Laser reflow method

Abstract

To improve the failure rate of a laser reflow device.SOLUTION: A laser reflow device according to the present invention, comprises: a laser pressurization head module that presses a bonding object formed of a plurality of electronic components arranged on a substrate by a light transmissive pressurization member, while irradiating a laser beam via the pressure member to bond the electronic components to the substrate; and a bonding object transfer module that transfers the bonding object in order to transfer the bonding object having transferred from one side of the laser pressurization head module to the other side thereof after passing through a reflow process of the laser pressurization head module.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laser reflow apparatus and a laser reflow method. More specifically, the present invention relates to a laser reflow apparatus that pressurizes a plurality of electronic components arranged on a substrate with a light-transmitting pressing member and irradiates the components with a laser to simultaneously bond and pressurize the electronic components, and a laser reflow method using this apparatus.

Background Art

[0002] In industrial laser processing, an application field with micron (μm)-level accuracy is micro laser processing, which is widely used in the semiconductor industry, display industry, printed circuit board (PCB) industry, smartphone industry, etc. Memory chips used in all electronic devices have seen the development of technology to minimize the circuit interval in order to achieve integration density, performance, and ultra-high-speed communication speed. However, currently, the technology of simply reducing the circuit line width and the interval between line widths cannot reach the required level, and the technology has been improved to the level of vertically stacking memory chips. The stacking technology up to 128 layers has already been developed by TSMC, and the technology of stacking up to 72 layers has been applied to mass production by Samsung Electronics, SK Hynix, etc.

[0003] In addition, the research and development of technologies for mounting memory chips, microprocessor chips, graphic processor chips, wireless processor chips, sensor processor chips, etc. in one package are in full swing, and a considerable level of technology has already been put into practical use.

[0004] However, in the development process of the aforementioned technology, since more electrons must be involved in the signal processing process inside the ultra-high speed / ultra-high capacity semiconductor chip, the power consumption increases, and the problem of cooling treatment for heat generation is raised. Furthermore, in order to achieve the requirements of ultra-high speed signal processing and ultra-high frequency signal processing for more signals, a technical problem has been raised that a large amount of electrical signals must be transmitted at ultra-high speed. Also, the number of signal lines must increase, and the signal interface lines to the outside of the semiconductor chip can no longer be processed by the one-dimensional lead wire method. The ball grid array (BGA) method (Fan-In BGA) that processes two-dimensionally at the bottom of the semiconductor chip or the method called Fan-in Wafer-Level-Package (FIWLP), and the method of placing a signal layout redistribution layer under the ultra-fine BGA layer at the bottom of the chip and providing a secondary fine BGA layer below it (referred to as Fan-out BGA or Fan-out Wafer-Level-Package (F0WLP) or Fan-out Panel-Level-Package (FOPLP)) are applied.

[0005] In recent years, in the case of semiconductor chips, products with a thickness of 200 μm or less, including the EMC (Epoxy-Mold Compound) layer, have emerged. In order to attach such a micron-level ultra-hard thin semiconductor chip with a thickness of only a few hundred microns to an ultra-hard thin PCB, when applying a mass reflow (MR) process such as the thermal reflow oven technology, which is a conventional surface mount technology (SMT) standard process, the semiconductor chip is exposed to an air temperature environment of 100 to 300 degrees (°C) for several hundred seconds. Therefore, various forms of soldering bonding failures may occur, such as chip-boundary warpage, PCB-boundary warpage, and random-bonding failure by thermal shock due to the difference in the coefficient of thermal expansion (CTE).

[0006] Therefore, recently, looking at the configuration of the laser reflow device that has been in the spotlight, in the method of bonding by irradiating a laser while pressing the bonding object (semiconductor chip or integrated circuit IC) with the laser head module for several seconds, bonding is performed by irradiating a laser in the form of a surface light source corresponding to the size of the semiconductor chip or integrated circuit (IC).

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

[0008] Regarding such a laser reflow apparatus with a pressurization method, referring to Patent Document 1, while irradiating the back surface of a flip chip with a laser to heat the flip chip, a configuration of a flip chip heating and pressing module for pressing the flip chip onto a carrier substrate is disclosed.

[0009] However, the conventional laser reflow apparatus with a pressurization method disclosed in Patent Document 1 is separated into means for adsorbing a chip and moving it to a bonding position, and means for heating the back surface of the chip via a laser and pressing the chip onto a carrier substrate. Therefore, when bonding a plurality of semiconductor chips such as a semiconductor strip, it is necessary to repeat the operation of irradiating a laser while pressing one semiconductor chip by the number of semiconductor chips, so there is a problem that the working time increases.

[0010] On the other hand, referring to Patent Document 2, the laser reflow apparatus configuration described in the same patent states that bonding processing is possible in a manner where the laser head conveys horizontally while the pressing head presses a plurality of flip chips simultaneously and irradiates each flip chip with a laser one by one in sequence, or a single laser head irradiates a plurality of flip chips with a laser simultaneously.

[0011] However, according to the conventional laser reflow apparatus configuration of Patent Document 2 described above, since a single laser source is used, it is difficult to irradiate a uniform laser beam because the laser beam enters a plurality of flip chips arranged on a substrate at a plurality of angles. Therefore, it is expected that there will be many technical difficulties in uniformly performing reflow processing on a plurality of flip chips without defects.

[0012] Therefore, in the conventional laser reflow apparatuses disclosed in Patent Documents 1 and 2, while sequentially pressurizing and irradiating a single flip chip one by one, the overall working time is prolonged. On the other hand, even when irradiating a single laser beam onto a plurality of flip chips horizontally arranged in various substrate sizes for a plurality of processes, it is virtually difficult to transfer uniform thermal energy to each flip chip. Therefore, in order to improve the bonding failure rate, a great deal of research and development and efforts are required.

Summary of the Invention

Problems to be Solved by the Invention

[0013] Therefore, the present invention has been invented to solve the above problems. The present invention is configured such that the size of the pressurization and laser projection area processed at one time can be easily adjusted by replacing the translucent pressurizing member so as to correspond to the sizes of various substrates. Therefore, an object of the present invention is to provide a laser pressurizing head module for a laser reflow apparatus in which a large amount of processing can be performed simultaneously on a plurality of electronic components by pressurization and laser reflow, while the failure rate is significantly improved.

[0014] Another object of the present invention is to provide a laser pressurizing head module for a laser reflow apparatus in which a large amount of processing can be performed while irradiating a homogenized laser beam while simultaneously pressurizing a plurality of electronic components, and the failure rate is significantly improved.

[0015] Further, the present invention is configured such that the pressure can be set and adjusted independently for each edge portion of a plate-shaped holder unit to which a translucent pressurizing member is attached so as to correspond to the sizes of various substrates. Therefore, an object of the present invention is to provide a laser pressurizing head module for a laser reflow apparatus in which a large amount of processing can be performed by simultaneously pressurizing a plurality of electronic components and irradiating a laser beam and performing a reflow process at one time, while the failure rate is significantly improved.

[0016] The present invention is configured such that, regardless of the size of a bonding object on which a plurality of electronic components are seated on a substrate, a conveyor system can carry the bonding object into and out of a reflow processing area at once, and the bonding object is gradually preheated to a predetermined temperature during conveyance for loading, so that a stable temperature rise up to the solder melting temperature is achieved without defects during laser reflow processing. Therefore, an object of the present invention is to provide a laser reflow apparatus that can perform a large amount of processing by simultaneously pressing a plurality of electronic components and irradiating them with a laser beam to perform reflow processing at once, while significantly improving the defect rate.

[0017] The present invention is configured to immediately detect and compensate for the temperature imbalance between the substrate and the electronic components constituting the bonding object by precisely monitoring the area where the multi-laser beam is superimposed and irradiated with a plurality of temperature sensing sensors, thereby preventing bonding defects of specific electronic components. As a result, an object of the present invention is to provide a multi-laser module for a laser reflow apparatus that can perform a large amount of processing by simultaneously pressing a plurality of electronic components and irradiating them with a laser beam to perform reflow processing at once, while significantly improving the bonding defect rate due to temperature imbalance.

[0018] The present invention adjusts the arrangement shape of the electronic components located below the translucent pressing member before pressing so that it is located at the center of the pressing surface of the translucent pressing member, so that the pressure transmitted to the electronic components during pressing by the translucent pressing member is evenly distributed without being biased to one side. Therefore, an object of the present invention is to provide a laser reflow method for a laser reflow apparatus that can perform a large amount of processing by simultaneously pressing a plurality of electronic components and irradiating them with a laser beam to perform reflow processing at once, while significantly improving the defect rate.

[0019] The present invention is to provide a laser reflow method for a laser reflow apparatus that can perform a large amount of reflow processing on a plurality of electronic components at once without bonding defects by sequentially controlling the pressing and laser beam irradiation processes according to preset conditions, while significantly improving the defect rate.

Means for Solving the Problem

[0020] To achieve the above object, the present invention pressurizes a bonding object composed of a plurality of electronic components arranged on a substrate with a light-transmitting pressure member, and irradiates a laser beam through the pressure member to bond the electronic components to the substrate, a laser pressurizing head module, and a bonding object transfer module that transfers the bonding object to carry out the bonding object carried in from one side of the laser pressurizing head module to the other side through the reflow process of the laser pressurizing head module.

[0021] Further, the laser pressurizing head module includes a holder unit for detachably attaching the light-transmitting pressure member, and a probe unit provided above the holder unit for inspecting the flatness of the pressure member mounted on the holder unit.

[0022] Further, the laser beam is a square laser beam homogenized by a beam shaper.

[0023] Further, the laser beam is irradiated with laser beams superimposed from two or more laser modules.

[0024] Further, the holder unit includes a lower plate plate having a through hole formed in the central portion so that the light-transmitting pressure member can be fitted, locked, and seated.

[0025] Further, the light-transmitting pressure member can be realized by any one of Quartz, Sapphire, Fused Silica Glass, or Diamond.

[0026] Further, the holder unit further includes a mask plate that is coupled to the upper portion of the lower plate with the light-transmissive pressing member seated thereon, and has a vent hole formed at the center thereof through which a laser beam passes.

[0027] Further, the through hole of the mask plate has a rectangular shape having an area equal to or larger than the pressing surface of the light-transmissive pressing member.

[0028] Further, the bottom surface of the lower plate has a shape in which the left and right edge portions are gently rounded.

[0029] Further, flatness adjusting means for adjusting the flatness of the light-transmissive pressing member by finely moving the edge of the lower plate in the vertical direction is further provided at each edge portion of the lower plate.

[0030] Further, the flatness adjusting means includes press brackets provided at each edge portion of the light-transmissive pressing member and the holder unit, and a vertical driving unit provided on one side of the press bracket and configured to convey the press bracket in the vertical direction in response to the driving of a motor.

[0031] Further, the vertical driving unit includes a ball screw and a motor for vertical conveyance of the press bracket, and a guide member for guiding the linear motion of the press bracket.

[0032] Further, the probe unit includes a probe for measuring flatness by piercing at least one or more points on the upper surface of the light-transmissive pressing member, a moving means for moving the probe horizontally or vertically, and a probe bracket for fixing the probe and the moving means.

[0033] Further, the probe probes by piercing at least four points including the edge points of the square on the upper surface of the light-transmissive pressing member.

[0034] Further, a protective film is further provided below the translucent pressing member to prevent gas (fumes) generated during laser bonding from adhering to the bottom surface of the translucent pressing member.

[0035] Further, the protective film can be realized by polytetrafluoroethylene resin (PTFE) or perfluoroalkoxy resin (PFA).

[0036] Further, the protective film is supplied by a reel-to-reel type protective film conveyance unit that conveys the rolled protective film to one side while unwinding it.

[0037] Further, the translucent pressing member includes a base material having a generally square panel shape as a whole, and a pressing surface that is formed to protrude from the bottom surface of the base material and is formed in a planar shape so that the bottom surface corresponds to a plurality of electronic components.

[0038] Further, between the base material and the pressing surface, at least one or more stepped portions that are recessed inward so that the area of the pressing surface is narrower than the area of the base material are further provided.

[0039] Further, a laser light blocking layer is formed on the side surface of the base material, the bottom surface, and the side surface of the stepped portion.

[0040] Further, the pressing surface is divided into two or more parts by lattice grooves having a certain depth.

[0041] Further, a laser light blocking layer is further formed on the inner surface and the bottom surface of the lattice grooves.

[0042] Further, the laser light blocking layer is composed of one or two or more composite layers selected from an Inconel coating layer, a diffuse reflection processed layer, or an HR (High Reflection) coating layer.

[0043] Further, the pressing surface has a square shape.

[0044] Furthermore, the edges on both sides of the pressing surface are chamfered or rounded.

[0045] In addition, an elastic damper layer is further provided on the pressing surface.

[0046] Also, the elastic damper layer can be realized with a silicon material.

[0047] The laser pressing head module includes a rectangular holder unit for detachably mounting a light-transmissive pressing member, and a pressure balancer that initializes the self-weights of the holder unit and the light-transmissive pressing member to the zero point by pressing the self-weights of the holder unit and the light-transmissive pressing member in the opposite direction while supporting the lower ends of the edges of the holder unit, and further includes a press unit that is provided in a non-contact state above each edge of the holder unit and presses each edge of the holder unit with a set pressure independently.

[0048] Also, the pressure balancer is composed of an air cylinder.

[0049] Also, the pressure balancer is composed of an elastic spring.

[0050] And the press unit is arranged separately, one for each edge, so as to press each edge of the holder unit with a set pressure independently.

[0051] Also, the press unit includes a press bracket that non-contactly grips each edge portion of the holder unit, and a pressing cylinder that is attached to the upper end of the press bracket and presses the holder unit downward by a set pressure respectively.

[0052] Also, a precision pneumatic cylinder that can finely set and adjust the pressing force in kgf units is adopted for the pressing cylinder.

[0053] And, the pressure cylinder is further provided with a pressure sensing sensor for measuring the pressure during pressurization and constantly feeding back the pressure.

[0054] Also, above the holder unit, an ionizer unit is further provided for cleaning the upper surface of the light-transmissive pressurizing member from dust adsorption by static electricity.

