WO2009057855A1

WO2009057855A1 - A clip for fixing of shield can

Info

Publication number: WO2009057855A1
Application number: PCT/KR2008/000188
Authority: WO
Inventors: Nack Hwan Jeong
Original assignee: Pocons Co. Ltd
Priority date: 2007-11-01
Filing date: 2008-01-11
Publication date: 2009-05-07
Also published as: JP2011501477A; KR100886591B1; CN101242735A; KR20080006506A; CN101242735B; JP5161970B2

Abstract

A shield can fixing clip is disclosed. The object of the present invention is to provide a shield can fixing clip capable of being more securely fixed onto a printed circuit board (PCB) without deteriorating space utilization of the PCB and a holding force of the PCB with respect to the shield can. According to the present invention, a shield can fixing clip to fix to a printed circuit board (PCB) a shield can provided to cover electronic parts mounted on the PCB, the shield can fixing clip comprises a plurality of first fixing units fixed in contact with the PCB, a second fixing unit disposed between the first fixing units and fixed in contact with the PCB, an extension unit flanged from each edge of the second fixing unit upward and outward to be spaced apart from the PCB, a connection unit formed as an inclination to connect the extension unit with the first fixing unit, and a pair of resilient pieces formed upright at the extension unit, facing each other, to clamp a sidewall of the shield can.

Description

Description A CLIP FOR FIXING OF SHIELD CAN

Technical Field

[1] The present invention relates to a shield can fixing clip, and more particularly to a shield can fixing clip capable of being more securely fixed onto a printed circuit board (PCB) without deteriorating space utilization of the PCB and a holding force thereof with respect to the shield can. Background Art

[2] Generally, electromagnetic waves are very useful in some fields such as wireless communication and radar. However, the electromagnetic waves may affect operations of electronic apparatuses. This phenomenon, which is called Electro Magnetic Interference (EMI), not only generates noise with the electronic apparatuses but also does harm to human bodies.

[3] Accordingly, in recent days, electronic parts such as a semiconductor device mounted on a printed circuit board (PCB) inside the electronic apparatuses are covered with a shield can so that the EMI generated from the electronic parts can be interrupted and prevented from affecting not only the apparatus itself including the electronic parts but also other peripheral electronic apparatuses. Such a shield can generally has a box form with an opened lower side to cover the electronic parts.

[4] Also, the shield can is generally mounted on the PCB by a clip connected to the PCB to clamp sidewalls of the shield can.

[5] FIG. 1 through to FIG. 3 shows the structure of the clip for fixing the shield can according to a conventional art.

[6] As shown in FIG. 1 through FIG. 3, a conventional shield can fixing clip 1 is arranged on a PCB 3 around electronic parts in corresponding number and position to each sidewall 2a of a shield can 2. The shield can fixing clip 1 comprises a plurality of fixing units 4 fixed in contact with the PCB 3, a plurality of base units 5 formed between the respective fixing units 4 as spaced apart from the PCB 3, and a plurality of pairs of resilient pieces 6 each extended upwards from both sides of each base unit 5 to face each other in the form of a clamp to hold the sidewall of the shield can 2.

[7] The fixing unit 4 is connected to the PCB 3 by soldering an outline thereof. Each of the resilient pieces 6 is bent inwardly at the middle part between upper and lower parts thereof so that the middle part projects toward the sidewall 2a inserted in between the pair of resilient pieces 6.

[8] Here, the reason for spacing the base unit 5 apart from the PCB 3 is to prevent solder from flowing to the base unit 5 during the soldering of the fixing unit 4 onto the PCB 3. More specifically, if the solder flows up to the resilient pieces 6 along the base unit 5 and hardens at the resilient pieces 6, resilience of the resilient pieces 6 may be deteriorated, accordingly deteriorating the holding force of the shield can 2. Thus, the base unit 5 is preferably spaced from the PCB 3 to prevent deterioration of the holding force of the shield can 2.

