JP2007035992A - Surface-mounted nut for printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means whereby there is made unnecessary the removing work of a film sheet stuck on the top surface of a surface-mounted nut having a screw hole passed up and down thoroughly, in order to suck the nut by the sucking head of an automatic surface-mounted-component mounting apparatus, and there is eliminated the discrepancy of the positional relation between the sucking nozzle of the automatic mounting apparatus and the held surface-mounted nut, even though the behavior of the sucking nozzle is changed quickly and violently. <P>SOLUTION: On the bottom surface of a surface-mounted nut 6 for mounting it on a printed wiring board, a flat film sheet 7 is stuck, or there is so stuck a semi-spherical film sheet wherein a semi-spherical form protrusion having its diameter somewhat smaller than the diameter of a screw escaping hole 1a bored in the printed wiring board 1 is formed, as to insert the protrusion of the semi-spherical film sheet into the screw escaping hole 1a bored in the printed wiring board 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to automatic mounting of a surface mounting component on a printed wiring board. Specifically, a surface mounting nut having through holes on the upper and lower surfaces is sucked and transferred by a suction portion of a suction nozzle tip of a surface mounting component automatic mounting device. It is related with the means which enables.

When mounting a component on a printed circuit board, the tip of the suction nozzle maintaining the negative pressure inside the suction nozzle of the surface mounting component automatic mounting device is brought into close contact with the center of the upper surface of the surface mounting component, and the surface mounting component is used for the suction. The suction nozzle is transferred to a predetermined position on the printed wiring board while being sucked and held by the nozzle tip. However, a component having an uneven surface or a through hole on the upper surface of the component cannot be sucked by the suction nozzle of the surface mounting component automatic mounting device, and therefore the surface mounting component is transferred to a predetermined position on the printed wiring board. I can't do it.

In order to cope with the above-mentioned problem, as seen in Patent Document 1, an invention in which a film sheet is attached to the upper surface opening of a flanged surface mounting nut that is fitted into a mounting hole formed in a printed wiring board and has a flange at the upper end. Has been made. However, the lower surface of a part to be fastened such as a shield case screwed to the surface mount nut and the upper surface of the flange of the surface mount nut are separated by the film sheet to form a contact surface for realizing a good conductive path I can't do it. For this reason, the complicated operation | work which removes the film stuck to the upper surface opening of this surface mounting nut with a flange before screwing of a to-be-fastened component was required.

FIG. 5 shows a case where the suction nozzle tip of the surface mounting component automatic mounting apparatus has a flat surface that can be continuously sucked into the screw hole of the surface mounting nut having a through hole as a screw hole in the vicinity of the center of the component. Thus, a means for adsorbing and holding the flat surface by the adsorbing nozzle of the surface mounting component automatic mounting apparatus while avoiding the screw hole on the upper surface of the surface mounting nut 36 has been put into practical use. However, because the suction position is offset from the center of gravity of the center part of the surface mount nut, if there is a sudden change in direction of movement during the transfer by the suction nozzle, a rotational moment centered on the suction point is generated due to inertia. However, the surface mounting nut rotates around the suction nozzle as the center of the rotation axis, causing a problem that the surface mounting nut is displaced from a predetermined position of the printed wiring board.
JP 2004-79975 A

In the conventional example in which a film is attached to an upper surface opening of a nut having a flange at the upper end and fitted in an attachment hole formed in a printed wiring board as seen in Patent Document 1, an object to be fastened is fastened to the nut. The bottom surface and the top surface of the nut flange are separated from each other by the film, so that a contact surface for realizing a good conductive path cannot be formed. Therefore, the component to be fastened is attached to the top surface opening of the flanged nut before fastening. The complicated work of removing the worn film is required. Further, the removed film needs to be treated as waste, and has an environmental problem.

A flat surface that has a through-hole as a screw hole near the center of the surface-mounting nut, but the suction nozzle tip of the surface-mounting component automatic mounting device can suck the upper surface of the surface-mounting nut continuously from the screw hole. In the conventional example in which the flat surface is sucked and held by the suction nozzle of the surface mount component automatic mounting device while avoiding the screw hole on the upper surface of the surface mount nut, the suction position is the center of gravity position of the center portion of the surface mount nut. Therefore, when there is a sudden change in direction of movement during the transfer by the suction nozzle, a rotation moment centered on the suction point is generated due to the inertia of the surface mount nut, and a predetermined position on the surface mount wiring board This causes the problem of slipping off or rotating and mounting.

In a surface mount nut to be mounted on a printed wiring board, a screw of the surface mount nut in which an upper surface of the surface mount nut for transferring the surface mount nut to a predetermined position of the printed wiring board is adsorbed by a tip opening of an adsorption nozzle A film sheet is stuck on the lower surface including the holes.

In the surface mount nut to be mounted on the printed wiring board, the film sheet attached to the lower surface including the screw hole of the surface mount nut has a slightly smaller diameter than the diameter of the screw escape hole formed in the printed wiring board. A protrusion is formed, and the protrusion is inserted into a screw escape hole formed in the printed wiring board.

