KR102228432B1 - Laser pressure head module of laser reflow equipment - Google Patents

Abstract

The laser pressurizing head module of the laser reflow apparatus of the present invention is a laser bonding electronic parts to a substrate by pressing a plurality of electronic parts arranged on a substrate with a translucent pressurizing member and irradiating a laser beam through the pressurizing member. A laser pressurizing head module of a reflow device, comprising: a holder unit for replaceably mounting the translucent pressurizing member; And a probe unit provided above the holder unit to inspect the flatness of the pressing member mounted on the holder unit.

Description

Laser pressure head module of laser reflow equipment

The present invention relates to a laser reflow apparatus, and more particularly, to a laser pressurizing head module of a laser reflow apparatus for bonding electronic parts by irradiating a laser in a state in which a plurality of electronic parts are pressed and pressed with a light-transmitting pressurizing member. .

Micro laser processing is an application field with micron (㎛) precision in industrial laser processing, and is widely used in the semiconductor industry, the display industry, the printed circuit board (PCB) industry, and the smartphone industry. Memory chips used in all electronic devices have developed a technology that minimizes the circuit spacing in order to realize the integration, performance and ultra-high communication speed, but now the required technology level is achieved simply by reducing the circuit line width and line width interval. It was difficult to do so, so it became the level of stacking memory chips in a vertical direction. The stacking technology up to 128 layers has already been developed by TSMC, and the technology of stacking up to 72 layers is being applied to mass production at Samsung Electronics and SK Hynix.

In addition, technology development to mount memory chips, microprocessor chips, graphic processor chips, wireless processor chips, and sensor processor chips in one package is being intensively researched and developed, and a considerable level of technologies are already being applied in practice.

However, in the process of development of the above-mentioned technology, since more and more electrons have to participate in the signal processing process inside the ultra-high speed/ultra-high capacity semiconductor chip, the power consumption increases, and the issue of cooling treatment for heat has been raised. In addition, a technical issue has been raised that a large amount of electrical signals must be transmitted at an ultra-high speed in order to achieve the requirements of ultra-high-speed signal processing and ultra-high-frequency signal processing for more signals. In addition, since the number of signal lines must be increased, the signal interface lines to the outside of the semiconductor chip can no longer be processed by the one-dimensional lead wire method, but the Fan-In BGA method (Fan-In BGA), which processes two-dimensionally under the semiconductor chip. Or Fan-in Wafer-Level-Package (FIWLP)), and a Signal Layout Redistribution Layer under the ultra-fine BGA layer under the chip, and a second fine BGA layer under the chip. The method (referred to as Fan-Out BGA or Fan-Out Wafer-Level-Package (FOWLP) or Fan-Out Panel-Level-Package) has been successfully applied.

Recently, in the case of semiconductor chips, products with a thickness of 200 μm or less including an EMC (Epoxy-Mold Compound) layer have appeared. In order to attach a micron-class ultra-thin semiconductor chip with a thickness of only a few hundred microns to an ultra-thin PCB, mass reflow (such as Thermal Reflow Oven) technology, a standard process for surface mount technology (SMT). MR) process exposes semiconductor chips in an air temperature environment of 100 to 300 degrees Celsius (℃) for hundreds of seconds, so chip-boundary warpage (PCB) due to differences in coefficient of thermal expansion (CTE) -Various types of soldering bonding defects such as PCB-Boundary Warpage and Random-Bonding Failure by Thermal Shock may occur.

Accordingly, looking at the configuration of a laser reflow device that has recently been in the spotlight, a laser head module presses a bonding object (semiconductor chip or integrated circuit IC) for several seconds and irradiates a laser for bonding. (IC) Bonding is performed by irradiating a laser in the form of a surface light source corresponding to the size.

For such a pressurized laser head module, referring to Korean Patent No. 0662820 (hereinafter referred to as'priority document 1'), the flip chip is heated by irradiating a laser on the rear surface of the flip chip. A configuration of a flip-chip heat-pressing module for compressing the carrier substrate is disclosed.

However, the conventional pressurized laser head module disclosed in Prior Document 1 has a means for adsorbing a chip and moving it to a bonding position, and for heating the back surface of the chip through a laser and simultaneously pressing the chip to a carrier substrate. Since they are separated by means, in the case of bonding a plurality of semiconductor chips such as a semiconductor strip, the operation of irradiating a laser while pressing a single semiconductor chip must be repeatedly performed as many as the number of semiconductor chips, thereby increasing the working time.

Meanwhile, referring to Korean Patent Laid-Open Patent 2018-0137887 (hereinafter referred to as'priority document 2'), the laser pressure head configuration mentioned in the patent is in the horizontal direction while the pressure head presses several flip chips at the same time. It briefly mentions that the bonding process is possible by irradiating a laser to each flip chip sequentially one by one or by irradiating a laser to several flip chips simultaneously by a single laser head.

