JP2007266628A - Underfilling method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underfilling method of semiconductor devices which makes it possible to control the amount of supply of an underfill material as precisely as possible. <P>SOLUTION: Prior to the mounting of a semiconductor device on a printed-wiring board 11, a fluid 35 of an ultraviolet curing resin is supplied from a nozzle 21 toward the surface of the printed-wiring board 11. When a specified quantity of fluid 35 is spouted out, the fluid is irradiated with ultraviolet rays from a penetrating aperture 26 formed in the nozzle 21. In the fluid exposed to the ultraviolet rays, a solidification reaction occurs. By this solidification reaction, the viscosity of the fluid is increased. By a partial increase in the viscosity, a partition is formed for the fluid inside the nozzle 21. Between the partition and the fluid 35 spouted out from the tip of the nozzle 21, the fluid is interrupted comparatively easily. Accordingly, it is possible to control the quantity of supply of the fluid spouted out from the nozzle with high precision, by adjusting the interruption of the fluid in this way. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an underfill method for filling an underfill material into a space defined between a semiconductor device such as a flip chip mounted on a printed wiring board and the surface of the printed wiring board.

  An underfill method for applying a fluid of an underfill material (for example, an ultraviolet curable resin or a thermosetting resin) to the surface of the printed wiring board prior to mounting the semiconductor device on the surface of the printed wiring board is conventionally known. The semiconductor device is mounted on an underfill material stacked on the surface of the printed wiring board. When the underfill material is cured while the semiconductor device is pressed against the surface of the printed wiring board, the semiconductor device can be fixed to the surface of the printed wiring board. According to this underfill method, even if the distance between the semiconductor device and the surface of the printed wiring board is narrowed, the underfill material is applied to every corner of the space defined between the semiconductor device and the surface of the printed wiring board. The fluid can go around. Such a space is surely filled with underfill material.

  In such an underfill method, it is necessary to accurately control the coating amount of the fluid, that is, the supply amount for each semiconductor device. If the supply amount of the fluid is too large, the fluid of the underfill material overflows from the periphery of the semiconductor device. This interferes with post-processing of printed circuit boards. Conversely, if the amount of fluid supplied is too small, metal connection bumps that establish electrical connection between the semiconductor device and the printed wiring board may not be completely encased or exposed on the surface of the printed wiring board. The metal wiring pattern may not be completely covered. If such connection bumps and wiring patterns are left exposed, there is a concern that the corrosion of the connection bumps and wiring patterns will proceed.

  On the other hand, in the above-described underfill method, the underfill material must be cured in order for each individual semiconductor device. Therefore, a great amount of time is spent mounting the semiconductor device. In addition, the semiconductor device must be pressed against the surface of the printed wiring board when the underfill material is cured. Since the underfill material is cured while the pressing force against the semiconductor device is maintained, the structure of the underfill device for realizing such an underfill method is likely to be complicated.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a semiconductor device underfill method capable of controlling the supply amount of the underfill material as accurately as possible. It is another object of the present invention to provide an underfill device for a semiconductor device that can realize such an underfill method. Furthermore, an object of the present invention is to provide an underfill material-filled syringe, a printed wiring board, and a pretreatment method for underfill that are greatly useful in accurately controlling the supply amount of the underfill material. Furthermore, the present invention provides an underfill device having a relatively simple structure even when an underfill material is supplied to the surface of the printed wiring board prior to mounting the semiconductor device on the printed wiring board. An object is to provide a filling method.

In order to achieve the above object, according to the first aspect of the present invention, the step of supplying a reactive curable resin fluid from the nozzle toward the surface of the printed wiring board prior to mounting the semiconductor device on the surface of the printed wiring board. And a step of increasing the viscosity of the fluid in the nozzle when a predetermined amount of the fluid is ejected. A method of underfilling a semiconductor device is provided.

  In such an underfill method, when the viscosity of the fluid is increased in the nozzle, a partition is formed in the fluid in the nozzle by such partial increase in viscosity. The fluid can be interrupted relatively easily between the fluid ejected from the tip of the nozzle and the partition. Thus, if the interruption of the fluid can be adjusted, the supply amount of the fluid ejected from the nozzle can be controlled with relatively high accuracy. Here, the reactive curable resin may include a photocured resin that cures when exposed to light, a thermoset resin that cures when exposed to heat, and a resin that cures based on other reactions.

  According to the second invention, prior to mounting of the semiconductor device on the surface of the printed wiring board, a step of supplying a fluid of photocurable resin from the nozzle toward the surface of the printed wiring board, and a predetermined amount of the fluid And a step of irradiating the fluid with a light beam from a transmission window formed in the nozzle at the time of jetting.

