JPH06268367A - Device for processing electronic parts with light beams - Google Patents

Abstract

PURPOSE:To perform the energy saving of the electric power of a light source and also to reduce the influence of heat upon the periphery at the time of processing with a light beam by forming a plurality of light conducting paths for a light beam toward a lead line from a linear light source with light conducting reflector plates arranged in parallel to each other. CONSTITUTION:A number of oval light conducting reflector plates 15 which have substantially same cross-sectional shape as the longitudinal section of an optical path are provided at a predetermined interval along the direction of the major axis of a linear halogen lamp 3 within the space of an optical path which is defined by the curved surfaces 2A, 2B of a concave elliptic reflecting mirror 2 and are extendingly provided from the place directly under the halogen lamp 3 to the place directly above the opening of a shutter 4, and a number of light conducting paths 16 are formed therebetween. Thereby, a light beam in an outgoing light beams, for instance, which has a specific angular component is reflected by a reflecting plate 15 once or plural times to be incident upon a lead line. Therefore, such a light beam can be efficiently utilized for light beam work as well to be able to increase energy efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light beam processing apparatus, and more particularly to a method for soldering a plurality of lead rows drawn to the outer peripheral side of a flat package to a circuit board pattern by irradiating a light beam. The present invention relates to a light beam processing device for electronic components used.

[0002]

2. Description of the Related Art Among such IC flat packages, in recent years, IC flat packages with two-way leads and four-way leads (SOP, QFP) have gradually become the mainstream, and accordingly, the above-mentioned optical beam processing is performed. In addition, there is a demand for a technique for rapidly soldering a plurality of lead rows that are drawn out to each side of the outer periphery of the package.

On the other hand, each lead row is linear (rectangular) via a plurality of optical systems which correspond to the number of side surfaces of the package, that is, the number of lead rows, which is composed of a combination of a light source and a concave elliptical reflecting mirror or the like. Various methods have been proposed in which the above-mentioned light beams are simultaneously irradiated to perform soldering. In this case, as shown in FIGS. 1 to 3, in order to uniformly irradiate the light beam from each light source with the most efficient rectangular pattern A to each lead row as a processed portion on the side of the package QFP. A concave elliptical reflecting mirror R and a linear light source P located at the focal point thereof are used, and the optical path shutter C focuses the light beam L of the pattern A corresponding to the lead row in a predetermined region (x, y).

However, as shown in FIG. 2, for example, regarding the distribution of the light beam in the x direction (longitudinal direction of the linear light source P), effective light emitted from the linear light source P to a predetermined processing area A is used. In addition to the beam L, there is a light beam LA that deviates from the processing area at both ends in the x direction, which causes a loss and significantly reduces the utilization efficiency of the entire light energy, and the light beam irradiated to the peripheral portion causes a circuit board or the like. There is a risk of causing adverse effects such as thermal deformation and thermal alteration.

Regarding the distribution of the light beam in the y-direction, a nearly intended distribution can be obtained by condensing from the concave elliptical reflecting mirror R, but in this case as well, there is a light beam diffusing in other than the condensing portion, This may cause a thermal effect on the peripheral circuit board or other package.

In order to avoid the influence of the ambient light, it has been proposed to provide a light shielding member S in the vicinity of the light source P as shown in FIG. 3 and utilize only the focused light by reflection. However, in this method, the direct light LC having the highest thermal efficiency from the light source P is blocked or reflected by the light blocking member and cannot be directly used, so that the utilization efficiency of light energy is reduced.

In order to solve the above-mentioned problems of the prior art, an object of the present invention is to provide an optical energy when a lead on each side is evenly soldered by a light beam from a linear light source in an IC flat package. It is an object of the present invention to provide a light beam processing apparatus capable of increasing the efficiency of the above method as much as possible to save energy of light source power, and at the same time, reducing the influence of heat exerted on the periphery during optical processing.

