KR101858440B1

KR101858440B1 - Laser soldering apparatus and method

Info

Publication number: KR101858440B1
Application number: KR1020170107974A
Authority: KR
Inventors: 최병찬; 강기석
Original assignee: 최병찬; 강기석; 주식회사 엔디테크
Priority date: 2017-08-25
Filing date: 2017-08-25
Publication date: 2018-06-28

Abstract

A laser soldering apparatus according to the present invention includes: a controller; A transfer unit for transferring the first object and the second object; And a solder portion, which is operated by the control of the control portion and which performs soldering to form a bonding surface, wherein the solder portion is a laser that applies heat to the solder ball, A laser generator for generating a laser beam; A beam expander for adjusting an output range of the laser; And at least one head portion for applying a laser via the beam expander to the solder ball to be ejected between the first object and the second object and ejecting the solder ball, wherein the at least one head portion melts the solder ball Primary soldering between the first object and the second object; And secondary soldering which heats and distributes the solder bumps which are the solder balls which are melted.

Description

[0001] LASER SOLDERING APPARATUS AND METHOD [0002]

The present invention relates to a laser soldering apparatus and method.

Generally, in a semiconductor process, a soldering process is performed in which a semiconductor chip is bonded to a printed circuit board (PCB) using a solder. Here, the soldering process may include a step of printing a solder made of an alloy of lead and tin at a predetermined position of a printed circuit board, and then attaching the solder to the printed circuit board by heating the solder at a high temperature. Such a soldering process is generally referred to as a reflow soldering process and is widely applied throughout the industry.

However, the conventional reflow soldering apparatus is large in size and requires a long time for the soldering process. In order to solve this problem, a soldering apparatus using laser has been developed, but the conventional laser soldering apparatus has a problem that damage or voids are generated in the solder after the soldering process.

Korean Patent Publication No. 2017-0024491 (Feb.

It is an object of the present invention to provide a laser soldering apparatus and method for performing a primary soldering and a secondary soldering process to bond a first object and a second object to increase the degree of bonding and reduce the defect rate .

One embodiment of the present invention is a laser soldering apparatus in which solder is stably bonded to a first object and a second object by performing preheating in the vicinity of a joint surface between a first object and a second object in primary and secondary soldering processes, And a method thereof.

An embodiment of the present invention provides a laser soldering apparatus and method in which solder is introduced into a spaced space or a stepped space between respective objects to increase a joint area even if the first object and the second object are spaced apart or have step differences The purpose.

An object of the present invention is to provide a laser soldering apparatus and method for confirming a soldering state bonded to a target object to determine whether the soldered state is defective or not, and re-performing soldering when the soldering state is defective.

A control unit; A transfer unit for transferring the first object and the second object; And a solder part operated by the control of the first object and the second object located on the transfer part and performing soldering to form a joint surface, wherein the solder part generates a laser for applying heat to the solder ball A laser generator; A beam expander for adjusting the output range of the laser; And at least one head portion for applying a laser via a beam expander to a solder ball to be ejected between the first object and the second object and ejecting the solder ball, wherein the at least one head portion melts the solder ball, Primary soldering between two objects; And secondary soldering which heats and distributes the solder bumps which are molten solder balls.

The head portion is one, and the primary soldering and the secondary soldering can be sequentially performed by one head portion.

In addition, the head part can perform a preheating process between the first soldering and the second soldering process on the first object and the second object.

In addition, the head portion includes the first head portion and the second head portion, and the first head portion performs the primary soldering, and the second head portion performs the secondary soldering.

Further, at least one of the first head portion and the second head portion may perform a preheating process between the primary soldering and the secondary soldering process to the first object and the second object.

Further, the head portion includes the first head portion, the second head portion, and the third head portion, and can perform the primary soldering and the secondary soldering sequentially.

Also, the preheating process may be performed between the primary soldering and the secondary soldering process to the first object and the second object.

In addition, the preheating process may be performed by a laser beam having a Gaussian beam shape or a flat top beam shape, or by defocusing a laser beam.

Also, the transmission of the laser may be a fiber laser transmitted through the optical fiber to the head portion.

In addition, for example, there may be a plurality of head parts, and may further include a division module for dividing an optical fiber so as to connect the optical fiber to the plurality of head parts separately, thereby transferring the fiber laser. have. However, if there is only one head part, the division module may not be included.

Also, the fiber laser can be selectively transmitted to the plurality of heads by the control unit or the division module.

