KR102327167B1 - Laser pressure head module of laser reflow equipment - Google Patents

Abstract

The laser pressure head module of the laser reflow apparatus of the present invention is a laser for bonding electronic components to a substrate by pressing a plurality of electronic components arranged on a substrate with a light-transmitting pressing member and simultaneously irradiating a laser beam through the pressing member. A laser pressurizing head module of a reflow apparatus, comprising: a circular or polygonal holder unit for replaceably mounting the light-transmitting pressurizing member; and a press unit which is respectively shaft-coupled to three points around the edge of the holder unit and forms a triangle when the shaft-coupled points are connected with an imaginary line.

Description

Laser pressure head module of laser reflow equipment

The present invention relates to a laser reflow apparatus, and more particularly, to a laser pressure head module of a laser reflow apparatus for bonding electronic components by irradiating a laser while pressing a plurality of electronic components with a light-transmitting pressure member. .

In industrial laser processing, an application field with micron (㎛) level precision is micro laser processing, which 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 technologies to reduce the circuit spacing to a minimum to realize the degree of integration, performance, and ultra-high-speed communication speed. It has become difficult to stack memory chips in a vertical direction. The stacking technology up to 128 layers has already been developed by TSMC, and the stacking technology up to 72 layers is being applied to mass production by Samsung Electronics and SK Hynix.

In addition, technology development for mounting a memory chip, a microprocessor chip, a graphic processor chip, a wireless processor chip, a sensor processor chip, etc. in one package is intensely researched and developed, and a considerable level of technology is already being applied in practice.

However, in the process of developing the above-mentioned technology, more and more electrons have to participate in the signal processing process inside the ultra-high-speed/ultra-high-capacity semiconductor chip, so the power consumption increases, and the issue of cooling processing for heat has been raised. In addition, in order to achieve the requirements of ultra-high-speed signal processing and ultra-high frequency signal processing for more signals, a technical issue that large amounts of electrical signals must be transmitted at high speed has been raised. In addition, since the number of signal lines has to be increased, it is no longer possible to process the signal interface lines to the outside of the semiconductor chip using a one-dimensional lead wire method, but a ball grid array (BGA) method (Fan-In BGA) that processes two-dimensionally at the bottom of 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 is installed under it. The method (referred to as Fan-Out BGA or Fan-Out Wafer-Level-Package (FOWLP) or Fan-Out Panel-Level-Package) is being 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. As such, in order to attach micron-level ultra-thin semiconductor chips with a thickness of only several hundred microns to ultra-thin PCBs, the same mass reflow (SMT) standard process, Thermal Reflow Oven technology, is used. When the MR) process is applied, the semiconductor chip is exposed to an air temperature environment of 100 to 300 degrees (℃) for a period of several hundred seconds. - 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 been in the spotlight recently, a laser head module presses a bonding object (semiconductor chip or integrated circuit IC) for a few seconds while irradiating a laser to bond the semiconductor chip or integrated circuit. (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 Registration No. 0662820 (hereinafter referred to as 'Prior Document 1'), the flip chip is heated by irradiating a laser to the rear surface of the flip chip, while the flip chip is A configuration of a flip-chip hot-pressing module for compressing the substrate to the carrier substrate is disclosed.

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

Meanwhile, referring to Korean Patent Application Laid-Open No. 2018-0137887 (hereinafter referred to as 'Prior Document 2'), the laser pressurizing head configuration mentioned in the same patent simultaneously presses several flip chips and the laser head moves in a horizontal direction. It is generally mentioned about the possibility of bonding processing by irradiating each flip chip with a laser one by one or by simultaneously irradiating lasers on several flip chips by a single laser head.

However, according to the conventional laser pressurizing head configuration of the above-mentioned Prior Document 2, since a single laser source is used, the homogenized laser beam is irradiated and defective as the laser beam is incident at various angles on a plurality of flip chips disposed on the substrate. Reflowing a plurality of flip chips without it is expected to be technically difficult.

