CN2545794Y

CN2545794Y - Location resilient piece

Info

Publication number: CN2545794Y
Application number: CN 02231290
Authority: CN
Inventors: 陈惟诚
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-05-08
Filing date: 2002-05-08
Publication date: 2003-04-16
Anticipated expiration: 2012-05-08

Abstract

The utility model provides location shrapnel, which can be welded on the connecting pad of a circuit board through the surface welding technique. The shrapnel comprises an installation part which is joined with the circuit board; and a resilient arm part which is extended from the installation part. The installation part is provided with a first connecting section, a second connecting section and a tapping section which is arranged between the first connecting and the second connecting section. The second connecting section is shorter than the corresponding connecting pad on the circuit board. The distances between the tapping section and the two connecting sections are roughly the same. The surface tensions of a soldering tin between the two ends of each connecting section are roughly counteracted when passing a reflow oven. A distance is left between the lower edge of the resilient arm and the connecting pad, so the resilient piece is accurately welded on the connecting pad of the circuit board without any skewing.

Description

Location resilient piece

Technical field

The utility model relates to a kind of Location resilient piece, particularly relates to a kind ofly being installed in the Location resilient piece on the circuit board by surface mounting technology (SurfaceMount Technology).

Background technology

Surface mounting technology (SMT) be will be bonded on shortly earlier on the circuit board circuit element pin place or on the metallic pad (pad) of circuit board last layer scolding tin, and after all circuit elements being placed in the position of corresponding connection pad on the circuit board, send the reflow stove in the lump to the scolding tin fusion, wait back to be cooled just can correctly be soldered to the element pin on the circuit board.

As shown in Figure 1, when being installed in a kind of traditional shell fragment 3 on the circuit board 1,, just can shell fragment 3 be welded on the connection pad 11 during by the reflow stove by scolding tin 2 because 11 its length of the connection pad on the circuit board 1 are come shortly than the installation portion 31 of shell fragment 3 a little.But, because must be short than installation portion 31 in connection pad 11, and after scolding tin 2 fusions, the close surface tension that forms of surperficial energy state owing to 31 of connection pad 11 and installation portions, especially for the right side of installation portion among the figure 31, form a component very frivolous shell fragment pullled left, just cause offset as shown in Figure 2, make interelement each other the accuracy of contraposition reduce.And because the microminiaturized trend of electronic equipments such as mobile phone, PDA, make shell fragment 3 progressively be reduced to the size of 2 millimeters (mm), therefore shell fragment 3 not only terminates in skew after stressed, even may cause shell fragment 3 upsets to reach 90 °, has a strong impact on the yield of electronic equipment assembling.

Consult Fig. 3, if but become the area size design of metallic pad 11 with installation portion 31 when corresponding, after entering the heating of reflow stove, though the position of shell fragment 3 relatively is not easy skew, the scolding tin 2 that is stamped in connection pad 11 positions but may be dissipated to elastic arm's 32 lower edges of shell fragment 3 because capillarity is progressively overflow.Therefore, the former scolding tin 2 that should be distributed in 11 of installation portion 31 and connection pads, solidify near elastic arm 32 root edge places extend to installation portion 31 unavoidablely, cause elastic arm 32 elasticity to weaken, therefore when elastic arm 32 is subjected to external force pressure, promptly can produces the stress concentration phenomenon with the interface (as figure mid point 6) of not climbing the tin part and shell fragment 3 is produced and rupture climbing the tin part.

Therefore, the less shell fragment of size needs special location structure can utilize surface mounting technology that shell fragment is welded on the connection pad of circuit board accurately, securely, and avoids the elasticity impairment of shell fragment, just can meet the demand of high density electronic component now.

The utility model content

The purpose of this utility model is to provide a kind of Location resilient piece that is easy to contraposition and can not causes skew.

Another purpose of the present utility model be to provide a kind of can be under the situation that does not influence its elastic reaction and can utilize surface mounting technology to be installed in Location resilient piece on the circuit board.

A purpose more of the present utility model is to provide a kind of and difficultly produces the stress concentration phenomenon because of climbing tin at its elastic arm's lower edge, and Location resilient piece that can long-acting use.

The purpose of this utility model is achieved like this, and a kind of Location resilient piece is provided, and it utilizes surface mounting technology to be engaged on the circuit board, and Location resilient piece comprises an installation portion that engages with circuit board and an elastic arm by the installation portion extension.Installation portion has: one away from the elastic arm and the first then section that is connected with circuit board, one contiguous elastic arm and is connected with circuit board and with the first then second then section of spacer segment, and one fall between and be connected the first then tap section followed section of section and second.Tap section and circuit board be a spacing separately, and defines a headspace.