[0055] Also, the bonding object transfer module includes an input conveyor on which a bonding object composed of a plurality of electronic components arranged on a substrate seats for loading, vacuum chucking means for vacuum-adsorbing and fixing the bonding object supplied from the input conveyor, and an output conveyor on which the bonding object after the laser reflow process seats for unloading.

[0056] Furthermore, the input and output conveyors include a conveyor frame, a pair of wire track means provided on both sides at the upper part of the conveyor frame, and horizontal transfer means provided on one side of the conveyor frame for linearly moving the conveyor frame in the horizontal direction.

[0057] Also, on one side of the conveyor frame of the input and output conveyors, width adjustment means is further provided so that the width of the conveyor frame can be expanded or reduced to accommodate bonding objects of different sizes.

[0058] And, the conveyor frame of the input conveyor is further provided with a preheating stage for preheating the bonding object to a predetermined temperature.

[0059] Also, on one side of the vacuum chucking means, a vision unit is further provided for monitoring the presence or absence of normal loading of the bonding object.

[0060] Furthermore, a picker unit for transporting each bonding object is further provided in the section between the input and output conveyors and the vacuum chucking means.

[0061] The picker unit further includes a vacuum suction pad on a flat plate and a vertical drive unit for vertically transporting the vacuum suction pad.

[0062] The vacuum chucking means further includes a porous suction plate for adsorbing and fixing the bonding object, and a horizontal conveying means for reciprocally moving the porous suction plate and the heating block from the input region of the bonding object through the laser reflow processing region to the output region.

[0063] The porous suction plate is formed by being divided into a rectangular central suction plate for adsorbing the central portion of the bottom surface of the bonding object, and an edge suction plate arranged so as to surround the periphery of the central suction plate and adsorbing the bottom edge of the bonding object.

[0064] Furthermore, suction holes for adsorbing the bottom edge of the bonding object are further formed in the edge suction plate.

[0065] The edge suction plate is formed of an aluminum material.

[0066] Furthermore, a heating block is further provided below the porous suction plate.

[0067] The laser pressurization head module further includes a multi-laser module that superimposes and irradiates a plurality of laser beams on the bonding object in a state of being divided from each other, and a temperature sensing sensor that is provided in the region between the multi-laser modules and senses the temperature of a plurality of points on the bonding object by irradiating the beam through a light-transmitting pressurizing member.

[0068] Further, the multi-laser module is composed of a pair of multi-laser modules facing each other.

[0069] Further, the temperature sensing sensor is composed of a single infrared temperature sensing sensor, and the single infrared temperature sensing sensor sequentially irradiates infrared rays to a plurality of points of the bonding object.

[0070] Further, the single infrared temperature sensing sensor sequentially irradiates infrared rays to a plurality of points in the peripheral and central portions within the region where a plurality of laser beams are superposed and irradiated.

[0071] Further, the temperature sensing sensor is composed of a plurality of infrared temperature sensing sensors, and the plurality of infrared temperature sensing sensors simultaneously irradiate infrared rays to a plurality of points of the bonding object.

[0072] In addition, the plurality of infrared temperature sensing sensors simultaneously irradiate infrared rays to a plurality of points in the peripheral and central portions within the region where a plurality of laser beams are superposed and irradiated.

[0073] Furthermore, the multi-laser module further includes a beam profiler for measuring the output and intensity of each laser beam.

[0074] Also, in a laser reflow method of a laser reflow apparatus for bonding electronic components to a substrate by pressing a bonding object having a plurality of electronic components arranged on a rectangular substrate with a light-transmissive pressing member and irradiating a laser beam through the pressing member, a) before the light-transmissive pressing member presses the bonding object, a step of photographing the shape in which electronic components are arranged in a predetermined range located directly below the pressing surface of the light-transmissive pressing member by the vision unit; b) a step of determining that the photographed shape in which the electronic components are arranged is positioned so as to correspond to the pressing surface; c) when it is determined that the electronic components are positioned so as to correspond to the pressing surface, a step of moving the light-transmissive pressing member downward to press the bonding object and irradiating the bonding object with a laser beam through the light-transmissive pressing member; d) a step of moving the light-transmissive pressing member upward to release the pressing state by stopping the irradiation of the laser beam; and e) a step of horizontally transporting the light-transmissive pressing member above electronic components in a predetermined range to be reflowed next.

[0075] Further, in the step b), b1) a step of determining whether or not the electronic components are symmetrically positioned with respect to the center line of the pressing surface of the light-transmissive pressing member when the photographed shape in which the electronic components are arranged in the predetermined range is viewed from the side; and b2) when the photographed shape in which the electronic components are arranged is symmetrically positioned with respect to the center line of the pressing surface of the light-transmissive pressing member, determining that it is positioned so as to correspond to the pressing surface, and when it is not positioned so as to correspond to the pressing surface, adjusting the horizontal position of the light-transmissive pressing member so that the shape in which the electronic components are arranged is symmetrically positioned with respect to the center line of the pressing surface of the light-transmissive pressing member.

[0076] In addition, the laser beam is superimposed and irradiated from two or more laser modules.

[0077] Furthermore, the laser modules are arranged symmetrically with respect to each other, and the laser beams have the same beam irradiation angle.

[0078] In addition, laser beams are simultaneously irradiated from each of the laser modules.

[0079] In addition, laser beams are sequentially irradiated from each of the laser modules.

[0080] In addition, before the step c), a step of preheating the bonding object at the lower part is further provided.

[0081] In addition, in the step of preheating the bonding object at the lower part, the surface temperature of the bonding object is maintained below 200°C.

[0082] In addition, in the step c), by irradiating the bonding object with a laser beam through a light-transmissive pressing member, the surface temperature of the bonding object is heated to 200°C or higher.

[0083] In addition, in a laser reflow method of a laser reflow apparatus for bonding electronic components to a substrate by pressing a bonding object having a plurality of electronic components arranged on a rectangular substrate with a light-transmissive pressing member and irradiating the pressing member with a laser beam, a) a step of moving the pressing surface of the light-transmissive pressing member downward and bringing it into contact with the bonding object without applying a pressing force; b) a step of irradiating the bonding object with a laser beam through the light-transmissive pressing member; and c) a step of releasing the irradiation of the laser beam and moving the light-transmissive pressing member upward are provided.

[0084] In addition, after the step a), a step of fixing the vertical movement of the light-transmissive pressing member is further provided.

[0085] In addition, after the step a), a predetermined set constant pressure is applied to the light-transmissive pressing member, and after the step b), a step of not fixing the vertical movement of the light-transmissive pressing member is further provided.

[0086] In addition, after the step a), the vertical movement of the light-transmissive pressing member is fixed, and after the step b), a step of applying a predetermined set constant pressure to the light-transmissive pressing member is further provided.

[0087] Further, after the step a), the vertical movement of the light-transmitting pressing member is fixed, and after the step b), there is a step of not fixing the vertical movement of the light-transmitting pressing member.

[0088] Further, in the step b), laser beams are superimposed and irradiated from two or more laser modules.

[0089] Further, laser beams are simultaneously irradiated from each of the laser modules.

[0090] Further, laser beams are sequentially irradiated from each of the laser modules.

[0091] Further, before the step b), there is a step of preheating the bonding object at the lower part.

[0092] Further, in the step of preheating the bonding object at the lower part, the surface temperature of the bonding object is maintained below 200°C.

Advantages of the Invention

[0093] The present invention described above can simultaneously hold and press a plurality of electronic components and irradiate a uniform laser beam to transmit equal thermal energy to the plurality of electronic components, and has the effect of significantly improving productivity by a large-scale laser reflow process.

[0094] Further, since the mask plate and the light-transmitting pressing member can be replaced so as to be able to cope with the size of the substrate and the arrangement shape of the electronic components, there is an effect that the defect rate is significantly reduced by uniformly performing the reflow process on all various substrates.

[0095] Further, since the problem that the peripheral part of the substrate of the electronic component is thermally damaged by the laser beam leaking out at the edge of the quartz constituting the pressing member and the deterioration of the substrate and the components is accelerated can be prevented, there is an effect that the defect rate is significantly reduced.

[0096] In addition, by configuring the pressure applied to each edge portion of the holder unit to which the translucent pressing member is attached to be independently set and adjusted, the defect rate caused by insufficient pressure acting on a plurality of electronic components arranged on the substrate or by applying excessive pressure is significantly improved.

[0097] In addition, there is an effect that a bonding object having a certain area on which a plurality of electronic components are seated on the substrate can be stably carried in and out of the laser reflow processing area at once.

[0098] In addition, by monitoring the temperature imbalance in the overlapping irradiation area of the multi-laser beam and immediately detecting and repairing it, the bonding defect rate is significantly improved.

[0099] In addition, the position of the translucent pressing member is adjusted so that the electronic component is not pressed down due to tilting to one side and the pressure is not evenly distributed. As a result, the defect rate caused by uneven pressure acting on a plurality of electronic components arranged on the substrate is significantly improved.

[0100] In addition, by precisely controlling the pressing by the translucent pressing member and the laser beam irradiation by the laser module in sequence according to the set reference values, various bonding defects such as poor solder contact and overflow caused by insufficient pressing force or excessive pressure acting on a plurality of electronic components arranged on the substrate are significantly improved.

Brief Description of the Drawings

[0101]

Figure 1

[0102]

Figure 2

[0103]

Figure 3

[0104]

Figure 4

[0105]

Figure 5

[0106]

Figure 6

Figure 9

[0107]

Figure 10

[0108]

Figure 11

[0109]

Figure 12

[0110]

Figure 13

[0111]

Figure 14

[0112]

Figure 15

[0113]

Figure 16a

[0114]

Figure 16b

[0115]

Figure 17

[0116]

Figure 18

[0117]

Figure 19

[0118]

Figure 20a

Figure 20c

[0119]

Figure 21

[0120]

Figure 22

[0121]

Figure 23

[0122]

Figure 24

[0123]

Figure 25

[0124]

Figure 26a

Figure 26b

[0125]

Figure 27

[0126]

Figure 28

[0127]

Figure 29

[0128]

Figure 30a

Figure 30e

[0129]

Figure 31a

Figure 31d

[0130]

BEST MODE FOR CARRYING OUT THE INVENTION

[0131] The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly has a different meaning. In this specification, terms such as "comprising", "having", or "providing" specify the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in this specification, and it should be understood that the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof is not precluded in advance.

[0132] Unless otherwise defined herein, all terms used in this specification, including technical and scientific terms, shall have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains.

[0133] Terms defined as in commonly used dictionaries shall be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted as having an ideal and overly formal meaning unless clearly defined herein.

[0134]

[0135] Hereinafter, with reference to the attached FIGS. 1 and 2, the laser reflow apparatus according to the present invention will be specifically described as follows.

[0136] FIG. 1 is an exemplary diagram showing the overall configuration of the laser reflow apparatus according to the present invention, and FIG. 2 is a block configuration diagram of FIG. 1.

[0137] The laser pressurization head module 300 of the laser reflow apparatus according to the present invention is supported by a porous material or a stage 111 having a structure capable of applying heat to the lower part, as shown in FIGS. 1 and 2, and is irradiated with a laser in the form of a surface light source onto a bonding object 11 that is conveyed while being supported. It includes at least one or more multi-laser modules 310 and 320, a light-transmitting pressurizing member 100 that is installed separately from the laser modules 310 and 320 and transmits a laser in the form of a surface light source, and a protective film 200 that protects the light-transmitting pressurizing member 100 from contamination.

[0138] First, the plurality of multi-laser modules 310 and 320 convert a laser generated by a laser oscillator and transmitted through an optical fiber into a surface light source and irradiate the bonding object 11. The laser modules 310 and 320 include a beam shaper (see FIG. 5) that converts a laser in the form of a spot into a surface light source, and a plurality of lens modules are arranged in the lens barrel at appropriate intervals from each other so that the surface light source emitted from the beam shaper irradiates the irradiation region of the bonding object (11). It can be realized by including an optical part (see FIGS. 5 to 9).

[0139] The laser modules 310 and 320 can move up or down 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.

[0140] The laser pressurization head module 300 of the laser reflow apparatus according to the present invention forms the light-transmissive pressurization member 100 that pressurizes the bonding object 11 and the laser modules 310 and 320 that irradiate the bonding object 11 with a surface light source form of laser separately from each other. After moving the laser modules 310 and 320 to a plurality of irradiation positions of the bonding object 11 in a state where the bonding object 11 is pushed down by the light-transmissive pressurization member 100 and then driving them, it is possible to shorten the tact time for one bonding object 11 and speed up the bonding operation for the entire plurality of bonding objects 11.

[0141] At that time, the light-transmissive pressurization member 100 is transported to the working position or the standby position by a light-transmissive pressurization member transport unit (not shown) in a predetermined form. As an example, the light-transmissive pressurization member transport unit can lower or raise the light-transmissive pressurization member 100, move it left and right, and then lower or raise it.

[0142] Although not shown in the drawings, the laser pressurization head module 300 of the laser reflow apparatus according to the present invention further includes a control unit (not shown) that controls the operation of the light-transmissive pressurization member transport unit using data input from a pressure sensing sensor (not shown) and a height sensor (not shown).

[0143] The pressure sensing sensor and the height sensor can be provided on the light-transmissive pressurization member 100, the light-transmissive pressurization member transport unit, and the stage 111 that supports the bonding object. For example, the control unit can receive data from the pressure sensing sensor and control the light-transmissive pressurization member transport unit so that the pressure reaches the target value, and can also receive data from the height sensor and control the light-transmissive pressurization member transport unit so that the height reaches the target value.

[0144] Further, a support part (not shown) supports a light-transmissive pressure member conveying part (not shown) movably. In one example, the support part can be implemented by a pair of gantries extending alongside the stage 111, and should be interpreted as including a configuration that supports the light-transmissive pressure member conveying part movably in the x-axis, y-axis, or z-axis.

[0145] The laser pressure head module 300 of the laser reflow apparatus according to the present invention can be realized by including one or more actuators that apply pressure to the light-transmissive pressure member 100, at least one pressure sensing sensor that senses the pressure exerted on the light-transmissive pressure member 100, and one or more height sensors that detect the height of the light-transmissive pressure member. The pressure sensing sensor can be realized by at least one load cell as an example, and the height sensor can be realized by a linear encoder.