In addition, the core of the optical fiber may be formed in a circular or polygonal shape.

In addition, the first object and the second object are bonded to each other and conveyed by the conveyance unit, and the head unit inspects the bonded joint faces before performing the first-order soldering, thereby inspecting whether the bonded joint faces are abnormal Can be performed.

Further, if it is judged that the inspection process is abnormal, the solder bumps can be sucked and removed, and the primary soldering and the secondary soldering can be performed.

Further, if it is judged as abnormal in the inspection process, secondary soldering can be performed.

In addition, the laser can be irradiated with an output in the form of a flat-top.

Also, for example, there are a plurality of head parts, and the laser can be divided and transmitted by a beam splitter to each head part. However, in case of one head part, the laser can be transmitted to one head part without being divided.

In addition, the object to be conveyed by the conveyance unit may further include a substrate, and the substrate may be arranged so that the first object and the second object can be stacked on the substrate.

The first object and the second object are placed on the transfer part and the first object and the second object are transferred to the solder side by the transfer part and the solder ball is melted by the laser irradiated from the at least one head part included in the solder part And then secondary soldering is performed in which primary soldering is performed to discharge the solder bumps at a point where the first object and the second object are jointed and the solder bumps, which are molten solder balls after the primary soldering, A laser soldering method is provided.

And, there is one head part, and primary soldering and secondary soldering can be sequentially performed by one head part.

Further, the head portion may further include a preheating process between the first and second soldering processes on the first object and the second object.

Further, at least one of the first head portion and the second head portion may further include a preheating process between the primary soldering and the secondary soldering processes to the first object and the second object.

Further, the first object and the second object may further include a preheating process between the primary soldering and the secondary soldering process.

In addition, a plurality of head units may be further included, and may further include a division module for dividing an optical fiber so as to connect the optical fiber to a plurality of the head units, thereby transferring the fiber laser.

In addition, the first object and the second object are bonded to each other and conveyed by the conveying unit, and the head part inspects the pre-bonded joint surface before performing the first-order soldering to judge whether or not there is an abnormality in the jointed surfaces It may further include an inspection process.

Further, there are a plurality of head parts, and the laser can be divided and transmitted to each head part by a beam splitter.

One embodiment of the present invention can provide a laser soldering apparatus and method for performing first and second soldering processes to bond a first object and a second object, thereby increasing the degree of bonding and lowering the percentage of defects.

One embodiment of the present invention is a laser soldering apparatus in which solder is stably bonded to a first object and a second object by performing preheating in the vicinity of a joint surface between a first object and a second object in primary and secondary soldering processes, And methods.

An embodiment of the present invention can provide a laser soldering apparatus and method in which solder is introduced into a spaced space or a stepped space between respective objects to increase a joint area even if the first object and the second object are spaced apart or have step differences have.

An embodiment of the present invention can provide a laser soldering apparatus and method for confirming a soldered state bonded to a target object to determine whether the soldered state is defective or not, and re-performing soldering when the soldered state is defective.

1 shows a laser soldering apparatus according to an embodiment of the present invention;
2 illustrates a control unit connected to a laser soldering apparatus according to an embodiment of the present invention.
3 is a view showing that a fiber laser according to another embodiment of the present invention is divided by a division module and connected to a head part
FIG. 4A is a view showing an arrangement of a first object and a second object according to an embodiment of the present invention. FIG. 4B is a view showing an arrangement of a first object and a second object according to another embodiment of the present invention. Lt; RTI ID = 0.0 >
5 is a view showing a state of preheating and heating through a laser according to an embodiment of the present invention;
6 is a view showing a preheating process and distribution of solder bumps according to an embodiment of the present invention;
7 is a diagram for comparing laser power distributions according to an embodiment of the present invention;
8 is a diagram for comparing surfaces processed through a flat-top laser power distribution according to an embodiment of the present invention;
9 is a view showing a configuration of a fiber for conveying a fiber laser according to an embodiment of the present invention
10 is a cross-sectional view of a core of a fiber according to an embodiment of the present invention;
11 is a flowchart showing a sequence of a laser soldering method including a preheating process according to an embodiment of the present invention
12 is a flowchart showing a sequence of a laser soldering method including an inspection process according to an embodiment of the present invention

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, this is merely an example and the present invention is not limited thereto.

In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intention or custom of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

The technical idea of the present invention is determined by the claims, and the following embodiments are merely a means for effectively explaining the technical idea of the present invention to a person having ordinary skill in the art to which the present invention belongs.

