Flip chip laser bonding apparatus and method

Abstract

To provide a flip-chip laser bonding apparatus and method by which semiconductor chips that are bent or warped or flip-chip type semiconductor chips that may be bent or warped by temperature rise are rapidly bonded to a substrate with high quality without contact defects of solder bumps.SOLUTION: A flip-chip laser bonding apparatus includes: a substrate support member 100 configured to adsorb, hold and support a lower surface of a substrate 10; a chip support member 200 configured to hold and support an upper surface of the semiconductor chip 20; a chip transfer unit 300 configured to transfer the chip support member relative to the substrate support member to align a position of the semiconductor chip with respect to the substrate; and a laser head 400 configured to bond the semiconductor chip to the substrate by irradiating the lower surface of the substrate supported on the substrate support member with laser light.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a flip-chip laser bonding apparatus and method, and more particularly to a flip-chip laser bonding apparatus and method for bonding a flip-chip type semiconductor chip to a substrate by using laser light. [Background technology]

[0002] As electronic products become smaller, flip-chip type semiconductor chips that do not use wire bonding are widely used. Flip-chip type semiconductor chips have a large number of solder bump type electrodes formed on the underside of the semiconductor chip, which are then bonded to the substrate at positions corresponding to the solder bumps formed on the substrate.

[0003] The methods of mounting a semiconductor chip to a substrate using the flip chip method are roughly divided into the reflow method and the laser bonding method. The reflow method is a method in which a semiconductor chip with flux applied to the solder bumps is placed on a substrate and then subjected to high-temperature reflow, thereby bonding the semiconductor chip to the substrate. The laser bonding method is a method in which a semiconductor chip with flux applied to the solder bumps is placed on a substrate, as in the reflow method, and then a laser beam is irradiated onto the semiconductor chip to transmit energy, causing the solder bumps to melt instantaneously and then solidify, thereby bonding the semiconductor chip to the substrate.

[0004] Recently, flip-chip type semiconductor chips have a tendency to be thin, with thicknesses of several tens of micrometers or less. When semiconductor chips are thin, they are often bent or warped due to internal stress of the semiconductor chip itself. When the semiconductor chip is deformed, the solder bumps of the semiconductor chip may be bonded without contacting the corresponding solder bumps of the substrate. This situation may cause defects in the semiconductor chip bonding process. In addition, when the temperatures of the semiconductor chip and the substrate rise in order to bond the semiconductor chip to the substrate, the semiconductor chip or the substrate may be partially bent or warped due to the difference in thermal expansion coefficients of the materials inside the materials. This phenomenon may also cause defects in the semiconductor chip bonding process.

[0005] The reflow method has the problem that the semiconductor chip is exposed to high temperatures for a long period of time, which causes the semiconductor chip to bend, and also has the problem that it takes a long time to cool the semiconductor chip, which reduces productivity.

[0006] In the case of TC bonder (Thermal Compression Bonder), the semiconductor chip is heated and bonded with a heating block. In this case, the heating method is by thermal conduction, so it takes time to heat the solder and the temperature of the semiconductor chip is unnecessarily raised, which can cause damage to the semiconductor chip.

[0007] Therefore, there is a need for a flip chip bonding apparatus or method that can perform a semiconductor chip bonding process quickly without increasing the temperature of the semiconductor chip. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been devised to meet the above-mentioned needs, and its object is to provide a flip-chip laser bonding apparatus and method capable of bonding a bent or warped semiconductor chip, or a flip-chip type semiconductor chip that may bend or warp due to temperature rise, to a substrate with high quality and speed without poor contact of the solder bumps. [Means for solving the problem]

[0009] In order to meet the above-mentioned needs, the flip chip laser bonding apparatus of the present invention is a flip chip laser bonding apparatus that bonds a flip chip type semiconductor chip to a substrate using a laser, and is characterized by including: a substrate support member that adsorbs, fixes and supports the underside of the substrate; a chip support member that fixes and supports the upper side of the semiconductor chip; a chip transfer unit that transfers the chip support member relative to the substrate support member so as to align the position of the semiconductor chip with respect to the substrate; and a laser head that irradiates a laser light to the underside of the substrate supported by the substrate support member to bond the semiconductor chip to the substrate.