[0146] When adjusting the pressure applied to the bonding object through the pressure sensing 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 sensing sensors, and also to confirm the height position value at the moment when the bonding object is bonded through one or more height sensors, or to provide technical data for finding a more accurate bonding height value, and to execute a function that can control the accurate height when performing a process that must maintain a certain height interval.

[0147] Further, the light-transmissive pressure member 100 can be realized as a base material that transmits the laser output from the laser modules 310 and 320. The base material of the light-transmissive pressure member 100 can be realized by any beam-transmissive material.

[0148] The base material of the light-transmissive pressure member 100 can be realized by, for example, any one of Quartz, sapphire, Fused Silica Glass, or diamond. However, the physical properties of the light-transmissive pressure member realized with a Quartz material are different from those of the light-transmissive pressure member realized with sapphire. For example, when irradiating with a 980 nm laser, the transmittance of the light-transmissive pressure member realized with a Quartz material is 85% - 99%, and the temperature measured on the bonding object is 100°C. On the other hand, the transmittance of the light-transmissive pressure member realized with sapphire is 80% - 90%, and the temperature measured on the bonding object is 60°C.

[0149] In other words, from the viewpoints of light transmittance and heat loss required for bonding, Quartz shows better performance than sapphire. However, when the present applicant inventor repeatedly tested the light-transmissive pressure member 100 while developing a laser reflow apparatus, it was found that the light-transmissive pressure member 100 realized with a Quartz material had problems such as cracks occurring or combustion occurring on the bottom surface during laser bonding, resulting in poor bonding quality. This was analyzed to be that the gas generated during laser bonding adhered to the bottom surface of the light-transmissive pressure member 100, and the laser heat source concentrated on the part where the gas adhered, increasing the thermal stress.

[0150] In order to prevent damage to the light-transmissive pressure member 100 realized with a Quartz material and improve durability, a thin film coating layer can be formed on the bottom surface of the light-transmissive pressure member realized with a Quartz material. The thin film coating layer formed on the bottom surface of the light-transmissive pressure member 100 can be implemented with a dielectric coating, which is a normal optical coating, or a SiC coating, or a metal material coating.

[0151] As shown in Fig. 1, the laser pressurization head module 300 of the laser reflow apparatus according to the present invention further includes a protective film 200 that prevents the gas (fumes) generated during laser bonding from adhering to the bottom surface of the translucent pressurizing member 100 below the translucent pressurizing member 100, and a protective film conveyance unit 210 that conveys the protective film 200.

[0152] The protective film conveyance unit 210 can be realized by a reel-to-reel method that conveys the protective film 200 wound in a roll shape to one side while unwinding it. The protective film 200 is an example, and it is preferably made of a material with a maximum use temperature of 300 degrees Celsius or higher and a continuous maximum use temperature of 260 degrees Celsius or higher, having excellent heat resistance. For example, the protective film 200 can be made of polytetrafluoroethylene resin (usually also called Teflon resin; polytetrafluoroethylene, PTFE) or perfluoroalkoxy resin. Perfluoroalkoxy resin (Per Fluroro Alkylvinvether copolymer; PFA) is a product that improves the heat resistance of fluorinated ethylene propylene resin, and its continuous maximum use temperature is recorded at the same 260 degrees Celsius as that of polytetrafluoroethylene resin, and it is a high-functional resin.

[0153]

[0154] Fig. 3 is a conceptual diagram of a single laser module according to an embodiment of the laser reflow apparatus according to the present invention, and Fig. 4 is a conceptual diagram of a multi-laser module according to another embodiment of the laser reflow apparatus according to the present invention.

[0155] Referring to Fig. 3, the present invention includes a single laser module 310 according to an embodiment, and thereby irradiates a single laser beam onto a PCB (Printed Circuit Board) substrate. According to an embodiment, the PCB substrate can be a flexible circuit board (Flexible PCB).

[0156] At this time, referring to FIG. 3, the laser beam irradiated by the first laser module 310 is irradiated onto the substrate in a state where it is deformed into a square beam shape with the intensity of the laser beam homogenized.

[0157] On the other hand, referring to FIG. 4, a multi-laser module according to another embodiment of the present invention is composed of, for example, a first laser module 310 and a second laser module 320. At the position where the electronic component of the bonding object 11 is attached, a superimposed laser beam homogenized by irradiating in a state where the first and second laser modules are superimposed is irradiated.

[0158] In FIG. 4, it is shown that the first laser beam is square and the second laser beam is circular, but both laser beams may be square. Also, the first and second laser beams may be irradiated simultaneously, or the second laser beam may be sequentially irradiated after preheating the bonding object 11 with the first laser beam.

[0159]

[0160] FIG. 5 is a configuration diagram of a multi-laser module according to another embodiment of the laser reflow apparatus according to the present invention.

[0161] In FIG. 5, each laser module 310, 320,... 330 includes a laser oscillator 311, 321, 331, a beam shaper 312, 322, 332, an optical lens module 313, 323, 333, a drive device 314, 324, 334, a control device 315, 325, 335, and a power supply unit 317, 327, 337, each provided with a cooling device 316, 326, 336.

[0162] Hereinafter, except when necessary, in order to avoid duplicate explanations, among the laser modules having the same configuration, the first laser module 310 will be mainly described.

[0163] The laser oscillator 311 generates a laser beam having a wavelength and output power within a predetermined range. The laser oscillator can be, for example, a diode laser (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-doped fiber laser, or a rare-earth-doped crystal laser. Alternatively, it can be implemented including a medium for emitting Alexandrite laser light having a wavelength of 755 nm, or a medium for emitting Nd:YAG laser light having a wavelength of 1064 nm or 1320 nm.

[0164] The beam shaper 312 converts a laser in the form of a spot generated by the laser oscillator and passing through the optical fiber into the form of an area beam having a flat top. The beam shaper 312 can include a square light pipe, a diffractive optical element (DOE), or a micro-lens array (MLA).

[0165] The optical lens module 313 adjusts the shape and size of the laser beam converted into the area beam form by the beam shaper and irradiates electronic components mounted on the PCB substrate or the irradiation region. The optical lens module combines a plurality of lenses to form an optical system, and the specific configuration of such an optical system will be specifically described later with reference to FIGS. 6 to 9.

[0166] The driving device 314 moves the distance and position of the laser module relative to the irradiation surface, and the control device 315 controls the driving device 314 to adjust the beam shape, beam area size, beam sharpness, and beam irradiation angle when the laser beam reaches the irradiation surface. In addition to the driving device 314, the control device 315 can also integrally control the operations of each part of the laser module 310.

[0167] On the other hand, the laser output adjustment unit 370 controls the amount of power supplied to each laser module from the power supply units 317, 327, and 337 corresponding to the laser modules 310, 320, and 330 according to a program received via the user interface or a preset program. The laser output adjustment unit 370 receives component-by-component, region-by-region, or overall reflow state information on the irradiation surface from one or more camera modules 350, and controls each power supply unit 317, 327, and 337 based on this information. Alternatively, control information from the laser output adjustment unit 370 can be transmitted to the control devices 315, 325, and 335 of the laser modules 310, 320, and 330, and the control devices 315, 325, and 335 can provide feedback signals for controlling the corresponding power supply units 317, respectively. Also, different from FIG. 6, it is also possible to distribute power to each laser module via one power supply unit. In this case, the laser output adjustment unit 370 must control the power supply unit.

[0168] When implementing the laser overlapping mode, the laser output adjustment unit 370 controls each laser module and the power supply units 317, 327, and 337 so that the laser beams from each laser module 310, 320, and 330 have the required beam shape, beam area size, beam sharpness, and beam irradiation angle. The laser overlapping mode is applied not only when preheating the area around the debonding target position using the first laser module 310 and further heating a narrower reflow target area using the second laser module 320, but also when appropriately distributing an additional heating function among the first, second, and third laser modules 310, 320,... 330 from the preheating function to control each laser module to have the required temperature profile.

[0169] On the other hand, when distributing one laser light source and inputting it to each laser module, the laser output adjustment unit 370 can be provided with a function of simultaneously adjusting the output and phase of each distributed laser beam. In such a case, the phase can be controlled so as to induce destructive interference between the laser beams, significantly improving the beam flatness, thereby further improving the energy efficiency.

[0170] On the other hand, when realizing the multi-position simultaneous processing mode, the laser output adjustment unit 370 controls one or more of the beam shape, beam area size, beam sharpness, beam irradiation angle, and beam wavelength of each laser beam so that part or all of the laser beams from each laser module are different. Also at this time, when distributing one laser light source and inputting it to each laser module, the laser output adjustment unit 370 may be provided with a function of simultaneously adjusting the output and phase of each distributed laser beam.

[0171] With this function, by adjusting the size and output of the laser beam, it is possible to perform or remove the bonding between the electronic component and the substrate within the irradiation surface. In particular, when removing a damaged electronic component on the substrate, as the area of the laser beam is minimized to the corresponding electronic component area, the heat from the laser beam applied to other adjacent normal electronic components existing on the substrate can be minimized. Therefore, it is possible to remove only the damaged electronic component to be removed.

[0172] On the one hand, when making the laser modules emit laser beams having different wavelengths for each of the plurality of laser modules, the laser modules are well absorbed by the plurality of material layers (for example, EMC layer, silicon layer, solder layer) included in the electronic components respectively. It can be composed of individual laser modules having wavelengths. Therefore, the laser debonding apparatus according to the present invention can execute an optimized bonding (Attathing or Bonding) or (Detaching or Debonding) process by selectively raising the temperature of the electronic component and the temperature of an intermediate bonding material such as solder, which is a connection material between the printed circuit board and the electronic component electrode, to be different. Specifically, all the energy of each laser beam is absorbed by the solder layer through both the EMC mold layer and the silicon layer of the electronic component, or the laser beam can heat the surface of the electronic component without passing through the EMC mold layer and conduct heat to the bonding part under the electronic component.

[0173] On the other hand, by using the above functions, after a certain area of the substrate including the reflow target electronic component area and its periphery is preheated to a predetermined preheating temperature by at least one first laser beam, the temperature of the reflow target electronic component area is selectively heated to the reflow temperature at which the melting of the solder occurs by at least one second laser beam. By utilizing such a selective heating effect, the present invention can also be used, for example, as a rework apparatus for efficiently removing electronic components from a substrate.

[0174]

[0175] FIGS. 6 to 9 are configuration diagrams of a laser optical system applicable to a single laser beam or a multi-laser module of the laser reflow apparatus of the present invention.

[0176] FIG. 6 shows an optical system with 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 enters the beam shaper 430, the beam shaper 430 converts the spot-shaped laser beam into a flat-top surface light source A1. The square laser beam A1 output from the beam shaper 430 is expanded to a desired size through the concave lens 440 and irradiates the imaging surface S with the expanded surface light source A2.

[0177]

[0178] FIG. 7 is a configuration diagram of a laser optical system according to another embodiment of the present invention.

[0179] The surface light source B1 from the beam shaper 430 is expanded to a predetermined size through the concave lens 440 and becomes a surface light source B2 that irradiates the first imaging surface S1. When it is desired to further expand this surface light source B2 for use, the boundary of the edge of the surface light source B2 may become less distinct due to additional expansion. Therefore, in order to obtain irradiation light with a clear edge even on the second imaging surface S2 of the final irradiation surface, a mask 450 is provided on the first imaging surface S1 to trim the edge.

[0180] The surface light source that has passed through the mask 450 is adjusted to be reduced (or expanded) to a desired size while passing through the zoom lens module 460 composed of a combination of one or more convex lenses and concave lenses, and forms a square irradiation light B3 on the second imaging surface S2 where electronic components are arranged.

[0181]

[0182] It is a configuration diagram of a laser optical system according to another embodiment of the present invention.

[0183] 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) C2, for example, in the x-axis direction while passing through at least a pair of cylindrical lenses 470, and is reduced (or enlarged), for example, in the y-axis direction while passing through at least a pair of cylindrical lenses 480 again, and is converted into a rectangular surface light source C3.

[0184] Here, the cylindrical lens is in a form obtained by cutting a cylindrical shape in the longitudinal direction, and has a function of enlarging or reducing the laser beam according to the form in which each lens is arranged in the vertical direction, and adjusts the laser beam in the x-axis or y-axis direction according to the form in which the lenses on the surface where the cylindrical lens is arranged are arranged in the x and y-axis directions.

[0185] Subsequently, the surface light source C3 is enlarged (or reduced) and adjusted to a desired size while passing through the zoom lens module 460 composed of a combination of one or more convex lenses and concave lenses, and forms a rectangular irradiation light C4 on the second imaging surface S2 where the electronic components are arranged.

[0186]

[0187] It is a configuration diagram of a laser optical system according to another embodiment of the present invention.

[0188] It can be understood that the optical system of FIG. 9 is a configuration in which a mask is applied to the optical system of FIG. 8 to trim the edge of the laser beam, and a final surface light source D5 with a sharper edge can be obtained compared to the case of FIG. 8.

[0189]

[0190] FIG. 10 is a perspective view of a main part schematically showing the holder unit configuration of the laser pressurizing head module of the present invention.

[0191] Referring to FIG. 10, the holder unit 500 according to the present invention is divided into a lower plate 510 into which the lower part of the flat plate-shaped light-transmitting pressing member 100 is fitted and seated, and a mask plate 520 that fits and engages with the upper part of the light-transmitting pressing member 100.

[0192] In addition, square through holes 510a and 520a are formed in the central portions of the lower plate 510 and the mask plate 520, respectively. Since the light-transmitting pressing member 100 is fitted and seated on the lower plate 510, at this time, it can be understood that the bottom surface 102 of the pressing member 100 is exposed downward through the through hole 510a of the lower plate 510.

[0193] On the other hand, in the above state, when the mask plate 520 is fitted and coupled to the upper surface of the light-transmitting pressing member 100, the mounting is completed with the central portion of the upper surface of the light-transmitting pressing member 100 exposed upward through the through hole 520a of the mask plate 520.

[0194]

[0195] FIG. 11 is a cross-sectional view of a main part schematically showing the configuration and operating state of the holder unit of the laser pressing head module of the present invention.