  In such an underfill method, when light is irradiated to the fluid from the transmission window, a solidification reaction is caused in the fluid exposed to the light. The viscosity of the fluid is increased by this solidification reaction. When the viscosity of the fluid in the nozzle is increased in this way, a partition is formed in the fluid in the nozzle by a partial increase in viscosity, as in the first invention. The fluid can be interrupted relatively easily between the fluid ejected from the tip of the nozzle and the partition. Thus, if the interruption of the fluid can be adjusted, the supply amount of the fluid ejected from the nozzle can be controlled with high accuracy. Here, as the photocurable resin, for example, an ultraviolet curable resin that cures when exposed to ultraviolet rays, or an ultraviolet curable resin that cures when exposed to heat as well as ultraviolet rays can be used.

  In order to realize such an underfill method, for example, a light-impermeable nozzle, a light-impermeable container connected to the base end of the nozzle and filled with a fluid of photo-curing resin, and a nozzle are formed. The underfill material filling syringe provided with the permeation | transmission window to be used should just be used. In such an underfill material-filled syringe, for example, the fluid of the photocurable resin can be ejected from the nozzle in accordance with the pressure applied to the container. When a light beam is irradiated toward the transmission window, the viscosity of the photocurable resin can be increased as described above.

  Moreover, it replaces with such an underfill material filling syringe, and a general underfill material filling syringe may be used. As is well known, this underfill material-filled syringe includes a light-impermeable nozzle and a light-impermeable container that is connected to the base end of the nozzle and is filled with a fluid of a photocurable resin. However, a cylindrical attachment is connected to the tip of the nozzle. As described above, a transmission window is formed in this attachment. The photo-curing resin fluid ejected from the nozzle passes through the attachment and ejects from the tip of the attachment. When a light beam is applied to the transmission window formed in the attachment, the viscosity of the photocurable resin can be increased in the attachment as described above. According to such an attachment, the viscosity of the fluid can be increased as desired without changing the structure of the underfill material-filled syringe.

When using such an underfill material-filled syringe, for example, an underfill device for a semiconductor device is connected to a processing table, a support head facing the processing table, and the support head, and moves the support head toward the ejection position. A positioning mechanism for causing, a dispenser coupled to the support head to supply pressure toward the support head, and a light source for irradiating light toward an irradiation area defined between the support head at the ejection position and the processing table You should prepare. The aforementioned underfill material-filled syringe is attached to the support head. The fluid of the photocurable resin can be ejected from the nozzle by the action of pressure supplied from the dispenser to the support head. In order to increase the viscosity of the fluid in the nozzle, the transmission window may be positioned in the irradiation region. For such positioning, the function of the positioning mechanism may be used.

  It is desirable that such an underfill device for a semiconductor device further includes a mask member that blocks the light beam traveling toward the processing table. If the light beam is blocked in this way, it can be surely avoided that the photo-curing resin ejected from the tip of the nozzle is immediately solidified.

  Furthermore, according to the third invention, the step of irradiating the downward surface of the printed wiring board with light while holding the semiconductor device covering the underfill material injection hole formed in the printed wiring board on the downward surface of the printed wiring board; And a step of supplying a fluid of a photo-curing resin from the upward surface side of the printed wiring board to the underfill material injection hole during the irradiation of the light beam.

  According to this underfill method, the fluid of the photocurable resin supplied to the underfill material charging hole is received by the semiconductor device. The fluid spreads between the semiconductor device and the downward surface of the printed wiring board. At this time, the overflowing photocured resin fluid is cured around the semiconductor device. The flow of the fluid is blocked by the cured photo-curing resin. The spread of the fluid is limited. It is possible to avoid the photocuring resin fluid spreading more than necessary.

  In realizing such an underfill method, an underfill device for a semiconductor device includes, for example, a support head that is positioned at an ejection position, a dispenser that is connected to the support head and supplies pressure toward the support head, and an ejection position. And a light source that irradiates light upward. The above-described underfill material-filled syringe may be attached to the support head. This underfill material-filled syringe is provided with a light-impermeable nozzle and a light-impermeable container that is connected to the base end of the nozzle and is filled with a fluid of a photo-curing resin, as in the conventional case. That's fine.

  Furthermore, according to the fourth aspect of the present invention, the conductive input / output pad arranged in the underfill material application planned area on the surface of the substrate body, and the conductive input / output pad defined in the underfill material application planned area The board body is drilled in the depopulated area of the conductive I / O pad specified in the area where the underfill material is to be applied and the overfill area underfill material hole that is drilled in the board body in the overcrowded area. There is provided a printed wiring board including a sparse side underfill material injection hole formed larger than the hole.

  Generally, when a semiconductor device is mounted on a printed wiring board, conductive connection bumps of the semiconductor device are received by input / output pads on the printed wiring board. In other words, the density of connection bumps can inevitably be determined according to the density of input / output pads. When the input / output pads, that is, the connection bumps are densely arranged as in the overcrowded area, even if the distance between the surface of the printed wiring board and the semiconductor device is narrow, the fluid of the underfill material is transmitted along the connection bumps. Easy to spread. On the other hand, even if the connection bumps are sparsely arranged as in a depopulated area, if the depopulated side underfill material injection hole enlarged according to the arrangement of the connection bumps is formed, the connection bumps are not assisted. In both cases, the fluid of the underfill material can easily spread between the semiconductor device and the surface of the printed wiring board. Such overcrowded side underfill material charging holes and sparse side underfill material charging holes may be formed integrally.