1 is a view showing a laser soldering apparatus according to an embodiment of the present invention.

Referring to FIG. 1, a laser soldering apparatus according to an embodiment of the present invention may include a controller (100 in FIG. 2), a solder portion 200, and a transfer portion 300. The controller (100 in FIG. 2) can perform the soldering process on the target object (400, 410, 420) by controlling the movement of the solder part (200) and the laser irradiation. The transfer unit 300 may transfer the object 400 (410, 420) while the first object 410 and the second object 420 to be bonded are stacked or arranged on a plane so as to be stepped.

Specifically, the solder portion 200 may include a laser generating portion 210, a beam expander 220, and at least one head portion 230 (231, 232, 233). The laser generated from the laser generating portion 210 can be adjusted in cross-sectional area of the beam through the beam expander 220. The cross sectional area of the adjusted beam may be the cross sectional area of the laser to be irradiated toward the object 400 (410, 420). The laser beam passed through the beam expander 220 can be transferred to the head portion 230 and primary soldering is performed in which the molten solder ball 1 is discharged from the head portion 230 and solder bumps 2 Can be performed between the target body 400 and the secondary soldering can be performed.

Further, in addition to the primary and secondary soldering, a preheating process can be further included. The preheating process may be performed at one or more of the points before or after the primary soldering or before or after the secondary soldering. For example, the solder bump 2 may be deteriorated in spreadability by the object 400 maintaining a relatively low temperature after the solder ball 1 is discharged to the object 400 side through the primary soldering and then the secondary soldering is performed. Which may lead to poor soldering such as cold soldering, cracking, poor bonding and the like. Here, the term " spreading " means the extent to which the solder bumps 2 are placed on the target object 400 and distributed so that a wider area of the target object 400 is contacted. Therefore, the preheating process may be performed after the primary soldering and before the secondary soldering to prevent the lowering of the spreadability due to the temperature of the object 400, which is maintained at a relatively lower temperature than the solder bumps. The preheating process will be described later in detail with reference to FIG.

The number of the head units 230 (231, 232, 233) may be plural. The laser beam may be directly connected to one head portion 231. In the case where there are a plurality of head portions 230, the beam splitter 241, May be divided and provided to the respective head portions 230. FIG. For example, if three heads 230 are provided and a laser is to be provided to each head 230, before the laser reaches the head 230 where the laser is transmitted, Beam splitters 241 and 242 may be located.

If there are a plurality of head parts 230, the head part 230 to be subjected to the primary soldering, secondary soldering, and preheating processes described above may be determined by the control part 100. This may be selectively determined and may be maintained in the standby state without performing either the primary soldering, the secondary soldering, or the preheating process. For example, three head portions 230 (231, 232, 233) may be included, but primary soldering, secondary soldering, and preheating may be performed by one head portion 231.

2 is a view illustrating a controller 100 connected to a laser soldering apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the controller 100 may control the laser generated from the laser generator 210. More specifically, the beam splitter 243 is disposed on the path of the laser beam transmitted from the beam expander 220 to the head unit 230 to allow the laser to reach the monitoring unit 500, The laser generator 210 can transmit the output of the laser to be irradiated to the target object 400 through the laser information. For example, the laser output required for primary soldering and the laser output required for secondary soldering may be different, and information for controlling the laser output may be transmitted to the laser generator. Of course, it is possible to control the information of the laser to be irradiated and to control the solder part 200 including the head part 230, so that it is required to perform the primary soldering, the secondary soldering and the preheating step performed on the object 400 It is possible to control so that an appropriate laser is irradiated.

3 is a view showing that a fiber laser FL according to another embodiment of the present invention is divided by the division module 600 and connected to the head part 230. FIG.

Referring to FIG. 3, as another embodiment of the present invention, the laser may be a fiber laser (FL). The fiber laser (FL) can be transmitted through an optical fiber. Of course, since the laser beam is transmitted through the optical fiber, there is no need to use an optical component such as a reflecting mirror for changing the path of the laser beam, and the laser transmission path does not need to maintain the linearity. .

The laser is transmitted to the division module 600 through an optical fiber 610 and may be divided from the division module 600 and transferred to each head part 230. The optical fibers 620, 630, and 640 may be connected to the respective head portions 230 (231, 232, and 233) individually, as described above. The head unit 230 may be independently controlled under the control of the control unit 100 by the individual connection.