[0196] Referring to FIG. 11, when the light-transmitting pressing member is irradiated with laser light by the multi-beam laser modules 310 and 320 located above in a state where it is mounted between the lower plate and the mask plate, it is understandable that the laser beam is transmitted downward through the through hole 520a of the mask plate 520 and the light-transmitting pressing member 100.

[0197] At this time, both left and right edge portions of the bottom surface of the lower plate 510 have a gently rounded shape. This is because when the protective film 200 located below the light-transmitting pressing member is pushed down while the light-transmitting pressing member 100 moves downward, the rounded edge portion of the lower plate 510 prevents the protective film 200 from being torn or damaged.

[0198] Further, as described above, the protective film 200 is pulled and wound by the protective film conveying units 210 disposed on both the left and right sides of the protective film 200. At this time, since the left and right edge portions of the bottom surface of the lower plate 510 are gently rounded, the protective film 200 can be fed without being damaged by the edges.

[0199] As described above, the light-transmissive pressing member 100 has laser beams irradiated thereon by the multi-laser modules 310 and 320 positioned above while simultaneously pressing a plurality of electronic components disposed on the substrate, which is the bonding object 11, at a constant depth. As a result, the laser reflow process proceeds while the solder located below the electronic components of the bonding object 11 is melted by the laser beams.

[0200] Thereby, the laser beams overlap each other to form a homogenized laser beam, and it can be understood that uniform thermal energy is transmitted to the solder located below the electronic components of the bonding object (11) through the through holes 520a of the mask plate 520 and the through holes 520a of the light-transmissive pressing member 100 and the lower plate 510.

[0201] At this time, when the overlapping laser beams are irradiated on the substrate portion around the electronic components, the peripheral substrate portion may be damaged by the thermal energy of the laser beams. Therefore, it is necessary to limit the irradiation to only the electronic components of the bonding object 11. For this purpose, in order to accurately perform the pressing and laser reflow processes only on the electronic components of the bonding object 11, it is desirable to design the area of the square through hole 520a of the mask plate 520 and the area of the pressing surface 102 of the light-transmissive pressing member 100 in consideration of the laser beam transmission path, overlapping area, etc.

[0202]

[0203] FIG. 12 is a perspective view of a main part schematically showing the configuration and operating state of the probe unit of the laser pressing head module of the present invention.

[0204] The main feature of the present invention is that the mask plate 520 and the translucent pressing member 100 are configured to be replaceable so as to accommodate various substrate sizes. Therefore, depending on whether to process substrates of different sizes or according to the shape and area where electronic components are arranged on the substrate, the translucent pressing member 100 and the mask plate 520 can be configured to be replaceable with different ones. In this case, the operator will select and replace an appropriate size from the pre-prepared translucent pressing member 100 and mask plate 520 having pressing surfaces of various different sizes as needed, and then measure the flatness by piercing the edge portion of the upper surface of the translucent pressing member 100 through the bar probe unit 600 shown in FIG. 12 for probing.

[0205] The probe unit 600 is composed of a needle-shaped probe 610, a probe transport unit 620 for horizontally or vertically transporting the probe, and a probe bracket 630 for supporting the probe and the transport unit.

[0206] Therefore, in order to process substrates of different sizes, when the operator replaces the translucent pressing member 100 and the mask plate 520 of other sizes, the probe 610 is transported in the horizontal or vertical direction, and as an example, by sequentially piercing and probing at least 4 points (indicated by X) at the edge portion on the upper surface of the translucent pressing member (100), the flatness of the translucent pressing member 100 can be measured.

[0207]

[0208] FIG. 13 is a side view schematically showing the vertical transport unit configuration and operating state of a laser pressing head module according to an embodiment of the present invention.

[0209] Hereinafter, referring to FIG. 13, the configuration and operating state of the vertical transport unit of the laser pressing head module are as follows.

[0210] According to one embodiment of the vertical transfer unit configuration, there are provided press brackets 720 provided at four edge portions of each of the translucent pressure member 100 and the holder unit 500, a pressure cylinder 730 provided above the press brackets, and a vertical drive unit that applies a driving force in the vertical direction to the press brackets 720. That is, as an example, it can be composed of a ball screw 750, a motor 760, and a guide member 770 for guiding the linear motion of the press bracket 720.

[0211] Therefore, before the bonding object 11 composed of the substrate and the electronic component is loaded below the translucent pressure member 100, the translucent pressure member 100 and the holder unit 500 are transported upward by driving the motor 760 of the vertical transfer unit. After the bonding object 11 is loaded, the translucent pressure member 100 and the holder unit 500 are transported downward again by driving the motor 760 and wait for pressurization. Then, by the operation of the pressure cylinder 730, the translucent pressure member 100 presses the bonding object 11 vacuum-adsorbed on the electrostatic chuck 940.

[0212] On the other hand, since a heating block 942 for preheating the bonding object 11 to a constant temperature is provided below the electrostatic chuck 940, while the bonding object 11 is seated on the electrostatic chuck 940 and being transported for laser reflow processing, the bonding object 11 is continuously preheated. For example, the temperature for preheating the bonding object 11 can be set to less than 200°C, and it is desirable to set the temperature to such an extent that thermal damage is not caused to the substrate or the like by the preheating.

[0213] On the other hand, as shown in FIG. 12, when the probe unit 600 measures the flatness of the translucent pressure member 100 and determines that the translucent pressure member 100 is inclined to either side, that is, when it is not flat, the vertical transfer unit is finely driven to transport the holder unit 500 upward or downward to adjust the flatness of the translucent pressure member 100.

[0214] More specifically, as a result of measuring the flatness of the light-transmitting pressure member 100 by the probe unit 600, if it is determined that one of the edges of the upper surface of the light-transmitting pressure member 100 is inclined to one side with respect to the other edges and is located at a low point, for example, the motor 760 of the edge portion located at the lower point operates to finely lift the edge of the holder unit 500 upward, thereby adjusting the overall flatness of the light-transmitting pressure member 100.

[0215] At this time, for the motor 760, for example, by installing an absolute encoder, the absolute position value of each edge portion of the holder unit 500 can always be maintained regardless of the power state, and it is desirable to automate the flatness adjustment process of the above-described light-transmitting pressure member (100) according to the control unit settings.

[0216]

[0217] FIG. 14 is a perspective view of a main part schematically showing the vertical conveyance unit configuration and operating state of a laser pressure head module according to another embodiment of the present invention, and FIG. 15 is a cross-sectional view of the main part of FIG. 14.

[0218] Hereinafter, with reference to the above drawings, the detailed configuration of the laser pressure head module of the present invention and the operating relationship by pressure and laser beam irradiation will be described in more detail according to an embodiment as follows.

[0219] Referring to the drawings, the pressure head of the present invention includes a light-transmitting pressure member 100 for transmitting a laser beam irradiated from laser sources 310 and 320 while pressing an electronic component, which is a bonding object 11. At this time, the light-transmitting pressure member 100 is mounted in a state of being replaceably fitted into a through hole formed in the central portion of the plate-shaped holder unit 500.

[0220] The holder unit 500 can be formed to have a circular or polygonal shape (see FIGS. 16a and 16b). Hereinafter, in FIGS. 14 and 15, it will be described assuming that it has an octagonal shape.

[0221] According to an embodiment of the present invention, press units 700 are respectively condensed at the thin points P1, P2, P3 around the grid lines of the octagonal holder unit 500. When the points where the press units are condensed are connected by an imaginary line L, a triangle is formed.

[0222] At this time, the imaginary triangle connecting the detailed points of the holder unit 500 can form an equilateral triangle, and it is desirable that the centroid G of the imaginary triangle coincides with the centroid G of the translucent pressing member 100.

[0223] The reason for designing the three-axis coupling points P1, P2, P3 around the edge of the holder unit 500 is that when two press units are shrink-coupled to connect the axis coupling points P1, P2, P3, it is stable. Since a triangular structure cannot be formed (that is, when connecting two points, a line segment is formed and an area cannot be formed), that is, while minimizing the number of condensation points that require flatness control, in order to form a stable axis coupling point of the imaginary triangle, three axis coupling points P1, P2, P3 are accurately and symmetrically configured on the holder unit 500.

[0224]

[0225] On the other hand, referring to FIG. 15, the press unit 700 includes a press bracket 720 having a certain height and shape, a pressure cylinder 730 that is mounted on the upper end of the press bracket and presses the holder unit 500 downward by a set pressure, and a bearing joint 780 whose one end is coupled to the cylinder rod 731 of the pressure cylinder 730 and whose other end is rotatably coupled to one of the detailed axis coupling points P1, P2, P3 of the holder unit 500. At this time, the pressure cylinder can employ a precision pneumatic cylinder (hereinafter, a positive hole cylinder) that can finely set and adjust the pressing force in kgf units.

[0226] At this time, a pressure sensing sensor 740 is further provided at the end of the cylinder rod 731 of each pressurizing cylinder 730.

[0227] The pressure sensing sensor 740 can be realized as a load cell as an example. When the cylinder rod of each pressurizing cylinder 730 is pulled out to pressurize each shaft coupling point of the holder unit 500, it constantly measures it, checks whether a pressure above the appropriate pressure is applied, and plays a role of feeding this back to a control unit (not shown).

[0228] On the other hand, a joint fastening part 510 is further provided at each of the three shaft engagement points of the holder unit 500, and each joint fastening part 510 is rotatably coupled to a bearing joint 780 by a pivot hinge.

[0229] Therefore, depending on whether the cylinder rod 731 of the pressurizing cylinder 730 is retracted or pulled out, the bearing joint 780 pivotally hinged to the end of the cylinder rod 731 also moves vertically together, and thereby the joint fastening part 510 and the holder unit 500 rotatably coupled to the bearing joint 780 also move together.

[0230] Therefore, by adjusting the pulling-out lengths of the cylinder rods 731 of the respective pressurizing cylinders 730 to be different, the holder unit 500 can be driven to tilt, and by adjusting the contact height of the holder unit 500, the pressing force can also be precisely adjusted.

[0231] Also, the end of the joint fastening part 510 is locked by a stopper 790 provided at the lower end of the press bracket 720 and is in a seated state. Thereby, the own weight of the holder unit 500 acting downward is offset by crossing the stopper 790, and it plays a role of maintaining flatness when vertically transporting the holder unit 500.

[0232] On one side of the press bracket 720, a vertical conveyance unit for moving the press bracket up and down in the vertical direction is further provided.

[0233] According to an embodiment of the vertical conveyance unit configuration below, it can be composed of press brackets 720 respectively provided at three shaft engagement points of the light-transmissive pressing member 100 and the holder unit 500, a pressing cylinder 730 provided at the upper part of the press bracket, 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.

[0234] With the above configuration, when the holder unit 500 moves downward, the light-transmissive pressing member 100 mounted on the holder unit 500 also moves downward together, and it is understandable that the electronic component 11 located thereunder is pushed down and pressed.

[0235] In addition, the flatness of the holder unit 500 may be distorted by vibrations generated during the progress of the reflow process or vibrations during the replacement of the light-transmissive pressing member 100. Therefore, it is desirable to set the flatness by initializing to the zero point at a certain period or after replacing the light-transmissive pressing member 100.

[0236]

[0237] FIG. 16a is a partial plan view showing a holder unit of a laser pressing head module according to the present invention formed in an octagon according to an embodiment.

[0238] First, the shape of the holder unit according to the present invention may be polygonal, and may basically be a triangular shape connecting three shaft coupling points P1, P2, and P3. More specifically, for geometric symmetry, it can be formed into an equilateral triangle by making the lengths of the virtual lines connecting each of the three shaft coupling points P1, P2, and P3 to the central centroid G equal.

[0239] Also, in Fig. 16a, since a square light-transmissive pressing member must be seated and accommodated inside the polygonal holder unit, an embodiment is shown in which the shape of the holder unit is octagonal so as to provide a larger area than the light-transmissive pressing member and thus sufficiently accommodate the square light-transmissive pressing member.

[0240] Therefore, the holder unit of the present invention is not limited to the octagonal shape shown in Fig. 16a, and can be realized in various polygonal shapes such as a triangle, a quadrilateral, or an octagon that can planarize a virtual triangle connecting three shaft coupling points P1, P2, and P3.

[0241]

[0242] On the other hand, Fig. 16b is a partial plan view showing the holder unit of the laser pressing head module according to the present invention formed in a circular shape according to another embodiment.

[0243] Also, the shape of the holder unit of the present invention may be polygonal or may be formed circularly according to other embodiments.

[0244] Therefore, even if the holder unit is formed circularly as shown in Fig. 16(b), the lengths of the virtual lines connecting each of the three shaft coupling points P1, P2, and P3 around the edge of the holder unit to the central centroid G are formed equal, so that the holder unit becomes geometrically symmetric and each shaft coupling point can be precisely pressed and controlled while maintaining a high flatness using only the minimum three shaft coupling points P1, P2, and P3.

[0245]

[0246] Therefore, as described above, the pressing head of the present invention irradiates the light-transmissive laser beam while simultaneously pressing and pressurizing a plurality of electronic components 11 using the light-transmissive pressing member 100 having a certain area, so that the reflow process can be performed at once. Compared with the conventional method of raising a small light-transmissive pressing member for each electronic component and pressurizing it by its own weight, the accuracy and productivity are greatly improved.

[0247] In addition, the pressing cylinder 730 adopts a positive hole cylinder that can precisely adjust the pressing force in Kgf units, so that the pressing force can be precisely adjusted. Accordingly, the operator can adjust the set pressure of the pressing cylinder 730 differently according to various variable factors such as the bending state of the FPCB substrate, so that the pressure balance applied to the electronic component 11 disposed below the large-area light-transmissive pressing member 100 of the present invention can be easily adjusted compared with the prior art.

[0248] On the other hand, different from the pressure set in each of the pressing cylinders 730, when a pressure exceeding the set pressure is applied, at this time, the pressure sensor 740 coupled to the end of the cylinder rod 731 of the pressing cylinder 730 senses this and feeds it back to a control unit (not shown).