Furthermore, according to the fifth aspect of the present invention, there is provided a pretreatment method for underfill, characterized in that plasma irradiation is performed on a planned application area of an underfill material defined on the surface of a printed wiring board.

  According to the plasma irradiation, the dirt attached to the surface of the printed wiring board is removed, and the wettability of the printed wiring board can be improved. If the wettability is improved in this way, the fluid of the underfill material can easily spread along the surface of the printed wiring board. In addition, if a large surface force is ensured around the planned application area as compared with the surface tension of the fluid, it is possible to reliably prevent the fluid from spreading beyond the planned application area.

  Furthermore, according to the sixth invention, a step of supplying a reactive curable resin fluid to the surface of the printed wiring board, and a semiconductor device mounted on the surface of the printed wiring board supplied with the reactive curable resin fluid There is provided a method for mounting a semiconductor device, comprising: a step of bringing an ultrasonic head into contact with the mounted semiconductor device; and a step of curing a fluid of a reactive curable resin.

  According to this mounting method, the ultrasonic vibration is transmitted from the ultrasonic head to the semiconductor device installed on the printed wiring board. As a result, the semiconductor device rolls along the surface of the printed wiring board at a high speed with a fine amplitude. Such rolling of the semiconductor device causes friction between the input / output pads on the printed wiring board and the conductive bumps on the semiconductor device side. Bonding is established between the conductive bump and the input / output pad by the action of frictional heat. Thus, the semiconductor device can be fixed on the printed wiring board. If the reactive curable resin can be cured at once after all the semiconductor devices are fixed on the printed wiring board in this manner, the processing time spent for mounting the semiconductor devices can be shortened. Moreover, according to such a mounting method, it is not necessary to continue to apply a pressing force to the semiconductor device when curing the reactive curable resin, and the mounting device for the semiconductor device can be configured with a relatively simple structure. . Here, the reactive curable resin may include a photocured resin that cures when exposed to light, a thermoset resin that cures when exposed to heat, and a resin that cures based on other reactions.

  In such a method for mounting a semiconductor device, it is desirable that a thin film be disposed between the semiconductor device and the ultrasonic head when the ultrasonic head is brought into contact therewith. As described above, when the ultrasonic head contacts the semiconductor device, the thin film is sandwiched between the semiconductor device and the ultrasonic head. Accordingly, the reactive cured resin fluid overflowing from the periphery of the semiconductor device adheres to the thin film. Adhesion of the reactive curable resin to the ultrasonic head can be reliably prevented. As a result, the ultrasonic head can reliably contact the semiconductor device with a large contact area. Transmission of ultrasonic vibrations to the semiconductor device can continue to be established reliably.

  Instead of using such a thin film, a flange may be formed on the outer periphery of the semiconductor device. These flanges face the stepped surface to the surface of the printed wiring board. According to such a semiconductor device, the overflowing fluid of the reactive cured resin is received by the step surface of the flange. It is possible to avoid the fluid from reaching the ultrasonic head around the flange as much as possible. As a result, as described above, adhesion of the reactive curable resin to the ultrasonic head can be reliably prevented.

  In forming such a semiconductor device, the semiconductor device dividing method includes a step of notching the first groove width into the wafer and cutting a second groove width smaller than the first groove width when cutting the semiconductor device from the wafer. What is necessary is just to provide the process of cut | disconnecting a semiconductor device along a notch. According to such a dividing method, the flange can be formed on the outer periphery of the semiconductor device relatively easily.

  As described above, according to the present invention, it is possible to control the supply amount of the underfill material as accurately as possible when supplying the fluid of the underfill material onto the printed wiring board.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 schematically shows the overall configuration of an underfill device for a semiconductor device according to a first embodiment of the present invention. The underfill device 10 includes, for example, a processing table 12 that receives a printed wiring board 11 on a horizontal plane, and a support head 13 that faces the processing table 12 and moves on a three-dimensional coordinate system set on the processing table 12. The three-dimensional coordinate system may be defined by, for example, an x coordinate axis and ay coordinate axis that are defined along the horizontal plane of the processing table 12 and a z coordinate axis that is orthogonal to the horizontal plane of the processing table 12. The movement of the support head 13 based on such a three-dimensional coordinate system is achieved with the help of the positioning mechanism 14, for example. The positioning mechanism 14 can be realized by, for example, a combination of guide mechanisms that guide the support head 13 along the x coordinate axis, the y coordinate axis, and the z coordinate axis.

