KR20200145187A - laser module of laser debonding device - Google Patents

Abstract

The present invention relates to a laser module of a laser debonding device for debonding a metal component from a substrate. The laser module comprises: a laser light source radiating a laser beam; a converter receiving the laser beam radiated from the laser light source and outputting energy generated by displacement of the laser beam; an optical unit reflecting the laser beam output from the converter to adjust a light path; and a scanning unit allowing the laser beam passing through the optical unit to be selectively radiated to only a soldering area of the metal component.

Description

Laser module of laser debonding device

The present invention relates to a laser module of a laser debonding apparatus, and more particularly, to a laser module of a laser debonding apparatus capable of removing a metal component in which soldering is melted by laser irradiation without contamination of a substrate.

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

In addition, technological developments for mounting memory chips, microprocessor chips, graphic processor chips, wireless processor chips, and sensor processor chips in one package are being intensively researched and developed, and a considerable level of technologies are already being applied in practice.

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

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

Accordingly, in the past, localized heating technology has been developed to rework soldering defects of various types of electronic components that occur during the soldering process, including the above causes, among which the most actively studied field. Is a soldering debonding technology by laser beam irradiation.

Conventional debonding technology by laser beam irradiation has the advantage of being non-contact, and since the method in which the laser light is directly absorbed by the semiconductor chip is the primary heat absorption mechanism, it has the advantage that there is no thermal shock due to the difference in the thermal expansion coefficient, and is very local. Since phosphorus heating is performed only for the necessary time, it has several advantages such as low power consumption, minimization of total heat input, minimization of thermal shock, and minimization of process time.

On the other hand, the laser head module of a conventionally known laser bonding device is a method of bonding by irradiating a laser while pressing the bonding object (semiconductor chip or integrated circuit IC) for several seconds, and corresponding to the size of the semiconductor chip or integrated circuit (IC). Bonding is performed by irradiating a surface light source type laser.

For such a pressurized laser head module, referring to Korean Patent No. 10-1245356 (hereinafter referred to as'priority literature'), a surface light source type laser is irradiated to the semiconductor chip while adsorbing the semiconductor chip by vacuum. The adsorption module and the pressure head configuration including the same are described.

However, in the conventional pressurized laser head module as described above, since the pressurizing head and the laser irradiation unit are manufactured and driven as one module, when bonding a plurality of semiconductor chips such as a semiconductor strip, a surface light source is formed while pressing one semiconductor chip. The operation of irradiating the laser of a must be repeatedly performed as many as the number of semiconductor chips.

Due to this, not only the total working time for bonding a plurality of semiconductor chips is increased, but also the cost of the entire equipment is rapidly increased as the heating head is additionally mounted.

On the other hand, even if the laser head module by laser beam irradiation is applied to the debonding device instead of the above-described pressurization head method, at present, the electronic parts separated by the laser are manually removed by the operator using a tool or a separate ejector device As it is removed by using, there is a problem that the substrate is contaminated by the heated and melted solder liquid, and there is also a risk that the operator may suffer a safety accident due to the high heat of the laser head module.

Accordingly, the present invention was invented to solve the above problems, and an object of the present invention is to provide a laser debonding device capable of immediately removing a metal component melted by laser irradiation on the spot without contamination of a substrate. To do.

The present invention for achieving the above object is, in a laser debonding device for debonding a metal component from a substrate, A laser light source for irradiating a laser beam; Receiving the laser beam irradiated from the laser light source, and Converter for outputting energy according to the displacement of the; Optical unit for adjusting the optical path by reflecting the laser beam output from the converter; And a scanning unit so that the laser beam passing through the optical unit is selectively irradiated only to the soldering area of the metal component.

The laser beam output to the converter may be either a surface light source or a spot light source.

The laser beam emitted from the scanning unit may be either a surface light source or a spot light source.

The laser beam emitted from the canning unit may be irradiated while sequentially rotating the soldering area of the metal component.

The scanning unit may determine the emission direction of the laser beam by rotating a plurality of mirrors.