4A and 4B are views showing the arrangement of the first object 410 and the second object 420 according to an embodiment of the present invention. FIG. 4A is a diagram showing the arrangement of the first object 410 and the second object 420, FIG. 4B is a view showing a state in which the first object 410 and the second object 410 according to another embodiment of the present invention are disposed at predetermined distances and the solder bumps 2 are positioned at the above- And the second object 420 is bonded onto the base material 450. FIG.

Referring to FIG. 4 (a), the object 400 (410, 420) may be arranged with a step or a predetermined distance D therebetween. For example, the first object 410 may be formed with a concave joint surface 411 on which the solder bump 2 can be positioned, and a second object body 410 disposed to form a step with the first object 410 420 may be formed.

The first object 410 may be formed with a concave bonding surface 411 on which the solder bumps 2 may be placed and may be formed on the second object 420 facing the first object 410 with the separation distance D, 411 may be formed. In this example, the two bonding surfaces 411 are formed, and the target body 400 arranged at a step or a distance D can be bonded while the solder bumps 2 are placed on the bonding surface 411 .

In the secondary soldering process described above, the solder bumps 2 are further irradiated with a laser while the solder bumps 2 are positioned, so that the solder bumps 2 are further dissolved so that the solder in the liquid phase can be distributed in the space formed by the step or the distance D do. The distribution can be expected to increase or improve the bonding strength by increasing the bonding area between the first object 410 and the second object 420 after curing of the solder.

Such an increase of the bonding force can increase the effect of the dissolved solder bumps 2 by improving the spreadability. The improvement in spreadability can be reduced due to the temperature difference between the object 400 and the solder bumps 2. Specifically, the temperature of the object 400 is room temperature, and the solder bumps 2 at a high temperature, which are located partially dissolved by the laser, may cause a temperature difference. The contact area between the solder bump 2 and the object 400 can be reduced if the spreadability is reduced on the joint surface 411 of the first object 410 due to the temperature difference.

Therefore, in order to improve the spreadability, a preheating process for reducing the temperature difference can be performed. The preheating process can be performed by changing the information such as the height of the head portion 230 or the laser output or the like so as to be spaced apart from the laser focus to form a distance between the laser focus and the object. Referring to FIG. 5, the head 230 can be preheated and heated by a laser, and the head 230 can receive a focal distance (F) and a defocusing (DF) Can be selectively adjusted.

When the object 400 is positioned at the focal length F, the laser output is concentrated, so that the metal object 400 may be melted or damaged due to heat. Therefore, in the case of irradiating the laser focused on the focal length F, it may be the case that the solder bump 2 is irradiated to the solder bump 2 for melting.

Further, when the object 400 is positioned at the non-focal distance DF, the laser output is dispersed and the laser irradiation area is increased. Therefore, when the object 400 is heated over a large area, Lt; / RTI > Therefore, in the case of irradiating the laser with a focus at the non-focal distance DF, the temperature difference between the solder bump 2 and the target object 400 may be minimized to increase the spreadability, thereby increasing the adhesion area.

Referring to FIG. 4B, the first object 410 and the second object 420 may be disposed on the base material 450 at a predetermined distance D and bonded by solder. Specifically, the object 400 (410, 420) may be disposed on the substrate 450 while being spaced apart from each other by a predetermined distance from each other when the object 400 is loaded on the transfer unit 300 and transported. That is, the substrate 450 and the object 400 (410, 420) may be sequentially stacked on the transfer unit 300 in an upward direction. Of course, this is explained only for the case of stacking in the vertical direction, and in the case of stacking in the horizontal direction, the member closer to the head part 230 can be the object 400. [

In the embodiment of FIG. 4 (b), the object 400 (410, 420) is horizontally spaced on the substrate while the object 400 (410, 420) . 4 (b), the solder bumps are located in the spaced apart spaces, and the contact surface 41 may be formed over the first object 410, the second object 420, and the substrate 450 in FIG. 4 (b).

The joining surface 411 may be concave on the object 410 or 420 so that the solder ball 1 may be discharged and positioned at a predetermined position in the state of the solder bump 2, The first object 420 and the second object 420. [ In this case, it may be the case that the concave formed surfaces 411 are formed in the respective objects 410 and 420.

The formation of such bonding surfaces 411 improves the spreadability and can lead to an increase in bonding force. The improvement in spreadability can be reduced due to the temperature difference between the object 400 and the solder bump 2. Specifically, the temperature of the object 400 is room temperature, and the solder bumps 2 at a high temperature, which are located partially dissolved by the laser, may cause a temperature difference. The contact area between the solder bump 2 and the object 400 can be reduced if the spreadability is reduced on the joint surface 411 of the first object 410 due to the temperature difference.

