KR101180481B1

KR101180481B1 - In-line reflow apparatus using a laser module

Info

Publication number: KR101180481B1
Application number: KR1020100099057A
Authority: KR
Inventors: 박홍진; 서종현
Original assignee: 주식회사 엘티에스
Priority date: 2010-10-12
Filing date: 2010-10-12
Publication date: 2012-09-06
Also published as: KR20120037543A

Abstract

Inline reflow method using a laser module according to an embodiment of the present invention includes a load step for transferring the loaded printed circuit board into the reflow device; A preheating step of preheating the printed circuit board, which is transferred by the transfer step and has a solder ball formed thereon, with an IR lamp; A soldering step of forming a laser beam into an area beam having a width direction and irradiating the printed circuit board preheated by the preheating step to melt and solder solder balls; And an unloading step of transferring the soldered printed circuit board to an unloading part for transferring. It includes, characterized in that the loading step, the IR lamp preheating step, the soldering step using the laser and the unloading step are sequentially performed along the inline.
According to this configuration, it is possible to implement a sequential temperature profile according to the atmosphere in the existing furnace, and to prevent discoloration of the surface of the PCB due to the rapid temperature rise, and to prevent the solder ball to bounce off.

Description

IN-LINE REFLOW APPARATUS USING A LASER MODULE}

The present invention relates to an inline reflow apparatus and a reflow method using a laser module, and more particularly, the present invention implements a sequential temperature profile by the atmosphere in the existing furnace, and the rapid rise of the temperature The present invention relates to an inline reflow apparatus and a reflow method using a laser module that not only prevents discoloration but also prevents solder balls from being thrown out.

As semiconductor devices become more integrated, the number of connection pads for connecting a semiconductor chip on which a semiconductor integrated circuit is formed with an external circuit increases, and accordingly, the number of lead lines of a semiconductor package mounted on a printed circuit board (PCB) also increases significantly. Was done.

As the number of lead wires increases, the conventional packaging technology using a lead frame cannot be applied to a highly integrated semiconductor chip of 500 pins or more.

Therefore, a new concept that can arrange output terminals of a semiconductor package using a large area of the lower surface of the semiconductor package has been developed with BGA package technology.

In this ball grid array (BGA) package technology, a semiconductor chip is mounted on a printed circuit board, solder balls are disposed corresponding to an output terminal of the printed circuit board, and an integrated circuit of the semiconductor package is a printed circuit. It is electrically connected to an external circuit of an electronic device through an output terminal of the board and a solder ball connected thereto.

In this case, the solder ball is formed on the opposite side of the printed circuit board on which the semiconductor integrated circuit is mounted, and a soldering process is required to electrically connect the solder ball to the output terminal of the printed circuit board.

Here, a device that mounts a semiconductor chip or the like on a surface of a printed circuit board, solders at an appropriate temperature, and hardens it is called a reflow device.

In the reflow apparatus, the printed circuit board on which the solder balls are placed is placed in a heating furnace, and the solder balls are heated at a constant temperature for a predetermined time, through which the solder balls are soldered to the output terminals of the printed circuit board.

However, referring to FIG. 1, the misleading profile for curing solder balls in such a reflow apparatus is subjected to thermal stress for about 210 seconds at a high temperature between about 50 degrees and about 240 degrees.

Therefore, the semiconductor device may be damaged by heat, and thus there is a problem in that the characteristics or lifespan of the semiconductor device are deteriorated.

In addition, as the temperature of the entire semiconductor package rises rapidly due to high heat, problems such as bending of the BGA substrate on which the solder balls are arranged or cracking of the semiconductor chip may occur.

In order to solve this problem, the present applicant has filed the application of "The Soldering System and Method for a Semiconductor Package Using Line Beam" as Patent Application No. 10-2009-0063241 on July 10, 2009. There was a problem that could not implement the sequential temperature file due to the atmosphere in progress, and there was a problem that the surface of the printed circuit board is discolored due to a sudden temperature rise, and also the solder ball is bounced out because the temperature of the highly volatile flux rises sharply There was an increasing problem.

The present invention is to solve the above-described problems, an object of the present invention is to form a laser beam to implement a sequential temperature profile by the atmosphere in the existing furnace, by using the laser beam forming the width dimension Inline reflow device and reflow method using a laser module that can reduce the laser intensity by reducing the intensity of the laser to reduce the discoloration of the printed circuit board surface, and to reduce the failure rate by adding an IR lamp to buffer the initial rise in the temperature of the flux To provide.