[9] Therefore, in a state where the clip 1 is fixed on the PCB 3 through the fixing unit 4, when the sidewall 2a of the shield can 2 is inserted in between the pair of resilient pieces 6 of the clip 1, the shield can 2 can be fixed to the clip 1 as outer and inner surfaces of the sidewall 2a are clamped by the pair of resilient pieces 6 formed at the both sides of the base unit 5.

[10] In addition, when the electronic parts covered by the shield can 2 require replacement in this state, separation of the shield can 2 can be performed easily. Simply by pulling up the shield can 2, the respective sidewalls 2a of the shield can 2 can escape from between the resilient pieces 6 of the clip 1. Disclosure of Invention Technical Problem

[11] However, in the above- structured conventional clip 1 for fixing a shield can 2, the base unit5 is wholly spaced apart from the PCB 3 and furthermore, the fixing unit 4 soldered to the PCT 3 has a relatively small area. Therefore, coherence between the clip 1 and the PCB 3 is so insufficient that the clip 1 may be separated from the PCB 3 during use of the electronic parts.

[12] For instance, in the clip 1 soldered on the PCB 3, in case that the resilient pieces 6 are a little deviated from a correct position corresponding to the sidewall 2a of the shield can 2, the resilient pieces 6 may be distorted while the sidewall 2a of the shield can 2 is being clamped by the resilient pieces 6 and therefore, the fixing unit 4 integrally formed with the resilient piece 6 may be separated from the PCB 3.

[13] In addition, considering that the clip 1 may be employed in vibrating apparatuses such as an air conditioner or a refrigerator, if coherence between the fixing unit 4 and the PCB 3 is insufficient, the fixing unit 4 may be separated from the PCB 3 due to vibration or impact generated during the operation of the electronic apparatuses.

[14] To prevent this, it is preferable to increase the coherence between the PCB 3 and the fixing unit 4 by enlarging the surface area of the fixing unit 4. In this case, however, the clip 1 would occupy too much area on the PCB 3, thereby deteriorating the space utilization of the PCB 3. Technical Solution

[15] Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a shield can fixing clip capable of being more securely fixed onto a PCB without causing deterioration of space utilization of the PCB and deterioration of a holding force thereof with regard to the shield can.

Advantageous Effects

[16] A shield can fixing clip according to the present invention is equipped with a second fixing unit, an auxiliary fixing unit and a curve unit. Therefore, a surface area of the clip for soldering to a PCB can be increased although the clip actually does not occupy too much area on the PCB in comparison with a conventional art. Accordingly, without causing deterioration of space utilization of the PCB, coherence between the clip and the PCB can be highly improved.

Brief Description of the Drawings [17] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: [18] Fig. 1 is a perspective view showing the structure of a conventional shield can fixing clip; [19] Fig. 2 is a sectional view showing a state where a sidewall of the shield can is clamped by the conventional shield can fixing clip; [20] Fig. 3 is a side view showing a state where a sidewall of the shield can is clamped by the conventional shield can fixing clip; [21] Fig. 4 is a perspective view showing the structure of a shield can fixing clip according to an embodiment of the present invention; [22] Fig. 5 is a sectional view showing the structure of a shield can fixing clip according to an embodiment of the present invention; [23] Fig. 6 is a perspective view showing a state where a plurality of the shield can fixing clips according to the embodiment of the present invention are fixed on the PCB; [24] Fig. 7 is a plan view showing the shield can fixing clip according to the embodiment of the present invention being fixed on the PCB; [25] Fig. 8 is a side view showing the shield can fixing clip according to the embodiment of the present invention being fixed on the PCB; [26] Fig. 9 is a sectional view showing a state before a sidewall of the shield can is clamped by the shield can fixing clip according to the embodiment of the present invention; [27] Fig. 10 is a sectional view showing a state where the sidewall of the shield can is being clamped by the shield can fixing clip according to the embodiment of the present invention; and [28] Fig. 11 is a sectional view showing a state after the sidewall of the shield can is completely clamped by the shield can fixing clip according to an embodiment of the present invention.

