Reflow apparatus comprising LED or LD, and reflow method using same

Abstract

The present invention relates to a reflow apparatus comprising a light emitting diode (LED) or a laser diode (LD), and a reflow method using same. The reflow apparatus comprises: a light source head module (10) in which a plurality of LED light sources or a plurality of LD light sources are arranged; and a carrier (30) for transferring, under the light source head module (10), a substrate on which a plurality of electronic components and solder for bonding each electronic component are disposed, wherein each of the plurality of LED light sources or the plurality of LD light sources is independently output-controlled.

Description

Reflow apparatus including LED or LD and reflow method using the same

[0001] The present invention relates to a reflow device including an LED (Light Emitting Diode) or an LD (Laser Diode) and a reflow method using the same, and more particularly, to a reflow device including an LED or LD capable of individually controlling a plurality of LED elements or LD elements arranged based on a relative positional relationship with respect to an electronic component, and a reflow method using the same.

[0002] In surface mount technology, which mounts surface mount components (SMDs) on the surface of a substrate, soldering is divided into flow / dip soldering and reflow soldering. Reflow soldering refers to a method of pre-supplying solder to the substrate's render and remelting the solder with an external heat source to bond the components. Reflow can be divided into IR reflow, a soldering method using an infrared heater, hot air reflow, which utilizes the conduction of hot gas, and vacuum reflow, which is performed in a vacuum. Laser reflow methods using a laser as a heat source are known in the field. Patent Publication No. 10-2021-0144282 discloses a linear transfer laser reflow method. Patent Publication No. 10-2020-0119047 also discloses a laser reflow device. The reflow method disclosed in the prior art utilizes a laser beam to irradiate electronic components to be bonded, thereby simultaneously bonding multiple electronic components and solder. Therefore, if the laser beam output is high, the substrate area may be damaged. Conversely, if the laser beam output is low, the solder may not be sufficiently heated, preventing the electronic components from bonding to the required level. Therefore, the laser beam output needs to be appropriately adjusted depending on the location of the electronic components, but the prior art does not disclose such a method.

[0003] The present invention is intended to solve the problems of prior art and has the following objectives.

[0004] An object of the present invention is to provide a reflow device including an LED or LD, in which the output of each of a plurality of light source elements arranged in a light source head module can be independently controlled according to the relative positions of electronic components, and a reflow method using the same.

[0005] According to a preferred embodiment of the present invention, a reflow apparatus including an LED or LD includes a light source head module in which a plurality of LED (light emitting diode) light sources or a plurality of LD (laser diode) light sources are arranged; and a carrier that transports a substrate on which a plurality of electronic components and solder for bonding each of the electronic components are arranged to the bottom of the light source head module, wherein each of the plurality of LED light sources or the plurality of LD light sources is independently output-controlled.

[0006] According to another suitable embodiment of the present invention, the present invention further comprises a vision unit for detecting and aligning the substrate.

[0007] According to another suitable embodiment of the present invention, a plurality of LED light sources or a plurality of LD light sources are arranged in an M*N (M, N are natural numbers) array structure.

[0008] According to another suitable embodiment of the present invention, the output of each LED light source or LD light source is determined by the relative positions of the component or solder and the irradiation surface of the light source and the component or solder.

[0009] According to another suitable embodiment of the present invention, the output of each LED light source or LD light source is adjusted according to the exposure level of the component or solder to the irradiated surface of the light source.

[0010] According to another suitable embodiment of the present invention, a reflow method including an LED or LD includes a step of arranging a plurality of light sources on a head to form a light source array; a step of moving and positioning a substrate on which components and solder are arranged below the head; a step of aligning the light sources based on positions of the components; and a step of individually controlling the light sources based on positions of the light sources relative to the components or solder.

[0011] According to another suitable embodiment of the present invention, the light source is a light emitting diode (LED) or a laser diode (LD).

[0012] According to another preferred embodiment of the present invention, the method comprises the step of generating component and solder position profiles in advance before alignment.

[0013] A reflow device including an LED or LD according to the present invention is configured such that a plurality of light sources are arranged in a predetermined shape on a plane in a light source head module, and the output of each light source is independently controlled based on the relative positions of the electronic components and solder to be bonded. This prevents the occurrence of poor contact or overflow of some solder that may occur when reflowing a plurality of electronic components placed on a board simultaneously, and also prevents process defects that may occur due to excessive light being applied to the board, such as yellowing. Accordingly, the work efficiency of the reflow process and the quality of the reflow-treated electronic components are improved, and the same or better quality is secured without applying an expensive laser optical system, thereby reducing the production cost required for the reflow process. The reflow device and method according to the present invention can be applied to various electronic component mounting processes, and the present invention is not limited thereby.