[0010] In addition, a flip chip laser bonding method according to the present invention is a flip chip laser bonding method for bonding a flip chip type semiconductor chip to a substrate using a laser, and is characterized by including the steps of: (a) adsorbing, fixing and supporting an underside of the substrate with a substrate support member; (b) fixing and supporting an upper side of the semiconductor chip with a chip support member; (c) transferring the chip support member relative to the substrate support member by a chip transfer unit to align the position of the semiconductor chip with respect to the substrate, and bringing the semiconductor chip into contact with the substrate; and (d) irradiating a laser beam to an underside of the substrate supported by the substrate support member with a laser head, thereby bonding the semiconductor chip to the substrate. Effect of the Invention

[0011] The flip chip laser bonding apparatus and method according to the present invention have the advantage that a flip chip type semiconductor chip that is bent or may be bent can be bonded to a substrate quickly with high quality without poor contact of the solder bumps. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a flip chip laser bonding apparatus according to one embodiment of the present invention. [Diagram 2] 2 is a schematic diagram for explaining the operation of the flip chip laser bonding apparatus shown in FIG. 1; [Diagram 3] 2 is a schematic diagram for explaining the operation of the flip chip laser bonding apparatus shown in FIG. 1; [Figure 4] 2 is a schematic diagram for explaining the operation of the flip chip laser bonding apparatus shown in FIG. 1; [Diagram 5] 2 is a flowchart illustrating a flip chip laser bonding method according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a flip chip laser bonding apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

[0014] The semiconductor chip bonded to the substrate by the flip chip laser bonding apparatus of the present invention is a concept including not only an individual element but also various types of flip chip type semiconductor components bonded to the substrate. A component in which an individual element is packaged or a multi chip module (MCM) type component can also be included in the semiconductor chip bonded to the substrate by the flip chip laser bonding apparatus of the present invention. The semiconductor chip and the substrate are bonded to each other by electrically connecting the electrodes formed on each of them by solder bumps such as solder balls or copper pillars. The substrate and the semiconductor chip are supplied with solder balls or copper pillars bonded to one of them, and the solder balls or copper pillars are bonded to the other by heating the pre-applied flux and solder bumps.

[0015] FIG. 1 is a schematic diagram of a flip-chip laser bonding apparatus according to one embodiment of the present invention.

[0016] As described above, solder bumps 21 such as solder balls and copper pillars are used as elements for connecting the substrate 10 and the semiconductor chip 20. In this embodiment, a case where copper pillars are used as the solder bumps 21 will be described as an example. The copper pillars 21 may be in a state where they are bonded to the semiconductor chip 20 in advance, or may be in a state where they are bonded to the substrate 10 in advance. In this embodiment, however, a case where the copper pillars 21 are bonded to the underside of the semiconductor chip 20 in advance, the substrate 10 is supplied in a state where flux is applied thereto, and the semiconductor chip 20 is bonded to the substrate 10 will be described as an example.

[0017] 1 and 2, the flip chip laser bonding apparatus of the present embodiment includes a substrate support member 100, a chip support member 200, a chip transfer unit 300 and a laser head 400. As shown in FIG.

[0018] The substrate support member 100 adheres to and fixes the lower surface of the substrate 10. The substrate support member includes a transmission portion 110 made of a transparent material. The transmission portion 110 is formed to occupy a position corresponding to at least a portion of the substrate 10 and is disposed to contact the lower surface of the substrate 10. The transmission portion 110 may be made of a quartz material or a porous resin. The laser light generated from the laser head 400 is irradiated to the lower surface of the substrate 10 through the transmission portion 110.

[0019] The substrate support member 100 adheres to and fixes the bottom surface of the substrate 10 by a vacuum suction method. Holes capable of transmitting a vacuum negative pressure are formed in the transmission part 110 or are arranged in the periphery adjacent to the transmission part 110 to adhere to the bottom surface of the substrate 10. A separate substrate transfer unit may be provided to supply the substrate 10 to the substrate support member 100 and to eject the substrate 10 with the semiconductor chip 20 bonded thereto to the outside.

[0020] The chip support member 200 fixes and supports the upper surface of the semiconductor chip 20 to be bonded to the substrate 10. In this embodiment, the chip support member 200, like the substrate support member 100, suctions and fixes the upper surface of the semiconductor chip 20 by a suction method. If necessary, the chip support member 200 can clamp and support the semiconductor chip 20 by various methods other than the suction method.

[0021] The chip transfer unit 300 transfers the chip support member 200 relative to the substrate support member 100 so as to align the position of the semiconductor chip 20 relative to the substrate 10. The chip transfer unit 300 horizontally transfers the chip support member 200 back and forth and left and right, and raises and lowers it up and down. The chip transfer unit 300 is also configured to rotate the chip support member 200 within a predetermined angle range about a vertical axis in the up and down direction. With this structure, the chip transfer unit 300 adjusts the position and direction of the semiconductor chip 20 adsorbed to the chip support member 200, and aligns it with respect to the substrate 10 supported by the substrate support member 100.