Therefore, in the prior art, as a single flip chip is sequentially pressed and reflowed one by one, the total working time has to be increased, and a single laser is applied to a plurality of flip chips horizontally arranged on various substrate sizes for a plurality of processes. Even if the beam is simultaneously irradiated, it is virtually difficult to evenly transmit sufficient thermal energy to each flip chip, so there is still a problem in that it is difficult to improve the bonding defect rate.

Accordingly, the present invention was invented to solve the above problems, and the present invention can independently set and adjust the pressure of each corner of the plate-shaped holder unit to which the light-transmitting pressing member is mounted to correspond to the size of various substrates. composed to be Accordingly, an object of the present invention is to provide a laser pressurizing head module of a laser reflow apparatus that simultaneously pressurizes and irradiates a laser beam to reflow a plurality of electronic components at a time, enabling mass processing and greatly improving the defect rate.

According to an embodiment of the present invention for achieving the above object, the electronic components are applied to the substrate by pressing a plurality of electronic components arranged on a substrate with a light-transmitting pressing member and simultaneously irradiating a laser beam through the pressing member. A laser pressure head module of a bonding laser reflow apparatus, comprising: a circular or polygonal holder unit for replaceably mounting the light-transmitting pressure member; and a press unit which is respectively shaft-coupled to three points around the edge of the holder unit and forms a triangle when the shaft-coupled points are connected with an imaginary line.

Also according to one embodiment, the press unit, a press bracket; a pressure cylinder mounted on the upper end of the press bracket to press the holder unit downward by a set pressure; and a bearing joint having one end coupled to the cylinder rod of the pressure cylinder and the other end rotatably coupled to one of three points of the holder unit.

In addition, according to one embodiment, the pressure cylinder is a precision pneumatic cylinder capable of finely setting and adjusting the pressure in kgf unit is adopted.

In addition, according to an embodiment, a joint fastening part is further provided at each of the three points of the holder unit, and each of the joint fastening parts is rotatably coupled to the bearing joint.

In addition, according to an embodiment, a stopper is further provided at the lower end of the press bracket, and one end of the joint fastening part is spread over the stopper.

In addition, according to an embodiment, a vertical transfer unit for vertically elevating the press bracket is further provided on one side of the press bracket.

In addition, according to an embodiment, the vertical transfer unit is configured to include a ball screw and a motor.

Also, according to an embodiment, the flatness of the holder unit is reset to zero after a certain period or after replacing the light-transmitting pressing member.

In addition, according to an embodiment, the virtual triangle connecting the three points of the holder unit is an equilateral triangle, and the center of gravity of the virtual triangle coincides with the center of gravity of the light-transmitting pressing member.

In addition, according to an embodiment, the laser beam is irradiated by overlapping laser beams from two or more laser sources.

In addition, according to an embodiment, a protective film for preventing gas (fumes) generated during laser bonding from adhering to the bottom surface of the light-transmitting pressing member is further included under the light-transmitting pressing member.

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

In addition, according to an embodiment, the protective film is supplied by a reel-to-reel-type protective film transfer unit that transfers to one side while unwinding the protective film wound in a roll shape.

According to the present invention as described above, a plurality of electronic components can be pressed and simultaneously irradiated with a homogenized laser beam, thereby greatly improving productivity by mass reflow processing.

In addition, the basic flatness of the holder unit is improved as well as the basic flatness of the holder unit is improved by significantly shortening the distance between the pressing shafts while minimizing the number of pressing shafts that need to be controlled by configuring the pressing shaft to support the holder unit on which the light-transmitting pressing member is mounted. In the laser reflow process that requires precision, when a plurality of electronic components are pressed, load deviation due to pressure distribution unevenness is minimized, so that flatness and defect rate due to pressure distribution unevenness are greatly improved.

