length L of the inner wall can 51 on the PBA 43 as shown in FIG. 10, and a plurality of legs 51 a are formed at regular intervals. When the legs 51a of the inner wall can 51 are shielded from the circuit elements Ns installed in the PBA 43, the legs 51a are inserted into holes formed in the PBA 43 to bend the legs. Solder as shown in 9.

The inner wall can 43 is the inner wall can 51 to separate and shield the bands 52 and 53 of each frequency region in the same PBA 43 that mounts the circuit elements Ns using the frequencies of different regions. The leg 51a of the ()) is inserted into the hole of the PBA (43) and bent at the back side and soldered (45) can be assembled more firmly than the conventional structure, and the automatic soldering in the mass production process that was not possible in the conventional structure.

The inner wall can 43 is soldered from the rear surface of the PBA 43 in a state where the body is bent by 90 degrees and the contact area with the PBA 43 is increased, thereby making the product extremely resistant to the impact on the left and right sides.

According to the present invention as described above it is possible to mass-produce with a much simpler mold structure than the prior art, it is possible to reduce the cost, easy assembly and maintenance of the product, can significantly increase the adhesive strength of the PBA and cans, Automatic soldering is an advantage.

Claims (2)

In the electromagnetic shielding device for separating and shielding the frequency of the other region of the circuit elements installed in the PBA in the unit used in the RF system, The inner wall can separating and shielding the circuit elements of the PBA is a plate bent along the shielding length to separate and shield the bands in the angular frequency region, and a plurality of legs are formed at regular intervals, and the legs of the inner wall can are connected to the PBA. Electromagnetic shielding can structure for RF system, characterized in that the bridge is bent in the formed hole and automatically soldered from the back of the PBA. 2. The electromagnetic shielding can structure of an RF system according to claim 1, wherein the inner wall can is soldered on the back surface of the PBA while the body wall is bent by 90 degrees to increase the contact area with the PBA.