[0022] The laser head 400 irradiates a laser beam onto the lower surface of the substrate 10 supported by the substrate support member 100. The laser beam irradiated from the laser head 400 is irradiated onto the lower surface of the substrate 10 through the transmission portion 110. The laser beam irradiated onto the substrate 10 heats the solder bumps 21 (solder balls or copper pillars) connecting the electrodes of the substrate 10 and the semiconductor chip 20 and the solder applied around them, thereby bonding the semiconductor chip 20 to the substrate 10. In this embodiment, the laser head 400 is disposed below the substrate support member 100 and irradiates the laser beam upward. In some cases, the laser head 400 may be disposed not directly below the substrate support member 100 but in a lateral or other direction. In this case, the laser head may be configured to irradiate the lower surface of the substrate 10 through the transmission portion 110 of the substrate support member 100 using an optical system such as a lens or a prism. The laser head 400 that generates the laser beam may be a light source of various known forms. It is also possible to use a laser head 400 made up of pixel elements as a light source that generates laser light.

[0023] Meanwhile, the flip chip laser bonding apparatus according to the present embodiment uses a substrate camera 510 and a chip camera 520 to respectively photograph the substrate 10 and the semiconductor chip 20 in order to accurately align the relative positions and directions of the semiconductor chip 20 and the substrate 10. The substrate camera 510 photographs the upper surface of the substrate 10 placed on the substrate support member 100. The chip camera 520 photographs the lower surface of the semiconductor chip 20 supported on the chip support member 200. The substrate camera 510 and the chip camera 520 may be fixedly installed, or the substrate camera 510 or the chip camera 520 may be installed on a separate transfer unit for transferring and may photograph an object while moving. In this embodiment, the substrate camera 510 is installed on the chip transfer unit 300 and photographs the position and direction of the substrate 10 while moving relative to the substrate 10. Also, the substrate camera 510 is installed in a fixed state on the lateral side of the substrate support member 100. The chip camera 520 photographs the semiconductor chip 20 moved by the chip transfer unit 300 from below to capture the position and direction of the chip.

[0024] The images captured by the substrate camera 510 and the chip camera 520 are transmitted to the control unit 600. The control unit 600 uses the images captured by the substrate camera 510 and the chip camera 520 to grasp the exact relative positions of the substrate 10 and the semiconductor chip 20. The control unit 600 controls the operation of the substrate support member 100, the chip support member 200, the chip transfer unit 300, and the laser head 400. The control unit 600 operates the chip transfer unit 300 based on the positions and directions of the substrate 10 and the semiconductor chip 20 to align the position and direction of the semiconductor chip 20 with respect to the substrate 10. Even in the case of mass-produced semiconductor chips 20 or substrates 10, the positions and directions may vary slightly. However, in the present invention, the positions and directions of the substrates 10 and the semiconductor chips 20 are grasped and aligned each time before bonding, thereby improving the quality.

[0025] Meanwhile, the chip support member 200 includes a tilting unit 210. When the chip transfer unit 300 lowers the chip support member 200 to contact the semiconductor chip 20 and clamp the semiconductor chip 20, the tilting unit 210 starts to contact the semiconductor chip 20 while tilting in accordance with the inclination of the upper surface of the semiconductor chip 20, as shown in Fig. 2. When the tilting unit 210 completely contacts the upper surface of the semiconductor chip 20, the chip support member 200 operates to suction and support the semiconductor chip 20.

[0026] The tilting unit 210 of this embodiment includes a fixed portion 211 and a contact portion 212. The fixed portion 211 is fixed to the body of the chip support member 200, and the contact portion 212 is installed so as to be capable of rotating and tilting with respect to the fixed portion 211. The opposing surfaces of the fixed portion 211 and the contact portion 212 are formed as curved surfaces and are configured to allow a relative tilt with respect to each other. In this embodiment, the fixed portion 211 is formed as a bulging hemisphere, and the surface of the contact portion 212 facing the fixed portion 211 is formed as a concave hemisphere. As a result, the contact portion 212 can tilt within a predetermined angle range along the curved surface of the contact surface with respect to the fixed portion 211. When the contact portion 212 tilts with respect to the fixed portion 211 in accordance with the inclination of the upper surface of the semiconductor chip 20, the tilting unit 210 maintains the tilt angle of the contact portion 212 with respect to the fixed portion 211 by a vacuum suction method. A mechanical part generally called an "air gyro" or a "copying apparatus" is used as the tilting unit 210. The contact portion 212 of the tilting unit 210 contacts the upper surface of the semiconductor chip 20 to suction and fix the upper surface of the semiconductor chip 20, and the tilting unit 210 maintains the inclination of the upper surface of the semiconductor chip 20 even when the chip conveying unit 300 applies pressure to the semiconductor chip 20 or adjusts the height of the semiconductor chip 20.