[0008]

The object of the present invention is to solder each lead row drawn out from each side of the outer circumference of a flat package with leads to a circuit pattern of a printed circuit board by irradiating a light beam. In a light beam processing apparatus for electronic parts, the apparatus has an elliptical cross section of a shape for focusing a light beam from a focus in one direction of the lead row, and aligns the cylinder axis direction with the other direction of the lead row. A cylindrical concave elliptical reflecting mirror provided as an optical system, and an optical system having a linear light source whose long axis direction is aligned with the cylindrical axial direction of the concave elliptical reflecting mirror and which is arranged along the focal point of the concave elliptical reflecting mirror. The optical system is provided so as to correspond to the lead rows, and the optical system extends from the linear light source in the direction toward the lead row and is provided at predetermined intervals along the long axis direction of the linear light source. Has a light guide reflection plate, thereby is achieved by an optical beam processing apparatus of electronic components, characterized in that the formation of the plurality of light guide for light beams towards the lead string from the linear light source.

In the optical system of the light beam processing apparatus of the above type, the shape of the projected cross section of the light beam with respect to the lead row is generally described in the optical path of the light beam emitted from the linear light source and reflected and focused by the concave elliptical reflecting mirror. Although an optical path shutter that shapes according to the shape of the lead row is provided, in a preferred specific example of the present invention, a reflection plate that forms the light guide path is provided below the linear light source and between the optical path shutter. Has been done.

In another preferable specific aspect of the present invention, irradiation of the lead row in the one direction is performed on the linear light source side of the light guide path formed from the linear light source toward the optical path shutter. A light shielding member for controlling is provided, and a light transmitting portion for direct light is formed in a region corresponding to the central portion of the light shielding member in the one direction.

[0011]

According to the present invention, the light beam reflecting mirror from the linear light source arranged at the focal point of the concave elliptical reflecting mirror is reflected by the reflecting curved surface portion and is focused in the direction toward the intended irradiation position. Through the opening of the optical path shutter provided in the optical path of the above-mentioned optical path.

In the present invention, as shown in FIG. 4, among the light beams emitted from the respective positions of the linear light source P in the longitudinal direction, the light beam L which goes straight to the opening of the lower shutter C is directly read. The corresponding positions in the longitudinal direction x of the row are irradiated.

On the other hand, of the emitted light beams, when the light beam LB having a specific angle component from a specific position passes through the light guide path H from the light source P toward the opening of the shutter C,
The light reaches the lower end of the light guide path H while being reflected by the reflection plates K on both sides thereof, and most of the light is condensed in a region regulated between the reflection plates K at both ends located corresponding to both ends in the longitudinal direction of the light source P. Then, the shutter C enters the opening of the shutter C.

If there is no light guide path H, these light beams LB are the light beams LB shown by dotted lines as shown in FIG.
In the present invention, it is possible to use a portion of the light beam that completely loses due to diffusion to a portion other than the intended welded portion. The energy efficiency is significantly increased.

Further, in the present invention, a light-shielding member having a light-transmitting portion is provided immediately below the light source to regulate the light beam distribution in the width direction y of the lead row in FIG. 3 to avoid the influence of heat on the periphery. At the same time, the straight light beam LC which is normally blocked by the light blocking member can be used as it is.

[0016]

EXAMPLE An example in which the present invention is applied to the light beam processing of a flat package with four-way leads will be specifically described below. 5 is a schematic view showing the whole of the device of the present invention, FIG. 6 is a front view of a light guide reflection plate and a light guide path portion thereof, and FIG. 7 is a side view of a reflection mirror including a light shielding member with a light transmitting portion.

As shown in FIG. 5, a pair of concave elliptical reflecting mirrors 2 and 2 composed of elliptical reflecting surfaces 2A and 2B facing each other are attached below a frame 1 of the light beam processing apparatus,
Each of the reflecting surfaces 2A and 2B has such a shape that the light beam is focused on a predetermined region in the row width direction of the leads (for example, the y direction in FIG. 1) on the pair of opposite sides of the package not shown. A linear halogen lamp 3 is provided along the focal point of the reflecting mirror 2 with its major axis aligned with the lead row direction (the y direction in FIG. 1).