[0249] Therefore, when a pressure equal to or higher than a certain level is sensed, the control unit performs an auto-balance process of adjusting to the set pressure value, or generates an alarm so that the operator can easily manually adjust the set pressure of each of the pressing cylinders 730 as needed.

[0250]

[0251] Also, although not shown in FIGS. 14 to 16a and 16b, the holder unit 500, the light-transmissive pressing member 100, and the press unit 700 can be installed on the light-transmissive pressing member conveying unit 140 and the support unit 150 seen in FIG. 2 earlier. The light-transmissive pressing member conveying unit 140 can be realized to be vertically conveyable in the vertical direction by, for example, vertical conveying means (for example, a motor and a ball screw device), and the support unit 150 can be realized by, for example, a gantry device.

[0252] Therefore, when the electronic component and the substrate, which are the bonding objects 11, are loaded, the holder unit 500, the translucent pressing member 100, and the press unit 700 are vertically conveyed upward so that the bonding object 11 can be loaded to a position directly below the translucent pressing member 100. After the bonding object 100 is loaded to a position directly below the pressing member 100, as the holder unit 500, the translucent pressing member 100, and the press unit 700 are vertically conveyed downward again to a position close to the bonding object 11, they are positioned in an atmospheric state for pressing.

[0253]

[0254] It is a principal part perspective view showing the translucent pressing member of the laser pressing head module according to the present invention. (a) illustrates the shape of the translucent pressing member having a single pressing surface according to one embodiment, and (b) is another embodiment. As an example, it illustrates the shape of the translucent pressing member having a pressing surface divided so as to correspond to each electronic component.

[0255] Next, looking at the structure of the translucent pressing member 100 according to an embodiment of the present invention with reference to FIGS. 17a and 17b, as shown in FIG. 17a, the translucent pressing member 100 of the present invention is a square plate-shaped base material 101. It has a structure in which a pressing surface 102 of a certain area protrudes upward. The area of the pressing surface 102 is desirably designed to correspond to the processing area of the bonding object 11 in consideration of the area of the bonding object 11 to be subjected to laser reflow processing at a time by a certain area.

[0256] At that time, the area of the pressing surface 102 is formed to be narrower than the area of the base material 101, and has at least one or more stepped portions 101a around the pressing surface 102. Further, a laser light blocking layer 103 and a shadow display are further formed on the side surface of the base material 101, the bottom surface, and the side surface of the stepped portion 101a except for the pressing surface 102 in order to prevent the light beam of the laser light.

[0257] On the one hand, referring to FIG. 17b, looking at the structure of the translucent pressing member 100 according to another embodiment of the laser pressing head module of the present invention, in FIG. 17a seen previously, a single pressing surface 102 was formed, but in FIG. 17b, in order to contact and press each of the plurality of electronic components included in the bonding object 11, the pressing surface 102 has a structure divided into a grid so as to correspond to the area of each electronic component. For this reason, in the structure as shown in FIG. 17b, it is necessary to design and process the pressing surface 102 so as to accurately correspond to the occupied area of each electronic component to be subjected to laser reflow processing.

[0258] Also in this case, as shown in FIG. 17b, a laser light blocking layer 103 (shadow display) is further formed on the side surface of the base material 101 other than the plurality of pressing surfaces 102 divided into a grid, the bottom surface and the side surface of the step portion 101a.

[0259] The laser light blocking layer 103 can generally be formed of various forms of special coating layers that absorb or reflect light. For example, it can be implemented by one or a composite layer of two or more of an Inconel coating layer that absorbs a laser beam, a diffused reflection processing layer in the form of frosted glass, or an HR (High Reflection) coating layer that reflects a laser beam. By coating the laser light blocking layer 103, the laser beam is accurately irradiated only to the electronic components of the bonding object 11 through the pressing surface 102 of the translucent pressing member 100, so that thermal damage to the substrate and damage caused thereby due to the laser beam being irradiated to the adjacent printed circuit board (PCB) portion around the electronic components are prevented.

[0260]

[0261] FIG. 18 is an operating state diagram showing a state in which the translucent pressing member according to the present invention is mounted on a pressing head, and FIG. 19 is an enlarged view of a main part of FIG. 18.

[0262] Referring to FIGS. 18 and 19, as described above, the translucent pressing member 100 of the present invention has a structure in which a pressing surface 102 having an area smaller than the area of the base material protrudes from the bottom surface of the rectangular base material 101. At this time, at least one or more stepped portions 131a are formed between the base material 101 and the pressing surface 102. As shown in FIG. 15, the stepped portion 101a is used for attaching the translucent pressing member 100 to the holder unit 500 of the reflow device.

[0263] On the other hand, a silicon damper layer 104 can be further formed on the pressing surface 102. Generally, electronic components arranged on a printed circuit board (PCB) constituting the bonding object 11 are not completely flat due to the characteristics of the ductile circuit board and have their own flexures. As a result, it can be understood that each electronic component is not at the same height on the horizontal line along the curved surface of the ductile circuit board, but is arranged at different heights.

[0264] At this time, when the pressing surface 102 of the translucent pressing member 100 simultaneously presses electronic components located at different heights on the curved surface of the ductile circuit board for bonding processing, the electronic components at relatively high positions receive a greater pressing force than the electronic components at low positions. As a result, the solder located below the electronic components at high positions may not be properly reflowed due to excessive pressing force, which may cause bonding defects.

[0265] Therefore, by further forming the silicon damper layer 104, which is a translucent elastic body according to an embodiment of the present invention, on the pressing surface 102, even if an excessive pressing force acts on the electronic components located above, the silicon damper layer 104 performs a damping function of absorbing a certain amount of the excessive pressing force.

[0266] On one hand, when the transparent pressing member 100 presses an electronic component, a laser beam is irradiated from the first or second laser module 310, 320 located above the transparent pressing member 100. The laser beam is irradiated onto the electronic component through the transparent pressing member 100, and thermal energy for reflow is transmitted.

[0267] Referring to FIG. 19, when a laser beam is irradiated through the transparent pressing member 100, since the laser light blocking layer 103 (shadow display) is formed on the side surface of the base material 101, the bottom surface and the side surface of the stepped portion 101a, as a result, the laser beam is blocked so as not to leak out to all other portions except the pressing surface 102.

[0268] Also, for uniform laser reflow processing, in the present invention, the shape and the protruding height of the pressing surface 102 are also presented as the main considerations in the design of the transparent pressing member 100. For example, as shown in FIG. 17a, when the pressing surface 102 is not formed in a square structure but in a rectangular structure, since the side surface area of the long side is larger than that of the short side of the rectangle, it can be predicted that the thermal energy by the laser beam on the long side is lost faster.

[0269] When such a deterioration phenomenon occurs, since the thermal energy is not uniformly transmitted to the plurality of electronic components pressed in a state of being disposed below the pressing surface 102, the electronic components at a position lower or higher than the appropriate bonding temperature are more likely to have bonding failures. According to a desirable embodiment, by designing the bottom surface shape of the pressing surface 102 into a square structure, heat dissipation through the side surface of the pressing surface 102 becomes uniform in the vertical and horizontal directions.

[0270] Also, even when the protruding height h of the side surface of the pressing surface 102 is formed too high, since there is a possibility that a large amount of heat dissipation occurs through the side surface of the stepped portion 101a, it is most desirable to minimize the protruding height h of the pressing surface 102 or the depth of the lattice groove 102a recessed between the divided pressing surfaces 102 within several millimeters.

[0271]

[0272] On the one hand, FIGS. 20a to 20c are schematic views showing various embodiments of the light-transmissive pressing member according to the present invention. FIG. 20a shows the case where the pressing surface edge is not processed, FIG. 20b shows the case where the pressing surface edge is chamfered, and FIG. 20c shows the case where the pressing surface edge is rounded.

[0273] Referring to the attached FIGS. 20a, b, and c, it has been described that a protective film 200 is provided below the light-transmissive pressing member 100 of the present invention as shown in FIG. 2 above to prevent the adsorption of gases (fumes). At that time, when the light-transmissive pressing member 100 is moved downward as shown in FIG. 20a to press the bonding object 11, the protective film 200 is also pressed together with the light-transmissive pressing member 100, and it is understandable that the protective film 200 is in contact with the edges on both sides of the pressing surface 132 at that time.

[0274] However, as described above, it can be predicted that when the protective film 200 repeatedly contacts both edges of the pressing surface 102, ultimately, problems such as the protective film 200 being torn or damaged will occur.

[0275] Therefore, in order to prevent this blockage, as shown in FIG. 20b, both ends of the pressing surface 102 are chamfered, or as shown in FIG. 20c. By rounding both ends in this way, additional considerations are presented during the design of the light-transmissive pressing member 100.

[0276]

[0277] Hereinafter, FIG. 21 is a cross-sectional view of a main part schematically showing the overall device configuration of the laser pressing head module according to an embodiment of FIG. 13, FIG. 22 is a plan view of the main part of FIG. 21, and FIG. 23 is an enlarged perspective view of the pressing unit of the laser pressing head module according to an embodiment of FIG. 13.

[0278] Hereinafter, with reference to the drawings, the detailed configuration of the laser pressurizing head module of the present invention and the operating relationship by pressurization and laser beam irradiation will be described in detail according to an embodiment as follows.

[0279] First, referring to FIGS. 21 and 22, the pressurizing head of the present invention is provided with a light-transmissive pressurizing member 100 for transmitting the laser beam irradiated from the laser sources 310 and 320 while pressing and pressurizing the electronic component 11 which is the bonding object. At this time, the light-transmissive pressurizing member 100 is mounted in a state of being placed in a through hole formed in the center of the plate-shaped holder unit 500. Thereby, when the holder unit 500 is moved downward, the light-transmissive pressurizing member 100 mounted on the holder unit can also move downward together and pressurize the electronic component 11 located thereunder.

[0280] In addition, press units 700 are arranged adjacent to each edge portion of the holder unit 500 in a non-contact state. First, it is supported by a pressure balancer 710 at the lower part of the holder unit 500, and the pressure balancer 710 is a buffer that pressurizes and cancels the self-weights of the light-transmissive pressurizing member 100 and the holder unit 500 in the opposite direction. As a component that plays a role, it can be implemented by, for example, an air cylinder or an elastic spring.

[0281] Therefore, after canceling the basic self-weights of the light-transmissive pressurizing member 100 and the holder unit 500 to a zero (0) value by the pressure balancer 710, it will wait in a state for pressurizing the light-transmissive pressurizing member 100.

[0282]

[0283] On the other hand, referring to FIG. 23, when looking in detail at other component configurations of the press unit 700, there is a press bracket 720 having a shape that wraps around each edge portion of the holder unit 500 in a non-contact state, and pressure cylinders 730a, 730b, 730c, 730d fixedly installed at the upper ends of the press bracket, and pressure sensors 740 provided at the ends of the cylinder rods of the pressure cylinders 730a, 730b, 730c, 730d.

[0284] At this time, the pressure sensing sensor 740 can be realized as a load cell, for example, and constantly measures this when the cylinder rods of the pressure cylinders 730a, 730b, 730c, 730d push in and pressurize each edge portion of the holder unit 500 while being pulled out, and plays a role of checking whether a pressure exceeding an appropriate pressure is applied and feeding this back.

[0285] Therefore, as described above, the pressing head of the present invention irradiates the translucent laser beam while pressing and pressurizing a plurality of electronic components 11 simultaneously using the translucent pressing member 100 having a certain area, so that the reflow process can be performed at once, and thus there is an effect that the productivity is significantly improved compared to the conventional method of placing a small translucent pressing member for each electronic component and pressurizing it by its own weight.

[0286] For this purpose, according to the present invention, the pressure cylinders 730a, 730b, 730c, 730d are separately installed so that the pressing force can be set independently for each corner of the holder unit 500, and a large-area pressing force adjustment is possible. Further, the pressure cylinders 730a, 730b, 730c, 730d can be realized by adopting precision pneumatic cylinders (hereinafter, positive hole cylinders) as an example that can precisely adjust the pressing force in Kgf units. Thus, according to various variable factors such as the bending state of the PCB substrate, by the operator adjusting the set pressures of the pressure cylinders 730a, 730b, 730c, 730d to be different from each other, the planar pressure balance of the large-area translucent pressing member 100 of the present invention can be easily adjusted compared to the prior art.

[0287] On the other hand, when a pressure equal to or higher than the set pressure is applied, which is different from the pressures set in the respective pressurizing cylinders 730a, 730b, 730c, and 730d, at this time, the pressure sensor 740 coupled to the end of the cylinder rod 731 of the pressurizing cylinders 730a, 730b, 730c, and 730d senses this and feeds it back to a control unit (not shown). Therefore, when a pressure equal to or higher than a certain level is detected, the control unit performs an auto-balance process to adjust to the set pressure value or generates an alarm so that the operator can easily manually adjust the set pressures of the respective pressurizing cylinders 730a, 730b, 730c, and 730d as needed.

[0288] Also, although not shown in FIGS. 21 to 23, the holder unit 500, the translucent pressurizing member 100, and the press unit 700 are provided in the translucent pressurizing member conveying unit 140 and the support unit 150 seen in FIG. 2 earlier. The translucent pressurizing member conveying unit 140 can be realized as being vertically conveyable in the vertical direction by, for example, vertical conveying means (e.g., a motor and a ball screw device), and the support unit 150 can be realized as a gantry device, for example.

[0289] Therefore, when the electronic component and the substrate, which are the bonding objects 11, are loaded, the holder unit 500, the translucent pressurizing member 100, and the press unit 700 are vertically conveyed upward so that the bonding objects 11 can be loaded to a position directly below the translucent pressurizing member (100). After the bonding objects 100 are loaded to a position directly below the pressurizing member 100, as the holder unit 500, the translucent pressurizing member 100, and the press unit 700 are vertically conveyed downward again to a position close to the bonding objects 11, they are positioned in an atmospheric state for pressurization.

[0290]

[0291] On the other hand, referring to FIGS. 21 and 22, above the holder unit 500, an ionizer 800 is further provided to remove contamination such as dust and other particles that settle on the upper surface of the light-transmissive pressing member. The light-transmissive pressing member 100 can be realized, for example, with a Quartz material. Even if the space where the process according to the present invention proceeds is a clean room environment, if some particles settle and are repeatedly stacked up, damage such as burning of the particles may be caused by irradiation of the laser beam.