An inline reflow apparatus using a laser module according to an embodiment of the present invention includes a load unit on which a printed circuit board is loaded; A preheater which is transferred from the rod and preheats a printed circuit board having a solder ball formed thereon using an IR lamp; A solder part for soldering the printed circuit board preheated by the preheat part by irradiating an area beam having a width direction dimension; And an unload unit to which the soldered printed circuit board is transferred and loaded. It includes, wherein the rod, preheating, soldering and unloading portion is characterized in that it is arranged in-line (In-Line).

The preheating unit may include an IR lamp driver, an IR lamp driver for driving the IR lamp to a gentle temperature rise for 90 seconds between 150 degrees and 180 degrees, and the IR lamp driver.

The solder part may include a laser beam oscillator for outputting a laser beam, an optical fiber bundle connected to the laser beam oscillator for split transmission of the laser beam, and an output end of the optical fiber bundle to connect the laser beam to a predetermined range of energy intensities. An optical system to be averaged so as to have an average, a head portion formed to irradiate a printed circuit board to form an area beam having a width direction dimension, and a laser beam emitted from an output end of the optical fiber bundle, an input end and an output end of the optical fiber bundle, A driving unit which operates after holding the head unit on the printed circuit board for a predetermined time; And

It may include a control unit for controlling the laser oscillation unit, the optical system, and the driving unit.

The head portion may be in the form of a box in which the laser bundle is arranged to have a width direction dimension.

The control unit may control the length of the head portion to be maintained on the printed circuit board so as to compensate for the energy intensity of the laser beam formed into the area beam irradiated from the head portion.

Inline reflow method using a laser module according to an embodiment of the present invention includes a load step for transferring the loaded printed circuit board into the reflow device; A preheating step of preheating the printed circuit board, which is transferred by the transfer step and has a solder ball formed thereon, with an IR lamp; A soldering step of forming a laser beam into an area beam having a width direction and irradiating the printed circuit board preheated by the preheating step to melt and solder solder balls; And an unloading step of transferring the soldered printed circuit board to an unloading part for transferring. / RTI >

The loading step, the IR lamp preheating step, the soldering step using the laser and the unloading step are sequentially performed along the inline.

The preheating step is performed gently for 90 seconds between 150 degrees and 180 degrees, and the soldering step includes: an output step of outputting a laser beam through the optical fiber bundle; An averaging step of averaging the laser beam to have a range of energy intensities; a beam shaping step of shaping the averaged laser beam into an area beam having a width direction dimension; And irradiating the molded laser beam to the printed circuit board at a predetermined time. It may include.

The beam forming step may be performed by arranging the optical fiber bundle to have a width direction dimension. The beam forming step may be performed by turning on and off the output of the optical fiber bundle.

The irradiation step can maintain a temperature between 170 to 240 degrees for 40 seconds.

As described above, according to the present invention, it is possible to implement a sequential temperature profile by the atmosphere in the existing furnace using a laser module, and by providing such a temperature profile sequentially and continuously to shorten the manufacturing process and manufacturing time Workability and productivity can be improved.

In addition, according to the present invention, by forming a laser beam by the laser module to increase the width direction dimension to reduce the laser intensity to reduce the discoloration of the printed circuit board, instead of increasing the laser irradiation time to buffer the sudden temperature rise. have.

In addition, according to the present invention, by using an IR lamp to buffer the initial temperature rise applied to the flux to cause a sudden temperature rise in the highly volatile flux can be solved the problem that the solder ball is thrown out to increase the defective rate.

1 is a graph showing the temperature profile by the atmosphere of the existing furnace.
2 is a schematic diagram of an inline reflow apparatus using a laser module according to an embodiment of the present invention.
3 is a partially enlarged view of a head unit for beam forming of an inline reflow apparatus using a laser module according to an embodiment of the present invention.
4 is a graph showing uniformity of a laser line beam having enlarged width dimensions in an inline reflow apparatus using a laser module according to an exemplary embodiment of the present invention.
5 is a flowchart illustrating an inline reflow method using a laser module according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, 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.