[0027] In the case of a multi-chip module type semiconductor chip 20, since a plurality of chips are combined and packaged, the upper surface of the semiconductor chip 20 may not be horizontal. In addition, if the internal structure of the semiconductor chip 20 is not uniform, such as in a multi-chip module, the upper surface of the semiconductor chip 20 is often not a perfect hexahedron due to differences in thermal expansion caused by temperature changes. That is, when the semiconductor chip 20 is heated during the bonding process, the upper surface of the semiconductor chip 20 may become slightly tilted. In the case of the flip chip laser bonding apparatus according to the present embodiment, the tilting unit 210 contacts the semiconductor chip 20 at an angle corresponding to the inclination of the upper surface thereof and adjusts the position, direction and height of the semiconductor chip 20 while maintaining the inclination angle, and presses the semiconductor chip 20 uniformly. Therefore, the position of the semiconductor chip 20 is maintained constant, and the pressure of the semiconductor chip 20 can be transmitted relatively uniformly. That is, if the upper surface of the semiconductor chip 20 and the contact surface of the chip support member 200 are not parallel to each other, the semiconductor chip 20 may move laterally when the semiconductor chip 20 is pressed, but when the tilting unit 210 is used to press the semiconductor chip 20, the position of the semiconductor chip 20 can be maintained.

[0028] Hereinafter, a process of carrying out an example of a flip chip laser bonding method according to the present invention using the flip chip laser bonding apparatus according to the present embodiment configured as described above will be described with reference to Figures 2 to 5. For the purpose of explanation, Figures 2 to 4 show an inclined top surface of the semiconductor chip 20 in an exaggerated manner.

[0029] In the case of a semiconductor chip 20, such as a component in which individual elements are packaged or a multi-chip module (MCM) type component, the upper surface of the semiconductor chip 20 is often slightly tilted. In addition, since the internal material of the semiconductor chip 20 is not uniform, the shape of the semiconductor chip 20 changes depending on the temperature due to differences in thermal expansion coefficients, which may cause the upper surface of the semiconductor chip 20 to be tilted. The flip chip laser bonding apparatus and method of the present embodiment aligns the position and direction of the semiconductor chip 20 while taking into account the inclination of the upper surface of the semiconductor chip 20, thereby dramatically improving the quality of the flip chip bonding process.

[0030] Usually, the substrate 10 and the semiconductor chip 20 are supplied in a pre-laminated state with flux applied thereto. In this state, the substrate support member 100 adsorbs, fixes, and supports the lower surface of the substrate 10 supplied from outside (step (a); S100). At this time, the semiconductor chip 20 is arranged on the substrate 10.

[0031] In this state, the chip support member 200 adsorbs, fixes and supports the upper surface of the semiconductor chip 20 arranged on the substrate 10 (step (b); S200). At this time, as shown in Fig. 2, the contact portion 212 of the tilting unit 210 is tilted with respect to the fixing portion 211 by the operation of the tilting unit 210, and the chip support member 200 adsorbs the semiconductor chip 20 while tilting in accordance with the inclination of the upper surface of the semiconductor chip 20.

[0032] 3, the chip transfer unit 300 raises the chip support member 200 to lift the semiconductor chip 20 on the substrate 10. The semiconductor chip 20 is lifted while the tilting unit 210 maintains the inclination of the upper surface of the semiconductor chip 20.

[0033] When the chip transfer unit 300 transfers the substrate camera 510 back and forth and left and right, the substrate camera 510, moving together with the chip support member 200, photographs the upper surface of the substrate 10 placed on the substrate support member 100 ((e) step: S300). The image photographed by the substrate camera 510 is transmitted to the control unit 600.

[0034] Next, as the chip transport unit 300 transports the chip support member 200 back and forth and left and right, the chip camera 520 photographs the underside of the semiconductor chip 20 supported by the chip support member 200 (step (f); S400). The image photographed by the chip camera 520 is transmitted to the control unit 600. As described above, while the tilt of the upper surface of the semiconductor chip 20 is maintained by the tilting unit 210, the chip camera 520 photographs the underside of the semiconductor chip 20, thereby photographing the semiconductor chip 20 at the tilt angle when it actually contacts the substrate 10. Therefore, the chip camera 520 can more accurately photograph the position of the semiconductor chip 20.