  An underfill material-filled syringe 15 filled with a fluid of an underfill material such as an ultraviolet curable resin is detachably mounted on the support head 13. The underfill material-filled syringe 15 is supplied with pressure, that is, air pressure, for example, from a dispenser 16 connected to the support head 13. When air pressure is supplied to the underfill material-filled syringe 15, the ultraviolet curable resin fluid filled in the syringe 15 is discharged from the syringe 15 toward the processing table 12 as will be described later. The ultraviolet curable resin may include those that cause a solidification reaction by the action of ultraviolet rays, and those that cause a solidification reaction by the action of heat as well as ultraviolet rays.

  As shown in FIG. 1, an ultraviolet irradiation device 17 is connected to the underfill material-filled syringe 15. The ultraviolet irradiation device 17 irradiates ultraviolet rays from the light source 18 toward the underfill material-filled syringe 15. As is clear from FIG. 1, the light source 18 may be fixed to the underfill material-filled syringe 15 by a mask member 19. Such a mask member 19 blocks ultraviolet rays irradiated from the light source 18 toward the processing table 12. Therefore, according to the mask member 19, ultraviolet rays emitted from the light source 18 do not reach the printed wiring board 11 on the processing table 12. Moreover, if the light source 18 is integrated with the underfill material-filled syringe 15 in this way, it is not necessary to provide a unique positioning mechanism for the light source 18 in order to realize the movement of the light source 18 that follows the underfill material-filled syringe 15. However, the light source 18 is not necessarily integrated with the underfill material-filled syringe 15, and a positioning mechanism may be separately provided for the underfill material-filled syringe 15 and the light source 18. Functions of the positioning mechanism 14, the dispenser 16, and the ultraviolet irradiation device 17 are controlled by a controller 21, for example.

  For example, as shown in FIG. 2, the underfill material-filled syringe 15 is formed integrally with a light-impermeable nozzle 21 and a proximal end of the nozzle 21, and is filled with a fluid of ultraviolet curable resin. And a permeable container 22. A piston 23 is disposed in the container 22. According to the piston 23, the internal space of the container 22 is divided into a pressure chamber 24 that communicates with the dispenser 16 and a resin chamber 25 that communicates with the nozzle 21. The resin chamber 25 stores a fluid of ultraviolet curable resin. When air pressure is introduced from the dispenser 16 to the pressure chamber 24, the piston 23 advances toward the nozzle 21. As a result, the ultraviolet curable resin fluid stored in the resin chamber 25 is pushed out from the tip of the nozzle 21 toward the processing table 12.

  A transmission window 26 is formed in the nozzle 21. For example, transparent glass or a synthetic resin plate is fitted into the transmission window 26. According to such a transmission window 26, the fluid of the ultraviolet curable resin that passes through the nozzle 21 can be exposed to the ultraviolet rays irradiated from the light source 18 of the ultraviolet irradiation device 17. However, as shown in FIG. 3, for example, the transmission window 26 is not necessarily formed in the nozzle 21, and may be formed in a cylindrical attachment 27 connected to the tip of the nozzle 21.

  Here, the underfill method realized by the above semiconductor device underfill apparatus 10 will be described in detail. Now, for example, as shown in FIG. 4, it is assumed that a semiconductor device (for example, flip chip) 32 in which spherical gold bumps 31 are arranged along the outline (periphery) is mounted on the printed wiring board 11. On the printed wiring board 11, conductive input / output pads 33 are formed corresponding to the arrangement of the gold bumps 31. According to such an arrangement of the input / output pads 33, the non-pad area 34 surrounded by the input / output pads 33 can be partitioned on the surface of the printed wiring board 11.

  When the printed wiring board 11 is installed on the processing table 12, the support head 13, that is, the underfill material-filled syringe 15 is positioned with respect to the printed wiring board 11, for example, as shown in FIG. In this positioning, the controller 20 supplies a drive command to the positioning mechanism 14. The drive command may include, for example, an x coordinate value and a y coordinate value specified according to a three-dimensional coordinate system set in the processing table 12. Thus, when the underfill material-filled syringe 15 is positioned at the standby position specified by the x-coordinate value and the y-coordinate value, the tip of the nozzle 21 faces the center of the non-pad area 34. The nozzle 21 is maintained in a posture orthogonal to the surface of the printed wiring board 11.

  Subsequently, the underfill material-filled syringe 15 is lowered to the ejection position as shown in FIG. In this downward movement, the controller 20 supplies a drive command to the positioning mechanism 14. In this drive command, the z coordinate value may be specified according to the above-described three-dimensional coordinate system. The nozzle 21 continues to be maintained in a posture orthogonal to the surface of the printed wiring board 11.