[0014] Figures 1 and 2 illustrate embodiments of a reflow device according to the present invention.

[0015] Figures 3 and 4 illustrate the relative positional relationship between a light source and an electronic component to be bonded in a reflow device according to the present invention.

[0016] Figure 5 illustrates another embodiment of a reflow device according to the present invention.

[0017] Fig. 6 illustrates an embodiment of a reflow method for an electronic component using an LED or LD according to the present invention.

[0018] Below, the present invention is described in detail with reference to embodiments shown in the attached drawings. However, the embodiments are for a clear understanding of the present invention and the present invention is not limited thereto. In the description below, components having the same drawing reference numerals in different drawings have similar functions and therefore will not be described repeatedly unless necessary for the understanding of the invention. Known components are briefly described or omitted, but they should not be understood as being excluded from the embodiments of the present invention.

[0019] Figures 1 and 2 illustrate embodiments of a reflow device according to the present invention.

[0020] Referring to FIGS. 1 and 2, a reflow apparatus including an LED (light emitting diode) or an LD (laser diode) includes a light source head module (10) in which a plurality of LED (light emitting diode) light sources or a plurality of LD (laser diode) light sources are arranged; and a carrier (20) that transports a substrate on which a plurality of electronic components and solder for bonding each of the electronic components are arranged to the bottom of the light source head module (10), and each of the plurality of LED light sources or the plurality of LD light sources is independently output controlled.

[0021] The head module (10) may have an overall rectangular plate shape, but is not limited thereto, and may have a shape corresponding to the shape of the substrate (30). The substrate (30) may be, for example, various types of substrates on which SMDs (surface mount components) are mounted, such as a printed circuit board (PCB) or a flexible circuit board. The substrate (30) may be received and transported in a carrier (20), and the carrier (20) may be moved along a conveyor (C) and positioned below the head module (10). The head module (10) may have an overall rectangular plate shape and includes a plurality of light sources (12_11 to 12_nm). Referring to FIG. 2, the head module (10) includes a base (11) having a structure similar to an electronic substrate and having an overall rectangular plate shape; and light sources (12_11 to 12_nm), such as a plurality of LED elements or a plurality of LD elements, arranged on the base (11). A plurality of light sources (12_11 to 12_nm) can be arranged in a matrix structure of, for example, M*N (M, N are natural numbers) dimensions, and solder can be melted by each light source (12_11 to 12_nm) to bond components. The light sources (12_11 to 12_nm) can be LED elements or LD elements, and the output of each light source (12_11 to 12_nm) can be independently controlled. The base (11) can have a shape corresponding to the substrate (30), and solder for bonding a plurality of components arranged on the substrate (30) can be heated by the plurality of light sources (12_11 to 12_nm). When the substrate accommodated in the carrier (20) is located below the head module (10), the substrate can be detected by a vision unit (40) such as a camera. Alignment marks may be displayed on the substrate or carrier (30), and the alignment marks may be detected by the vision unit (40). For example, the alignment marks may be displayed on four corners of the substrate or carrier (30), or the four corners may be alignment marks.The position of the reference surface of the substrate or carrier (30) can be confirmed by the alignment mark, and the confirmed position status can be transmitted to the control module. The control module can align the light source head module (10) with respect to the substrate or carrier (30), and for this purpose, the head module (10) can be moved up and down or left and right. In addition, the head module (10) can be rotated or tilted in one direction, and through the alignment process of the head module (10), the head module (10) and the substrate can become parallel to each other and the four corners can match. In this aligned state, a reflow process can be performed by the light source (12_11 to 12_nm) arranged in the head module (10).

[0022] According to one embodiment of the present invention, each of a plurality of LED light sources or a plurality of LD light sources has its output controlled independently. Light or laser may be emitted from the plurality of LED light sources or a plurality of LD light sources and irradiated onto a substrate. A plurality of components and solders may be arranged on the substrate, and the light or laser may need to be irradiated based on the components or solders. Specifically, the output of the light source that irradiates light or laser to a portion where the components or solders are located and the output of the light source that irradiates light or laser to a portion where the components and solders are not located need to be controlled. To this end, the output of the light sources (12_11 to 12_nm) arranged in the head module (10) needs to be controlled according to the arrangement positions of the components or solders. Below, a process of individually controlling the output of each light source (12_11 to 12_nm) in this way will be described.

[0023] Figures 3 and 4 illustrate the relative positional relationship between a light source and an electronic component to be bonded in a reflow device according to the present invention.