According to the present invention as described above, the metal component can be removed without the influence of other elements mounted around it by repeatedly and sequentially irradiating the soldering region of the metal component with a laser. That is, there is an effect of preventing the heat generated by focusing the laser beam on the soldering area from being transferred to other places.

1 is a conceptual diagram of a single beam module of a laser debonding apparatus according to an embodiment of the present invention
2 is an image of an FPCB substrate irradiated with a single laser beam by a laser debonding device according to an embodiment of the present invention
3 is a conceptual diagram of a configuration of a laser debonding apparatus according to an embodiment of the present invention
4 is a conceptual diagram of the configuration of a laser optical system according to an embodiment of the present invention
5 is an exemplary view of a laser debonding apparatus according to an example of the present invention

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

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

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

Hereinafter, the attached FIG. 1 is a conceptual diagram of a single beam module of a laser debonding apparatus according to an embodiment of the present invention, and FIG. 2 is an FPCB in which a laser beam is irradiated by a debonding apparatus according to an embodiment of the present invention. It is an image of the substrate.

Referring to FIG. 1, the laser debonding apparatus of the present invention includes a single laser module 310 according to an embodiment, and thus, irradiates a single laser beam onto an FPCB substrate. In this case, referring to FIG. 2, the laser beam irradiated by the first laser module 310 is irradiated on the substrate in a state deformed into a square beam shape.

That is, as the laser beam irradiated by the laser module 310 selectively heats the temperature of the defective soldering part to the debonding temperature at which the melting of the soldering occurs, the electronic component becomes a state in which it can be removed from the substrate, and then a certain type of ejector By means of an apparatus (refer to FIGS. 5 and 6), the defective electronic component in which the soldering is melted is sucked and removed from the substrate.

Hereinafter, a dual beam configuration and operation relationship according to the present invention will be described in detail according to an embodiment with reference to FIGS. 3 and 4.

3 is a schematic diagram of a configuration of a laser debonding apparatus according to an embodiment of the present invention.

3, the laser module 310 of the laser irradiation unit is a laser oscillator 311 having a cooling device 316, respectively, a beam shaper 312, an optical lens module 313, a driving device 314, a control device It is configured to include 315 and a power supply unit 317.

The laser oscillator 310 generates a laser beam having a wavelength and output power in a predetermined range. The laser oscillator is, for example, a diode laser (Laser Diode, LD) having a wavelength of '750nm to 1200nm' or '1400nm to 1600nm' or '1800nm to 2200nm' or '2500nm to 3200nm', or a rare earth medium fiber laser (Rare-Earth- Doped Fiber Laser) or rare-earth-doped crystal laser (Rare-Earth-Doped Crystal Laser), alternatively, a medium for emitting alexandrite laser light having a wavelength of 755 nm, or Nd Yag (Nd) having a wavelength of 1064 nm or 1320 nm. :YAG) It may be implemented including a medium for emitting laser light.

The beam shaper 312 converts a spot-shaped laser generated in the laser oscillator 310 and transmitted through an optical fiber into an area beam having a flat top. The beam shaper 312 may be implemented by including a Square Light Pipe, a Diffractive Optical Element (DOE), or a Micro-Lens Array (MLA).

The optical lens module 313 adjusts the shape and size of the laser beam converted to the surface light source form by the beam shaper to irradiate the electronic component or the irradiation area mounted on the PCB substrate. The optical lens module constitutes an optical system by combining a plurality of lenses.

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

Meanwhile, the laser power adjustment unit 370 controls the amount of power supplied to the laser module 310 from the power supply unit 317 corresponding to the laser module 310 according to a program received through a user interface or a preset program. The laser output adjustment unit 370 receives information on the state of debonding for each part, area, or all on the irradiation surface from one or more camera modules 350 and controls the power supply unit 317 based thereon.

In contrast, control information from the laser output control unit 370 is transmitted to the control device 315 of the laser module 310, and a feedback signal for controlling the corresponding power supply unit 317 in the control device 315 It is also possible to provide.