1 is an exemplary view showing the overall configuration of the laser pressure head module of the present invention laser reflow device
Figure 2 is a block diagram of Figure 1
3 is a conceptual diagram of a single laser beam module according to an embodiment of the present invention laser pressure head module
Figure 4 is a conceptual diagram of a multi-laser beam module according to another embodiment of the present invention laser pressure head module
5 is a configuration diagram of a multi-laser beam module according to another embodiment of the laser pressure head module of the present invention;
6 to 9 are diagrams of a laser optical system applicable to a multi-laser beam module according to another embodiment of the laser pressure head module of the present invention.
10 is a perspective view schematically showing the entire device configuration of the laser pressurizing head module of the present invention;
11 is a side cross-sectional view of the main part of FIG.
12a is a plan view of the main part of the holder unit of the present invention laser pressure head module formed in an octagon according to an embodiment;
12b is a plan view of the main part of the holder unit of the present invention laser pressurizing head module formed in a circular shape according to another embodiment;

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as "comprise" or "have" to "include" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the present specification exist, but one It should be understood that it does not preclude the existence or addition of other features or numbers, steps, operations, components, parts, or combinations thereof, or other features or more.

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

Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in 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 the accompanying FIGS. 1 and 2 .

FIG. 1 is an exemplary view showing the overall configuration of a laser reflow apparatus according to 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, a stage 111 in which a porous material or vacuum hole having a structure capable of applying heat to the lower portion is formed. ) and at least one multi-laser module (310, 320) that irradiates a laser in the form of a surface light source to the bonding object 11, which is supported and transported, and the laser module (310, 320) and is installed independently from the surface light source It is configured to include a light-transmitting pressing member 100 that transmits a laser in the form of a protective film 200 for protecting the light-transmitting pressing member 100 from contamination.

First, the plurality of multi-laser modules 310 and 320 convert a laser generated from a laser oscillator and transmitted through an optical fiber into a surface light source and irradiated to the bonding object 11 . The laser modules 310 and 320 include a beam shaper (see FIG. 5) that converts a spot type laser into a surface light source type, and a surface light source disposed below the beam shaper and emitted from the beam shaper to the bonding object ( 11), the plurality of lens modules may be embodied by including an optical unit (refer to FIGS. 5 to 9 ) in which a plurality of lens modules are mounted to be spaced apart from each other at an appropriate distance inside the barrel.

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 light-transmitting pressure member 100 for pressing the bonding object 11 and laser modules 310 and 320 for irradiating a laser in the form of a surface light source to the bonding object 11 . ) by separating and forming each other independently, the laser modules 310 and 320 are moved to a plurality of irradiation positions of the bonding object 11 in a state where the bonding object 11 is pressed with the light-transmitting pressing member 100 and then driven By doing so, it is possible to realize shortening of the tact time for one bonding object 11 and speeding up the bonding operation for the plurality of bonding objects 11 as a whole.

At this time, the light-transmitting pressing member 100 is moved to the working position or the standby position by the light-transmitting pressing member transfer unit 110 of a predetermined shape. Alternatively, it can be raised or moved to the left or right and then lowered or raised.

In addition, although not shown in the drawings, the laser pressure head module 300 of the laser reflow device according to the present invention uses data input from a pressure sensor (not shown) and a height sensor (not shown) to a light-transmitting pressure member It further includes a controller (not shown) for controlling the operation of the transfer unit 110 .

The pressure sensor and the height sensor may be installed on the stage 111 supporting the light-transmitting pressure member 100 and the light-transmitting pressure member transfer unit and the bonding object. For example, the control unit receives data from the pressure sensor and controls the light-transmitting pressing member conveying unit so that the pressure reaches a target value, and receives data from the height sensor to control the light-transmitting pressing member conveying unit to reach the target value of the height.