[0024] Referring to FIG. 3, the substrate (30) may include a substrate body (31) having a square plate shape; a plurality of components (32) arranged on the substrate body (31); and solder (33) for bonding each component (32) to the substrate body (31). A portion irradiated with light or laser by a light source (12_11 to 12_mn) arranged on the head module may be uniformly formed over the entire substrate body (31). In FIGS. 3 and 4, light source irradiation areas (12_11 to 12_MN) irradiated by the light source are indicated by dotted lines, and the light sources (12_11 to 12_mn) are positioned vertically above the light source irradiation areas (12_M1 to 12_MN) with respect to the substrate body (31). The light source irradiation area (12_M1 to 12_MN) can be adjusted in size or shape by a lens or similar adjusting means, and in this specification, the light source (12_11 to 12_mm) and the light source irradiation area (12_11 to 12_MN) are described assuming that they are positioned vertically separated from each other and are not distinguished in the XY-plane.

[0025] The component (32) may have a rectangular planar shape, and solder (33) may be provided in advance based on the four corners of the component (32). When the light source is arranged in an M*N matrix form, the light source irradiation areas (12_11 to 12_MN) may also have an M*N matrix form accordingly. The positions of the light source irradiation areas (12_11 to 12_MN) irradiated on the solder (33) provided at the four corners of the component (32) may be expressed as coordinates, and for example, four light source irradiation areas (12_11 to 12_MN) may be formed for one solder (33). Such light source irradiation areas (12_11 to 12_MN) may be expressed as coordinates, and for example, may be expressed as coordinates such as (x, y), (x, y+1), (x+1, y), and x+1, y+1) for one solder (33). In addition, other solders (33) can be indicated by x-coordinates such as x, x+1, x+2, and x+3, and y-coordinates such as y, y+1, y+2, and y+3. In this way, light sources (12_11 to 12_mn) or light source irradiation areas (12_11 to 12_MN) can be indicated by XY coordinates on the substrate (30). In addition, each component (32) or solder (33) can be indicated by XY coordinates. Specifically, a position profile of the component (32) or solder (33) can be generated in advance, and the pre-generated position profile can be stored. And the output of each light source (12_11 to 12_mn) can be adjusted based on the position profile of the component (32) or solder (33).

[0026] Referring to FIG. 4, which corresponds to an enlarged view of FIG. 3, the light source irradiation area can be divided into three different areas, and specifically, can be divided into a substrate irradiation area (12a) corresponding to an area where the component (32) and solder (33) are not placed; a melting irradiation area (12b) corresponding to the solder (33) or an area adjacent to the solder (33); and a component area (12c) corresponding to an area where the component (32) is located. In the presented embodiment, the irradiation areas indicated by (x, y), (x, y+1), (x, y+2), (x, y+3), (x+1, y), (x+1, y+3), (x+2, y), (x+2, y+3), (x+3, y), (x+3, y+1), (x+3, y+2), and (x+3, y+3) can correspond to the melting irradiation area (12b). And the areas indicated by (x+1, y+1), (x+2, y+2), (x+2, y+1) and (x+2, y+2) may correspond to the component irradiation area (12c). Information about the area map where the components (32) and solder (33) are placed in the substrate body (31) may be transmitted to the control module, and the control module may correspond the area map to the placement coordinates of the light sources (12_11 to 12_mn). And the area to which each light source (12_11 to 12_mn) belongs may be determined, and the output of the light source may be adjusted according to the determined area. For example, the light source irradiating the melting irradiation area (12b) may have a relatively high output. And the light source irradiating the substrate irradiation area (12a) may have a relatively low output. In comparison, the light source irradiating the component irradiation area (12c) may have a lower output than the light source of the melt irradiation area (12b) and a higher output than the light source of the substrate irradiation area (12a). In the presented embodiment, the light sources arranged in a matrix form may have an output distribution as illustrated on the right side of Fig. 4.In this way, the output of each light source is individually controlled based on the placement map of the component (32) or solder (33), thereby preventing deterioration of the substrate (30) or component (32) and improving the efficiency of the reflow process. Individual control of the light sources can be achieved in various ways and is not limited to the presented embodiments.

[0027] Figure 5 illustrates another embodiment of a reflow device according to the present invention.