  When the underfill material-filled syringe 15 reaches the ejection position, the controller 20 instructs the dispenser 16 to supply air pressure. The dispenser 16 sends air pressure of a predetermined pressure value toward the underfill material-filled syringe 15. In the underfill material-filled syringe 15, the piston 23 moves forward according to the air pressure introduced into the atmospheric pressure chamber 24 (see, for example, FIG. 2). As a result, the ultraviolet curable resin fluid 35 is ejected from the tip of the nozzle 21.

  The ultraviolet curable resin fluid 35 ejected from the nozzle 21 is received by the non-pad area 34 of the printed wiring board 11. At this time, the supply amount of the fluid 35 is determined in advance according to the size of the non-pad area 34. That is, the spread of the fluid 35 is stopped in the non-pad area 34 surrounded by the input / output pad 33. As a result, the ultraviolet curable resin fluid 35 is prevented from covering the input / output pad 33. The supply amount of the fluid 35 may be adjusted by, for example, the magnitude of the pressure value and the supply time of the air pressure.

  When the supply of air pressure is completed, the controller 20 instructs the ultraviolet irradiation device 17 to irradiate ultraviolet rays. As shown in FIG. 5C, the ultraviolet irradiation device 17 irradiates ultraviolet rays from the light source 18 toward the underfill material-filled syringe 15. In the underfill material-filled syringe 15, ultraviolet rays shine into the nozzle 21 from the transmission window 26.

  When the irradiation with ultraviolet rays is completed, the underfill material-filled syringe 15 rises again to the standby position as shown in FIG. The controller 20 supplies a drive command to the positioning mechanism 14 during this rise. In this drive command, the z-coordinate value may be specified according to the three-dimensional coordinate system as described above. When the underfill material-filled syringe 15 rises, the tip of the nozzle 21 is pulled away from the jetted ultraviolet curable resin fluid 35. Thus, prior to mounting of the semiconductor device 32, the supply of the fluid 35 is realized from the nozzle 21 toward the surface of the printed wiring board 11.

  When the supply of the fluid 35 is completed, the semiconductor device 32 is mounted on the surface of the printed wiring board 11 as shown in FIG. The gold bump 31 of the semiconductor device 32 is received by the input / output pad 33 on the printed wiring board 11 first. Subsequently, a pressing force is applied to the semiconductor device 32 in a direction orthogonal to the surface of the printed wiring board 11. The semiconductor device 32 is pressed against the surface of the printed wiring board 11. The gold bump 31 is crushed. As the gold bumps 31 are crushed, the distance between the semiconductor device 32 and the printed wiring board 11 is reduced. When the interval is narrowed in this manner, the sandwiched ultraviolet curable resin fluid 36 is pushed out toward the outer periphery of the semiconductor device 32 between the semiconductor device 32 and the surface of the printed wiring board 11. As a result, as shown in FIG. 6B, the ultraviolet curable resin fluid 36 spreads around the gold bump 31 received by the input / output pad 33. On the input / output pad 33, the gold bump 31 is completely buried in the fluid 36 of the ultraviolet curable resin.

  Thereafter, prior to releasing the pressing force, ultraviolet rays are irradiated toward the ultraviolet curable resin on the printed circuit board 11. When the ultraviolet curable resin is completely cured, the semiconductor device 32 is firmly fixed to the surface of the printed wiring board 11. Electrical connection is reliably established between the semiconductor device 32 and the printed wiring board 11 by the action of the gold bumps 31 and the input / output pads 33. Thus, the mounting of the semiconductor device 32 is completed.

  When the ultraviolet rays are irradiated as described above, the solidification reaction of the fluid is caused in the nozzle 21 in the ultraviolet irradiation region 37 as shown in FIG. 7A, for example. By this solidification reaction, the viscosity of the fluid is increased in the irradiation region 37. Due to such a partial increase in viscosity, a partition region 38 is formed in the fluid in the nozzle 21. According to this partition region 38, the fluid in the nozzle 21 is connected to the tip fluid region 39 that is continuous with the fluid 35 that is ejected toward the surface of the printed wiring board 11, and the fluid that is stored in the container 25. Divided into a residual flow zone 40.

  Thereafter, when the underfill material-filled syringe 15 rises, as shown in FIG. 7B, the fluid front end flow region 39 maintains continuity with the ejected fluid 36. Therefore, the tip flow area 39 is pulled out from the nozzle 21. On the other hand, the partition area 38 reliably remains in the nozzle 21. As a result, the fluid in the nozzle 21 is surely interrupted at the boundary between the tip flow region 39 and the partition region 38. Thus, if the fluid is always interrupted at the same position, the fluid can be ejected from the nozzle 21 with an accurate supply amount. On the other hand, when the partition area 38 is not formed according to the increase in viscosity, it has been confirmed that a slight variation occurs in the supply amount of the fluid. According to such variation, the supply amount of the fluid is too large and the fluid of the underfill material overflows from the periphery of the semiconductor device 32, or the supply amount of the fluid is too small so that the gold bumps 31 and the wiring pattern are formed. It may not be completely covered.