A “marking line” is formed on the film sheet at substantially the center of the screw hole of the surface mount nut that comes into contact with the lower surface including the screw hole of the surface mount nut attached to the printed wiring board.

In the surface mounting nut to be mounted on the printed wiring board, the film sheet is adhered to the lower surface including the screw hole of the surface mounting nut, and the position including the screw hole in the central portion of the nut is sucked and held by the suction nozzle. The surface mounting nut can be transferred by the suction nozzle, and the positional relationship between the suction nozzle and the held surface mounting nut does not shift even when the behavior of the suction nozzle is suddenly changed.

Even when the removal work of the film sheet adhered to the lower surface of the surface mounting nut is avoided after the surface mounting nut is mounted on the surface mounting wiring board, the upper surface of the surface mounting nut and the object to be fastened have good electrical contact surfaces. It becomes possible to form.

A protruding portion having a diameter slightly smaller than the diameter of the screw escape hole formed in the printed wiring board with which the film sheet sheet adhered to the lower surface including the screw hole of the surface mounting nut for the printed wiring board contacts. Even when the relationship between the center of the screw escape hole drilled in the printed wiring board and the center of the screw hole of the surface mount nut is offset by forming it so as to fit into the screw escape hole drilled in the board, the surface mount nut It is possible to automatically correct the position of the surface mounting nut along the protruding portion of the film sheet.

By forming a “marking line” in the approximate center of the film sheet attached to the lower surface including the screw hole of the surface mounting nut for the printed wiring board, the film sheet is fastened by the screw tip when the object to be fastened is fastened by the screw. As a result, the opening of a specific form such as a petal shape is formed with high reproducibility, and it is possible to eliminate inconveniences such as a broken piece of the film sheet falling into the electronic device.

Hereinafter, an embodiment of a surface mounting nut to be mounted on a printed wiring board according to the present invention will be described with reference to the drawings. FIG. 1 shows a case where a shield case 2 for electromagnetic shielding is fixed to a printed wiring board 1. An attachment tab 2a is formed integrally with the main body of the shield case 2 in the shield case 2, and a screw insertion hole 2b is formed in the center of the attachment tab 2a. A screw hole 6 a having a screw groove formed on the inner wall is formed in the center of the surface mount nut 6, and a solder terminal 6 b is formed at each corner of the surface mount nut 6. A solder pad 1b is formed on the upper surface of the printed wiring board 1 corresponding to the soldering terminal 6b of the surface mounting nut 6, and the soldering terminal 6b is fixed onto the solder pad 1b via solder.

As the assembly procedure of each part, cream solder is applied in advance to the solder pads 1b formed on the surface of the printed wiring board 1 shown in FIG. At the same time, a screw escape hole 1a is formed. When the surface mounting nut 6 is transferred to a predetermined position of the printed wiring board 1 by the component suction nozzle of the surface mounting component automatic mounting apparatus, the lower surface of the surface mounting nut 6 contacts the printed wiring board 1 via the cream solder. The component suction nozzle of the surface mount component automatic mounting apparatus is lowered until it comes into contact, whereby the soldering terminal 6b of the surface mount nut 6 is temporarily locked to the solder pad 1b of the printed wiring board 1.

When the printed wiring board 1 is exposed to a high temperature in the reflow furnace in this state, the cream solder is melted, and the lower surface of the soldering terminal 6b of the surface mounting nut 6 and the solder pad 1b of the printed wiring board 1 are soldered. . The printed wiring board 1 is taken out from the reflow furnace, the screw 3 is inserted into the screw insertion hole 2b formed in the center of the mounting tab 2a of the shield case 2, and is screwed into the screw hole 6a in the center of the surface mounting nut 6 to thereby print the wiring. The attachment of the shield case 2 to the substrate 1 is completed.

FIG. 2 is an orthographic view showing the first embodiment according to the present invention. As shown in FIG. 2C, a planar film sheet 7 is adhered to the lower surface of the surface mounting nut 6. When the component suction nozzle of the surface mount component automatic mounting apparatus abuts on the center of the upper surface of the surface mount nut 6 shown in FIG. 2C, the air in the screw hole 6a formed in the center of the surface mount nut 6 is absorbed. The planar film sheet 7 sucked out by the negative pressure in the nozzle and attached to the lower surface of the surface mounting nut 6 is attracted to the screw hole 6a side. The planar film sheet 7 is made of a member that can withstand the attraction strength. Since it is configured, the surface mounting nut 6 is sucked and held by a suction nozzle and transferred to a predetermined position on the surface of the printed wiring board 1.

  A plane which is left on the lower surface of the surface mounting nut 6 when the surface mounting nut 6 is soldered to a predetermined position of the printed wiring board 1 and a fastened object such as the shield case 2 is fastened to the screw hole 6a of the surface mounting nut 6 by the screw 3. Since the planar film sheet 7 can be pierced by the tip of the screw 3, it is possible to leave the planar film sheet 7 without the need for complicated removal work. Further, the upper surface of the surface mounting nut 6 is in contact with the lower surface of the object to be fastened, and a good conductive path can be formed by surface contact.