[0292] As a result, if the burning of the particles is repeated for a long time, the upper surface of the light-transmissive pressing member 100 will become increasingly discolored, and ultimately there is a possibility of damage such as cracks occurring in the light-transmissive pressing member 100. Therefore, the ionizer 800 is used to prevent the adsorption of particles in advance, such as removing the generation of static electricity on the upper surface of the light-transmissive pressing member 100 at any time.

[0293]

[0294] FIG. 24 is a perspective view according to an embodiment of the input area configuration and operation relationship of the bonding object transfer module according to the present invention. Hereinafter, referring to FIG. 24, looking at the mechanism configuration and operation relationship of the input area (loading area) of the bonding object according to the present invention, it is as follows.

[0295] The input area configuration first includes an input conveyor 910 for loading a bonding object of a certain area (for example, a PCB with a plurality of electronic components seated thereon) for laser reflow processing. The input conveyor 910 has hanger characters On both sides of the upper part of the conveyor frame 912 having a shape bent in the form of JPEG2025081506000002.jpg1117, a conveyor frame 912 having a shape bent by a pair of wires for conveying the bonding object 11 by conveyor is provided. Orbit means 911 is provided, and the wire orbit means 911 is coupled to the rotation axis of the orbit drive motor 913. Also, on one side of the conveyor frame 912, a width adjustment motor 915 is provided to expand or contract the width of the input conveyor 910 in order to accommodate bonding objects 11 of different sizes.

[0296] In addition, since a horizontal transfer unit 920 is mounted at one end of the conveyor frame 912, as the horizontal transfer unit 920 is transferred in the horizontal direction, the conveyor frame 912 is also moved together in the horizontal direction.

[0297] On the other hand, since a preheating stage 914 is provided on the upper part of the conveyor frame 912, the bonding object 11 is continuously preheated to a predetermined temperature (for example, 150 ° C) while staying above the preheating stage 914 before the bonding object 11 conveyed by the wire orbit means 911 is introduced into the laser reflow processing area, so that the temperature rises rapidly and stably to the melting temperature of the desired solder (for example, 250 ° C) by the irradiation of the laser beam during laser reflow.

[0298] On the other hand, in order for the input conveyor 910 to be horizontally conveyed on the preheating stage 914 in a preheating state and introduced into the reflow processing area, the bonding object 11 must be accurately transferred without fail onto the vacuum chuck 940. At this time, referring to FIG. 21, a picker unit 930 is further provided above the vacuum chuck 940, and the picker unit 930 includes a vacuum suction pad 931 for adsorbing the bonding object, a cylinder 932 for driving the vacuum suction pad in the vertical direction, and a support frame 933 for fixing the vacuum suction pad 931 and the cylinder 932.

[0299] Therefore, when the input conveyor 910 moves toward the vacuum chuck 940, the vacuum suction pad 931 of the picker unit 930 is moved upward by the drive of the cylinder 932. Then, when the bonding object 11 is positioned below the vacuum suction pad 931, the vacuum suction pad 931 is moved downward to adsorb the bonding object 11 and then conveyed upward again. After that, when the input conveyor 910 is horizontally conveyed back to its original position and exits from below the vacuum suction pad 931, the vacuum suction pad 931 is moved downward again to repeat the operation of placing the bonding object 11 on the vacuum chuck 940.

[0300] After that, since a horizontal conveying means, for example, a linear motor 941, is provided below the vacuum chuck 940, the vacuum chuck 940 and the bonding object 11 are both moved to the laser reflow processing area by the operation of the linear motor 941.

[0301] In addition, since a vision unit 934 is further provided on one side of the vacuum chuck 940, it constantly monitors whether the bonding object 11 is correctly seated and aligned on the vacuum chuck in the input area, i.e., whether it is a normal load.

[0302]

[0303] On the other hand, FIG. 25 is a perspective view showing the output area configuration and the operation relationship of the bonding object conveying module according to the present invention according to an embodiment. Hereinafter, referring to FIG. 25, the mechanism configuration and the operation relationship of the output area (unloading area) of the bonding object according to the present invention will be examined as follows.

[0304] The configuration of the output conveyor 950 is almost the same as that of the input conveyor 910 seen above. However, the difference from the configuration of the input conveyor 910 is that the preheating stage 914 for preheating the bonding object 11 is omitted on the output conveyor 950.

[0305] Therefore, when the bonding object 11 that has completed the laser reflow process is conveyed to the output area (unloading area) while seated on the vacuum chuck 940, the picker unit 970 adsorbs the bonding object 11 on the vacuum chuck 940 in the reverse order from when it was loaded and transfers it to the output conveyor 950. Then, after the output conveyor 950 horizontally conveys the object, the bonding object 11 is unloaded outside the apparatus via the wire track means 951.

[0306]

[0307] FIGS. 26a and 26b are exemplary views showing the configuration and operating relationship of the vacuum chucking means of the bonding object transfer module according to the present invention. FIG. 26a is a plan view and a side cross-sectional view showing the configuration of one embodiment of the porous adsorption plate, and FIG. 26b is a plan view and a side cross-sectional view showing the configuration of another example of the porous adsorption plate.

[0308] First, referring to FIG. 26a, the configuration of the vacuum chuck 940 according to an embodiment of the present invention has an upper surface composed of a plurality of porous adsorption plates, and the porous adsorption plates are for adsorbing the central portion of the bottom surface of the bonding object 11. It is divided into a rectangular central adsorption plate 943 and an edge adsorption plate 944 arranged so as to surround the periphery of the central adsorption plate for adsorbing the edge portion of the bottom surface of the bonding object 11.

[0309] At this time, referring to the plan view, when the bonding object 11 having a certain area is seated on the porous adsorption plates 943 and 944 and is vacuum-adsorbed by suction means (not shown in the drawing) such as an air compressor provided in the central adsorption plate 943 and the border adsorption plate 944, the bonding object 11 is fixed to the upper surface of the vacuum chuck 940 in a widely extended state.

[0310] Also, referring to the attached side cross-sectional view, the central suction plate 943 and the edge suction plate 944 are formed separately from each other with a certain interval therebetween. At this time, since the suction plate lifting unit 980 is installed below the central suction plate 943, when the central suction plate 943 is required, that is, in the configuration of the previously seen embodiment, it may have another embodiment configuration in which the picker units 930 and 970 are omitted. That is, the central suction plate 943 can directly receive the bonding object 11 from the input conveyor 910. In this case, in order for the central suction plate 943 to directly receive the bonding object 11 from the input conveyor 910, after being lifted upward, after the central suction plate 943 directly takes over the bonding object 11 from the wire track means 911 of the input conveyor 910, even if it is driven in a form of descending downward again, the object of the present invention can be sufficiently achieved.

[0311] Also, a heating block 942 can be further provided directly below the central suction plate 943. The heating block 942 serves to preheat the bonding object 11 to a predetermined temperature while the bonding object is being carried in until just before being subjected to laser reflow processing, similar to the preheating stage 914 of the input conveyor 910.

[0312]

[0313] On the other hand, FIG. 26b shows the configuration and operation relationship of another embodiment of the porous suction plate according to the present invention. The difference from the configuration of the embodiment shown in FIG. 26a seen previously is that the edge suction plate 945 is made of an aluminum material which is not the same porous material as the central suction plate, and a plurality of suction holes 944a are further formed in the circumferential direction adjacent to the central suction plate 943 of the edge suction plate 945 in order to more strongly adsorb the bottom edge portion of the bonding object 11. Since the other configurations and operation relationships are the same as those in the case of the embodiment with reference to FIG. 26a, detailed description thereof is omitted.

[0314] Also, as shown in FIGS. 26a and 26b, by adjusting the vacuum adsorption forces of the central adsorption plate 943 and the border adsorption plates 944 and 945 of the vacuum chuck 940, it is expected that the unique bending or wrinkles of the printed circuit board (PCB), for example, the flexible circuit board (Flexible PCB) of the bonding object 11 can be stretched to a certain extent, and thereby the vertical heights of the electronic components seated on the substrate are also improved to be located at substantially the same point. Therefore, the effect of improving the process defects can be obtained by preventing excessive pressure from acting on specific electronic components during laser reflow.

[0315]

[0316] FIG. 27 is a side view schematically showing the configuration and operation relationship of a multi-laser module according to another embodiment of the present invention. FIG. 28 is a perspective view of a main part showing an enlarged temperature sensing sensor configuration of FIG. 27. FIG. 29 is a plan view of a main part showing an enlarged bonding object configuration of FIG. 28.

[0317] Hereinafter, with reference to FIGS. 27 to 29, the configuration and operation relationship of a multi-laser module according to another embodiment of the present invention will be described.

[0318] First, referring to FIG. 27, a multi-laser module according to another embodiment of the present invention includes a pair of first laser modules 310 and a second laser module 320. An infrared temperature sensing sensor 810 is provided between the first laser module 310 and the second laser module 320 to measure the temperature of the laser beam superimposedly irradiated from the first and second laser modules 310 and 320.

[0319] On one hand, beam profilers 318 and 328 are respectively provided for the first laser module 310 and the second laser module 320, and constantly monitor the laser beam output, intensity, etc. of the first and second laser modules 310 and 320. The configuration of the beam profilers 318 and 328, as an example, is to irradiate or transmit a part of the laser beam output on the laser beam paths of the first and second laser modules 310 and 320 to the beam profiler, so that the output and intensity of the laser beam can be measured.

[0320] According to one embodiment, the infrared temperature sensing sensor 810 may be a single infrared temperature sensing sensor 810, and the single infrared sensing sensor measures the surface temperature value of the region 12 where the laser beams are superposed and irradiated from the first and second laser modules. At this time, the single infrared temperature sensing sensor 810 measures the temperature of a large number of points in the region where the laser beams are superposed and irradiated in sequence, so as to measure the overall temperature distribution value of the region where the laser beams are superposed and irradiated.

[0321] When such a temperature distribution value is measured to be non-uniform, for example, when the temperature value is measured to be higher than the solder melting temperature at a certain point, an overflow bonding defect due to overheating of the solder may occur. Conversely, when the temperature is measured to be lower than the solder melting temperature, there may be a bonding defect where the solder does not melt sufficiently and cannot be connected.

[0322] Therefore, in the present invention, by constantly measuring the temperature of the region where the infrared temperature sensing sensor 810 is superposed and irradiated, the output or intensity of each laser beam output from the first or second laser module 310, 320, the shape of the beam, etc. are adjusted to compensate the temperature distribution value in the superposed irradiation region 12.

[0323] On the other hand, in another embodiment of the present invention, a plurality of infrared temperature sensors 810 may be provided. Referring to FIG. 28, the plurality of infrared temperature sensors of the present invention may be composed of, for example, five temperature sensors 810#1, 810#2, 810#3, 810#4, and 810#5. One temperature sensor 810#1, 810#2, 810#3, and 810#4 may be arranged at each edge portion in the arrangement structure, and one temperature sensor 810#5 may be arranged in the central portion. Therefore, the five infrared temperature sensors 810#1, 810#2, 810#3, 810#4, and 810#5 irradiate infrared beams simultaneously. In this case, as shown in FIG. 29, the electronic components 11b#1, 11b#3, 11b#7, 11b#9 located at each edge portion of the square region 12 where the laser beams are overlapped and irradiated and the electronic component 11b#5 located in the central portion are irradiated with infrared beams and the temperature is measured.

[0324] At this time, the position and number of the electronic components 11b whose temperature is measured as described above are not specified, and the temperature of the substrate surface where no electronic component is arranged can also be measured. In order to obtain a more accurate temperature distribution value of the region where the laser beams are overlapped and irradiated, it can be achieved by measuring the temperature values of as many electronic components and substrates as possible.

[0325] On the other hand, in another method of compensating the temperature distribution value, it is also possible to compensate the temperature distribution value when adjusting the irradiation angle, height, etc. of the first or second laser beam.

[0326]

[0327] FIGS. 30a to 30e are relational diagrams showing the operation relationship of each step of the laser reflow method of the present invention. Hereinafter, when looking at each step of the laser reflow method according to an embodiment, it is as follows.

[0328] First, FIG. 30a is a state diagram in which the translucent pressing member 100 has moved above the center line Cn+1. When the pressing surface 102 of the translucent pressing member 100 is located on the center line Cn+1, the vision unit 934 photographs the electronic component 11b located below the pressing surface 102 of the translucent pressing member 100. At this time, when viewed from the side as shown in FIG. 30a, the vision unit 934 determines whether the electronic components 11b are arranged symmetrically about the center line Cn+1 of the pressing surface 102 of the translucent pressing member 100.

[0329] That is, with the shape in which the electronic components 11b located directly below the pressing surface 102 of the translucent pressing member 100 are arranged positioned to correspond to the area of the pressing surface 102, for example, in a state where the electronic components 11b are arranged in three rows as shown in FIG. 10a, it is determined whether the electronic components 11b are arranged symmetrically by 1.5 rows on each side with the center line Cn+1 of the pressing surface 102 as a reference. Thereby, when the pressing surface 102 of the translucent pressing member 100 presses the range (area) in which the electronic components 11b are arranged in three rows, pressure is not biased to either side and uniform pressing can be achieved.

[0330] Also, referring to the drawings, the electronic component 11b of the bonding object 11 is in a state of being arranged at a position where it is bonded together with the solder 11c for bonding on the upper surface of the substrate 11a. At this time, it is in a state of being vacuum-sucked and fixed by the vacuum chuck 940 at the silver lower part of the substrate 11a. At this time, since the heating block 942 is provided inside the vacuum chuck 940, the substrate 11a, the electronic component 11b, and the solder 11c, which are the bonding object 11, are continuously preheated to a predetermined temperature. For example, it is preferable that the preheating temperature is set to be less than the melting temperature of the solder, and for example, it can be maintained below 200°C, which is a temperature range in which no thermal damage is caused even if the substrate 11a and the electronic component 11b are exposed for a certain period of time or more.