In addition, the support part (not shown) supports the light-transmitting pressing member transfer part (not shown) to be movable. For example, the support part may be implemented as a pair of gantry extending in parallel with the stage 111, and includes a configuration for supporting the light-transmitting pressure member transfer part to be movable in the x-axis, y-axis, or z-axis. should be interpreted as being

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

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

In addition, the light-transmitting 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 with, for example, any one of quartz, sapphire, fused silica glass, or diamond. However, the physical properties of the light-transmitting pressing member made of quartz are different from the physical properties of the light-transmitting pressing member made of sapphire. For example, when irradiating a 980 nm laser, the transmittance of the light-transmitting 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 light-transmitting pressing 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 exhibits superior performance than sapphire. However, the inventor of the present application repeatedly tested the light-transmitting pressing member 100 while developing the laser reflow device. As a result, the light-transmitting pressing member 100 made of a quartz material is cracked during laser bonding. It was found that there was a problem in that the bonding quality was poor due to burning or the occurrence of burning on the bottom surface. It was analyzed that the gas (fumes) generated during laser bonding adheres to the bottom surface of the light-transmitting pressing member 100 , and the heat source of the laser is concentrated on the part to which the gas (fumes) is adhered, thereby increasing thermal stress.

In order to prevent damage to the light-transmitting pressure member 100 made of a quartz material and to improve durability, a thin film coating layer may be formed on the bottom surface of the light-transmitting pressure 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 dielectric coating or SiC coating or metal material coating, which is a conventional optical coating.

The laser pressurizing head module 300 of the laser reflow apparatus according to the present invention, as shown in FIG. 1, is a light-transmitting pressurizing member 100 under the light-transmitting pressurizing member 100, and gas (fumes) generated during laser bonding is applied to the light-transmitting pressurizing member 100 ) is implemented to further include a protective film 200 to prevent sticking to the bottom surface and a protective film transfer unit 210 for transferring 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 unwound and transferred to one side. The protective film 200 is preferably implemented with a material having excellent heat resistance, for example, the maximum use temperature is 300 degrees Celsius or more, and the continuous maximum use temperature is 260 degrees 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. Perfluoroalkoxy resin (Per Fluoro Alkylvinyether copolymer; PFA) is a product that improves the heat resistance of fluorinated ethylene propylene resin.

3 is a conceptual diagram of a single laser module according to an embodiment of the bonding object transport module of the present invention, and FIG. 4 is a conceptual diagram of a multi-laser module according to another embodiment of the bonding object transport module of the present invention.

Referring to FIG. 3, the present invention is provided with a single laser module 310 according to an embodiment, thereby irradiating a single laser beam on the FPCB substrate. At this time, 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 , the 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 an electronic component of the bonding object 11 . At this attachment position, the homogenized overlapping laser beam is irradiated by irradiating the first and second laser modules in an overlapping state.

4 shows 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 simultaneously irradiated, or the second laser beam may be sequentially irradiated after preheating the bonding object 11 by the first laser beam.

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

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

Hereinafter, except where necessary, the first laser module 310 among laser modules having the same configuration will be mainly described in order to avoid overlapping description.

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) having a wavelength of '750 nm to 1200 nm' or '1400 nm to 1600 nm' or '1800 nm to 2200 nm' or '2500 nm to 3200 nm' or a rare earth medium fiber laser (Rare-Earth- Doped Fiber Laser) or rare earth medium photonic crystal laser (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) may be implemented including a medium for emitting laser light.

The beam shaper 312 converts a spot type laser generated from a laser oscillator and transmitted through an optical fiber into an area beam type 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 the laser beam converted from the beam shaper to the surface light source shape to irradiate the electronic component mounted on the PCB board or the irradiation area. The optical lens module constitutes an optical system by combining a plurality of lenses, and the detailed 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 irradiated surface, and the controller 315 controls the driving 314 to form a beam when the laser beam reaches the irradiated surface and the size of the beam area. , adjust the beam sharpness and beam irradiation angle. The control device 315 may also integrally control the operation of each part of the laser module 310 in addition to the driving device 314 .

On the other hand, the laser power adjustment unit 370 is supplied to each laser module from the power supply unit 317, 327, 337 corresponding to each laser module (310, 320, 330) according to a program received through the user interface or a preset program. control the amount of power The laser output adjusting unit 370 receives information about each part, each area, or the entire reflow state on the irradiation surface from one or more camera modules 350 and controls each power supply unit 317 , 327 , 337 based on the received information. On the other hand, the control information from the laser power adjusting unit 370 is transmitted to the control devices 315, 325, 335 of each laser module 310, 320, 330, and in each of the control devices 315, 325, 335, respectively. It is also possible to provide a feedback signal for controlling the corresponding power supply 317 . In addition, unlike FIG. 6 , it is also possible to distribute power to each laser module through one power supply unit. In this case, the laser output adjusting unit 370 needs to control the power supply unit.