[0035] The control unit 600 analyzes the images captured by the substrate camera 510 and the chip camera 520 and calculates the difference in the relative positions and orientations of the substrate 10 and the chip.

[0036] The control unit 600 uses such a calculation result to operate the chip transfer unit 300. The chip transfer unit 300 transfers the chip support member 200 relative to the substrate support member 100, and aligns the position and direction of the semiconductor chip 20 relative to the substrate 10. As described above, since the chip transfer unit 300 has the function of rotating the semiconductor chip 20 about the vertical rotation axis, the chip transfer unit 300 aligns not only the position but also the direction of the semiconductor chip 20 to complete the alignment with the substrate 10.

[0037] In this state, the chip transferring unit 300 lowers the chip support member 200 (step (c); S500). As shown in FIG. 4, the semiconductor chip 20 is lowered so that the copper pillars 21 come into contact with the electrodes of the substrate 10. At this time, as described above, the tilting unit 210 adsorbs the semiconductor chip 20 while maintaining the inclination of the upper surface of the semiconductor chip 20, and the chip transferring unit 300 lowers the chip support member 200 to press the semiconductor chip 20 against the substrate 10. The chip transferring unit 300 is configured to sense and adjust the pressure when the chip support member 200 is lowered to apply pressure.

[0038] With the semiconductor chip 20 in contact with the substrate 10 in this manner by step (c), the control unit 600 operates the laser head 400 to irradiate laser light onto the underside of the substrate 10, thereby bonding the semiconductor chip 20 to the substrate 10 (step (d); S600).

[0039] As described above, the substrate support member 100 includes the transmission portion 110 made of a transparent material, so that the laser light generated from the laser head 400 passes through the transmission portion 110 and effectively transfers energy to the lower surface of the substrate 10.

[0040] In the case of a conventional TC bonder (Thermal Compression Bonder), since it uses a heat transfer method by conduction, it takes time to heat the solder bumps, and in the process, the temperature of the semiconductor chip 20 is unnecessarily raised, causing damage to the semiconductor chip 20. Unlike such a TC bonder, the flip chip laser bonding apparatus and method according to the present invention uses a laser beam to instantly melt the solder bumps and perform bonding. Therefore, the present invention has an advantage that the temperature of the semiconductor chip 20 itself does not increase significantly during the bonding process by the laser. In addition, the present invention has an advantage that the semiconductor chip 20 can be cooled quickly by preventing the temperature rise of the semiconductor chip 20 by blocking the laser beam immediately after the bonding is completed. Therefore, the present invention has an advantage that the quality of the semiconductor chip 20 bonding process is improved and the working speed is also very fast.

[0041] In addition, the flip chip laser bonding apparatus according to the present embodiment adjusts the pressure applied to the semiconductor chip 20 and the height of the semiconductor chip 20 using the chip transfer unit 300 while irradiating the laser beam through step (d) as described above. While the laser head 400 performs bonding using the laser beam, the temperature of the substrate 10 and the semiconductor chip 20 may rise to a certain degree, although not to the same level as that of a TC bonder. At this time, warpage deformation may occur in the substrate 10 or the semiconductor chip 20 due to the difference in thermal expansion coefficient of the materials. At this time, the chip transfer unit 300 maintains a force that applies pressure to the semiconductor chip 20 with an appropriate pressure, thereby preventing bonding failure due to deformation of the semiconductor chip 20 and the substrate 10. The substrate support member 100 and the chip support member 200 respectively adsorb the substrate 10 and the semiconductor chip 20 and maintain the vacuum pressure over a wide area, thereby further preventing warpage deformation of the substrate 10 and the semiconductor chip 20. On the other hand, the tilting member described above also tilts at an inclination corresponding to the inclination of the upper surface of the semiconductor chip 20, and plays a role in preventing warping deformation of the semiconductor chip 20 by applying pressure to the entire upper surface of the semiconductor chip 20 while maintaining that inclination angle.

[0042] Meanwhile, the control unit 600 can variably control the height of the semiconductor chip 20 by the chip transfer unit 300 according to the characteristics of the copper pillar 21 disposed between the semiconductor chip 20 and the substrate 10 .

[0043] First, the control unit 600 can operate the chip transport unit 300 to maintain a constant pressure on the semiconductor chip 20 while the laser head 400 is emitting light. As the solder bumps 21 melt due to the laser light, the semiconductor chip 20 can be slightly lowered, and the control unit 600 can maintain the pressure on the semiconductor chip 20 while continuing to lower the chip support member 200 in consideration of the descent of the semiconductor chip 20. In this manner, the semiconductor chip 20 can be accurately bonded while preventing warpage of the semiconductor chip 20 or the substrate 10.