6, showing the preheating process and the distribution of the solder bumps 2, the object 400 (410, 420) located at the non-focal length DF described above with reference to FIG. 5 Can be preheated. The solder bumps 2 can be positioned within the area of the preheated portion P to be preheated. More precisely, the peripheral portion of the solder bump 2, that is, the point to be bonded including the point to be bonded, can be the preheating portion P. A part of the step difference or the distance D between the solder bump 2 and the target bodies 410 and 420 may be included in the preheating part P and the step or the distance D side may include a secondary soldering The solder bumps 2 can be introduced by melting the solder bumps 2 in the process. As a result of the inflow, the solder can be hardened with the inflow portion 2a formed thereon, and the joining force can be further increased by increasing the joining area of the objects 410 and 420 by the inflow portion 2a.

7 is a diagram for comparing laser power distributions according to an embodiment of the present invention.

7 (a) and 7 (b) showing the Gaussian output distribution of the laser and FIGS. 7 (c) and 7 (d) showing the flat-top output distribution. Among the types of laser output that can be generated in the solder part 200 of the embodiment of the present invention, the Gaussian type laser has a weak influence on the center of the affected part of the laser gradually toward the edge, Influence can be concentrated.

On the other hand, it can be confirmed that the flat-top-type output distribution of the laser has a relatively uniform influence as compared with the Gaussian output distribution from the center portion at the position adjacent to the edge.

It is important that such influence is controlled so as to uniformly process the object 10 stacked in the height direction on the loading section 101 of FIG. 6 by a single laser irradiation, and uniform processing is performed by a uniform influence Can be implemented. For example, when irradiating a laser generating an influence with a Gaussian type power distribution, it is not possible to uniformly transmit the laser output in the laser energy distribution region in the soldering process and the preheating process. The solder bumps 2 positioned at the center of the preheating portion P when the laser is irradiated toward the target object 400 are adjusted to a non-focal distance so as to preheat the target object 400 at a predetermined temperature, And a relatively low output laser can be applied to the peripheral portion of the solder bump 2 for preheating.

Since the output is concentrated on the solder bump 2 in the process of transferring the laser output capable of sufficiently preheating the target object 400 to the target object 400 by the output distribution, the solder bumps 2 to be melted during the secondary soldering ) Can be melted during the preheating process. That is, since the solder bumps 2 are melted and contacted with the surfaces of the objects 410 and 420 which are not sufficiently preheated, not only the spreadability is lowered but also the bonding property may be lowered.

On the other hand, because of the laser irradiated with a flat-top type power distribution, the energy of the laser is uniformly spaced from the center by a certain distance and then sharply reduced. Thus, The part P can be preheated. This preheating process can be conducted for preheating by adjusting the laser power to a temperature at which the solder bumps 2 are not melted, that is, a temperature below the melting point of the solder bumps 2. [ The preheating part P of the object 400 can be preheated to a level close to the melting point of the solder bump 2 by the uniform laser output so that secondary soldering can be performed.

The surface of the resultant product processed by the Gaussian output distribution and the flat top output distribution described with reference to FIG. 7 is the surface processed by the Gaussian laser output distribution in FIG. 8 (a) Is a surface processed by a flat top laser power distribution.

8 (a), the Gaussian laser power distribution in which the output of the laser is concentrated at the center is not ablated due to the non-uniformity of the processed surface and adjacent to the outer side from the center with respect to the processing surface width, The width of the layer was formed wider than the processed surface of the laser with the flat top power distribution. This means that the machining energy depending on the output distribution does not uniformly affect the machined surface and affect the machined surface non-uniformly.

Such non-uniformity may not be evident at the time of machining at the focal length F which is extremely narrow. However, as described above, the non-focal distance DF at which the machining area is reduced and the output is decreased at the time of preheating is formed It can be evident in some cases. Therefore, in the present embodiment, when the preheating process is included, it is preferable that the laser is irradiated in a flat-top output form.

9 is a diagram showing the configuration of an optical fiber 610 for transferring a fiber laser FL according to an embodiment of the present invention.