When will utilize surface mounting technology to be installed on Location resilient piece on the circuit board, can be earlier respectively on circuit board first, second then the relative connection pad of section adhere to an amount of scolding tin, again Location resilient piece is placed connection pad position on the circuit board.In the time of by the reflow stove, the scolding tin between Location resilient piece and connection pad, its surface tension is roughly offset, and can make Location resilient piece correctly on the connection pad that is positioned at circuit board and be difficult for skew.

For further specifying above-mentioned purpose of the present utility model, design feature and effect, the utility model is described in detail below with reference to accompanying drawing.

Description of drawings

Fig. 1 is a schematic diagram, and it shows a kind of traditional shell fragment and is engaged in the connection pad situation short than the shell fragment bonding station on the circuit board and on the circuit board.

Fig. 2 one is similar to the end view of Fig. 1, and it shows traditional shell fragment in the situation of skew to the left with being subjected to the pulling force influence when circuit board engages.

Fig. 3 is a schematic diagram, and it shows connection pad and the isometric situation of traditional shell fragment bonding station on the circuit board, and the phenomenon concentrated of stress, and dotted line is the deformation of traditional shell fragment after stressed among the figure.

Fig. 4 is a stereogram, and it shows first preferred embodiment of the utility model Location resilient piece.

Fig. 5 is that first preferred embodiment places the schematic side view on the circuit board, and it shows the situation that the scolding tin that engages Location resilient piece does not also solidify.

Fig. 6 is the schematic side view that first preferred embodiment is engaged in circuit board, there is shown the scolding tin that engages Location resilient piece and solidifies the situation that afterwards reaches an equilbrium position.

Fig. 7 is the stereogram of the utility model Location resilient piece second preferred embodiment.

Fig. 8 is the stereogram of the utility model Location resilient piece the 3rd preferred embodiment.

Embodiment

Consult Fig. 4, first preferred embodiment of the utility model Location resilient piece 4 is to be welded on the circuit board 1 by scolding tin 2, and constitutes a circuit board arrangement 5, and circuit board 1 has and Location resilient piece 4 corresponding one first connection pad 12 and one second connection pads 13.

Location resilient piece 4 comprises an

installation portion

41, and 41 of installation portions have the first then then section 412 of

section

411 and 1 second separately.First follows section 411 and second then is connected with a tap section 413 between the section 412.Tap section 413 by first then an end of section 411 upwards the bending back is towards first then section 412 direction horizontal-extendings, and bending downwards then sections 412 engages with second again, so

tap section

413 and 1 of circuit board can form a headspace 414.And first then section 411 and second then section 412 can be welded on first connection pad 12 and second connection pad 13 by scolding tin 2 respectively.In the present embodiment, the length of first connection pad 12 is that then section 411 is identical with first haply, and the length of second connection pad 13 then is less than the second then length of section 412.In addition, the spacing of first connection pad 12 and second connection pad 13 is approximately identical to tap section 413 length of Location resilient piece 4, and its function and purpose will be illustrated hereinafter.

Elastic arm 42 is by a side of installation portion 41, just from second then up bending and the oppositely extension of section 412, Location resilient piece 4 is constituted the sheet metal that is the U font as an accumbency, make elastic arm 42 be subjected to external force (as an electronic component, figure does not show) press down and when producing deformation, just can produce a elastic force, make elastic arm 42 be returned to original position in contrast to external force direction, guarantee electronic component and Location resilient piece 1 electrical contact good.

Consult Fig. 5, when utilizing surface mounting technology to be welded on Location resilient piece 4 on the circuit board 1, explanation as the front, can be earlier at first connection pad 12, second connection pad, 13 last layer scolding tin 2, respectively first of Location resilient piece 4 is followed section 411 again, second follows section 412 is seated in corresponding first connection pad 12, on the relative position of second connection pad 13, and since the spacing of first connection pad 12 and second connection pad 13 roughly the length with tap section 413 is identical, when therefore wanting to be placed on Location resilient piece 4 on the circuit board 1, by the tap section 413 and first connection pad 12, the gap phase contraposition that second connection pad is 13 just can be placed in Location resilient piece 4 on first connection pad 12 and second connection pad 13 easily.And when Location resilient piece 4 was admitted to the reflow stove together with circuit board 1, scolding tin 2 will melted by heating, makes Location resilient piece 4 be welded on the circuit board 1.