2 is a schematic diagram of an inline reflow apparatus using a laser module according to an embodiment of the present invention, Figure 3 is a head unit for beam shaping of the inline reflow apparatus using a laser module according to an embodiment of the present invention 4 is a partially enlarged view, and FIG. 4 is a graph showing uniformity of a laser line beam having enlarged width dimensions in an inline reflow apparatus using a laser module according to an exemplary embodiment of the present invention.

2 to 3B, an inline reflow apparatus 100 using a laser module according to an embodiment of the present invention includes a load unit 110, an alignment inspection unit 120, and flux dotting. The unit 130, the solder ball mounter (Solder Mounter) 140, the preheater 150, the solder 160, the magazine unload (170), including the load unit 110, preheating unit The 150, the solder 160, and the unloaded 170 are arranged in-line, and preheating and soldering are sequentially performed.

A plurality of printed circuit boards P is mounted on the rod part 110.

The alignment inspection unit 120 checks whether the printed circuit board P transferred from the rod unit 110 to the conveyor belt C is transferred to the correct position and aligned or that a defect occurs in the printed circuit board P. FIG.

The flux dotting unit 130 is aligned with and contacted with the upper portion of the printed circuit board (P) to form a flux at a position corresponding to the solder ball (S) to perform a plus dotting process. The flux can easily fix the position of the solder ball (S) to be formed later to prevent the solder ball (S) from being oxidized.

The solder ball mounter 140 is disposed on the printed circuit board P, and forms the solder ball S at a position where the upper flux of the printed circuit board P is formed.

The preheating part 150 is transferred from the rod part 110 and preheats the printed circuit board P having the solder ball S formed therebetween about 120 degrees to 170 degrees.

In one embodiment of the present invention, to implement a sequential temperature profile according to the atmosphere in the existing furnace, and to prevent the phenomenon that the solder ball bounces due to the instantaneous rise in temperature by the laser beam is irradiated to the highly volatile flux The preheater 150 uses an IR lamp.

That is, the preheater 150 includes an IR lamp 154, an IR lamp driver 155, and an IR lamp controller 156.

As such, by using the IR lamp as the preheater 150, a gentle temperature profile as shown in FIG. 1 was implemented to prevent solder balls from being splashed by the laser beam irradiation.

In addition, by spreading the solder ball (S) by preheating to a predetermined temperature lower than the melting temperature of the solder ball (S) for a sufficient time to solder the printed circuit board (P).

On the other hand, in the reflow apparatus using the conventional line beam can be melted by providing a temperature higher than the melting temperature of the solder ball (S) in the case of using a laser line beam, as shown in Figure 1, the printed circuit board And there was a problem that could not be maintained for about 40 seconds between about 220 degrees to 270 degrees higher than the melting temperature of the solder ball (S) so that the adhesion of components such as semiconductor chips.

Accordingly, in one embodiment of the present invention, the solder part 160 is disposed after the preheating part 150. The laser beam is formed into an area beam having an increased width direction by using a laser module. By soldering the printed circuit board (P) preheated by the preheater 150.

That is, as shown in Figure 3, the solder portion 160 in the width direction of the beam of the line beam to be maintained for about 40 seconds at a temperature higher than the melting temperature of the solder ball (S), that is about 220 to 270 degrees Increasing the dimension reduced the laser beam intensity and increased the laser irradiation time instead of the reduced laser beam intensity.

To this end, in order to solder the printed circuit board P, the solder part 160 includes a laser beam oscillator 161, a fiber bundle 162, an optical system 163, a head bundle 164, a driver 165, and a controller 166. ).

The laser beam oscillator 161 oscillates a laser beam, and is disposed above the solder part 150 to minimize the size of the solder part 160, and the printed circuit board P is preferably supplied to the lower part.

The optical fiber bundle 162 has one end portion to which the laser beam generated from the laser beam oscillation unit 161 is divided and input, and the optical fiber bundle 162 is arranged in the longitudinal direction as shown in FIG. By arranging several more along the width direction, an area beam can be formed, and the intensity | strength of a laser beam can be reduced and rapid temperature rise can be prevented.

The optical system 163 is disposed at the other end of the optical fiber bundle 162 (or high power line beam generator) to form a laser beam into a homogenized area beam having a width dimension.

The head part 164 receives the homogenized laser beam from the optical system 163 and irradiates the solder ball S formed on the second surface of the printed circuit board P of the semiconductor package with the area beam having the required energy. .

The driving unit 165 selects an input / output end (or a high power line beam generator) of a plurality of optical fibers in the optical system 163 and moves the head unit 164 along the X, Y, or Z axis.