[0044] Secondly, the control unit 600 may operate the chip transfer unit 300 to maintain the height of the semiconductor chip 20 constant while the laser head 400 is emitting light. Depending on the characteristics of the solder or copper pillar 21, the position of the semiconductor chip 20 with respect to the substrate 10 may change due to excessive pressure. In preparation for such a case, when the laser light starts to be irradiated, the semiconductor chip 20 may not be lowered any more and may be maintained at the initial height and the solder on the substrate 10 may melt. In particular, unlike the above and illustrated cases, when the semiconductor chip 20 is bonded to the substrate 10 using conductive balls (solder balls) instead of the copper pillars 21, maintaining the height of the semiconductor chip 20 constant may be a method of achieving higher bonding quality. The molten solder is bonded while maintaining the copper pillars or solder balls at the positions of the electrodes of the substrate 10 and the semiconductor chip 20 by capillary action and surface tension, thereby enabling high-quality and rapid bonding.

[0045] Third, the control unit 600 may operate the chip transfer unit 300 to minutely lower the height of the semiconductor chip 20 to a predetermined height while the laser head 400 is emitting light, and then to maintain the height at a constant level. The control unit 600 eliminates the lifting and lowering motion of the chip transfer unit 300 so that the height of the semiconductor chip 20 can be appropriately changed or maintained according to the temperature and irradiation time of the laser light irradiated by the laser head 400 according to the characteristics of the substrate 10, the semiconductor chip 20, the solder, the copper pillar 21, or the solder balls, thereby achieving optimal quality. That is, the control unit 600 may control the chip transfer unit 300 to change or maintain the height of the chip support member 200 according to a preset appropriate profile.

[0046] By laser bonding the flip-chip type semiconductor chip 20 using the various methods described above, it is possible to bond the flip-chip type semiconductor chip 20 quickly and with high quality while preventing the occurrence of defects, even when the directivity of the electrodes is very high and the size of the solder balls or copper pillars 21 is very small.

[0047] In particular, the flip chip laser bonding apparatus of the present invention does not irradiate the upper surface of the semiconductor chip 20 with a laser beam, but irradiates the lower surface of the substrate 10 through the transmitting portion 110, so that the semiconductor chip 20 can be bonded with high quality while minimizing damage or thermal deformation of the semiconductor chip 20. Recently, the semiconductor chip 20 is highly integrated like a multi-chip module, and different types of semiconductor elements are often combined into one package to form the semiconductor chip 20. Therefore, when the laser beam is irradiated to the upper surface of the semiconductor chip 20, the intensity of the laser beam passing through the semiconductor chip 20 is not uniform depending on the position. Therefore, in such a case, it is difficult to improve the quality of the laser bonding process. However, when the laser beam is irradiated through the lower surface of the substrate 10 as in the present invention, the substrate 10, which is made of a relatively uniform thickness and material compared to the semiconductor chip 20, can transmit the laser beam uniformly and realize effective melting of the solder. Also, in such a case, the bonding process can be performed only with a laser beam of a relatively low energy level due to the relatively thin thickness of the substrate 10. In addition, in this case, since the energy level of the laser light transmitted to the semiconductor chip 20 is significantly lower than in other cases, there is an advantage in that the semiconductor chip 20 can be effectively prevented from being damaged or broken during the bonding operation.

[0048] In addition, the flip chip laser bonding apparatus and method of the present invention uses a laser beam as an energy source, so that the solder balls or solder can be heated in a short time, and can be cooled quickly to room temperature simply by shutting off the laser beam source. Therefore, compared to the conventional method of heating the semiconductor chip 20 using a heating block in a TC bonder or the like, there is an advantage that the semiconductor chip 20 can be bonded to the substrate 10 at a dramatically faster speed. At the same time, there is an advantage that the time during which the semiconductor chip 20 is exposed to a temperature higher than room temperature can be minimized, so that the semiconductor chip 20 can be bonded while minimizing the possibility of breakage or damage to the semiconductor chip 20.

[0049] In addition, the flip chip laser bonding apparatus and method of the present invention takes into account the case where the top surface of the semiconductor chip 20 is tilted, and uses the tilting unit 210 to photograph the semiconductor chip 20 while maintaining the tilt angle of the semiconductor chip 20 when it is in contact with the substrate 10, aligns the position and direction of the semiconductor chip 20, and presses the semiconductor chip 20 against the substrate 10, thereby enabling a more accurate flip chip bonding process to be performed.