The light beam from the halogen lamp 3 focused on the reflection curved surfaces 2A and 2B is applied to the package through the openings of the shutters 4 and 4 of a pair of optical paths provided at the bottom of the pedestal 1. In addition, a reflecting mirror 2 at the central portion in FIG. 5 and a pair of reflecting mirrors (not shown) facing the reflecting mirror 2 are similarly provided corresponding to the corresponding sides of the other pair of the packages.

A step motor 5 is placed above the pedestal 1, and the vertical driving force obtained by converting the rotational force of the step motor 5 is applied to a pair of left and right link mechanisms 7 and 7, respectively. It transmits to the pair of left and right concave elliptical reflecting mirrors 3 and 3 and moves them along the guide shafts 8 and 8 in the horizontal direction in the figure so that the irradiation areas of the respective concave elliptic reflecting mirrors 3 and 3 are changed by the package. For example, they are formed so as to correspond to different sizes in the width direction (intervals between the lead rows on both sides).

The light beam processing apparatus further comprises a package holding / moving mechanism 9, which is shown in FIG.
It has a holding / moving pipe 11 which is directly connected to an air cylinder 10 which operates vertically in the middle. The lower end of the pipe 11 can pass through a guide block 12 provided at the bottom of the pedestal 1 and descend to a position in close contact with the center of the upper surface of the package, and its upper end is connected to a vacuum source (not shown). There is.

On the other hand, a cooling air supply pipe 13 is fixedly provided to the gantry 1 in parallel with the holding / moving pipe 11, and the lower end portion of the cooling air supply pipe 13 is blown with a plurality of downwardly opening cooling air in the guide block 12. The outlet 14 is communicated with, and its upper end portion is connected to a cooling air source (not shown).

As shown in FIG. 6, the concave elliptical reflecting mirror 2 is used.
In the optical path space defined by the reflective curved surfaces 2A, 2B, a large number of light guide reflectors 15 having an elliptical cross section whose shape is almost the same as the longitudinal section of the optical path are arranged along the long axis direction of the linear halogen lamp 3. Are provided at predetermined intervals and extend from just below the halogen lamp 3 to just above the opening of the shutter 4 to form a large number of light guide paths 16 therebetween.

The number of the reflection plates 15 is experimentally determined by the effective length of the linear light source 3 in the lengthwise direction, the distance between the light source and the package, and the thickness of the reflection plate 15 is within a range in which thermal strain or the like can be tolerated. It is preferable to make it as thin as possible. In the figure, 17 is a lamp socket, and 18 is a reflector mounting member.

On the other hand, as shown in FIG. 7, in the position directly below the halogen lamp 3 in the optical path of the reflecting mirror 2 (see FIG. 3), the light beam in the y direction of the package lead row is in the target irradiation area. A light blocking member is provided for limiting only.

In the present embodiment, the large number of reflectors 1
Retaining rods 19 extending therethrough for fixing 5
19 are provided with a space 20 formed between them, and these holding rods 19, 19 are installed at positions corresponding to the light-shielding plate of FIG. 3, and a reflective coating is applied to the surface thereof to form a light-shielding member. It is designed to work.

In this embodiment, the holding rod 1
A space 20 between the nine and nineteen is located immediately below the halogen lamp 3 and functions as a light transmitting portion for directing a light beam from the halogen lamp 3 directly to the package side.

With the light beam processing apparatus of the present embodiment, when soldering each lead row of the QFP as shown in FIG. 1, for example, the package to be processed is first moved by a vacuum suction moving mechanism (not shown). It is positioned at a predetermined position on the circuit board installed below the gantry 1.

After confirming the positioning of the package, the air cylinder 10 shown in FIG. 5 is operated to lower the holding / moving pipe 11 of the package holding / moving mechanism 9 from the position shown in FIG. Each lead row of is evenly adhered to the circuit board.

Next, the step motor 5 is actuated to move the pair of concave elliptical reflecting mirrors 2 and 2 horizontally along the guide shafts 8 and 8 via the left and right link mechanisms 7 and 7 by the vertically moving block 6 in the figure. It is moved and adjusted so that the light beams from the pair of reflecting mirrors 2 and 2 are irradiated corresponding to the lead rows on both sides having different intervals depending on the package (along with this, the concave surface reflection located in the central portion in FIG. 5). The positions of the mirror 2 and the concave elliptical reflecting mirror (not shown) which composes the mirror 2 are also adjusted similarly.