The controller 166 controls these 161, 162, 163, 164, and 165.

The control unit 166 may control the driving unit 165 to move the head unit 164 to increase the irradiation time in order to compensate for the laser beam with reduced energy intensity in the optical fiber bundle 162 or the optical system 163. In addition, the input and output ends of the plurality of optical fibers in the optical system 163 may be selected and driven in response to the driving of the driving unit 165.

The driving unit 165 further includes a sliding unit 165a for sliding the head unit 164 in the X-axis direction, the Y-axis direction, or the Z-axis direction, where a plurality of semiconductor packages are mounted. Can be stably irradiated with the line beam.

In this way, the solder ball S can be soldered by irradiating the laser beam in the form of a line only on the region where the solder ball S is formed, thereby preventing the semiconductor device from being damaged in the soldering process, and also widening the laser beam. By beam-beaming irradiation to increase the directional dimension, it is possible to prevent the phenomenon of discoloration of the printed circuit board surface or jumping of the solder ball due to rapid temperature rise.

In addition, since the sequential temperature profile due to the existing furnace atmosphere can be achieved, the soldering performance is stable, the harmful gas generated when soldering the printed circuit board P is reduced, and the thermal damage degree is reduced, so that the next generation large glass Also suitable for sealing specifications.

In addition, after pre-heating the printed circuit board P with an IR lamp and soldering using a laser module, the manufacturing process and manufacturing time can be shortened to improve workability and productivity, and reduce manufacturing cost. This can enhance corporate competitiveness.

In addition, there is no need to preheat and solder the printed circuit board P by varying the temperature of the laser beam from time to time with one laser device, and control only the solder part 160 after preheating with the preheating part 150 made of an IR lamp. By soldering the printed circuit board P, almost no load is generated.

In addition, since the size of the soldering system 100 is small, the installation area and the installation cost are reduced compared to the existing Furnace (furnace). Accordingly, the soldering system 100 is easily transported and installed, which is economically efficient.

Meanwhile, according to an embodiment of the present invention, since the laser beam is moved by using the optical fiber bundle 162 (or the high power line beam generator), even if it is a long distance, it may or may not be focused using a separate optical system. It is convenient to work with.

Area where the laser beam proceeds through a plurality of optical fibers 162a, 162b, 163c… (or a high power line beam generator) and at least two or more are selected through the control unit 166 to shape the laser beam. It can be irradiated with a beam.

The optical system 163 is formed in a box shape, and the optical fibers are intimately filled in the first and second orifice units 153a and 163a of the box, and these optical fibers are turned on to irradiate an area beam.

As shown in FIG. 4, the energy intensity of the laser beam incident on the input portion of the optical fiber bundle 162 (or the high power line beam generator) is averaged at the output portion of the optical system 163, and in the present invention, averaged energy. A laser beam with intensity can be used for the reflow process of semiconductor packaging technology.

<Description of the method>

For the inline reflow method using a laser module according to an embodiment of the present invention will be described in the flow chart shown in Figure 5, will be described in order to convenience.

1. Load step S510 >

The printed circuit board P loaded on the loader unit 110 is transferred into the reflow apparatus 100, and the printed circuit board P is transferred to the correct position and aligned, or the printed circuit board P is defective. It is examined using the alignment checker 120 to see if it has occurred.

2. Flux Dotting ( Flux Dotting ) step

The flux dotting unit 130 is aligned with and contacted with the upper portion of the printed circuit board P to form flux at a position corresponding to the solder ball S to perform a plus dotting process. The flux can easily fix the position of the solder balls to be formed later, while preventing the solder balls S from oxidizing.

3. Solder ball Supply stage

The printed circuit board P is transported to supply the solder balls S, the solder ball mounter 140 is aligned with the upper portion of the printed circuit board P, and the upper flux of the printed circuit board P is formed. Form the solder ball (S) at the position.

4. Preheating Step S520 >

The printed circuit board P having the solder ball formed thereon is used for about 90 seconds between about 150 to 180 degrees according to the temperature profile shown in FIG. Preheat at moderate temperature changes.

5. Soldering Step < S530 >

The laser beam is molded and irradiated into an area beam having an increased width direction in an area beam using a laser module to solder the printed circuit board P preheated by the preheater 150.