[0050] Although the present invention has been described and illustrated by way of preferred embodiments, the scope of the present invention is not limited to the embodiments described and illustrated above.

[0051] For example, although the chip support member 200 has been described as including the tilting unit 210, it is possible to configure a flip chip laser bonding apparatus that does not include the tilting unit 210 in some cases. In this case, the chip support member does not tilt along the upper surface of the semiconductor chip 20, but adsorbs and presses the semiconductor chip 20 with a contact surface that is formed horizontally. Also, even if the chip support member 200 includes the tilting unit 210, the chip support member 200 can use tilting units configured in various structures and forms other than those described and illustrated.

[0052] Although the above description has been given of an example of a method in which the copper pillars 21 are supplied in a state in which they are pre-bonded to the underside of the semiconductor chip 20, and then bonded to the substrate 10, the flip-chip laser bonding apparatus and method of the present invention can also be used in a case in which solder bumps are supplied in a pre-bonded state to the substrate 10, and then the semiconductor chip 20 is bonded to the substrate 10. The present invention can also be applied to a bonding process in which electrodes of the semiconductor chip 20 and the substrate 10 are connected by solder using conductive balls (solder balls) or similar structures as solder bumps, in addition to the copper pillars 21.

[0053] Although the flip chip laser bonding apparatus having the substrate camera 510 and the chip camera 520 has been described above as an example, it is also possible to configure a flip chip laser bonding apparatus having a structure without the substrate camera 510 or the chip camera 520. In this case, the positions of the substrate 10 and the semiconductor chip 20 are measured in advance using a camera or other device, and the control unit receives the input of the measured value and operates the chip transfer unit 300 to align the substrate 10 and the semiconductor chip 20. Even in the case of a flip chip laser bonding apparatus having the substrate camera 510 and the chip camera 520, it is also possible to configure a flip chip laser bonding apparatus in which the installation structure and transfer structure of the substrate camera and the chip camera are variously modified as necessary.

[0054] Also, the above description and illustration have been given of an example in which one semiconductor chip 20 is bonded to a substrate 10, but this is shown for convenience of explanation. In most cases, the flip chip laser bonding apparatus and method according to the present invention are performed in a manner in which a plurality of semiconductor chips 20 are bonded to one substrate 10. In this case, the flip chip laser bonding apparatus and method according to the present invention can be performed in a manner in which a plurality of semiconductor chips 20 are sequentially bonded to one substrate 10 one by one. In some cases, the flip chip laser bonding apparatus and method according to the present invention can be configured to suck two or more semiconductor chips 20 at a time to a chip support member, align their positions relative to the substrate 10, and then bond them to the substrate 10.

[0055] In addition, although the substrate support member 100 has been described above as having the transmission portion 110 made of a transparent material, in some cases, the substrate support member may be configured to support the bottom surface of the substrate 10 using a translucent material without the transmission portion 110. In this case, too, a portion of the laser light can be transmitted through the bottom surface of the substrate 10 to heat the solder and perform bonding. [Explanation of symbols]

[0056] 10 Substrate 20. Semiconductor Chips 21 Solder bumps 100 Substrate support member 110 Transparent part 200 Chip support member 210 Tilting Unit 211 Fixed part 212 Contact part 300 Chip Transfer Unit 400 Laser Head 510 Board Camera 520 Chip Camera 600 Control section

Claims

1. A flip-chip laser bonding apparatus that bonds a flip-chip type semiconductor chip to a substrate using a laser, comprising: a substrate support member that adsorbs and supports a lower surface of the substrate; a chip support member that fixes and supports an upper surface of the semiconductor chip; a chip transfer unit for transferring the chip support member relative to the substrate support member so as to align the semiconductor chip with respect to the substrate; a laser head that irradiates a laser beam onto a lower surface of the substrate supported by the substrate support member to bond the semiconductor chip to the substrate; a controller for controlling operations of the substrate support member, the chip support member, the chip transfer unit, and the laser head; the control unit controls the chip transfer unit to adjust the height of the chip support member, and causes the chip transfer unit to lower the chip support member while the laser head is irradiating the laser light. Flip chip laser bonding equipment.

2. 2. The flip chip laser bonding apparatus of claim 1, wherein the substrate support member includes a transmission portion made of a transparent material to transmit the laser light irradiated from the laser head to the substrate.

3. 3. The flip chip laser bonding apparatus of claim 2, wherein the transmissive portion of the substrate support member is formed of quartz.

4. 2. The flip chip laser bonding apparatus according to claim 1, wherein the chip support member adheres to an upper surface of the semiconductor chip to fix and support the semiconductor chip.