Best Mode for Carrying Out the Invention

[29] In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a shield can fixing clip to fix to a printed circuit board (PCB) a shield can provided to cover electronic parts mounted on the PCB, the shield can fixing clip comprising a plurality of first fixing units fixed in contact with the PCB, a second fixing unit disposed between the first fixing units and fixed in contact with the PCB, an extension unit flanged from each edge of the second fixing unit upward and outward to be spaced apart from the PCB, a connection unit formed as an inclination to connect the extension unit with the first fixing unit, and a pair of resilient pieces formed upright at the extension unit, facing each other, to clamp a sidewall of the shield can.

[30] The first and second fixing units may be fixed onto the PCB by soldering the outline thereof.

[31] One of the first fixing units may be disposed in the middle of the shield can fixing clip with respect to a length direction, and both sides of the middle first fixing unit are symmetrical in weight and shape. An auxiliary fixing unit may be extended from one side of the middle first fixing unit perpendicularly to the length direction of the shield can fixing clip.

[32] The extended length of the auxiliary fixing unit may be less than the whole width of the middle first fixing unit and greater than a half width of the middle first fixing unit.

[33] At least one of the three first fixing units may be further provided with at least one curve unit formed at the outline thereof, so as to increase the soldering area of the first fixing units.

[34] The curve unit may be formed by concavely cutting the first fixing units so that only the outline length of the first fixing units is increased without increase in the contacting area between the first fixing units and the PCB.

[35] The curve unit may be formed at the first fixing units disposed at both ends of the shield can fixing clip with respect to the length direction. Mode for the Invention

[36] Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[37] Fig. 6 shows part of the structure of a PCB applying a shield can fixing clip according the embodiment of the present invention. As shown in Fig. 6, electronic parts 20 including a semiconductor device are mounted on a PCB 10. Around the outside of the electronic parts 20, a shield can 30 is mounted to cover the electronic parts 20 and thereby interrupt EMI of the electronic parts 20. [38] The shield can 30 is removably mounted on the PCB 10, that is, to be easily fixed to and separated from the PCB 10. Such fixing and separating of the shield can 30 can be achieved by a shield can fixing clip 40 according to the embodiment of the present invention.

[39] The shield can 30 has a cubic box form with four sidewalls 31 and a ceiling wall 32 integrally formed altogether and an opened lower part so as to cover the electronic parts 20 by receiving the electronic parts 20 therein. The shield can 30 may be made of a tin-plated steel sheet to effectively interrupt electromagnetic waves.

[40] A plurality of the shield can fixing clips 40 are mounted on the PCB 10 around the electronic parts 20 to removably fix the shield can 30 by clamping a lower part of each sidewall 31 of the shield can 30. The shield can fixing clip 40 may be arranged at positions on the PCB 10 corresponding to the sidewalls 31 of the shield can 30 and also in the corresponding number to the sidewalls 31. In addition, the sidewall 31 may include a stepped groove 31a in the middle of a lower end thereof, which is the part actually clamped by the shield can fixing clip 40 so that, when the sidewall 31 is clamped by the shield can fixing clip 40, any gap is not generated between the PCB 10 and both side lower ends of the sidewall 31 adjacent to the stepped groove 31a.

[41] Referring to Figs. 4 and 5, the shield can fixing clip 40 comprises three first fixing units 41 and 42 arranged at intervals along a length direction thereof, a second fixing unit 43 disposed between the respective first fixing units 41 and 42 and fixed in contact with the PCB 10, extension units 43a flanged from both edges of the second fixing unit 43 upward and outward, a connection unit 46 having an inclined form to connect the extension units 43a with the first fixing units 41 and 42 that contact with the PCB 10, and a pair of resilient pieces 44 and 45 formed upright at each outer edge of the extension unit 43a to face each other so as to clamp the sidewall 31 of the shield can 30. The first and second fixing units 41, 42 and 43 are fixed onto the PCB 10 by soldering the outline thereof.