In order to realize a reliable breakage of the tip flow region 39 with respect to the partition region 38, the viscosity of the partition region 38 is about 1.5 times the viscosity of the tip flow region 39, that is, the viscosity before irradiation with ultraviolet rays (= about 3000 cps to 6000 cps) What is necessary is just to set above. However, if the viscosity is too high, the fluidity of the fluid is completely lost, which hinders the subsequent supply of the fluid. Therefore, in setting the viscosity, such fluidity must be taken into consideration.
The viscosity of the partition area 38 may be controlled based on the ultraviolet irradiation time.

  In the underfill method as described above, the ultraviolet irradiation amount may be determined by blinking of the light source 18. For example, the ultraviolet irradiation amount is determined using a shutter (not shown) that opens and closes the transmission window 26. May be.

  FIG. 8 schematically shows a mounting device 42 for fixing the semiconductor device 32 to the printed wiring board 11 on which the fluid 35 of the ultraviolet curable resin is stacked. The mounting apparatus 42 includes a processing table 43 that receives the printed wiring board 11 in a horizontal plane, for example, and an ultrasonic head 44 that faces the processing table 43. The ultrasonic head 44 can be positioned with respect to the processing table 43 by using the positioning mechanism 45 as described above.

  An ultrasonic vibration device 46 and a decompression device 47 are connected to the ultrasonic head 44. The ultrasonic vibration generated by the ultrasonic vibration device 46 is transmitted from the vibrator 48 to the ultrasonic head 44. As a result, the ultrasonic head 44 can roll at high speed in the horizontal direction with a fine amplitude of, for example, 2 μm. The decompression device 46 sucks, for example, air from a decompression path 49 formed in the ultrasonic head 44.

  A film supply device 51 is disposed between the ultrasonic head 44 and the processing table 43. The film supply device 51 includes a drive roll 54 that winds up a thin film tape 53 wound around a slave roll 52. When the drive roll 54 rotates, the thin film tape 53 can cross the space formed between the ultrasonic head 44 and the processing table 43. The thin film tape 53 may be made of, for example, Teflon resin or polyimide resin. The functions of the positioning mechanism 45, the ultrasonic vibration device 46, the decompression device 47, and the film supply device 51 are controlled by a controller 55, for example.

  Here, a semiconductor device mounting method realized by the mounting apparatus 42 as described above will be described in detail. Now, for example, as shown in FIG. 8, a scene is assumed in which a semiconductor device 32 is mounted on a printed wiring board 11 on which a fluid 35 of an ultraviolet curable resin is stacked. First, the ultrasonic head 44 is positioned with respect to the semiconductor device 32. Thereafter, for example, as shown in FIG. 9, the ultrasonic head 44 is lowered. The tip of the ultrasonic head 44 contacts the semiconductor device 32. When the ultrasonic head 44 is positioned or lowered, the controller 55 supplies a drive command to the positioning mechanism 45.

  Subsequently, the controller 55 instructs the decompression device 47 to suck air. When air is sucked from the decompression path 49, the pressure in the decompression path 49 decreases. As a result, the semiconductor device 32 is attracted to the tip of the ultrasonic head 44. In establishing such adsorption, the thin film tape 53 is previously formed with a through hole (not shown) for bringing the semiconductor device 32 and the tip of the decompression path 49 into contact with each other.

  When the semiconductor device 32 is fixed to the ultrasonic head 44 in this way, the controller 55 instructs the ultrasonic vibration device 46 to generate ultrasonic vibration. The generated ultrasonic vibration is transmitted from the vibrator 48 to the ultrasonic head 44. The ultrasonic head 44 rolls at high speed with a fine amplitude. The roll of the ultrasonic head 44 is reliably transmitted to the semiconductor device 32. Such rolling of the semiconductor device 32 causes friction between the input / output pads 33 on the printed wiring board 11 and the gold bumps 31 on the semiconductor device 32 side. Bonding is established between the gold bump 31 and the input / output pad 33 by the action of frictional heat. The semiconductor device 32 is fixed on the printed wiring board 11.

When the joining is established, the operation of the ultrasonic vibration device 46 stops. Subsequently, when the operation of the decompression device 47 is stopped, the pressure in the decompression path 49 increases. Semiconductor device 3 for ultrasonic head 44
The adsorption of 2 is released. With the help of the positioning mechanism 45, the ultrasonic head 44 rises again. The operations of the ultrasonic vibration device 46, the decompression device 47, and the positioning mechanism 45 are performed based on a command output from the controller 55.

  Thereafter, the ultraviolet curable resin fluid 35 is irradiated with ultraviolet rays. When the ultraviolet curable resin is completely cured, the mounting of the semiconductor device 32 is completed. The curing of the ultraviolet curable resin may be performed every time each semiconductor device 32 is mounted on the surface of the printed wiring board 11 or after a plurality of semiconductor devices 32 are mounted on the surface of the printed wiring board 11. May be. However, if the ultraviolet curable resin is cured after all the semiconductor devices 32 are mounted, it can greatly contribute to shortening and simplifying the work process.