Referring to FIG. 9, an optical fiber 610 may be composed of a core 611 to which a fiber laser FL is transferred and a cover 612, 613, 614, 615, and 616. Specifically, the core 611 has a structure capable of transmitting the laser through total internal reflection or the like, and the coatings 612, 613, 614, 615, 616 function to protect the core 611 from impact without exposing the core 611 to the outside And may include one or more components. For example, the plurality of sheaths 612, 613, 614, 615, and 616 may include materials such as impact absorbing polyvinyl chloride, aramid yarn for improving durability, polyimide, silicon, and the like.

Further, the shape of the core 611 located in the coatings 612, 613, 614, 615, and 616 may be variously formed. The various types of cores may be of various shapes, such as rectangular, polygonal, circular, and the like. Depending on the size and shape of these cores, the size and quality of the laser may vary. 10 (a), 10 (b), 10 (c), 10 (d) and 10 (e). As in the present embodiment, the cores 611a, 611b, 611c, 611d, and 611e in the coatings 612a, 612b, 612c, 612d, and 612e may have various shapes.

11 is a flowchart illustrating a procedure of a laser soldering method including a preheating process according to an embodiment of the present invention.

Referring to FIG. 11, the laser soldering method may basically include a target object placement step S1, a primary soldering step S2, a secondary soldering step S3, and a completion S4. Further, it may further include a preheating step (S2-1).

First, in the method that does not include the pre-heating step (S2-1), the object 400 can be placed on the transfer unit 300. [ The arrangement may be arranged at a step or a predetermined interval between the first object 410 and the second object 420. The stepped or predetermined gap may be a distance between the first object 410 and the second object 420 so that the solder bump 2 may flow into the inflow part 2a when the secondary soldering step S3 is performed, Or a spaced distance D that is spaced apart by a predetermined distance.

Subsequently, the disposed object 400 (410, 420) is placed adjacent to the head part 230 of the solder part 200, and the solder ball 1 discharged from the head part 230 can be seated. The seating is formed in a concave joining portion 411 formed at one or more positions of the first object 410 and the second object 420. The joining surface 411 is formed by joining the first object 410 and the second object 420 420 may be provided on a step portion formed on the basis of the arrangement of the first object 410 and the second object 420 and on the surface on which the distance D between the first object 410 and the second object 420 is formed.

The second soldering may be performed on the object 400 on which the solder ball 1 is mounted by the head 230 or other head 230 that has performed the first soldering. The second soldering is a process in which the solder bump 2 is formed by melting the solder ball 1 discharged by performing the first soldering, and then the solder bump 2 is reheated through the laser irradiation so that the solder bump 2 is bonded to the target body 400 .

It can be completed when secondary soldering is performed.

Furthermore, the laser soldering method may further include a preheating step (S2-1). The preheating step S2-1 may be an auxiliary step of the soldering process in which the object 400 is preheated before the soldering process so that the solder can be better bonded. For example, a preheating process may be performed before the secondary soldering step is performed after the primary soldering step. In this case, the object 400 on which the primary soldering is performed can be preheated in the periphery of the solder bump 2 and the solder bump 2 before the secondary soldering is performed. By subjecting the object to preheating, the degree of bonding of the solder at the time of secondary soldering can be increased.

However, the laser in the preheating step S2-1 can be defocused, that is, the laser can be irradiated with the object 400 at the laser and the non-focal distance DF. Therefore, the preheating range can be increased by not focusing the laser. Here, the laser can be irradiated while maintaining the non-focal distance DF, and at the same time, the laser output shape can show a flat top output shape. This type of output is to prevent the output from being lowered as the distance from the center of the area irradiated with the laser is increased and the influence of the laser is concentrated in the center when the laser is irradiated to preheat the object 400.

The Gaussian output pattern that is intensively influenced at the center of the laser irradiation area has a high possibility of melting the solder bump 2 located at the center of the preheating portion P and melting the solder bump 2 at the time of preheating The object 400 is not preheated to a predetermined temperature, and the spreadability of the solder bump may be impaired. As a result, the degree of bonding between the objects 400 by the solder can be lowered.

12 is a flowchart showing a procedure of a laser soldering method including an inspection step (S1-1) according to an embodiment of the present invention.

Referring to FIG. 12, the laser soldering method may basically include an object placing step S1, a primary soldering step S2, a secondary soldering step S3, and a completion S4. Further, it may further include a preheating step (S2-1).

First, in the method that does not include the pre-heating step (S2-1), the object 400 can be placed on the transfer unit 300. [ The arrangement may be arranged at a step or a predetermined interval between the first object 410 and the second object 420. The predetermined interval is set by the first object 410 and the second object 420 so that the solder bump 2 may be introduced and the inflow portion 2a may be formed when the secondary soldering step S3 is performed And may be arranged stepped or spaced apart distance D.