On the other hand, when a plurality of laser modules are configured to emit laser beams having different wavelengths, the laser irradiation unit absorbs a plurality of material layers (e.g., EMC layer, silicon layer, solder layer) included in the electronic component well. It can be composed of individual laser modules having a wavelength of.

Accordingly, the laser debonding device according to the present invention selectively increases the temperature of the electronic component and the temperature of the intermediate bonding material such as solder, which is a connection material between the printed circuit board or the electrode of the electronic component. Bonding) or separation (detaching or debonding) process may be performed.

Specifically, by transmitting both the EMC mold layer and the silicon layer of the electronic component, all the energy of each laser beam is absorbed into the solder layer, or the laser beam does not penetrate the EMC mold layer and heats the surface of the electronic component to It is also possible to conduct heat to the bonding portion of.

4 is a conceptual diagram of a configuration of an optical laser system according to an embodiment of the present invention.

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

Hereinafter, the configuration and operation relationship of the laser module according to the present invention will be described in detail with reference to FIG. 5. First, the laser module 600 of the present invention will be described below in some configurations excluding the laser oscillator 311, the cooling device 316, and the driving device 314 in the above-described laser module.

As shown in FIG. 5, the laser module 500 of the laser debonding apparatus of the present invention may include a light source, a converter, an optical unit, and a scanning unit.

The light source irradiates a laser beam. It may include a converter that receives the beam irradiated from the light source and outputs energy according to the displacement of the laser beam. In this case, the laser beam output from the converter may be either a surface light source or a spot light source.

It may include an optical unit for adjusting the optical path by reflecting the laser beam output to the converter.

A scanning unit may be included so that the laser beam passing through the optical unit is selectively irradiated only to the soldering area of the metal component 520 formed on the substrate 510.

Here, the scanning unit may determine the emission direction of the laser beam by rotating a plurality of mirrors. That is, the beam emitted by the mirror rotation can be irradiated only to the soldering area of the metal component.

Here, the laser beam emitted from the scanning unit may sequentially rotate and irradiate the soldering region of the metal component. If irradiation is repeated through rotation in this way, it is possible to irradiate other devices mounted on the substrate while minimizing the effect of temperature.

When the soldering area of the metal component 520 is heated through such a process, a separate vacuum chuck (not shown) or the like may debond the metal component 520. The metal component 520 may be an SUS material or an aluminum material.

The mentioned scanning unit may use a galvo scanner system or a piezoelectric scanner system, and may be applied differently according to design requirements.

In addition, the scanning unit may be included in the optical unit to be integrally configured.

In addition, the present invention is not limited only by the above-described embodiment, and since the same effect can be created even when the detailed configuration, number, and arrangement structure of devices are changed, those of ordinary skill in the art It is stated that various configurations can be added, deleted, and modified within the scope of technical ideas.

500: laser module 510: substrate
520: metal component

Claims (5)

In the laser debonding apparatus for debonding metal components from a substrate,
A laser light source that irradiates a laser beam;
A converter for receiving the laser beam irradiated from the laser light source and outputting energy according to the displacement of the laser beam;
An optical unit that reflects the laser beam output from the converter to adjust an optical path; And
A laser module of a laser debonding apparatus comprising: a scanning unit so that the laser beam passing through the optical unit is selectively irradiated only to the soldering area of the metal component. The method of claim 1,
The laser module of the laser debonding apparatus, wherein the laser beam output to the converter is either a surface light source or a spot light source. The method of claim 1,
The laser module of the laser debonding apparatus, wherein the laser beam emitted from the scanning unit is either a surface light source or a spot light source. The method of claim 1,
The laser module of the laser debonding apparatus, wherein the laser beam emitted from the scanning unit is irradiated while sequentially rotating the soldering region of the metal component. The method of claim 1,
The laser module of the laser debonding apparatus, wherein the scanning unit determines the emission direction of the laser beam by rotating a plurality of mirrors.

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