FIG. 3 is an orthographic view showing a second embodiment of the present invention. A hemispherical film sheet 17 is attached to the lower surface of the surface mounting nut 16. The hemispherical film sheet 17 is formed with a hemispherical projection 17a at the center, and the center point of the hemispherical projection 17a is highly accurate with the center of the screw hole 16a formed in the surface mounting nut 16. Is aligned. For this reason, even when the surface mounting nut 16 is transferred to a predetermined position on the printed wiring board 1, a slight positional deviation caused by vibration of the surface mounting component automatic mounting device or the like is also generated on the lower surface of the surface mounting nut 16. The position is automatically corrected so that the provided hemispherical protrusion 17a is fitted into the screw escape hole 1a of the printed wiring board 1.

FIG. 4 is an orthographic view showing the third embodiment of the present invention, and a hemisphere is formed at the center of the hemispherical film sheet 27 adhered to the lower surface of the surface mounting nut 26 as in the second embodiment. A planar protrusion 27a is formed. A cross-shaped marking line 27b shown in FIG. 4A is engraved in a part of the center of the protruding portion 27a of the hemispherical film sheet 27. When the screw 3 is screwed onto the surface mounting nut 26, the protruding portion 27a of the hemispherical film sheet 27 is easily pushed along the cross-shaped scribing line 27b by the tip of the screw 3, and the wrinkles are petals. Such an opening is formed with high reproducibility, and the inconvenience that the broken piece of the spherical film sheet 27 falls into the electronic device can be avoided.

Note that the shape of the marking line is not limited to “cross-characters”, but functions similarly in the case of “single-character” or a radial pattern disposed on the center axis object. It is also possible to apply the marking line to the planar film sheet described in the first embodiment, and the opening as in the petal is formed with high reproducibility, and the fragment of the planar film sheet is an electron. The inconvenience of falling into the equipment can be avoided.

In addition, as the second and third embodiments, a hemispherical film sheet has been described, but a conical shape, a pyramid shape, a deformed cone shape in which the angle of the tip portion of each cone shape is changed, and the like, It is obvious that the same effect can be obtained by aligning the center of the projecting portion of the cone-shaped or deformed-conical shape with the center of the screw hole formed in the surface mounting nut with high accuracy. .

The present invention describes a surface mount nut to be mounted on a surface mount printed board. However, the present invention is not limited to the surface mount nut, and can be suitably applied to other surface mount components having through holes in the vertical direction.

It is a disassembled perspective view which shows the mounting state of the surface mounting nut to the printed wiring board concerning this invention. It is an orthographic view of the surface mount nut showing the first embodiment of the present invention. It is an orthographic projection figure of the surface mount nut which shows the 2nd Embodiment of this invention. It is an orthographic projection figure of the surface mount nut which shows the 3rd Embodiment of this invention. It is a perspective view which shows the 1st prior art example of the suction holding method of the surface mounting nut by a suction nozzle. It is an orthographic projection figure which shows the conventional example of a surface mounting nut. It is a perspective view which shows the 2nd prior art example of the adsorption mounting method of the surface mounting nut of the prior art example shown in FIG.

Explanation of symbols

1: Printed wiring board 1a: Screw escape hole 1b: Solder pad 1c: Circuit copper foil 2: Shield case 2a: Mounting tab 2b: Screw insertion hole 3: Screw 5: Component adsorption nozzle 6: Surface mounting nut 6a: Screw hole 6b : Soldering terminal 7: Planar film sheet 16: Surface mounting nut 16a: Screw hole 16b: Soldering terminal 17: Hemispherical film sheet 17a: Projection part 26: Surface mounting nut 16a: Screw hole 16b: Soldering terminal 27 : Hemispherical film sheet 27a: Protruding part 27b: Cross mark mark 36: Surface mount nut 36a: Screw hole 36b: Solder terminal 46: Surface mount nut 46a: Screw hole 46b: Solder terminal 47: Planar film Sheet

Claims (3)

A surface-mounting nut for a printed wiring board, wherein a film sheet is attached to a lower surface including a screw hole of the surface-mounting nut in a surface-mounting nut to be mounted on a printed wiring board of an electronic device. In the surface mount nut for a printed wiring board according to claim 1, a film sheet in which a protrusion having a diameter slightly smaller than the diameter of the screw escape hole is attached to the lower surface including the screw hole of the surface mount nut, A surface mounting nut for a printed wiring board, wherein the protruding portion of the film sheet adhered to the surface mounting nut is fitted into a screw escape hole formed in the printed wiring board and attached to the printed wiring board. The film sheet surface pasted on the lower surface of the surface mount nut according to claim 1 and the film sheet surface at the intersection of the central axis of the screw hole drilled in the surface mount nut A surface mount nut for a printed wiring board characterized by forming a "line".

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