Further, a pair of optical path shutters 4 and 4 (and another pair of optical path shutters not shown in the direction perpendicular thereto) provided on the bottom of the gantry 1 are simultaneously adjusted via a step motor and an interlocking mechanism which are also not shown. Then, the projected cross section of the light beam from each concave elliptical reflecting mirror 3 to each lead row is adjusted according to the shape of the lead row.

After the above setting work, each halogen lamp 3 is lit and emitted at a predetermined rating so that its light beam is incident on the reflection area of the lead row from each concave reflecting mirror 2 through the shutter 4 and a predetermined amount. Due to the beam shape, the lead rows on each side are soldered simultaneously.

Here, the light beam from the halogen lamp (linear light source) 3 is simultaneously irradiated to the lead rows on the four sides of the package as shown in FIG. 1, but in this case, regarding the x-direction region of the package, As shown in FIG. 4, among the light beams emitted from the respective positions on the long axis of the linear light source P (halogen lamp 3 in FIG. 6), the straight light beam L that is directed toward the opening of the shutter C immediately below is as it is. The light is guided straight through the light guide path H (light guide path 16 in FIG. 6) of FIG. 4 and is irradiated through the shutter along the longitudinal region of the lead row shown in FIG.

On the other hand, of the emitted light beams, for example, the light beam LB in FIG. 4 having a specific angle component is reflected once or a plurality of times by the reflector K (reflector 15 in FIG. 6). It is incident on the lead row in the direction area. These light beams LB are light beams that cause a loss of light energy by diffusing to a region other than the intended region if they go straight as shown by the dotted line in FIG. 4, and such light beams are used in this embodiment. The part of the beam LB can also be effectively used for the light beam processing, the energy efficiency thereof is significantly improved, and the power consumption is significantly reduced.

On the other hand, as shown in FIG. 7, the halogen lamp 3
Most of the light beam from is blocked by the light-shielding members 19 and 19 directly below, and is focused in the y-direction region of the lead row shown in FIG. 3 and does not diffuse to the periphery, so that the light distribution in the y-direction is sharp. In addition, unnecessary thermal strain does not occur on the peripheral substrate and the like. In this case, in this embodiment, the light beam (beam LC in FIG. 3) traveling straight from the halogen lamp 3 is shielded by the light shielding member 1.
Since the light is radiated to the central portion of the y-direction region of the lead row in FIG. 3 through the light transmitting portion 20 as a gap between 9 and 19, the loss due to reflection is reduced and the utilization efficiency of light energy is improved.

Further, in the present embodiment, the lead row on each side of the package is brought into close contact with the circuit board by pressing by the holding / moving pipe 11 of the package moving mechanism 9,
For example, even if the circuit board is warped due to thermal strain, the light beam processing is performed on the package in a state where the lead rows on each side are evenly pressed against the board.

During thermal processing with a light beam, unevenness in surface tension may occur during melting of the solder cream, which may cause local inclination or displacement between the package and the substrate. In this embodiment, the package is held / moved. Since the pipe 11 is uniformly pressed against the substrate as a whole, such inclination or deviation, or soldering failure due to it, does not occur at all.

Next, when the light beam processing is completed, a cooling air supply device (not shown) is operated to operate the cooling air supply pipe 1.
Cooling air is supplied to 3 and the cooling air is blown downward from the cooling air outlet 14 of the guide block 12 provided at the bottom of the gantry 1 onto the upper surface of the package. As a result, the molten soldered portion of the lead row is rapidly cooled and becomes ready to be moved.

A vacuum suction device (not shown) is operated to vacuum-suck the processed package on the lower end of the holding / moving pipe 11 and transfer the package to a predetermined place by the package holding / moving moving mechanism 9.

In the present invention, gold or gold alloy coating is applied to all the reflection surfaces of the light beams such as the reflection curved surfaces 2A and 2B, the light guide reflection plate 15 and the light shielding member 19 plate in each part of the device. As a result, most of the light in the near infrared or infrared region of the halogen lamp is reflected, so that the thermal efficiency is improved and the influence of heat on each member of the optical system can be reduced.