Subsequently, the disposed object 400 (410, 420) is placed adjacent to the head part 230 of the solder part 200, and the solder ball 1 discharged from the head part 230 can be seated. The seating is formed in a concave joining portion 411 formed at one or more positions of the first object 410 and the second object 420. The joining surface 411 is formed by joining the first object 410 and the second object 420 420 and a surface on which the distance D between the first object 410 and the second object 420 are formed.

The second soldering may be performed on the object 400 on which the solder ball 1 is mounted by the head 230 or other head 230 that has performed the first soldering. The second soldering is a process in which solder bumps 2 discharged from a solder ball 1 melted by a first soldering process are reheated through laser irradiation to bond the solder bumps 2 to the target object 400 .

It can be completed when secondary soldering is performed.

Further, in the inspection step S1-1, when the object 400 is disposed on the transfer unit 300, the object 400 on which the primary or secondary soldering has already been performed can be placed. Accordingly, the transfer unit 300 transfers the target object 400 to the head unit 230, and the head unit 230 preferentially inspects the state of the solder 1, 2 without performing the primary soldering immediately . &Lt; / RTI >

At this time, the solder 1, 2 inspected in the inspection step S1-1 may be subsequently subjected to primary or secondary soldering according to the degree of the abnormal state. For example, when the discharge point of the solder ball deviates from a predetermined criterion and primary soldering is to be performed again, the head portion 230 may melt the laser by adding the laser to the solder located at a position outside the predetermined reference. The liquefied solder can be carried out sequentially from the primary soldering step (S2) after being sucked and processed by the suction part (not shown) of the head part.

Further, the solder 1, 2 inspected in the inspection step S1-1 may be subsequently subjected to secondary soldering according to the degree of the abnormal state. For example, when the molten state of the solder bump 2 or the inflow part 411 formed between the objects does not meet the predetermined criterion, the head part 230 irradiates the laser to perform the secondary soldering step Or perform the secondary soldering step immediately.

Of course, when the abnormal state of the solder can not be detected in the inspection step S1-1, it is determined that the solder is completed, and it can be determined that the solder is completed without performing the primary or secondary soldering.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, . Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by equivalents to the appended claims, as well as the appended claims.

1: solder ball
2: Boulder bump
2a: inlet
100:
200: solder part
210: laser generator
220: beam expander
230: Head portion
231: first head portion
232: second head portion
233: third head part
241, 242, 243: beam splitter
300:
400: object
410: first object
420: second object
411:
450: substrate
500: Monitoring section
600: Split module
610, 620, 630, 640: optical fiber
611: Core
612, 613, 614, 615 Cloth
FL: fiber laser
D: separation distance
P: preheating part
F: Focal Length
DF: Non-focal length
S1: batch step
S1-1: Inspection step
S2: Primary soldering step
S2-1: Preheating step
S3: Secondary soldering step
S4: Completion phase

Claims

A control unit;
A transfer unit for transferring the first object and the second object; And
And a solder portion that is operated by the control of the control portion and forms a bonding surface by performing soldering on the first object and the second object located on the transfer portion,
The solder portion,
A laser generator for generating a laser to apply heat to the solder ball;
A beam expander for adjusting an output area of the laser;
And one or more heads for applying a laser beam passed through the beam expander to the solder balls ejected between the first object and the second object and ejecting the solder balls,
First soldering by melting the solder ball by the at least one head portion to provide between the first object and the second object; And secondary soldering in which solder bumps, which are the solder balls melted, are heated and distributed, are sequentially performed,
A preheating step through the laser is performed between the primary soldering and the secondary soldering process in a preheating part which is a part of the first object and the second object,
Wherein the first object and the second object are bonded together and transported by the transporting unit,
Wherein the head section performs an inspection process for inspecting the bonded joint faces before performing the primary soldering to determine whether the bonded joint faces are abnormal or not, A laser soldering apparatus for performing soldering.

The method according to claim 1,
The head portion is one,
Wherein the primary soldering and the secondary soldering are sequentially performed by one head part.

The method of claim 2,
Wherein:
And performs a preheating process on the first object and the second object between the primary soldering process and the secondary soldering process.

The method according to claim 1,
Wherein the head portion includes a first head portion and a second head portion,
Wherein the first head portion performs the primary soldering and the second head portion performs the secondary soldering.