When implementing the laser overlap mode, the laser output adjustment unit 370 is configured so that the laser beam from each laser module (310, 320, 330) has a required beam shape, beam area size, beam sharpness and beam irradiation angle to each laser module and Controls the power supply (317, 327, 337). The laser overlap mode uses the first laser module 310 to preheat the area around the debonding target position and uses the second laser module 320 to further heat the narrower reflow target area, as well as the preheating function to It also applies when controlling each laser module to have a required temperature profile by properly distributing the additional heating function between the first, second, and third laser modules 310, 320, ... 330.

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

On the other hand, when implementing a multi-position simultaneous processing mode, the laser power adjusting unit 370 makes a part or all of the laser beams from each laser module different so that the beam shape, beam area size, beam clarity, and beam irradiation of each laser beam are different. Controls one or more of angle and beam wavelength. Even at this time, when one 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 power adjusting unit 370 .

Through this function, bonding between the electronic components and the substrate in the irradiation surface can be performed or bonding can be removed by adjusting the laser beam size and output. In particular, when a damaged electronic component is removed from the substrate, the application of heat by the laser beam to other adjacent 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. Thereby, it is possible to remove only the damaged electronic component to be removed.

On the other hand, when a plurality of laser modules emit laser beams having different wavelengths, the laser module is a laser module in which a plurality of material layers (eg, EMC layer, silicon layer, solder layer) included in an electronic component absorb well. It can consist of individual laser modules with wavelengths. Accordingly, the laser debonding apparatus 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). Bonding) or separation (Detaching or Debonding) process may be performed. Specifically, it penetrates both the EMC mold layer and the silicon layer of the electronic component so that all energy of each laser beam is absorbed by the solder layer, or the laser beam does not penetrate the EMC mold layer and heats the surface of the electronic component to lower the electronic component It is also possible to conduct heat to the bonding portion of the

Meanwhile, by utilizing the above function, a predetermined region of the substrate including the electronic component area to be reflowed and its surroundings is preheated to a predetermined preheating temperature by at least one first laser beam, and then at least one second laser beam is applied. By this, the temperature of the electronic component region to be reflowed is selectively heated up to the reflow temperature at which solder melting occurs.

6 to 9 are diagrams of a laser optical system applicable to a single laser beam or a multi-laser module of the bonding object transport module of the present invention.

6 is an optical system of 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 is incident on the beam shaper 430, the beam shaper 430 ), converts a spot-shaped laser beam into a flat-top-shaped surface light source A1, and a square laser beam A1 output from the beam shaper 430 passes through a concave lens 440 to a desired size. It is irradiated to the image-forming surface (S) with the enlarged surface light source (A2).

7 is a configuration 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 the surface light source B2 irradiated to the first imaging surface S1. If 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 enlargement, so that the final irradiation surface is the second imaging surface S2 ), the edge is trimmed by installing a mask 450 on the first imaging surface S1 in order to obtain the irradiated light with a clear 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 one or more convex and concave lenses, and the second imaging surface on which electronic components are disposed. A rectangular 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 passes through at least a pair of cylindrical lenses 470 and is enlarged (or reduced) in the x-axis direction, for example. (C2) and again passing through at least a pair of cylindrical lenses 480, for example, is reduced (or enlarged) in the y-axis direction and converted into a rectangular-shaped surface light source C3.

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

Then, 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 one or more convex and concave lenses, and the second imaging surface S2 on which electronic components are disposed. ) to form a rectangular irradiation light C4.

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

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 the final surface light source D5 having a sharper edge can be obtained compared to the case of FIG. will be able

Hereinafter, Figure 10 is a perspective view schematically showing the entire device configuration of the laser pressurizing head module of the present invention, and Figure 11 is a sectional side view of the main portion of Figure 10 .