Further, in the apparatus of the present invention, the package holding / moving mechanism 9 for adsorbing the central portion of the package to be processed and carrying it out from the processing area is provided, and the package is held at the lower end of the holding / moving pipe 11. Since the circuit board is pressed against the circuit board, the beam rows on the respective sides of the package can be brought into close contact with predetermined positions of the circuit board evenly during the beam processing for effective soldering.

Further, in combination with the holding / moving pipe 11, a cooling air supply pipe 1 for cooling the package during processing is provided.
Since No. 3 is provided, the processing is speeded up by cooling after the light beam processing, and the effect of shortening the working time is further improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a light beam irradiation area of an IC flat package to which the present invention is applied.

FIG. 2 is an explanatory diagram showing an optical path of a light beam in a lamp axis direction of an irradiation area in a conventional light beam processing apparatus using a linear light source.

FIG. 3 is an explanatory diagram showing an optical path of a light beam in the other direction of an irradiation area in a conventional light beam processing apparatus using a linear light source.

FIG. 4 is an explanatory diagram showing an operation of a light guide path in the light beam processing apparatus of the present invention using a linear light source.

FIG. 5 is a sectional view showing an outline of an embodiment of the present invention.

FIG. 6 is a front view showing a part of a light guide reflection plate and a light guide path in a main part of the embodiment of the present invention.

FIG. 7 is a side view showing a concave elliptical reflecting mirror as an essential part of the embodiment of the present invention.

[Explanation of symbols]

 1 ... Frame, 2 ... Concave elliptical reflecting mirror 2A, 2B ... Reflective curved surface 3 ... Linear light source (halogen lamp) 4 ... Shutter 5 ... Step motor 6 ... Vertical movement block 7 ... Link mechanism 8 …… Guide shaft 9 …… Package holding / moving mechanism 10 …… Air cylinder 11 …… Holding / moving pipe 12 …… Guide block 13 …… Cooling air supply pipe 14 …… Cooling air outlet 15 …… Light guide reflector 16 ...... Light guide 17 ...... Lamp socket 18 ...... Mounting member 19 ...... Shading member 20 ...... Shading part QFP ...... 4 direction package A ...... Irradiation area of lead row R ...... Concave elliptical reflecting mirror P ...... Linear Light source H: Light guide path K: Light guide reflection plate L: Light beam (irradiation area) LA, LB ... Light beam (outside irradiation area) LC: Straight light

Claims (3)

[Claims] 1. A light beam processing apparatus for an electronic component for soldering each lead row drawn out from each side of the outer periphery of a flat package with leads to a circuit pattern of a printed circuit board by irradiating a light beam with the light beam. A cylindrical concave elliptical reflecting mirror in which the device has an elliptical cross section of a shape that focuses a light beam from a focus in one direction of the lead row and the cylinder axis direction is aligned with the other direction of the lead row. And an optical system having a linear light source whose long axis direction is aligned with the cylindrical axis direction of the concave elliptical reflecting mirror and arranged along the focal point of the concave elliptical reflecting mirror, corresponding to each of the lead rows. Wherein the optical system includes parallel light guide reflectors extending from the linear light source in a direction toward the lead row and provided at predetermined intervals along a long axis direction of the linear light source. And Thereby, a plurality of light guide paths for a light beam directed from the linear light source to the lead row are formed, and a light beam processing device for electronic parts. 2. The shape of the projected cross section of the light beam onto the lead row is defined in the optical path of the light beam emitted from the linear light source and reflected and focused by the concave elliptical reflecting mirror. 2. An optical path shutter that is shaped according to the above, wherein a reflection plate that forms the light guide path is provided so as to extend below the linear light source and between the optical path shutters.
The described light beam processing apparatus. 3. A light shielding member for controlling irradiation of the lead row in the one direction is provided below the linear light source of a light guide path formed from the linear light source toward the optical path shutter, and The light beam processing apparatus according to claim 1, wherein a light transmitting portion for direct light from the light source is formed in a region corresponding to a central portion of the light shielding plate in the one direction.