The method of claim 4,
Wherein at least one of the first head portion and the second head portion performs a preheating process between the primary soldering and the secondary soldering process to the first object and the second object.

The method according to claim 1,
Wherein the head portion includes a first head portion, a second head portion and a third head portion, and performs the primary soldering and the secondary soldering in sequence.

The method of claim 6,
And performs a preheating process between the primary soldering and the secondary soldering process to the first object and the second object.

The method according to one of claims 3, 5 and 7,
Wherein the preheating process is performed by defocusing the laser.

The method according to claim 1,
Wherein the laser is a fiber laser transmitted through the optical fiber to the head portion.

The method of claim 9,
Wherein a plurality of the head portions are provided,
Further comprising a division module for dividing the optical fiber and delivering a fiber laser so that the optical fiber is individually connected to the plurality of head portions.

The method of claim 10,
Wherein the fiber laser is selectively transmittable to the plurality of heads by the controller or the division module.

The method of claim 9,
Wherein the core of the optical fiber is formed in a circular or polygonal shape.

delete

The method according to claim 1,
Wherein the solder bump is sucked and removed, and the primary soldering and the secondary soldering are performed when it is judged in the inspecting step to be abnormal.

delete

The method according to claim 1,
Wherein the laser is irradiated with an output in the form of a flat-top.

The method according to claim 1,
Wherein a plurality of the head portions are provided,
Wherein the laser is divided and transmitted by a beam splitter to each of the head portions.

The method according to claim 1,
Wherein the transfer object of the transfer unit further comprises a substrate,
Wherein the substrate is arranged so that the first object and the second object can be stacked on the substrate.

Arranging the first object and the second object on the transfer unit,
The first object and the second object are transported to the solder side by the transfer unit,
Performing primary soldering in which solder balls are melted by a laser irradiated from at least one head part included in the solder part, and then discharged at a point where the first object and the second object are jointed,
Performing secondary soldering in which the solder bumps, which are the solder balls melted after the primary soldering, are distributed to the junctions by irradiating the laser,
Performing a preheating process by the laser between the primary soldering and the secondary soldering process in a preheating unit that is a part of the first object and the second object,
Wherein the first object and the second object are joined to each other and are transported by the transporting unit,
Wherein:
Further comprising the step of inspecting the bonded joint surfaces before performing the primary soldering to determine whether there is an abnormality in the bonded joint surfaces. If it is determined that the bonded joint faces are abnormal, the secondary soldering is performed / RTI >

The method of claim 19,
The head portion is one,
Wherein the primary soldering and the secondary soldering are sequentially performed by one head part.

The method of claim 20,
Wherein:
Further comprising a preheating step between the primary soldering and the secondary soldering process to the first object and the second object.

The method of claim 19,
Wherein the head portion includes a first head portion and a second head portion,
Wherein the first head portion performs the primary soldering and the second head portion performs the secondary soldering.

23. The method of claim 22,
Wherein at least one of the first head portion and the second head portion further comprises a preheating process between the primary soldering and the secondary soldering process to the first object and the second object.

The method of claim 19,
Wherein the head portion includes a first head portion, a second head portion, and a third head portion, and performs the primary soldering and the secondary soldering in sequence.

27. The method of claim 24,
Further comprising a preheating step between the primary soldering and the secondary soldering process to the first object and the second object.

23. The method of claim 23 or 25,
Wherein the preheating process is performed by defocusing the laser.

The method of claim 19,
Wherein the laser is a fiber laser transmitted through an optical fiber to the head portion.

28. The method of claim 27,
Wherein a plurality of the head portions are provided,
Further comprising a division module for dividing the optical fiber and transferring a fiber laser so that the optical fiber is individually connected to the plurality of head portions.

29. The method of claim 28,
Wherein the fiber laser is selectively transmittable to the plurality of heads by a control unit or a division module.

28. The method of claim 27,
Wherein the core of the optical fiber is formed in a circular or polygonal shape.

delete

The method of claim 19,
Wherein the solder bump is sucked and removed, and the primary soldering and the secondary soldering are performed when it is determined that the solder bump is abnormal.

delete

The method of claim 19,
Wherein the laser is irradiated with an output in the form of a flat-top.

The method of claim 19,
Wherein a plurality of the head portions are provided,
Wherein the laser is divided and transmitted by a beam splitter to each of the head portions.

The method of claim 19,
Wherein the transfer object of the transfer unit further comprises a substrate,
Wherein the substrate is disposed so that the first object and the second object can be stacked on the substrate.