Hereinafter, with reference to the drawings, a detailed configuration of the laser pressurizing head module of the present invention and an operation relationship according to pressurization and laser beam irradiation will be described in detail according to an embodiment as follows.

Referring to the drawings, the pressing head of the present invention includes a light-transmitting pressing member 100 for transmitting the laser beam irradiated from the laser sources 310 and 320 in a state where the electronic component, which is the bonding object 11, is pressed and pressed. At this time, the light-transmitting pressing member 100 is installed in a state where it is inserted in the through hole formed in the central portion of the plate-shaped holder unit 500 to be replaced.

The holder unit 500 may be formed to have a circular or polygonal shape (see FIG. 12 ), but in FIGS. 10 and 11 , it is assumed that the holder unit 500 has an octagonal shape.

According to one embodiment, the press unit 700 is shaft-coupled to three points (P1, P2, P3) around the edge of the octagonal-shaped holder unit 500, respectively, at this time, the point at which the press unit is shaft-coupled. When connected with an imaginary line (L), a triangle is formed.

At this time, the virtual triangle connecting the three points of the holder unit 500 may constitute an equilateral triangle, and the center of gravity (G) of the virtual triangle and the center of gravity (G) of the light-transmitting pressing member 100 coincide This is preferable.

The reason why the three-axis shaft coupling points (P1, P2, P3) are designed around the rim of the holder unit 500 is that when the two press units are shaft coupled, the shaft coupling points (P1, P2, P3) are stable when connecting Since a triangular structure cannot be formed (that is, when two points are connected, a line segment cannot be formed and an area cannot be formed), that is, the number of axial coupling points that require flatness control can be minimized while maintaining a stable shape of a virtual triangle. In order to configure the shaft coupling point, three shaft coupling points (P1, P2, P3) are precisely and symmetrically configured in the holder unit 500 .

Meanwhile, referring to FIG. 11 , the press unit 700 is a press bracket 720 having a predetermined height and shape, which is mounted on the upper end of the press bracket and presses the holder unit 500 downward by a set pressure. Cylinder 730, one end is coupled to the cylinder rod 731 of the pressure cylinder 730 and the other end is rotatably coupled to one of the three shaft coupling points P1, P2, P3 of the holder unit 500, respectively It is configured to include a bearing joint (780). At this time, the pressure cylinder may be a precision pneumatic cylinder (hereinafter referred to as a hole cylinder) capable of finely setting and adjusting the pressure in kgf units.

At this time, a pressure sensor 740 is further provided at the end of the cylinder rod 731 of each of the pressure cylinders 730 .

The pressure sensor 740 may be implemented as, for example, a load cell, and when the cylinder rod of each pressure cylinder 730 is drawn out and pressurizes each shaft coupling point of the holder unit 500, it is constantly pressed. Measured with the , it checks whether a pressure higher than an appropriate pressure is applied, and serves to feed it back to the control unit (not shown).

Meanwhile, a joint fastening part 510 is further provided at each of the three shaft coupling points of the holder unit 500 , and each joint fastening part 510 is pivotally coupled to the bearing joint 780 .

Therefore, as the cylinder rod 731 of the pressure cylinder 730 is drawn in or withdrawn, the bearing joint 780 pivotally coupled to the end of the cylinder rod 731 is also moved in the vertical direction, and thus the bearing joint ( The joint fastening part 510 and the holder unit 500 rotatably coupled to the 780 are also moved together.

Therefore, the holder unit 500 can be driven inclinedly by adjusting the length of the cylinder rod 731 of each pressure cylinder 730 to be different, and accordingly, the pressing force is also reduced by adjusting the contact height of the holder unit 500 . can be precisely adjusted.

In addition, the end of the joint fastening part 510 is caught by the stopper 790 provided at the lower end of the press bracket 720 and is seated. ) serves to maintain flatness when the holder unit 500 is vertically transported while being offset by spanning.

In addition, a vertical transfer unit is further provided on one side of the press bracket 720 to elevate the press bracket in a vertical direction.