However, according to the conventional laser pressurizing head configuration of Prior Document 2, a single laser beam is simultaneously irradiated onto a plurality of flip chips at various angles using a single laser module, thereby irradiating a homogenized laser beam and irradiating a plurality of A lot of technical difficulties are expected to reflow the flip chip.

Therefore, conventionally, the total working time was inevitably increased by sequentially pressing and reflowing a single flip chip one by one, and a single laser was applied to a plurality of flip chips horizontally arranged on various substrate sizes for multiple processing. Even if the beams are irradiated at the same time, it is practically difficult to evenly transmit sufficient heat energy to each flip chip, and thus, there remains a problem in that it is difficult to improve the bonding defect rate.

Accordingly, the present invention is invented to solve the above problems, and the present invention is configured to easily adjust the size of the pressure and laser light-transmitting area processed at once by replacing the translucent pressing member to correspond to the size of various substrates. do. Accordingly, an object of the present invention is to provide a laser pressurizing head module of a laser reflow apparatus in which a plurality of electronic parts can be simultaneously pressed and mass-processed by laser reflow, while a defect rate is greatly improved.

The present invention for achieving the above object is a laser reflow for bonding electronic components to a substrate by pressing a plurality of electronic components arranged on a substrate with a translucent pressing member and irradiating a laser beam through the pressing member. A laser pressurizing head module of an apparatus, comprising: a holder unit for replaceably mounting the translucent pressurizing member; And a probe unit provided above the holder unit to inspect the flatness of the pressing member mounted on the holder unit.

In addition, the laser beam is composed of a square laser beam homogenized by a beam shaper.

In addition, the laser beam is irradiated by overlapping laser beams from two or more laser modules.

In addition, the holder unit is composed of a lower plate having a through hole formed in the central portion so that the light-transmitting pressing member can be inserted, caught, and seated.

In addition, the holder unit further includes a mask plate having a through hole formed at a central portion to allow the laser beam to pass therethrough, and coupled to an upper portion of the lower plate while the translucent pressing member is seated on the lower plate.

In addition, the through hole of the mask plate has a square shape having an area greater than or equal to the pressing surface of the light-transmitting pressing member.

In addition, the bottom surface of the lower plate has a shape in which left and right corner portions are gently rounded.

Further, at each corner portion of the lower plate, a flatness adjusting means for adjusting the flatness of the light-transmitting pressing member by finely moving the corner of the lower plate in the vertical direction is further provided.

In addition, the flatness adjusting means, a press bracket installed at each corner of the light-transmitting pressing member and the holder unit; And a vertical driving part installed on one side of the press bracket and transferring the press bracket in a vertical direction.

In addition, the vertical drive unit may include a ball screw and a motor for vertical transfer of the press bracket; And a guide member for guiding the linear motion of the press bracket.

In addition, the probe unit may include a probe for measuring flatness by piercing at least one or more points on the upper surface of the light-transmitting pressing member; Moving means for horizontally or vertically moving the probe; And a probe bracket for fixing the probe and the moving means.

In addition, the probe is a total of four or more, including the square corner points of the upper surface of the light-transmitting pressing member to be probed.

In addition, it is configured to further include a protective film that prevents gas (fumes) generated during laser bonding from adhering to the bottom surface of the light-transmitting pressing member under the light-transmitting pressing member.

In addition, the protective film is implemented with polytetrafluoroethylene resin (PTFE) or perfluoroalkoxy resin (PFA).

In addition, the protective film is supplied by a reel-to-reel type protective film transfer unit that unwinds the roll-shaped protective film and transports it to one side.

According to the present invention as described above, it is possible to simultaneously press a plurality of electronic components and simultaneously irradiate a homogenized laser beam, thereby significantly improving productivity by mass processing.

In addition, since the mask plate and the light-transmitting pressurizing member can be replaced to correspond to the size of the substrate or the arrangement shape of the electronic component, the defect rate is significantly reduced by uniformly reflowing all of the various substrates.