That is, in the state in which the width of the beam beam of the line beam is increased by using the solder unit 160 to reduce the intensity of the laser beam, the laser irradiation time is increased instead of the intensity of the reduced laser beam, thereby preheating the printing by the step S520. The circuit board P is soldered.

5-1. Output stage S531 >

The laser oscillator 161 generates a laser beam under the control of the laser controller 166 and outputs a laser beam through the optical fiber bundle 162.

5-2. Averaging Step S532 >

In the optical system 163, the laser beam is averaged to have a range of energy intensities.

5-3. Laser beam forming step S533 > And increase in irradiation time <534>

The laser beam outputted along the optical fiber bundle 162 and the optical system 163 is controlled on and off by the head unit 164 under the control of the controller 166, and the laser beam is shaped to improve the width direction of the laser beam. Increase time to compensate for reduced energy intensity.

6. Unload Step S540 >

The soldered printed circuit board P is transferred and loaded in the unloading unit 170. At this time, steps S510 to S560 are inline and sequentially performed.

7. Cooling Step S550 >

The printed circuit board P on which step S540 is completed is cooled with nitrogen or air.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

110: loader
150: preheating unit
154 IR lamp
161: laser oscillation unit
162: optical fiber bundle
163: optical system
164: head
165 drive unit
166: control unit

Claims

A load unit on which a printed circuit board is loaded;
A preheater which is transferred from the rod and preheats a printed circuit board having a solder ball formed thereon using an IR lamp;
A solder part for soldering the printed circuit board preheated by the preheat part by irradiating an area beam having a width direction dimension; And
An unload unit to which the soldered printed circuit board is transferred and loaded; Including;
The rod part, preheating part, solder part and unload part are arranged in-line,
The preheating unit is an inline reflow device using a laser module including an IR lamp, an IR lamp driver and an IR lamp control unit for driving the IR lamp to increase the temperature gently between 150 degrees and 180 degrees.

delete

The method of claim 1,
The solder part may include a laser beam oscillator for outputting a laser beam, an optical fiber bundle connected to the laser beam oscillator for split transmission of the laser beam, and an output end of the optical fiber bundle to connect the laser beam to a predetermined range of energy intensities. An optical system for averaging the optical system, a head portion shaped to irradiate a printed circuit board to form an area beam having a width direction dimension, and a laser beam emitted from an output end of the optical fiber bundle, an input end and an output end of the optical fiber bundle, A driving unit which operates after holding the head unit on the printed circuit board for a predetermined time; And
Inline reflow apparatus using a laser module including a control unit for controlling the laser oscillation unit, the optical system, and the driving unit.

The method of claim 3, wherein
The head unit is an inline reflow device using a laser module of the box shape in which the laser bundle is arranged having a width direction dimension.

The method of claim 4, wherein
The control unit is an inline reflow apparatus using a laser module for controlling the length of time the head portion is maintained on the printed circuit board to compensate for the energy intensity of the laser beam formed into the area beam irradiated from the head portion.

A loading step of transferring the loaded printed circuit board into the reflow apparatus;
A preheating step of preheating the printed circuit board, which is transferred by the transfer step and has a solder ball formed thereon, with an IR lamp;
A soldering step of forming a laser beam into an area beam having a width direction and irradiating the printed circuit board preheated by the preheating step to melt and solder solder balls; And
An unloading step of transferring the soldered printed circuit board to an unloading part for transferring the soldered printed circuit board; Including;
The loading step, the IR lamp preheating step, the soldering step using the laser and the unloading step are sequentially performed along the inline,
The preheating step is inline reflow method using a laser module is made for 90 seconds between 150 degrees to 180 degrees.

delete

The method according to claim 6,
The soldering step is
An output step of outputting a laser beam through the optical fiber bundle;
Averaging said laser beam to have a range of energy intensities;
A beam shaping step of shaping the averaged laser beam into an area beam having a width direction dimension; And
An irradiation step of irradiating the molded laser beam on the printed circuit board at a predetermined time; Inline reflow method using a laser module comprising a.

The method of claim 8,
The beam forming step is an in-line reflow method using a laser module formed by arranging the optical fiber bundle to have a width direction dimension.

The method of claim 9,
The beam forming step is an in-line reflow method using a laser module made by on and off the output of the optical fiber bundle.

The method of claim 8,
The irradiation step is an inline reflow method using a laser module for maintaining a temperature between 170 to 240 degrees for 40 seconds.