Consult Fig. 6, though because the area of second connection pad 13 is followed section 412 less than second, make Location resilient piece 4 can be subjected to second then section 412 below scolding tin 2 effect of surface tension and be moved to the left, but, in case produce after a little skew, first then section 411, second then section 412 belows near scolding tin 2 surface tension at tap section 414 places, therefore skew and draw Location resilient piece 4 to the right.Therefore, for whole Location resilient piece 4, at last its equilbrium position will be roughly with original Fig. 5 in identical, make Location resilient piece 4 accurately can not be offset or move to being positioned on the circuit board 1.In the present embodiment, also since the area of second connection pad 13 less than the second then area of section 412, therefore scolding tin 2 is difficult for rising to the bending place of Location resilient piece 4 when solidifying, just can not rise to elastic arm 42 and installation portion 41 junctions yet, make elastic arm 42 be guaranteed its elasticity, avoid the stress concentration phenomenon shown in Fig. 3, therefore when elastic arm 42 is subjected to external force pressure, promptly be difficult for producing the situation of fracture.

In addition, more preferably, because a part of scolding tin 2 is climbed tin in headspace 414, can make Location resilient piece 4 except original scolding tin 2 pulling force (first follows then scolding tin 2 pulling force of section 412 belows of section 411, second) perpendicular to circuit board 1, more increase many pulling force perpendicular to tap section 413, Location resilient piece 4 more can be fixed on the circuit board 1, avoid coming off because external force pulls.

Consult Fig. 7 and Fig. 8, they show the second and the 3rd preferred embodiment of the utility model Location resilient piece 4 respectively.Because in following embodiment the inside, Location resilient piece 4 most structures, function are all identical with first embodiment, therefore do not remake detailed explanation, below only be illustrated with regard to its place different with first embodiment, and for convenience's sake, will use identical label to represent identical structure.

Among Fig. 7, second preferred embodiment of Location resilient piece 4 also can illustrated can accurately be welded on the circuit board 1 as top, different is, can selectivity form a circular tap hole 415 of opening up and down on the installation portion 41, make scolding tin 2 when Overwelding and rewelding furnace,, and can not influence elastic arm 42 elastic reaction by capillarity and along the periphery of tap hole 415 tin of climbing, also can increase the pulling force of different directions, Location resilient piece 4 can be strengthened being fixed on the circuit board 1.Certainly, tap hole 415 is not limited to the circle among the figure, and other similar form with polygon or conduit also can reach identical purpose.

Among Fig. 8, both side edges at the installation portion 41 of Location resilient piece 4, also can selectivity form the recessed edge 416 of two sides that cave inward, the main effect of the recessed edge 416 of side is identical with tap hole 415 among second embodiment, make scolding tin 2 before near elastic arm 42, just can climb tin by the recessed edge 416 of side, avoid causing elastic arm 42 situation of fracture easily because scolding tin 2 is connected in elastic arm's 42 lower edges by capillarity.

In sum, when utilizing surface mounting technology to be soldered to the utility model Location resilient piece 4 on the circuit board 1, follow section 411 by first, the second then setting of section 412, and first connection pad 12 corresponding and second connection pad 13 on the circuit board 1 with it, make the Location resilient piece 4 can be easily to being positioned on the connection pad, and avoid the effect of surface tension of scolding tin and cause its welding after offset, also can avoid simultaneously scolding tin 2 to borrow capillarity to flow to elastic arm 41 and influence its spring function, or produce the phenomenon that stress is concentrated and generation is ruptured, can reach effect of the present utility model really.

Certainly, those of ordinary skill in the art will be appreciated that, above embodiment is used for illustrating the utility model, and be not to be used as qualification of the present utility model, as long as in connotation scope of the present utility model, all will drop in the scope of the utility model claims variation, the modification of the above embodiment.

Claims

1. Location resilient piece that is used for being soldered on the circuit board, described Location resilient piece comprises an installation portion that engages with described circuit board, and one by an end of the described installation portion elastic arm that extends of bending upwards, it is characterized in that described installation portion has:

One first follows section, and it is away from described elastic arm and smooth on described circuit board for touching;

One second then section, it is in abutting connection with described elastic arm and smooth on circuit board for touching, and with described first then section is separately; And

One tap section, it be connected in described first then section and described second then section, and with the described circuit board spacing of being separated by.

2. Location resilient piece as claimed in claim 1 is characterized in that: it is recessed to have at least one side in the both side edges of described installation portion.

3. Location resilient piece as claimed in claim 1 is characterized in that: described installation portion has the tap hole of at least one up/down perforation.