[0331] If the bonding object 11 is not preheated as described above, during the laser reflow process in this step, the bonding object 11 must be rapidly heated from room temperature to the melting temperature of the solder 11c only by the thermal energy of the laser beam. In this case, the rapid heating may cause bonding defects such as overflow in the solder 11c. Therefore, if the temperature is increased step by step from the preheating temperature to the melting temperature of the solder 11c, the solder 11c can melt stably and bonding defects can be minimized. For example, here, the melting temperature of the solder 11c may vary depending on the material of the solder, but may be 200 °C or higher, which is the melting temperature of a general solder paste.

[0332]

[0333] FIG. 30b is a state diagram in which the light-transmissive pressing member 100 is pressed and irradiated with a laser beam along the center line Cn+1. As shown in FIG. 10a, when it is determined that the center line Cn+1 of the pressing surface 102 of the light-transmissive pressing member 100 by the vision unit 934 coincides with the center line of the electronic component 11b to be bonded, the light-transmissive pressing member 100 moves downward to press the electronic component 11b.

[0334] At that time, a laser beam can be irradiated simultaneously or sequentially with the pressing of the light-transmissive pressing member 100. For example, when the light-transmissive pressing member 100 is pressed, a laser beam can be superimposed and irradiated on the electronic component 11b from the multi-laser module, the first laser module 310, and the second laser module 320 located above.

[0335] Thereby, the bonding object 11 is gradually heated from the preheating temperature to the melting temperature of the solder 11c by the laser beam irradiated in a superimposed manner, and finally, the solder 11c located below the electronic component 11b melts while the bonding of the electronic component 11b to the substrate 11a is completed. (The height difference before and after bonding is denoted as hc in FIG. 30a.)

[0336]

[0337] Figure 30c is a state diagram in which the translucent pressing member has moved above the center line Cn+2, Figure 30d is a state in which the position of the translucent pressing member has been corrected to a new center line Cn+2', and Figure 30e is a state diagram in which the translucent pressing member is pressed and irradiated with a laser at the center line Cn+2'.

[0338] Referring to Figure 30c, after the previous laser reflow process is completed, the translucent pressing member 100 is horizontally transported to the center line Cn+2 of the three rows of electronic components 11b in order to press and perform laser reflow processing on the three rows of electronic components 11b within the next predetermined range. At this time, the vision unit 934 photographs the arrangement shape of the electronic components 11b disposed below the pressing surface 102 of the translucent pressing member 100 again.

[0339] By the way, at this time, as shown in Figure 30c, if it is determined that the electronic components 11b disposed below the pressing surface 102 of the translucent pressing member 100 are not symmetrically arranged with respect to the center line Cn+2, the pressing and laser irradiation are not immediately advanced. The reason is that when the translucent pressing member 100 is pressed in this state, since the electronic components 11b are asymmetrically arranged with respect to the center line Cn+2 of the pressing surface 102 of the translucent pressing member 100, the pressing force during pressing is biased toward one side, resulting in bonding failure.

[0340] Therefore, in order to prevent this, in the present invention, as shown in Figure 30d, the control unit (not shown) moves the horizontal position of the translucent pressing member 100 to a new center line Cn+2', and accordingly, the horizontal position of the translucent pressing member 100 is corrected at the corrected center line Cn+2'. As a result, the horizontal position is corrected so that the electronic components 11b disposed below the translucent pressing member 100 are symmetrically arranged with respect to the corrected center line Cn+2'. In this state, as shown in Figure 30e, the translucent pressing member 100 moves downward to press the electronic components 11b and irradiate them with a laser beam.

[0341]

[0342] On the other hand, referring to FIG. 30e, the translucent pressing member 100 moves to the corrected center line Cn+2' and the pressing proceeds. At this time, the first and second laser modules 310 and 320 do not correct the horizontal position with respect to the corrected center line Cn+2', and irradiate the laser beam based on the center line Cn+2 before correction.

[0343] The reason why the laser modules 310 and 320 do not correct the horizontal position along the translucent pressing member 100 as described above is that when the laser beam is irradiated based on the corrected center line Cn+2', there is a risk that the laser beam will be irradiated again to the electronic component where the bonding has already been completed, and when the laser beam is re-irradiated to the solder 11c that has been reflowed, the solder 11c may melt again, thereby causing bonding failure. Therefore, in the present invention, when pressing and laser irradiating the asymmetrically arranged electronic components 11b, after horizontally transporting and correcting the position of only the translucent pressing member 100 to the corrected center line Cn+2' without correcting the position of the first or second laser modules 310 and 320, and then pressing and irradiating with the laser, it is possible to minimize the occurrence of various bonding failure factors as described above.

[0344]

[0345] It is a state diagram showing the operation relationship for each step of the laser reflow method according to the present invention. Hereinafter, looking at various bonding modes that can be combined for each step according to the examples, it is as follows.

[0346] First, referring to FIG. 31a, the first bonding mode of the present invention is the most basic bonding mode. The pressing surface 102 of the translucent pressing member 100 moves downward and contacts the bonding object 11 without applying a pressing force, the step of irradiating the bonding object 11 with a laser beam through the translucent pressing member 100, and then the step of releasing the irradiation of the laser beam and raising the translucent pressing member 100 can proceed.

[0347] At that time, in the stage where the translucent pressing member 100 contacts without applying a pressing force, as shown in FIG. 13 above, it is connected by the motor 760 and the ball screw 750 by driving the motor 760. The press bracket 720 comes to move downward, and since the holder unit 500 and the translucent pressing member 100 are mounted on the press bracket 720, finally the translucent pressing member 100 is moved downward by driving the motor.

[0348] Referring to FIG. 31b in the next step, when the translucent pressing member 100 is moved downward and contacts the electronic component 11b of the bonding object 11, a driving force is provided to move the translucent pressing member 100 downward. The driving of the motor 760 is stopped, and the translucent pressing member 100 comes into a state of contacting the upper surface of the electronic component 11b without applying a pressing force. At that time, since the motor is in a locked state, the height of the translucent pressing member 100 is fixed so that it does not move vertically either.

[0349] Next, as shown in the next step of FIG. 31c, with the translucent pressing member 100 contacting the upper surface of the electronic component 11b, the multi-laser module provided above the translucent pressing member 100, that is, the first laser module 310 and the second laser module 320, irradiate the bonding object 11 with laser beams through the translucent pressing member 100.

[0350] At that time, the laser beam can be transmitted as a homogenized laser beam to the plurality of electronic components 11b and the solder 11c by being superposed and irradiated. As described above, since the bonding object 11 has already been preheated at a certain preheating temperature, for example, less than 200°C, the laser beam can be stably heated from the preheating temperature to the melting temperature of the solder 11c, for example, 250°C, without rapidly heating the bonding object 11 to the melting temperature of the solder 11c. Thus, when the laser reflow is started, since the pressing surface 102 of the translucent pressing member 100 is in contact with the upper surface of the solder 11c, the electronic component 11b located above the solder 11c is confined so as not to bend or stretch upward when the solder 11c melts.

[0351] After that, when soldering is completed, the irradiation of the laser beam is released and the translucent pressing member 100 is moved upward, thereby completing the first bonding mode.

[0352]

[0353] On the other hand, let's look at an embodiment of another bonding mode in which several steps are added in the first bonding mode.

[0354] Similar to the first bonding mode described above, in the second bonding mode, after the translucent pressing member 100 contacts the electronic component 11b of the bonding object 11, the pressing cylinder 730 provided above the translucent pressing member 100 presses the translucent pressing member 100 with a certain pressure.

[0355] Thereafter, when the laser beam is irradiated while the translucent pressing member 100 presses the bonding object 11 as described above, as the solder 11c of the bonding object 11 melts, the pressing force is released. At this time, it is expected that the height of the electronic component 11b will be lowered by the compression of the solder 11c by a certain height (see hc in Fig. 31a). When the motor 760 is unlocked in this state, the translucent pressing member 100 will gradually move downward due to its own weight. Eventually, the translucent pressing member 100 will move downward by the amount of the pressing force applied by the pressing cylinder 730, so the pressing force is maintained.

[0356] Therefore, the second bonding mode is different from the initial bonding mode in that a pressing force is applied before the laser beam is irradiated, and when the solder 11c to which the laser beam is applied melts, the translucent pressing member 100 also moves downward while maintaining the pressing force. As a result, since the pressing force applied to the solder 11c is kept constant when the solder 11c melts, it is expected to reduce the lifting of the electronic component 11b and the poor connection of the solder 11c, and obtain a high-density soldering effect.

[0357]

[0358] Also, the third bonding mode is the same as the first bonding mode described above in that after the translucent pressing member 100 contacts the electronic component 11b of the bonding object 11, the laser beam is irradiated without applying a pressing force.

[0359] After the laser beam is irradiated, the pressing cylinder 730 is driven to apply a certain pressing force to the translucent pressing member 100 and the bonding object 11. At this time, the motor 760 is locked and fixed so that the translucent pressing member 100 cannot move vertically, and only the pressing cylinder 730 applies the pressing force. The third bonding mode is different from the first bonding mode in that a pressing force is applied after the laser beam is irradiated.

[0360]

[0361] The fourth bonding mode is the same as the third bonding mode up to the stage of irradiating the laser beam, but there is a difference in that, instead of applying a pressing force after the irradiation of the laser beam, the height of the light-transmissive pressing member 100 is changed.

[0362] Therefore, when the irradiation of the laser beam starts, the lock of the motor is released, and the light-transmissive pressing member 100 gradually moves downward, and finally gradually presses the electronic component 11b and the molten solder 11c. Thus, it is possible to prevent bonding failure caused by a sudden pressing force being applied to the solder 11c melted by the laser beam.

[0363]

[0364] As described above, there are possibilities of various embodiments in terms of adjusting the pressure change due to the melting of the solder to prevent bonding failure in the bonding mode.

[0365] Therefore, the present invention is not limited only by the embodiments described above, and even if the detailed configuration, number, and arrangement structure of the device are changed, or the detailed steps are changed and added, the same effects can be produced. Thus, it is explicitly stated that those having ordinary knowledge in the relevant technical field can add, delete, and modify various configurations within the scope of the technical idea of the present invention.

[0366]

[0367] Description of Reference Numerals

[0368] 11: Bonding object 11a: Substrate

[0369] 11b: Electronic component 12: Laser overlapping irradiation region

[0370] 100: Light-transmissive pressing member 101: Base material

[0371] 101a: Step portion 102: Pressing surface

[0372] 102a: Lattice groove 103: Laser light blocking layer

[0373] 104: Silicon damper layer 200: Protective film

[0374] 210: Protective film conveying unit 310: First laser module

[0375] 318, 328: Beam profiler 320: Second laser module

[0376] 500: Holder unit 510: Lower plate

[0377] 520: Mask plate 600: Probe unit

[0378] 610: Probe 620: Probe conveying unit

[0379] 630: Probe bracket 700: Press unit

[0380] 710: Pressure balancer 720: Press bracket

[0381] 730: Pressing cylinder 740: Pressure sensing sensor

[0382] 750: Ball screw 760: Motor

[0383] 770: Guide member 780: Bearing joint

[0384] 790: Stopper 800: Ionizer

[0385] 810: Infrared temperature sensing sensor 811: Infrared irradiation point

[0386] 910: Input conveyor 920, 960: Horizontal conveying unit

[0387] 930, 970: Suction pad 934: Vision unit

[0388] 940: Vacuum chuck 942: Heating block

[0389] 943: Porous adsorption plate 950: Output conveyor

[0390] 980: Adsorption plate lifting unit

[0391]

Claims

1. a laser pressure head module that applies pressure to a bonding object, which is a plurality of electronic components arranged on a substrate, with a light-transmitting pressure member and that irradiates a laser beam through the pressure member to bond the electronic components to the substrate; A laser reflow apparatus comprising a bonding object transport module that transports a bonding object transported from one side of the laser pressure head module so that the bonding object can be transported to the other side after undergoing reflow processing of the laser pressure head module.

2. The laser pressure head module includes a holder unit for attaching the light-transmitting pressure member in a replaceable manner; 2. The laser reflow apparatus according to claim 1, further comprising a probe unit provided above the holder unit for inspecting flatness of the pressure member attached to the holder unit.

3. 2. The laser reflow apparatus according to claim 1, wherein the laser beam is a rectangular laser beam homogenized by a beam shaper.

4. 2. The laser reflow apparatus according to claim 1, wherein the laser beam is emitted by two or more laser modules in a superimposed manner.

5. 2. The laser reflow apparatus according to claim 1, wherein the holder unit comprises a lower plate having a through hole formed in the center thereof so that the light-transmitting pressure member can be fitted and seated therein.

6. 2. The laser reflow apparatus according to claim 1, wherein the light-transmitting pressure member is made of any one of quartz, sapphire, fused silica glass, and diamond.

7. 6. The laser reflow apparatus according to claim 5, wherein the holder unit further comprises a mask plate having a vent hole formed in a center portion thereof so that the laser beam can pass through, and the mask plate is coupled to an upper portion of the lower plate with the translucent pressure member seated on the lower plate.

8. 8. The laser reflow apparatus according to claim 7, wherein the through-hole of the mask plate is a rectangle having an area larger than or equal to the pressure surface of the light-transmitting pressure member.

9. 6. The laser reflow apparatus according to claim 5, wherein the bottom surface of the lower plate has left and right edge portions that are gently rounded.

10. 6. The laser reflow apparatus according to claim 5, further comprising flatness adjusting means provided at each edge of the lower plate for finely moving the edge of the lower plate in a vertical direction to adjust the flatness of the light-transmitting pressure member.

11. The flatness adjusting means includes a press bracket provided on each edge of the light-transmitting pressure member and the holder unit; 11. The laser reflow apparatus according to claim 10, further comprising a vertical drive unit provided on one side of the press bracket and configured to transport the press bracket in a vertical direction in response to driving of a motor.

12. The vertical drive unit includes a ball screw and a motor for vertically transporting the press bracket, The laser reflow apparatus according to claim 11 , further comprising a guide member for guiding the linear motion of the press bracket.

13. The probe unit includes a probe for measuring flatness by piercing at least one point on an upper surface of the light-transmitting pressure member; a moving means for transporting the probe in a horizontal or vertical direction; and 3. The laser reflow apparatus according to claim 2, further comprising a probe bracket for fixing the probe and the moving means.