[42] In order to fix the shield can 30 onto the PCB 10 using the above- structured shield can fixing clip 40, the shield can fixing clip 40 is fixed first onto the PCB 10 by soldering the first and second fixing units 41, 42 and 43 at positions corresponding to the respective sidewalls 31 of the shield can 30.

[43] According to the embodiment of the present invention, a soldering area of the shield can fixing clip 40 can be expanded by the existence of the second fixing unit 43. Therefore, the shield can fixing clip 40 can be more securely fixed on the PCB 10. In addition, however, the shield can fixing clip 40 does not occupy too much area on the PCB 10 by the second fixing unit 43, compared to the conventional shield can fixing clip.

[44] In case that solder flows to the resilient pieces 44 and 45 during the soldering of the first and second fixing units 41, 42 and 43, resilience of the resilient pieces 44 and 45 would be deteriorated, accordingly deteriorating a holding force of the resilient pieces 44 and 45 with respect to the sidewall 31 of the shield can 30. However, in this embodiment, since the resilient pieces 44 and 45 are disposed higher than the first and second fixing units 41, 42 and 43 by the existence of the connection unit 46 and the extension unit 43a and therefore spaced apart from the PCB 10, the solder can be prevented from flowing to the resilient pieces 44 and 45 while the outline of the first and second fixing units 41, 42 and 43 are soldered onto the PCB 10. As a result, while fixing efficiency of the shield can fixing clip 40 to the PCB 10 is improved, deterioration of the resilience of the resilient pieces 44 and 45 can be prevented. In addition, the holding force of the resilient pieces 44 and 45 with respect to the sidewall 31 of the shield can 30 can also be prevented.

[45] Here, the second fixing unit 43 and the extension unit 43a can be manufactured simply by pressure-transforming an inside of a planar plate inwardly, the inside which will be the second fixing unit 43.

[46] The shield can fixing clip 40 is moved as vacuum-picked by a nozzle (not shown) of semiconductor manufacturing technology (SMT) equipment (not shown) to be mounted on the PCB 10. Here, because the first fixing unit 42 disposed in the middle among the three first fixing units 41 and 42 forms a vacuum picking surface with respect to the nozzle (not shown), it is preferred that both sides of the middle first fixing unit 42 are symmetrical in weight and shape such that the shield can fixing clip 40 does not incline to any side as vacuum-picked by the nozzle (not shown).

[47] As aforementioned, an upper surface of the middle first fixing unit 42 among the three first fixing units 41 and 42 forms the vacuum picking surface. For this, in this embodiment, an auxiliary fixing unit 42a is formed at one side of the middle first fixing unit 42, being extended perpendicularly to a length direction of the shield can fixing clip 40, such that width of the middle first fixing unit 42 is increased.

[48] By the existence of the auxiliary fixing unit 42a, a contacting surface of the middle first fixing unit 42 with the PCB 10 can be further increased. Accordingly, coherence between the shield can fixing clip 40 and the PCB 10 can be highly improved. In the drawings, an imaginary line is drawn to define the auxiliary fixing unit 42a distinctively from the middle first fixing unit 42.

[49] To prevent the contacting area between the shield can fixing clip 40 and the PCB 10 from being actually increased by the auxiliary fixing unit 42a, the auxiliary fixing unit 42a is preferably directed to the electronic parts 20 when the shield can fixing clip 40 is mounted on the PCB 10, as shown in Fig. 6. Therefore, when the shield can 30 is mounted, the auxiliary fixing unit 42a is disposed inside the shield can 30, not affecting space utilization of the PCB 10. [50] In the state where an area of the middle first fixing unit 42 is increased by the auxiliary fixing unit 42a, the nozzle (not shown) can perform the vacuum-picking of the shield can fixing clip 40 more easily without interference with the resilient pieces 44 and 45.