  In the mounting method as described above, the thin film tape 53 is sandwiched between the semiconductor device 32 and the ultrasonic head 44 when the ultrasonic head 44 contacts the semiconductor device 32. Therefore, for example, as apparent from FIG. 9, the ultraviolet curable resin fluid 35 overflowing from the periphery of the semiconductor device 32 adheres to the thin film tape 53. The adhesion of the ultraviolet curable resin to the ultrasonic head 44 can be reliably prevented. The ultrasonic head 44 can always keep in contact with the semiconductor device 32 with a large contact area. Therefore, transmission and adsorption of ultrasonic vibrations to the semiconductor device 32 can be reliably maintained. If the fluid of the ultraviolet curable resin adheres to the tip of the ultrasonic head 44, the semiconductor device 32 is not attracted to the ultrasonic head 44, and the vibration of the ultrasonic head 44 is not transmitted to the semiconductor device 32. Sometimes.

  The thin film tape 53 to which the fluid of the ultraviolet curable resin is attached is wound up by the drive roll 54. If the drive roll 54 is wound up every time the ultrasonic head 44 comes into contact with the semiconductor device 32, a new thin film film tape unwound from the slave roll 52 is interposed between the semiconductor device 32 and the ultrasonic head 44. 53 can always be arranged. The ultraviolet curable resin adhering to the thin film tape 53 can be reliably collected by the drive roll 54.

  In order to prevent the ultraviolet curable resin from adhering to the ultrasonic head 44, a flange 58 may be formed on the outer periphery of the semiconductor device 57 as shown in FIG. The step surface 59 defined by the flange 58 faces the surface of the printed wiring board 11. According to such a semiconductor device 57, as apparent from FIG. 10, the overflowing ultraviolet curable resin fluid 35 is received by the stepped surface 59 of the flange 58. It is possible to avoid the fluid 35 from reaching the ultrasonic head 44 around the flange 58 as much as possible. As a result, as described above, the adhesion of the ultraviolet curable resin to the ultrasonic head 44 can be reliably prevented.

  Here, a method for forming the semiconductor device 57 as described above will be briefly described. First, as shown in FIG. 11A, when the individual semiconductor device 57 is cut out from the wafer 61, a notch 62 having a first groove width W <b> 1 is formed on the surface of the wafer 61. For example, a cut saw 63 having a first thickness corresponding to the first groove width W1 may be used to form the notches 62. Subsequently, as illustrated in FIG. 11B, the individual semiconductor devices 57 are separated along the formed notches 62. In this separation, the notch 62 is provided with a notch 64 having a second groove width W2 smaller than the first groove width W1. For the notch 64, for example, a cut saw 65 having a second thickness corresponding to the second groove width W2 may be used. If the notches 64 are made along the center line of the notches 62, the step surfaces 59 can be formed in the pair of semiconductor devices 57 arranged with the notches 62 interposed therebetween.

In the mounting method of the semiconductor devices 32 and 57 using the ultrasonic head 44 as described above, not only the ultraviolet curable resin as described above can be used for the underfill material, but also the thermosetting resin and other reactive properties. A cured resin may be used for the underfill material.

  FIG. 12 schematically shows the overall configuration of an underfill device for a semiconductor device according to a second embodiment of the present invention. The underfill device 71 includes, for example, a processing table 73 that receives the printed wiring board 72 in a horizontal plane, and a support head 74 that faces the processing table 73 and moves on a three-dimensional coordinate system set in the processing table 73. A light source 76 of an ultraviolet irradiation device 75 is embedded in the processing table 73. The light source 76 of the ultraviolet irradiation device 75 irradiates ultraviolet rays upward.

  The three-dimensional coordinate system may be defined by, for example, an x coordinate axis and ay coordinate axis that are defined along the horizontal plane of the processing table 73 and a z coordinate axis that is orthogonal to the horizontal plane of the processing table 73. The movement of the support head 74 based on such a three-dimensional coordinate system is achieved with the help of the positioning mechanism 77, for example. The positioning mechanism 77 can be realized by, for example, a combination of guide mechanisms that guide the support head 74 along the x coordinate axis, the y coordinate axis, and the z coordinate axis.

  An underfill material-filled syringe 78 filled with a fluid of an underfill material such as an ultraviolet curable resin is detachably attached to the support head 74. The underfill material-filled syringe 78 is supplied with pressure, that is, air pressure, from a dispenser 79 connected to the support head 74, for example. When air pressure is supplied to the underfill material-filled syringe 78, the ultraviolet curable resin fluid filled in the syringe 78 is discharged from the syringe 78 toward the processing table 73 as described above. The ultraviolet curable resin may include those that cause a solidification reaction by the action of ultraviolet rays, and those that cause a solidification reaction by the action of heat as well as ultraviolet rays. The functions of the positioning mechanism 77, the dispenser 79, and the ultraviolet irradiation device 75 are controlled by a controller 80, for example.