1 is an exemplary view showing the overall configuration of a laser pressurizing head module of the laser reflow apparatus of the present invention
2 is a block diagram of FIG. 1
3 is a conceptual diagram of a single laser module according to an embodiment of the present invention laser pressure head module
4 is a conceptual diagram of a multi-laser module according to another embodiment of the present invention laser pressurizing head module
5 is a block diagram of a multi-laser module according to another embodiment of the present invention laser pressurizing head module
6 to 9 are configuration diagrams of a laser optical system applicable to a multi-laser module according to another embodiment of the laser pressurizing head module of the present invention.
10 is a perspective view of a main part schematically showing the configuration of a holder unit of the laser pressurizing head module of the present invention
11 is a cross-sectional view of a main part schematically showing the configuration and operation state of the holder unit of the laser pressurizing head module of the present invention
12 is a perspective view of a main part schematically showing the configuration and operation state of the probe unit of the laser pressurizing head module of the present invention
13 is a side view schematically showing the configuration and operation of the vertical transfer unit of the present invention laser pressure head module

The terms used in the present specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "include" or "have" to "include" are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination thereof described in the present specification. It is to be understood that the possibility of the presence or addition of other features, numbers, steps, actions, components, parts, or combinations thereof, or any further features, is not excluded in advance.

Unless otherwise defined in the specification, all terms including technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present specification. Shouldn't.

Hereinafter, a reflow apparatus according to the present invention will be described in detail with reference to FIGS. 1 and 2.

1 is an exemplary view showing the overall configuration of a laser pressurizing head module of the laser reflow apparatus of the present invention, and FIG. 2 is a block diagram of FIG. 1.

The laser pressurizing head module 300 of the laser reflow apparatus according to the present invention, as shown in FIGS. 1 and 2, includes a porous material having a structure capable of applying heat to the lower portion or a stage 111 having a vacuum hole. ) At least one multi-laser module (310, 320) that irradiates a surface light source type laser to the bonding object 11 that is supported and transported, and is installed independently from the laser module (310, 320), and is a surface light source. It is configured to include a light-transmitting pressurizing member 100 that transmits the type of laser, and a protective film 200 that protects the light-transmitting pressurizing member 100 from contamination.

First, the plurality of multi-laser modules 310 and 320 convert the laser generated by the laser oscillator and transmitted through the optical fiber into a surface light source to irradiate the bonding object 11. The laser modules 310 and 320 include a beam shaper that converts a spot-shaped laser into a surface light source (see FIG. 5), and a surface light source that is disposed under the beam shaper and emitted from the beam shaper is a bonding object ( A plurality of lens modules may be implemented by including an optical unit (see FIGS. 5 to 9) that are spaced apart from each other and mounted inside the barrel so as to be irradiated to the irradiation area of 11).

The laser modules 310 and 320 may rise or fall along the z-axis, move left or right along the x-axis, or move along the y-axis for alignment with the bonding object 11.

The pressure head 300 of the laser reflow apparatus according to the present invention includes a translucent pressure member 100 that presses the bonding object 11 and a laser module 310 and 320 that irradiates a surface light source type laser to the bonding object 11. ) Are formed to be separated from each other, so that the laser modules 310 and 320 are moved to a plurality of irradiation positions of the bonding object 11 while pressing the bonding object 11 with the translucent pressing member 100 and then driven. By doing so, it is possible to shorten the tact time for one bonding object 11 and speed up the bonding operation for all of the plurality of bonding objects 11.

At this time, the light-transmitting pressing member 100 is moved to a working position or a standby position by a light-transmitting pressing member conveying unit (not shown in the drawing) of a predetermined type, for example, the translucent pressing member conveying unit lowering or It can be raised or moved to the left or right and then lowered or raised.

In addition, although not shown in the drawing, the laser pressure head module 300 of the laser reflow apparatus according to the present invention uses data input from a pressure sensor (not shown) and a height sensor (not shown) to transmit a light-transmitting pressure member. It further includes a control unit (not shown) for controlling the operation of the transfer unit.

The pressure sensing sensor and the height sensor may be installed on the light-transmitting pressing member 100, the light-transmitting pressing member transfer unit, and the stage 111 supporting the bonding object. For example, the control unit may receive data from the pressure sensor and control the light-transmitting pressurizing member transfer unit so that the pressure reaches the target value, and also control the light-transmitting pressurization member transfer unit to receive data from the height sensor and reach the target height.

In addition, the support (not shown) supports the translucent pressing member transfer unit (not shown) to be movable. As an example, the support unit may be implemented as a pair of gantry extending parallel to the stage 111, and includes a configuration that supports the translucent pressing member transfer unit to be movable in the x-axis, y-axis, or z-axis. It should be interpreted as being.

The pressure head 300 of the laser reflow device according to the present invention includes at least one actuator that applies pressure to the light-transmitting pressure member 100 and at least one pressure sensor that senses the pressure applied to the light-transmitting pressure member 100, and a light-transmitting device. It may be implemented by including one or more height sensors for detecting the height of the pressing member. The pressure sensor may be implemented with at least one load cell as an example, and the height sensor may be implemented with a linear encoder.