[51] The length extended by the auxiliary fixing unit 42a is preferably less than the whole width of the middle first fixing unit 42 and greater than a half width of the middle first fixing unit 42, such that the vacuum-picking of the nozzle (not shown) can be smoothly performed without interference between the auxiliary fixing unit 42a and the electronic parts 20.

[52] In addition, in the shield can fixing clip 40 according to the embodiment of the present invention, at least one of the three first fixing units 41 and 42 is further provided with at least one curve unit 41a formed at the outline thereof, so as to increase the soldering area of the first fixing units 41 and 42.

[53] For example, preferably, the curve unit 41a is formed by concavely cutting the first fixing units 41 and 42 so that only the outline length of the fixing units 41 and 42 is increased without increase in the contacting area between the first fixing units 41 and 42 and the PCB 10.

[54] Although the curve unit 41a may be formed to the all three first fixing units 41 and

42, it is preferable to provide the curve unit 41a only at two fixing units 41 disposed at both ends of the shield can fixing clip 40 with respect to the length direction, so as not to complicate processing of the shield can fixing clip 40. According to this embodiment, the first fixing units 41 and 42 each have a rectangular form, and the curve unit 41a is formed only at an end side of the first fixing units 41 disposed at both ends of the shield can fixing clip 40. In Fig. 7 through to Fig. 11, a reference numeral A denotes the soldering area of the shield can fixing clip 40 soldered to the PCB 10.

[55] As described above, with the curve unit 41a, the second fixing unit 43 and the auxiliary fixing unit 42a provided, although the area on the PCB 10 occupied by the shield can fixing clip 40 is actually not much increased in comparison with the conventional art, the soldering area of the shield can fixing clip 40 with respect to the PCB 10 is increased. Consequently, coherence between the shield can fixing clip 40 and the PCB 10 can be highly improved without causing deterioration of the space utilization of the PCB 10.

[56] In a state where the shield can fixing clip 40 is fixed on the PCB 10, the respective sidewalls 31 of the shield can 30 are inserted in between respective pairs of the resilient pieces 44 and 45 of the shield can fixing clip 40. By this, the shield can 30 is clamped by the resilient pieces 44 and 45 of each shield can fixing clip 40 with the sidewalls 31 thereof, thereby being fixed on the PCB 10 conveniently.

[57] When the electronic parts 20 need to be replaced in this state, the shield can 30 can be easily removed. Simply by pulling the shield can 30 upward, the sidewalls 31 of the shield can 30 can be taken out from between the resilient pieces 44 and 45 of the respective shield can fixing clips 40.

[58] If the resilient pieces 44 and 45 of the shield can fixing clip 40 clamp the sidewall 31 more firmly, the holding force of the shield can fixing clip 40 is improved. Therefore, although some impact or vibration is applied to the PCB 10, the shield can fixing clip 40 can be stably fixed on the PCB 10 without shaking. For this purpose, the resilient pieces 44 and 45 according to the embodiment of the present invention are structured to more firmly hold the sidewall 31.

[59] More specifically, first grip units 44a and 45a are formed to clamp the sidewall 13 more strongly, by bending middle parts of the resilient pieces 44 and 45 with respective to a vertical direction inwardly so that the middle parts protrude toward the sidewall 31 inserted in between the resilient pieces 44 and 45.

[60] Therefore, inner and outer surfaces of the sidewall 31 inserted in between the resilient pieces 44 and 45 are resiliently pressed and fixed by the first grip units 44a and 45a. Here, an interval between the resilient pieces 44 and 45 above the first grip units 44a and 45a is formed greater than thickness of the sidewall 31 at an upper part and gradually narrowed downward, in order to guide the insertion of the sidewall 31 in between the resilient pieces 44 and 45.