Hereinafter, looking at the configuration of the vertical transfer unit according to an embodiment, a press bracket 720 installed at three shaft coupling points of the light-transmitting pressure member 100 and the holder unit 500, respectively, and a pressure cylinder installed on the press bracket ( 730), a ball screw 750 and a motor 760 for driving the press bracket 720 in the vertical direction, and a guide member 770 for guiding the linear motion of the press bracket 720. have.

With the above configuration, when the holder unit 500 is moved downward, the light-transmitting pressing member 100 mounted on the holder unit 500 is also moved downwardly, and the electronic component 11 located below it is pressed and pressed. It is understandable to do.

In addition, since the flatness of the holder unit 500 may be distorted by vibration generated during the reflow process or vibration when the light-transmitting pressure member 100 is replaced, a certain period or replacement of the light-transmitting pressure member 100 It is desirable to reset the flatness by resetting it to zero after doing so.

12A is a plan view of the main part of the holder unit of the laser pressure head module of the present invention formed in an octagon according to an embodiment.

First, the shape of the holder unit of the present invention may be a polygon, and may be basically a triangular shape connecting the three shaft coupling points (P1, P2, P3). In more detail, it can be formed in an equilateral triangle by forming the same length of an imaginary line connecting each of the three axis coupling points P1, P2, P3 and the center of gravity G for geometric symmetry.

In addition, in Fig. 12a, since the rectangular light-transmitting pressing member must be seated and accommodated inside the polygonal holder unit, the shape of the holder unit is provided in an octagonal shape to sufficiently accommodate the rectangular light-transmitting pressing member by providing a larger area than the light-transmitting pressing member. looks like

Therefore, the holder unit of the present invention is not limited to the octagonal shape shown in FIG. 12A, and may include a imaginary triangle connecting the three shaft coupling points P1, P2, and P3 in a planar shape. A triangle, a square, or an octagon. It may be implemented as a polygonal shape of various types, such as

On the other hand, Figure 12b is a plan view of the main part formed in a circular shape according to another embodiment of the holder unit of the present invention laser pressure head module.

In addition, the shape of the holder unit of the present invention may be a polygon, it is also possible to be formed in a circle according to another embodiment.

Therefore, even when the holder unit is formed in a circular shape as in FIG. 12b , the length of the virtual line connecting each of the three shaft coupling points (P1, P2, P3) around the holder unit edge and the center of gravity (G) is the same, so the holder unit This geometrical symmetry is achieved, and it is possible to precisely press and control each shaft coupling point while maintaining high flatness using only the minimum of three shaft coupling points (P1, P2, P3).

Therefore, as described above, the pressing head of the present invention performs reflow processing at once by irradiating the transmissive laser beam while simultaneously pressing and pressing the plurality of electronic components 11 using the transmissive pressing member 100 having a predetermined area. By being able to do this, there is an effect that the precision and productivity are greatly improved compared to the conventional method in which a small translucent pressing member is raised for each electronic component and pressed by its own weight.

In addition, the pressing force can be precisely adjusted by adopting a hole cylinder capable of precisely adjusting the pressing force in units of Kgf, and through this, the pressing force can be precisely adjusted by the operator according to various variable factors such as the bending state of the FPCB substrate. By adjusting the set pressure of the cylinder 730 differently, it is possible to easily adjust the pressure balance applied to the electronic components 11 disposed below the large-area light-transmitting pressing member 100 of the present invention compared to the prior art.

On the other hand, when a pressure greater than or equal to the set pressure is applied, unlike the pressure set in each of the pressure cylinders 730 , the pressure sensor 740 coupled to the end of the cylinder rod 731 of the pressure cylinder 730 detects this. Thus, it is fed back to the control unit (not shown).

Therefore, when a pressure above a certain level is sensed, the control unit performs auto-balancing processing to adjust to a set pressure value or generates an alarm so that the operator can easily adjust the set pressure of each of the pressurization cylinders 730 manually as needed do.