14. 14. The laser reflow apparatus according to claim 13, wherein the probe pierces a total of four or more points including a square edge of the upper surface of the light-transmitting pressure member for probing.

15. 3. The laser reflow apparatus according to claim 2, further comprising a protection film disposed under the transparent pressure member to prevent fumes generated during laser bonding from adhering to a bottom surface of the transparent pressure member.

16. 16. The laser reflow apparatus according to claim 15, wherein the protective film is made of polytetrafluoroethylene resin (PTFE) or perfluoroalkoxy resin (PFA).

17. The laser reflow apparatus according to claim 15, wherein the protective film is supplied by a protective film transport unit of a reel-to-reel type that transports the rolled protective film in one direction while loosening it.

18. The light-transmitting pressure member includes a base material having a rectangular panel shape as a whole, 2. The laser reflow apparatus according to claim 1, further comprising a pressure surface that is formed on the bottom surface of the base material to protrude therefrom and that is formed flat so as to correspond to a plurality of electronic components.

19. 20. The laser reflow apparatus according to claim 18, further comprising at least one step portion recessed inward between the base material and the pressure surface such that an area of ​​the pressure surface is smaller than an area of ​​the base material.

20. 20. The laser reflow apparatus according to claim 18, wherein a laser light blocking layer is formed on the side surface of the base material and on the bottom surface and side surface of the step portion.

21. 20. The laser reflow apparatus according to claim 18, wherein the pressure surface is divided into two or more parts by a lattice groove having a certain depth.

22. The laser reflow apparatus according to claim 21 , further comprising a laser light blocking layer formed on an inner side and a bottom surface of the grating groove.

23. 22. The laser reflow apparatus according to claim 20, wherein the laser light blocking layer is made of one of an Inconel coating layer, a diffuse reflection processing layer, and a High Reflection (HR) coating layer, or a composite layer of two or more of them.

24. The laser reflow apparatus according to claim 18 , wherein the pressure surface has a rectangular shape.

25. 25. The laser reflow apparatus according to claim 24, wherein both side edges of the pressure surface are chamfered or rounded.

26. The laser reflow apparatus according to claim 18 , further comprising an elastic damper layer on the pressure surface.

27. The laser reflow apparatus of claim 26, wherein the elastic damper layer is made of silicon.

28. The laser pressure head module includes a rectangular holder unit for attaching the light-transmitting pressure member in a replaceable manner; a pressure balancer that initializes the weights of the holder unit and the light-transmitting pressure member to zero by applying pressure in an opposite direction to the weights of the holder unit and the light-transmitting pressure member while supporting the lower ends of each edge of the holder unit; 2. The laser reflow apparatus according to claim 1, further comprising a press unit provided above each edge of the holder unit in a non-contact state and for independently pressing each edge of the holder unit with a set pressure.

29. 29. The laser reflow apparatus according to claim 28, wherein the pressure balancer is an air cylinder.

30. 29. The laser reflow apparatus of claim 28, wherein the pressure balancer is comprised of an elastic spring.

31. 29. The laser reflow apparatus according to claim 28, wherein the press units are divided and arranged so that each press unit applies a pressure to each edge of the holder unit independently with a preset pressure.

32. The press unit includes a press bracket that holds each edge portion of the holder unit in a non-contact manner; 32. The laser reflow apparatus according to claim 31, further comprising a pressure cylinder attached to an upper end of the press bracket and configured to press the holder units downward with a set pressure.

33. The laser pressure head module includes a circular or polygonal holder unit for attaching the light-transmitting pressure member in a replaceable manner; 2. The laser reflow apparatus according to claim 1, further comprising a press unit which is condensed to three points around the edge of the holder unit, and which forms a triangle when the condensed points are connected by imaginary lines.

34. The press unit includes a press bracket and a pressure cylinder attached to an upper end of the press bracket and configured to press the holder unit downward with a set pressure; and 34. The laser reflow apparatus according to claim 33, further comprising a bearing joint having one end connected to the cylinder rod of the pressure cylinder and the other end rotatably connected to one of three points of the holder unit.

35. The laser reflow apparatus according to claim 34, wherein each point of the holder unit is further provided with a joint fastening portion, and each of the joint fastening portions is rotatably coupled to a bearing joint.

36. The laser reflow apparatus according to claim 35, further comprising a stopper at a lower end of the press bracket, the stopper being straddled by one end of the joint fastening portion.

37. 35. The laser reflow apparatus according to claim 34, further comprising a vertical conveying section provided on one side of the press bracket for vertically raising and lowering the press bracket.

38. 38. The laser reflow apparatus according to claim 37, wherein the vertical transport unit is provided with a ball screw and a motor.

39. 34. The laser reflow apparatus according to claim 33, wherein the flatness of the holder unit is initialized and reset to zero point at a fixed interval or after replacing the light-transmitting pressure member.

40. 34. The laser reflow apparatus according to claim 33, wherein an imaginary triangle connecting three points of the holder unit is an equilateral triangle, and the center of gravity of the imaginary triangle coincides with the center of gravity of the light-transmitting pressure member.

41. 35. The laser reflow apparatus according to claim 32 or 34, wherein the pressure cylinder is a precision pneumatic cylinder capable of minutely setting and adjusting a pressure in kgf units.

42. 42. The laser reflow apparatus of claim 41, wherein the pressure cylinder further includes a pressure sensor for measuring the pressure during pressure application and constantly feeding back the pressure.

43. 34. The laser reflow apparatus according to claim 28 or 33, further comprising an ionizer unit disposed above the holder unit for cleaning an upper surface of the light-transmitting pressure member from dust adhesion caused by static electricity.

44. The bonding object transport module includes an input conveyor on which a bonding object, which is a plurality of electronic components arranged on a substrate, is seated for loading; a vacuum chucking means for vacuum-adsorbing and fixing the bonding object supplied from the input conveyor; and 2. The laser reflow apparatus according to claim 1, further comprising an output conveyor on which the bonding objects that have been subjected to the laser reflow process are seated for removal.

45. The input and output conveyors include a conveyor frame and A pair of wire track means provided on both sides of the upper portion of the conveyor frame; 45. The laser reflow apparatus of claim 44, further comprising a horizontal transport means provided on one side of the conveyor frame for linearly moving the conveyor frame in a horizontal direction.

46. 46. ​​The laser reflow apparatus of claim 45, wherein one side of the conveyor frame of the input and output conveyors is further provided with a width adjustment means for expanding or reducing the width of the conveyor frame to accommodate bonding objects of different sizes.

47. 46. ​​The laser reflow apparatus according to claim 45, wherein a conveyor frame of the input conveyor further includes a preheating stage for preheating the bonding objects to a predetermined temperature.

48. 45. The laser reflow apparatus according to claim 44, further comprising a vision unit on one side of the vacuum chucking means for monitoring whether the bonding object is properly loaded.

49. 45. The laser reflow apparatus according to claim 44, further comprising a picker unit for delivering objects to be bonded to each of the input and output conveyors in a section between the input and output conveyors and the vacuum chucking means.

50. The picker unit includes a vacuum suction pad on a flat plate; 50. The laser reflow apparatus according to claim 49, further comprising a vertical drive unit for transporting the vacuum suction pad in a vertical direction.

51. The vacuum chucking means comprises a porous suction plate for suction-fixing an object to be bonded; 45. The laser reflow apparatus according to claim 44, further comprising a horizontal transport means for reciprocating the porous suction plate and the heating block from an input area of ​​the bonding object through a laser reflow processing area to an output area.

52. The porous suction plate includes a rectangular central suction plate for suctioning a central portion of a bottom surface of an object to be bonded; 52. The laser reflow apparatus according to claim 51, further comprising border suction plates arranged around the central suction plate for suctioning the bottom edge of the bonding object.

53. 53. The laser reflow apparatus of claim 52, wherein the border suction plate further includes a suction hole for suctioning an edge of a bottom surface of the bonding object.

54. 53. The bonding object transport module of a laser reflow apparatus according to claim 52, wherein the border suction plate is made of an aluminum material.

55. 52. The bonding object transfer module of claim 51, further comprising a heating block provided under the porous suction plate.

56. The laser pressure head module includes a multi-laser module that is arranged separately from each other and irradiates the bonding object with a plurality of superimposed laser beams; 2. The laser reflow apparatus according to claim 1, further comprising temperature sensors provided in gap regions of the multi-laser modules for detecting temperatures at a plurality of points on an object to be bonded by irradiating a beam through a light-transmitting pressure member.

57. 57. The laser reflow apparatus according to claim 56, wherein the multi-laser module is composed of a pair of multi-laser modules facing each other.

58. 57. The laser reflow apparatus according to claim 56, wherein the temperature sensor is a single infrared temperature sensor, and the single infrared temperature sensor sequentially irradiates infrared rays to multiple points on the bonding object.

59. 59. The laser reflow apparatus according to claim 58, wherein the single infrared temperature sensor sequentially irradiates infrared rays to a plurality of points in a periphery and a central portion within an area where a plurality of laser beams are irradiated in a superimposed manner.

60. 57. The laser reflow apparatus according to claim 56, wherein the temperature sensor is composed of a plurality of infrared temperature sensors, and the plurality of infrared temperature sensors simultaneously irradiate infrared rays to a plurality of points on the bonding object.

61. 61. The laser reflow apparatus according to claim 60, wherein the plurality of infrared temperature sensors simultaneously irradiate infrared rays to a plurality of points among a periphery and a central portion within an area where the plurality of laser beams are irradiated in a superimposed manner.

62. 57. The laser reflow apparatus of claim 56, wherein the multi-laser module further comprises a beam profiler for measuring the power and intensity of each laser beam.

63. A laser reflow method for a laser reflow apparatus in which a bonding object, which is a rectangular substrate on which a plurality of electronic components are arranged, is pressed against a light-transmitting pressure member, pressure is applied, and a laser beam is irradiated through the pressure member to bond the electronic components to the substrate, comprising: a) before the light-transmitting pressure member presses the bonding object, a vision unit captures an image of a shape of electronic components arranged within a predetermined range located directly under a pressure surface of the light-transmitting pressure member; b) determining whether the photographed shape of the electronic components in the predetermined area is positioned to correspond to the pressure surface; c) when it is determined that the electronic component is positioned to correspond to the pressing surface, a light-transmitting pressing member is moved downward to press the bonding object, and a laser beam is irradiated onto the bonding object via the light-transmitting pressing member; d) stopping the irradiation of the laser beam to move the light-transmitting pressure member upward to release the pressure; and e) A laser reflow method using a laser reflow apparatus, comprising a step of horizontally transporting the light-transmitting pressure member to above a predetermined range of electronic components to be subjected to a next reflow process.

64. The step b) includes a step of: b1) determining whether the electronic components are positioned symmetrically with respect to a center line of a pressure surface of a light-transmitting pressure member when the photographed shape of the electronic components arranged within a predetermined range is viewed from the side; b2) When the photographed shape of the electronic component is symmetrically positioned with respect to the center line of the pressure surface of the light-transmitting pressure member, it is determined that the electronic component is positioned to correspond to the pressure surface. However, if the electronic components are not arranged to correspond to the pressure surface, a step of adjusting the horizontal position of the light-transmitting pressure member so that the shape of the electronic components arranged is symmetrical with respect to the center line of the pressure surface of the light-transmitting pressure member is provided.

65. 64. The laser reflow method according to claim 63, wherein the laser beam is superimposed and irradiated from two or more laser modules.

66. 64. The laser reflow method of claim 63, wherein the laser modules are arranged symmetrically to each other, and the laser beams have the same beam irradiation angle.

67. 67. The laser reflow method according to claim 66, wherein the laser beams are emitted from the laser modules simultaneously.

68. 67. A laser reflow method for a laser reflow apparatus according to claim 66, wherein the laser beams are sequentially irradiated from the laser modules.

69. 64. The laser reflow method of claim 63, further comprising a step of preheating the bonding object at a lower part before the step c).

70. 70. The laser reflow method of claim 69, wherein the preheating of the bonding object at the lower portion maintains a surface temperature of the bonding object at less than 200[deg.] C.

71. 64. The laser reflow method of claim 63, wherein in step c), the bonding object is heated to a surface temperature of 200[deg.] C. or more by irradiating the bonding object with a laser beam through a light-transmitting pressure member.

72. A laser reflow method for a laser reflow apparatus in which a bonding object, which is a rectangular substrate on which a plurality of electronic components are arranged, is pressed against the substrate by a light-transmitting pressure member, and a laser beam is irradiated through the pressure member to bond the electronic components to the substrate, comprising: a) moving a pressure surface of the light-transmitting pressure member downward to contact the bonding object without applying pressure; b) irradiating a laser beam onto an object to be bonded through the light-transmitting pressure member; and c) a step of canceling the irradiation of the laser beam and moving the light-transmitting pressure member upward, the laser reflow method comprising the steps of:

73. 73. The laser reflow method of claim 72, further comprising the step of fixing the vertical movement of the light-transmitting pressure member after the step a).

74. 73. The laser reflow method of claim 72, further comprising the steps of: applying a constant pressure to the light-transmitting pressure member after the step a); and not fixing the vertical movement of the light-transmitting pressure member after the step b).

75. 73. The laser reflow method of claim 72, further comprising the steps of: fixing the vertical movement of the light-transmitting pressure member after the step a); and applying a predetermined constant pressure to the light-transmitting pressure member after the step b).

76. 73. The laser reflow method of claim 72, further comprising the steps of: fixing the vertical movement of the light-transmitting pressure member after the step a); and not fixing the vertical movement of the light-transmitting pressure member after the step b).

77. 73. The laser reflow method according to claim 72, wherein in the step b), the laser beam is emitted from two or more laser modules in a superimposed manner.

78. 73. The laser reflow method according to claim 72, wherein the laser beams are irradiated simultaneously from the laser modules.

79. 78. A laser reflow method for a laser reflow apparatus according to claim 77, wherein the laser beams are sequentially irradiated from the laser modules.

80. 73. The laser reflow method of claim 72, further comprising the step of preheating the bonding object at a lower portion before the step b).

81. 81. The laser reflow method of claim 80, wherein the step of preheating the bonding object at the lower part maintains a surface temperature of the bonding object at less than 200°C.

Images