By adjusting the pressure applied to the object to be bonded through the pressure sensor, in the case of a large area, it is possible to control so that the same pressure can be transmitted to the object to be bonded through a plurality of actuators and a plurality of pressure sensors. Through the height sensor, it provides technical data to check the height position value at the moment when the object to be bonded is bonded or to find a more accurate value of the bonding height. It performs a function that can be controlled.

In addition, the translucent pressing member 100 may be implemented as a base material that transmits the laser output from the laser modules 310 and 320. The base material of the light-transmitting pressing member 100 can be implemented with any beam-transmitting material.

The base material of the light-transmitting pressing member 100 may be implemented by any one of, for example, quartz, sapphire, fused silica glass, or diamond. However, the physical characteristics of the light-transmitting pressing member made of quartz material are different from the physical characteristics of the light-transmitting pressing member made of sapphire. For example, when irradiating a 980 nm laser, the transmittance of the translucent pressing member made of quartz material is 85% to 99%, and the temperature measured at the bonding object is 100°C. On the other hand, the transmittance of the translucent pressurizing member made of sapphire is 80% to 90%, and the temperature measured at the bonding object is 60°C.

That is, in terms of light transmittance and heat loss required for bonding, quartz shows superior performance than sapphire. However, the inventors of the present application have repeatedly tested the translucent pressurizing member 100 while developing the laser reflow device. As a result, the translucent pressurizing member 100 made of a quartz material is cracked during laser bonding. It has been found that there is a problem in that the bonding quality is defective due to the occurrence of burning on the floor or the bottom surface. It was analyzed that gases generated during laser bonding adhered to the bottom surface of the light-transmitting pressurizing member 100, and the heat source of the laser was concentrated in a portion to which fumes adhered to increase thermal stress.

In order to prevent damage and improve durability of the light-transmitting pressurizing member 100 made of a quartz material, a thin film coating layer may be formed on the bottom surface of the light-transmitting pressurizing member made of a quartz material. The thin film coating layer formed on the bottom surface of the light-transmitting pressing member 100 may be implemented as a conventional optical coating, such as dielectric coating, SiC coating, or metallic material coating.

In the laser pressurizing head module 300 of the laser reflow apparatus according to the present invention, as shown in FIG. 1, gases generated during laser bonding are transmitted to the lower portion of the translucent pressurizing member 100. ) Is implemented to further include a protective film 200 to prevent sticking to the bottom surface of the protective film 200 and a protective film transfer unit 210 for transporting the protective film 200.

The protective film transfer unit 210 may be implemented in a reel-to-reel method in which the protective film 200 wound in a roll shape is released and transferred to one side. As an example, the protective film 200 is preferably implemented with a material having excellent heat resistance with a maximum use temperature of 300 degrees Celsius or more and a continuous maximum use temperature of 260 degrees Celsius or more. For example, the protective film 200 may be implemented with a polytetrafluoroethylene resin (commonly referred to as a Teflon resin; Polytetrafluoroethylene, PTFE) or a purple alkoxy resin. Per Fluoro Alkylvinyether copolymer (PFA) is a product that improves the heat resistance of fluorinated ethylene propylene resin, and it is a highly functional resin with a continuous maximum operating temperature of 260 degrees Celsius like polytetrafluoroethylene resin.

3 is a conceptual diagram of a single laser module according to an embodiment of the present invention laser pressing head module, Figure 4 is a conceptual diagram of a multi-laser module according to another embodiment of the present invention laser pressing head module.

Referring to FIG. 3, the present invention includes a single laser module 310 according to an embodiment, and thus a single laser beam is irradiated onto the FPCB substrate. In this case, referring to FIG. 3, the laser beam irradiated by the first laser module 310 is irradiated on the substrate in a state in which the intensity of the laser beam is transformed into a homogenized square beam shape.

Meanwhile, referring to FIG. 4, a multi-laser module according to another embodiment of the present invention includes, for example, a first laser module 310 and a second laser module 320, and is an electronic component of the bonding object 11. At the attached position, the first and second laser modules are irradiated in a superimposed state to irradiate a homogenized superimposed laser beam.

In FIG. 4, it is illustrated that the first laser beam has a square shape and the second laser beam has a circular shape, but both laser beams may have a square shape. In addition, the first laser beam and the second laser beam may be irradiated at the same time, or the second laser beam may be sequentially irradiated after preheating of the bonding object 11 by the first laser beam.

5 is a block diagram of a multi-laser module according to another embodiment of the present invention laser pressurizing head module.

In FIG. 5, each of the laser modules 310, 320, ... 330 is a laser oscillator 311, 321, 331, each having a cooling device (316, 326, 336), a beam shaper (312, 322, 332) , Optical lens modules 313, 323, 333, driving devices 314, 324, 334, control devices 315, 325, 335, and power supply units 317, 327, 337.