In addition, although not shown in FIGS. 10 to 12 , the holder unit 500 , the light-transmitting pressing member 100 , and the press unit 700 are installed in the light-transmitting pressing member transfer unit 140 and the support unit 150 as previously described in FIG. 2 . can be The light-transmitting pressing member transfer unit 140 may be implemented to be vertically transferred in the vertical direction by, for example, a vertical transfer means (eg, a motor and a ball screw device), and the support unit 150 may be implemented as a gantry device, for example. can be

Therefore, when the electronic component and the substrate, which are the bonding object 11, are put in, the holder unit 500, the light-transmitting pressing member 100, and the press unit 700 are vertically transported upward so that the bonding object 11 is the light-transmitting pressing member. (100), and after the bonding object 100 is put in to the position directly below the pressing member 100, the holder unit 500, the light-transmitting pressing member 100, and the press unit ( 700) is positioned in a standby state for pressurization as it is vertically transported downward again to a position close to the bonding object 11.

In addition, the present invention is not limited only by the above-described embodiment, and since it is possible to create the same effect even when changing the detailed configuration or number and arrangement of the device, those of ordinary skill in the art will present the present invention It is specified that various additions, deletions, and modifications are possible 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: joint fastening part
700: press unit 720: press bracket
730: pressure cylinder 740: pressure sensor
780: bearing joint 790: stopper

Claims (13)

A laser pressure 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 light-transmitting pressure member and simultaneously irradiating a laser beam through the pressure member,
a circular or polygonal holder unit for replacing the light-transmitting pressing member; and
A press unit that is shaft-coupled to three points around the edge of the holder unit and forms a triangle when connecting the shaft-coupled points with an imaginary line,
The press unit,
press bracket;
a pressure cylinder mounted on the upper end of the press bracket to press the holder unit downward by a set pressure; and
One end is coupled to the cylinder rod of the pressure cylinder and the other end includes a bearing joint rotatably coupled to one of three points of the holder unit,
Laser pressurized head module of laser reflow device. delete The method of claim 1,
The pressure cylinder is a precision pneumatic cylinder capable of finely setting and adjusting the pressing force in kgf unit is adopted,
Laser pressurized head module of laser reflow device. The method of claim 1,
A joint fastening part is further provided at each of the three points of the holder unit, and each joint fastening part is rotatably coupled to a bearing joint,
Laser pressurized head module of laser reflow device. 5. The method of claim 4,
A stopper is further provided at the lower end of the press bracket, and one end of the joint fastening part is spread over the stopper,
Laser pressurized head module of laser reflow device. The method of claim 1,
At one side of the press bracket, a vertical transfer unit for elevating and lowering the press bracket in a vertical direction is further provided,
Laser pressurized head module of laser reflow device. 7. The method of claim 6,
The vertical transfer unit is configured to include a ball screw and a motor,
Laser pressurized head module of laser reflow device. The method of claim 1,
The flatness of the holder unit is reset to zero after a certain period or after replacing the light-transmitting pressing member,
Laser pressurized head module of laser reflow device. The method of claim 1,
The virtual triangle connecting the three points of the holder unit is an equilateral triangle, and the center of gravity of the virtual triangle coincides with the center of gravity of the light-transmitting pressing member,
Laser pressurized head module of laser reflow device. The method of claim 1,
The laser beam is irradiated by overlapping laser beams from two or more laser sources,
Laser pressurized head module of laser reflow device. The method of claim 1,
A lower portion of the light-transmitting pressure member, further comprising a protective film preventing gas (fumes) generated during laser bonding from sticking to the bottom surface of the light-transmitting pressure member,
Laser pressurized head module of laser reflow device. 12. The method of claim 11,
The protective film is implemented with polytetrafluoroethylene resin (PTFE) or perfluoroalkoxy resin (PFA),
Laser pressurized head module of laser reflow device. 13. The method of claim 12,
The protective film is supplied by a protective film transfer unit of a reel-to-reel method, which transfers to one side while unwinding the protective film wound in a roll form,
Laser pressurized head module of laser reflow device.

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