[0028] Referring to FIG. 5, the substrate may be a flexible circuit board (53) and may be maintained in a wound state on a first reel (51). At least one component and solder may be placed on a flexible circuit board (53), and the flexible circuit board (53) wound on a first reel (51) may be unwound from the first reel (51) and wound on a second reel (52) for a reflow process. A light source head module (10) may be placed between the first reel (51) and the second reel (52), and a vision unit (40) may be placed. For the reflow process, the first and second reels (51, 52) may be rotated, and accordingly, the flexible circuit board (53) may be moved downwards of the light source head module (10) while being kept in a flat state. A predetermined alignment mark may be detected by the vision unit (40), and when the alignment mark is detected, the light source head module (10) may be aligned with respect to the flexible circuit board (53). And the distance between the flexible circuit board (53) and the light source may be measured, and the distance between the flexible circuit board (53) and the light source may be measured as described above. The reflow process can proceed while the light sources arranged in the light source head module (10) are individually controlled for output based on the placement map of components or solders. In this way, the reflow device according to the present invention can be applied to a reel-to-reel structure, but is not limited thereto.

[0029] Fig. 6 illustrates an embodiment of a reflow method for an electronic component using an LED or LD according to the present invention.

[0030] Referring to FIG. 6, a method for reflowing electronic components using an LED or LD includes a step (P61) in which a plurality of light sources are arranged on a head to form a light source array; a step (P62) in which a substrate on which components and solder are arranged is moved and positioned below the head; a step (P65) in which the light sources are aligned based on the positions of the components; and a step (P66) in which the light sources are individually controlled based on the relative positions of the light sources with respect to the components or solder. In addition, the light sources are light emitting diodes (LEDs) or laser diodes (LDs). In addition, a step (P64) in which a component and solder position profile is generated in advance before alignment is performed is included.

[0031] A reflow process may be performed to mount surface mount components on a substrate such as a printed circuit board, and solder may be heated and melted by a head to mount the components on the substrate. A light source such as an LED or LD may be placed on the head, and the light sources may be arranged in an M*N matrix (M and N are natural numbers) (P61). A substrate on which components and solder are placed may be moved and positioned below the head, and the lower surface of the head on which the light sources are placed and the substrate may have corresponding shapes (P62). A light source array profile may be generated (P63), and specifically, each light source may be identified by coordinates. When the coordinates for each light source placed on such a head are set, the same coordinate system may be applied to form a position profile or arrangement map of components and solder on the substrate (P64). The coordinates of each component and solder may be determined, and accordingly, a light source corresponding to each component and solder may be determined. The substrate and head can be aligned (P65), and in the aligned state, the light sources can be positioned to correspond to the component area, the solder area, and the substrate area. In this way, the output of each light source corresponding to different areas can be individually controlled according to the corresponding area (P66). This prevents damage to the substrate or components, while allowing the reflow process to proceed efficiently. The light sources corresponding to the components and solder can be classified in various ways and are not limited to the presented embodiments.

[0032] While the present invention has been described in detail above with reference to the presented embodiments, those skilled in the art will appreciate that various modifications and variations can be made without departing from the technical spirit of the present invention. The present invention is not limited by such modifications and variations, but is instead limited by the appended claims.

Claims

1. A light source head module (10) in which a plurality of LED (light emitting diode) light sources or a plurality of LD (laser diode) light sources are arranged; and It includes a carrier (20) that transports a substrate on which a plurality of electronic components and solder for bonding each electronic component are arranged to the bottom of the light source head module (10). A reflow device including an LED or LD, characterized in that each of a plurality of LED light sources or a plurality of LD light sources has an independently controlled output.

2. A reflow device including an LED or LD, further comprising a vision unit (40) for detecting and aligning the substrate according to claim 1.

3. A reflow device including an LED or LD, characterized in that, in claim 1, a plurality of LED light sources or a plurality of LD light sources are arranged in an M*N (M, N are natural numbers) array structure.

4. A reflow device including an LED or LD, characterized in that, in claim 1, the output of each LED light source or LD light source is determined by the relative positions of the component or solder and the irradiation surface of the light source and the component or solder.

5. A reflow device including an LED or LD, characterized in that the output of each LED light source or LD light source in claim 1 is controlled according to the exposure level of the component or solder to the irradiation surface of the light source.

6. A step in which multiple light sources are arranged on the head to form a light source array; A step in which a substrate with components and solder placed thereon is moved to the bottom of the head and positioned; A step in which the light source is aligned based on the position of the part; and A reflow method comprising an LED or LD, wherein the light sources are individually controlled based on the relative position of the light sources with respect to the component or solder.

7. A reflow method including an LED or LD, characterized in that the light source in claim 6 is an LED (light emitting diode) or an LD (laser diode).

8. A reflow method including an LED or LD, comprising a step of generating a component and solder position profile in advance before alignment, according to claim 6.

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