Hereinafter, the first laser module 310 of each laser module having the same configuration will be mainly described in order to avoid redundant description, except when necessary.

The laser oscillator 311 generates a laser beam having a wavelength and output power in a predetermined range. The laser oscillator is, for example, a diode laser (Laser Diode, LD) or a rare earth medium fiber laser (Rare-Earth- Doped Fiber Laser) or Rare-Earth-Doped Crystal Laser. Alternatively, a medium for emitting alexandrite laser light having a wavelength of 755 nm, or Nd Yag (Nd) having a wavelength of 1064 nm or 1320 nm. :YAG) It may be implemented including a medium for emitting laser light.

A beam shaper 312 converts a spot-shaped laser generated in a laser oscillator and transmitted through an optical fiber into an area beam having a flat top. The beam shaper 312 may be implemented by including a Square Light Pipe, a Diffractive Optical Element (DOE), or a Micro-Lens Array (MLA).

The optical lens module 313 adjusts the shape and size of a laser beam converted into a surface light source form by a beam shaper to irradiate it to an electronic component or an irradiation area mounted on a PCB substrate. The optical lens module constitutes an optical system through a combination of a plurality of lenses, and a specific configuration of such an optical system will be described later in detail with reference to FIGS. 6 to 9.

The driving device 314 moves the distance and position of the laser module with respect to the irradiation surface, and the control device 315 controls the driving device 314 to control the beam shape and the beam area size when the laser beam reaches the irradiation surface. , Adjust the beam sharpness and beam irradiation angle. The control device 315 may also integrally control the operation of each unit of the laser module 310 in addition to the driving device 314.

Meanwhile, the laser output adjustment unit 370 is supplied to each laser module from the power supply units 317, 327, 337 corresponding to each laser module 310, 320, 330 according to a program received through a user interface or a preset program. Controls the amount of power to be used. The laser output adjustment unit 370 receives information on the reflow status of each part, area, or entire reflow on the irradiation surface from one or more camera modules 350 and controls each power supply unit 317, 327, 337 based on this. In contrast, the control information from the laser output control unit 370 is transmitted to the control devices 315, 325, 335 of each laser module (310, 320, 330), and each control device (315, 325, 335) It is also possible to provide a feedback signal for controlling the corresponding power supply unit 317. In addition, unlike FIG. 6, it is possible to distribute power to each laser module through one power supply unit. In this case, the power supply unit must be controlled by the laser output adjustment unit 370.

When implementing the laser superimposition mode, the laser power adjustment unit 370 includes each laser module and the laser module so that the laser beam from each laser module 310, 320, 330 has a required beam shape, a beam area size, beam sharpness, and a beam irradiation angle. Controls the power supply units 317, 327, and 337. In addition to the case of preheating the area around the debonding target position using the first laser module 310 and additionally heating the narrower reflow target area using the second laser module 320, the preheating function or The additional heating function is appropriately distributed among the first, second, and third laser modules 310, 320, ... 330 to control each laser module to have a required temperature profile.

Meanwhile, when a single laser light source is distributed and input to each laser module, a function for simultaneously adjusting the output and phase of each distributed laser beam may be provided in the laser output adjusting unit 370. In this case, the beam flatness can be remarkably improved by controlling the phase to induce destructive interference between the respective laser beams, thereby further increasing energy efficiency.

On the other hand, in the case of implementing a multi-position simultaneous processing mode, the laser power adjustment unit 370 is used to ensure that some or all of the laser beams from each laser module are different. Controls one or more of the angle and the beam wavelength. Even at this time, in the case of distributing one laser light source and inputting it to each laser module, the laser output adjusting unit 370 may have a function for simultaneously adjusting the output and phase of each of the distributed laser beams.

Through this function, bonding between the electronic components in the irradiation surface and the substrate can be performed or the bonding can be removed by adjusting the laser beam size and output. In particular, in the case of removing damaged electronic components on the substrate, the application of heat by the laser beam to other adjacent electronic components or normal electronic components existing on the substrate can be minimized by minimizing the area of the laser beam to the corresponding electronic component area. Accordingly, it is possible to remove only the damaged electronic component to be removed.

On the other hand, in the case of emitting laser beams with different wavelengths for each of the plurality of laser modules, the laser module will absorb a plurality of material layers (e.g., EMC layer, silicon layer, solder layer) included in the electronic component. It can be composed of individual laser modules with wavelengths. Accordingly, the laser debonding device according to the present invention selectively increases the temperature of the electronic component and the temperature of the intermediate bonding material such as solder, which is a connecting material between the printed circuit board or the electrode of the electronic component, to be optimized for bonding (Attaching or Bonding) or separation (detaching or debonding) process may be performed. Specifically, by transmitting both the EMC mold layer and the silicon layer of the electronic component so that all the energy of each laser beam is absorbed by the solder layer, or the laser beam does not pass through the EMC mold layer and heats the surface of the electronic component, the lower part of the electronic component It is also possible to conduct heat to the bonding portion of the.