[61] At a lower part of the first grip units 44a and 45a, second grip units 44b and 45b are formed by cutting in the middle of the resilient pieces 44 and 45 with respect to the length direction of the shield can fixing clip 40, to press the sidewall 31 together with the first grip units 44a and 45 a.

[62] The second grip units 44b and 45b comprise fixed parts 44b 1 and 45b 1 and free end parts 44b2 and 45b2. The second grip units 44b and 45b are formed by cutting the resilient pieces 44 and 45 along an outline thereof except for the fixing ends 44b 1 and 45b 1 such that the fixed parts 44b 1 and 45b 1 are fixed to the first grip units 44a and 45a. After the cutting, the free end parts 44b2 and 45b2 are bent inwardly to be disposed in a space between the resilient pieces 44 and 45. The second grip units 44b and 45b are inclined downward from the fixed parts 44b 1 and 45b 1 fixed to the first grip units 44a and 45a to the free end parts 44b2 and 45b2 disposed at a lower part, such that an interval between the free end parts 44b2 and 45b2 is less than the interval between the first grip units 44a and 45 a.

[63] Fig. 9 through to Fig. 11 illustrate the insertion process of the sidewall 31 in between the resilient pieces 44 and 45. Referring to Fig. 10 showing the sidewall 31 being inserted in between the first grip units 44a and 45a, as the first grip units 44a and 45a are widened in an arrowed direction B, with the sidewall 31 inserted in between the first grip units 44a and 45a, the free end parts 44b2 and 45b2 of the second grip units 44b and 45b are forced to come into contact with each other in an arrowed direction C. As the sidewall 31 is inserted in between the second grip units 44b and 45b more and more, the sidewall 31 is firmly clamped by both the first grip units 44a and 45a and the second grip units 44b and 45b as shown in Fig. 11.

[64] Moreover, with the above structure including the first and second grip units 44a, 45a,

44b and 45b, although the interval between the first grip units 44a and 45 a are widened more than the thickness of the sidewall 31 during use of the shield can fixing clip 40 and therefore unable to clamp the sidewall 31, the free end parts 44b2 and 45b2 of the second grip units 44b and 45b can be maintained in a narrowed state. Therefore, clamping of the sidewall 31 can be maintained by the second grip units 44b and 45b.

[65] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

[1] A shield can fixing clip to fix to a printed circuit board (PCB) a shield can provided to cover electronic parts mounted on the PCB, the shield can fixing clip comprising: a plurality of first fixing units fixed in contact with the PCB; a second fixing unit disposed between the first fixing units and fixed in contact with the PCB; an extension unit flanged from each edge of the second fixing unit upward and outward to be spaced apart from the PCB; a connection unit formed as an inclination to connect the extension unit with the first fixing unit; and a pair of resilient pieces formed upright at the extension unit, facing each other, to clamp a sidewall of the shield can. [2] The shield can fixing clip according to claim 1, wherein the first and second fixing units are fixed onto the PCB by soldering the outline thereof. [3] The shield can fixing clip according to claim 1, wherein one of the first fixing units is disposed in the middle of the shield can fixing clip with respect to a length direction, both sides of the middle first fixing unit are symmetrical in weight and shape, and an auxiliary fixing unit is extended from one side of the middle first fixing unit perpendicularly to the length direction of the shield can fixing clip. [4] The shield can fixing clip according to claim 3, wherein the extended length of the auxiliary fixing unit is less than the whole width of the middle first fixing unit and greater than a half width of the middle first fixing unit. [5] The shield can fixing clip according to claim 2, wherein at least one of the three first fixing units is further provided with at least one curve unit formed at the outline thereof, so as to increase the soldering area of the first fixing units. [6] The shield can fixing clip according to claim 5, wherein the curve unit is formed by concavely cutting the first fixing units so that only the outline length of the first fixing units is increased without increase in the contacting area between the first fixing units and the PCB. [7] The shield can fixing clip according to claim 6, wherein the curve unit is formed at the first fixing units disposed at both ends of the shield can fixing clip with respect to the length direction.