5. 5. The flip chip laser bonding apparatus according to claim 4, wherein the chip support member includes a tilting unit that contacts an upper surface of the semiconductor chip and supports the semiconductor chip by suction while tilting in accordance with an inclination of the upper surface of the semiconductor chip.

6. the chip support member supports the semiconductor chip while maintaining an angle tilted by the tilting unit in accordance with an inclination of an upper surface of the semiconductor chip; 6. The flip chip laser bonding apparatus of claim 5, wherein the chip transfer unit transfers the chip support member while maintaining the inclined angle of the semiconductor chip by the chip support member.

7. 7. The flip chip laser bonding apparatus of claim 6, wherein the tilting unit of the chip support member includes a contact portion that contacts and supports an upper surface of the semiconductor chip, and a fixed portion that supports the contact portion so that the contact portion can be tilted, the fixed portion and the contact portion have curved surfaces facing each other to enable relative tilting, and the angle of the contact portion relative to the fixed portion is maintained by air pressure.

8. 2. The flip chip laser bonding apparatus according to claim 1, wherein the semiconductor chip is bonded to the substrate using either a solder ball or a copper pillar as a solder bump.

9. a substrate camera that captures an image of an upper surface of the substrate placed on the substrate support member; a chip camera for photographing a bottom surface of the semiconductor chip supported by the chip support member; 2. The flip chip laser bonding apparatus of claim 1, wherein the control unit operates the chip transfer unit to adjust a position and a direction of the semiconductor chip with respect to the substrate using images captured by the substrate camera and the chip camera.

10. A flip-chip laser bonding method for bonding a flip-chip type semiconductor chip to a substrate using a laser, comprising: (a) adsorbing, fixing and supporting a lower surface of the substrate by a substrate support member; (b) fixing and supporting an upper surface of the semiconductor chip with a chip support member; (c) transferring the chip support member relative to the substrate support member by a chip transfer unit so as to align the semiconductor chip with respect to the substrate, and bringing the semiconductor chip into contact with the substrate; (d) irradiating a laser beam onto a bottom surface of the substrate supported by the substrate support member with a laser head to bond the semiconductor chip to the substrate; Including, the steps (a), (b), (c), and (d) are respectively performed using a control unit that controls the operation of the substrate support member, the chip support member, the chip transfer unit, and the laser head; The step (c) includes a step of the controller controlling the chip transporting unit to adjust the height of the chip support member, and a step of the controller operating the chip transporting unit to lower the chip support member while performing the step (d). Flip chip laser bonding method.

11. 11. The flip chip laser bonding method of claim 10, wherein step (a) is performed using the substrate support member having a transmission portion formed of a transparent material so that the laser light irradiated from the laser head in step (d) can be transmitted to the substrate.

12. 12. The flip chip laser bonding method of claim 11, wherein the step (a) is performed using the substrate support member having the transmissive portion made of quartz.

13. 11. The flip chip laser bonding method according to claim 10, wherein in the step (b), the chip support member adheres to an upper surface of the semiconductor chip, thereby fixing and supporting the semiconductor chip.

14. 14. The flip chip laser bonding method according to claim 13, wherein step (b) is performed using the chip support member having a tilting unit that contacts the top surface of the semiconductor chip and supports the semiconductor chip by suction while tilting in accordance with the inclination of the top surface of the semiconductor chip.

15. In the step (b), the tilting unit supports the semiconductor chip while maintaining an angle inclined in accordance with an inclination of an upper surface of the semiconductor chip; 15. The flip chip laser bonding method of claim 14, wherein in step (c), the chip support member is transferred while maintaining the inclination angle of the semiconductor chip in step (b).

16. 16. The flip chip laser bonding method of claim 15, wherein step (b) is performed using the chip support member including a contact portion that contacts and supports an upper surface of the semiconductor chip, and a fixing portion that supports the contact portion in a tiltable manner, the fixing portion and the contact portion having curved surfaces facing each other to be able to tilt relative to each other, and the tilting unit that maintains the angle of the contact portion relative to the fixing portion by air pressure.

17. The flip chip laser bonding method of claim 10, wherein the semiconductor chip is bonded to the substrate using either a solder ball or a copper pillar as a solder bump.

18. (e) photographing an upper surface of the substrate placed on the substrate support member with a substrate camera; (f) photographing the underside of the semiconductor chip supported by the chip support member with a chip camera; 11. The flip chip laser bonding method of claim 10, wherein in step (c), a position and a direction of the semiconductor chip with respect to the substrate are adjusted using the images captured in steps (e) and (f).

Images