Meanwhile, by utilizing the above functions, after preheating the area of the electronic component to be reflowed and a certain area of the substrate including the periphery thereof by at least one first laser beam to a predetermined preheating temperature, at least one second laser beam Accordingly, the temperature of the electronic component region to be reflowed is selectively heated to the reflow temperature at which solder melting occurs.

6 to 9 are configuration diagrams of a laser optical system applicable to a single laser module or a multi-laser module of the laser pressurizing head module of the present invention.

6 is an optical system having the simplest structure applicable to the present invention. When the laser beam emitted from the beam transmission optical fiber 410 is focused through the convex lens 420 and incident on the beam shaper 430, the beam shaper 430 ), the spot-shaped laser beam is converted to a flat-top type surface light source (A1), and the square laser beam (A1) output from the beam shaper 430 is the desired size through the concave lens 440 The image-forming surface S is irradiated with the enlarged surface light source A2.

7 is a block diagram of a laser optical system according to another embodiment of the present invention.

The surface light source B1 from the beam shaper 430 is enlarged to a predetermined size through the concave lens 440 to become a surface light source B2 irradiated to the first imaging surface S1. When the surface light source (B2) is to be further enlarged and used, the boundary of the edge portion of the surface light source (B2) may become more unclear according to the additional expansion, so that the final irradiation surface is the second imaging surface (S2). ) In order to obtain irradiation light with a clear edge, a mask 450 is installed on the first imaging surface S1 to trim the edge.

The surface light source passing through the mask 450 is reduced (or enlarged) to a desired size while passing through the zoom lens module 460 composed of a combination of at least one convex lens and a concave lens, and the second imaging surface on which the electronic component is placed Square irradiation light B3 is formed in (S2).

8 is a block diagram of a laser optical system according to another embodiment of the present invention.

After the square surface light source C1 from the beam shaper 430 is enlarged to a predetermined size through the concave lens 440, it is enlarged (or reduced) in the x-axis direction, for example, passing through at least a pair of cylindrical lenses 470 (C2) and again passing through at least a pair of cylindrical lenses 480, it is reduced (or enlarged) in the y-axis direction, for example, and converted into a rectangular surface light source C3.

Here, the cylindrical lens is a shape obtained by cutting a cylindrical shape in the longitudinal direction, and functions to expand or reduce the laser beam according to the shape in which each lens is arranged in the vertical direction, and the lens on the surface on which the cylindrical lens is placed is x, y Depending on the shape arranged in the axial direction, the laser beam is adjusted in the x-axis or y-axis direction.

Subsequently, the surface light source C3 is enlarged (or reduced) to a desired size while passing through the zoom lens module 460 composed of a combination of at least one convex lens and a concave lens, and the second imaging surface S2 on which the electronic component is disposed. ) To form a rectangular irradiation light C4.

9 is a block diagram of a laser optical system according to another embodiment of the present invention.

It is understood that the optical system of FIG. 9 has a configuration for trimming the edge of the laser beam by applying a mask to the optical system of FIG. 8, and it is understood that a final surface light source D5 having a sharper edge can be obtained compared to the case of FIG. I will be able to.

10 is a perspective view of a main part schematically showing the configuration of a holder unit of the laser pressurizing head module of the present invention.

Referring to Figure 10, the holder unit 500 according to the present invention, the lower plate 510 in which the lower portion of the flat-shaped light-transmitting pressing member 100 is inserted and seated, and the upper portion of the light-transmitting pressing member 100 is fitted and coupled. It is divided into a mask plate (520).

In addition, since the lower plate 510 and the mask plate 520 have rectangular through holes 510a and 520a respectively formed at the center of the lower plate 510 and the mask plate 520, the light-transmitting pressing member 100 is inserted into the lower plate 510 and seated. It is understood that the bottom surface 100a of the member 100 is exposed downward through the through hole 510a of the lower plate 510.

Meanwhile, as the mask plate 520 is fitted and coupled to the upper surface of the translucent pressing member 100 in the above state, the central portion of the upper surface of the translucent pressing member 100 is exposed upward through the through hole 520a of the mask plate 520 Mounting is completed in the state that it is installed.

11 is a cross-sectional view schematically showing the configuration and operation of the holder unit of the laser pressurizing head module of the present invention.

Referring to FIG. 11, when the laser is irradiated by the dual-beam laser modules 310 and 320 located above with the light-transmitting pressing member mounted between the lower plate and the mask plate, the through hole 520a of the mask plate 520 and the It is understandable that the laser beam is transmitted downward through the translucent pressing member 100.

At this time, the left and right corners of the bottom of the lower plate 510 have a smoothly rounded shape, which means that the protective film 200 located below the translucent pressing member moves downward while the translucent pressing member 100 moves downward. When pressed, the protective film 200 is not damaged by tearing or scratching by the rounded corners of the lower plate 510.

In addition, the protective film 200 is pulled and wound by the protective film transfer unit 210 disposed on both left and right sides of the protective film 200 as described above, and even at this time, the left and right corners of the bottom surface of the lower plate 510 are smooth. Since it is rounded, the protective film 200 can be fed without being damaged by the corners.

As described above, the light-transmitting pressing member 100 simultaneously presses a plurality of electronic components disposed on the substrate, which is the bonding object 11, to a predetermined depth, and the laser beam is transmitted by the multi-laser modules 310 and 320 located above. As a result of the irradiation, the laser reflow treatment is performed while the solder located under the electronic component of the bonding object 11 is melted by the laser beam.

Thereby, the laser beams overlap each other to form a homogenized laser beam, and the bonding object through the through hole 520a of the mask plate 520 and the through hole 520a of the light-transmitting pressing member 100 and the lower plate 510 It is understandable that uniform heat energy is transmitted to the solder located under the electronic component in (11).

In this case, when the superimposed laser beam is irradiated on a peripheral substrate other than an electronic component, since the peripheral substrate portion may be damaged by the thermal energy of the laser beam, it is necessary to be irradiated only on the electronic component of the bonding object 11. There is. To this end, the area of the square through hole 520a of the mask plate 520 and the area of the pressing surface 100a of the translucent pressing member 100 in order to accurately pressurize and laser reflow only the electronic components of the bonding object 11 are laser beams. It is desirable to design in consideration of the transmission path and the overlapping area of the.

12 is a perspective view of a main part schematically showing the configuration and operation state of the probe unit of the laser pressurizing head module of the present invention.

The main feature of the present invention is that the mask plate 520 and the translucent pressing member 100 are interchangeable so as to correspond to the sizes of various substrates. Therefore, the light-transmitting pressing member 100 and the mask plate 520 can be replaced with different ones depending on the shape and area of the electronic component disposed on the substrate or processing a different size substrate. In this case, the operator selects and replaces an appropriate size of the translucent pressing member 100 and the mask plate 520 prepared in advance to have a pressing surface of various different sizes as needed, and then, as shown in FIG. The flatness is measured by probing the corners of the upper surface of the translucent pressing member 100 through the probe unit 600.

The probe unit 600 may include a needle-shaped probe 610, a probe transfer unit 620 that horizontally or vertically transfers the probe, and a probe bracket 630 that supports the probe and the transfer unit.

Therefore, when the operator replaces the translucent pressing member 100 and the mask plate 520 of different sizes in order to process a substrate of a different size, the probe 610 is transferred in a horizontal or vertical direction, for example, a translucent pressing member. (100) It is possible to measure the flatness of the light-transmitting pressing member 100 by sequentially piercing at least four corners (marked X) of the upper surface and probing.

13 is a side view schematically showing the configuration and operation of the vertical transfer unit of the laser pressurizing head module of the present invention.

Hereinafter, a configuration and operation state of the vertical transfer unit of the laser pressurizing head module will be described with reference to FIG. 13.

Looking at the configuration of the vertical transfer unit according to an embodiment, a press bracket 720 installed at four corners of each of the translucent pressing member 100 and the holder unit 500, and a pressure cylinder 730 installed above the press bracket , A vertical driving unit for applying a driving force to the press bracket 720 in a vertical direction; That is, for example, it may be composed of a ball screw 750 and a motor 760, and a guide member 770 for guiding the linear motion of the press bracket 720.

Therefore, before the bonding object 11 made of the substrate and electronic parts is put under the light-transmitting pressing member 100, the light-transmitting pressing member 100 and the holder unit 500 are driven by the motor 760 of the vertical transfer unit. After being transferred upward and the bonding object 11 is put in, the translucent pressing member 100 and the holder unit 500 are transferred downward by driving the motor 760 again to prepare for pressing. Thereafter, the light-transmitting pressing member 100 presses the bonding object 11 by the operation of the pressing cylinder 730, and a detailed description of the pressing process will be omitted.

Meanwhile, as shown in FIG. 12, when the probe unit 600 measures the flatness of the light-transmitting pressing member 100 and determines that the light-transmitting pressing member 100 is inclined to one side, that is, it is not flat. In this case, the vertical transfer unit is finely driven to transfer the holder unit 500 upward or downward, thereby adjusting the flatness of the light-transmitting pressing member 100.

In more detail, as a result of measuring the flatness of the translucent pressing member 100 by the probe unit 600, one of the four corners of the upper surface of the translucent pressing member 100 is located at a lower point inclined to one side compared to the other. If it is determined that there is, for example, the motor 760 at the corner located at the lower point is operated to finely lift the corner of the holder unit 500 upward, so that the overall flatness of the light-transmitting pressing member 100 Is to adjust.

At this time, by installing an absolute encoder in the motor 760, for example, it is possible to always maintain the absolute position value of each corner portion of the holder unit 500 regardless of the power state, and the above-described translucent pressing member It is preferable to automate the process of adjusting the flatness of (100) through the setting of the control unit.

In addition, the present invention is not limited only by the above-described embodiment, and since the same effect can be created even when the detailed configuration, number, and arrangement structure of the device is changed, those of ordinary skill in the art the present invention. It is stated that it is possible to add, delete, and transform various configurations within the scope of the technical idea of

100: permeable pressing member 100a: pressing surface
200: protective film 210: protective film transfer unit
310: first laser module 320: second laser module
500: holder unit 510: lower plate
520: mask plate 600: probe unit 610: probe 620: probe transfer unit 630: probe bracket 720: press bracket
730: pressure cylinder 750: ball screw
760: motor 770: guide member

Claims (15)

A laser pressing head module of a laser reflow apparatus for bonding electronic components to a substrate by pressing a plurality of electronic components arranged on a substrate with a translucent pressing member and simultaneously irradiating a laser beam through the pressing member,
A holder unit for replacing the light-transmitting pressing member; And
It is provided above the holder unit and includes a probe unit for inspecting the flatness of the pressing member mounted on the holder unit;
The holder unit,
It includes a lower plate having a through hole formed in the central portion so that the light-transmitting pressing member is inserted and can be caught and seated,
The probe unit,
A probe for measuring flatness by piercing at least one point on the upper surface of the light-transmitting pressing member; Moving means for horizontally or vertically moving the probe; And a probe bracket for fixing the probe and the moving means,
When the operator replaces the translucent pressurizing member with a translucent pressurizing member of a different size, the probe is transferred in a horizontal or vertical direction and at least four points including the corner points of the upper surface of the replaced translucent pressurizing member are sequentially punctured and probed. To measure the flatness of the light-transmitting pressing member,
Laser pressure head module of the laser reflow device. The method of claim 1,
The laser beam is a square laser beam homogenized by a beam shaper,
Laser pressurization head module of the laser reflow device. The method of claim 1,
The laser beam is irradiated by overlapping laser beams from two or more laser modules,
Laser pressurization head module of the laser reflow device. delete The method of claim 1,
The holder unit,
Further comprising a mask plate coupled to the upper portion of the lower plate in a state in which a through hole is formed so that the laser beam can pass through the center portion and the translucent pressing member is seated on the lower plate,
Laser pressurization head module of the laser reflow device. The method of claim 5,
The through hole of the mask plate,
A square shape having an area equal to or larger than the pressing surface of the light transmitting pressing member,
Laser pressurization head module of the laser reflow device. The method of claim 1,
The bottom surface of the lower plate has a shape in which the left and right corner portions are gently rounded,
Laser pressurization head module of the laser reflow device. The method of claim 1,
At each corner of the lower plate,
A flatness adjusting means for adjusting the flatness of the light-transmitting pressing member by finely moving the edge of the lower plate in the vertical direction is further provided,
Laser pressurization head module of the laser reflow device. The method of claim 8,
The flatness adjusting means,
Press brackets installed at the corners of the translucent pressing member and the holder unit; And
It is installed on one side of the press bracket and comprises a vertical driving unit for transporting the press bracket in the vertical direction according to the driving of the motor,
Laser pressurization head module of the laser reflow device. The method of claim 9,
The vertical drive unit,
Ball screw and motor for vertical transfer of the press bracket; And
Including a guide member for guiding the linear motion of the press bracket,
Laser pressurization head module of the laser reflow device.
delete delete The method of claim 1,
Further comprising a protective film that prevents gas (fumes) generated during laser bonding from adhering to the bottom surface of the translucent pressurizing member under the translucent pressurizing member,
Laser pressurization head module of the laser reflow device. The method of claim 13,
The protective film is implemented with polytetrafluoroethylene resin (PTFE) or perfluoroalkoxy resin (PFA),
Laser pressurization head module of the laser reflow device. The method of claim 13,
The protective film is supplied by a reel-to-reel type protective film transfer unit that unwinds the protective film wound in a roll form and transports it to one side,
Laser pressurization head module of the laser reflow device.

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