  Here, the underfill method realized by the semiconductor device underfill device 71 as described above will be described in detail. In carrying out this underfill method, the semiconductor device 82 is fixed to the printed wiring board 72 in advance. For fixing the semiconductor device 82, for example, as shown in FIG. 13, solder bumps soldered to the input / output pads 83 on the printed wiring board 72, or ultrasonic vibrations to the input / output pads 83 as described above. Conductive connection bumps 84 such as gold bumps to be joined may be used. These connection bumps 84 may be disposed along the outline (periphery) of the semiconductor device 82, for example, as described above.

  An underfill material injection hole 85 formed in the printed wiring board 72 is connected to a space defined between the semiconductor device 82 and the printed wiring board 72 while being surrounded by the connection bumps 84. When the printed wiring board 72 is installed on the processing table 73, the semiconductor device 82 is disposed between the underfill material insertion hole 85 and the light source 76 of the ultraviolet irradiation device 75, as is apparent from FIG. That is, the semiconductor device 82 covers the underfill material injection hole 85 with the downward surface of the printed wiring board 72.

  Subsequently, the support head 74, that is, the underfill material-filled syringe 78 is lowered while being positioned with respect to the printed wiring board 72. As described above, the controller 80 supplies a drive command to the positioning mechanism 77 during positioning and lowering. When the underfill material-filled syringe 78 reaches the ejection position in this manner, the tip of the underfill material-filled syringe 78, that is, the nozzle 86 enters the underfill material charging hole 85.

When the underfill material filled syringe 78 reaches the ejection position, the controller 80 instructs the dispenser 79 to supply air pressure. The dispenser 79 sends air pressure of a predetermined pressure value toward the underfill material-filled syringe 78. As a result, as described above, the fluid 88 of the ultraviolet curable resin is ejected from the tip of the nozzle 86. The fluid 88 of the ultraviolet curable resin is supplied to the underfill material injection hole 85 from the upward surface side of the printed wiring board 72. The supplied UV curable resin fluid 88 is received by the semiconductor device 82. A space defined between the semiconductor device 82 and the surface of the printed wiring board 72 is filled with a fluid 88 of an ultraviolet curable resin.

  While the ultraviolet curable resin fluid 88 is poured from the nozzle 86, the controller 80 instructs the ultraviolet irradiation device 75 to irradiate ultraviolet rays. The downward surface of the printed wiring board 72 is irradiated with ultraviolet rays from the light source 76. As a result, the overflowing ultraviolet curable resin fluid cures around the semiconductor device 82. The flow of the fluid 88 is blocked by the cured ultraviolet curable resin. Therefore, the spread of the fluid is limited. It can be avoided that the fluid of the ultraviolet curable resin spreads more than necessary.

  When the supply of air pressure is completed, the underfill material-filled syringe 78 rises again. As described above, the controller 80 supplies a drive command to the positioning mechanism 77 during this ascent. Thereafter, when the irradiation of ultraviolet rays is continued, the fluid 88 of the ultraviolet curable resin is completely cured. The mounting of the semiconductor device 82 is completed.

  In carrying out the underfill method as described above, the underfill material charging hole 85 formed in the printed wiring board 72 is, for example, as shown in FIG. It may be configured with a material insertion hole 92. That is, in this printed wiring board 72, a plurality of input / output pads 95 are arranged in the underfill material application planned area 94 on the surface of the substrate body 93. In the planned application area 94, an overcrowded area 96 and a depopulated area 97 of the input / output pad 95 can be partitioned based on an arbitrary standard. The overfilled underfill material charging hole 91 is disposed in the overcrowded area 96, while the depopulated side underfill material charging hole 92 is disposed in the depopulated area 97. As is apparent from FIG. 14, the sparse side underfill material charging hole 92 is formed larger than the overcrowded side underfill material charging hole 91. In addition, the sparse side underfill material charging hole 92 is formed integrally with the overlying side underfill material charging hole 91. The expected application area 94 may be defined based on the outline shape of the semiconductor device mounted on the printed wiring board 72.

  In such a situation where the semiconductor device is mounted on the printed wiring board 72, the conductive connection bumps of the semiconductor device are received by the input / output pads 95 on the printed wiring board 72. In other words, the density of the connection bumps can inevitably be determined according to the density of the input / output pads 95. When the input / output pads 95, that is, the connection bumps are densely arranged as in the overcrowded region 96, even if the distance between the surface of the printed wiring board 72 and the semiconductor device is narrow, the underfill material is transmitted along the connection bumps. The fluid is easy to spread. On the other hand, even if the connection bumps are sparsely arranged as in the depopulated area 97, if the depopulated side underfill material injection hole 92 enlarged according to the arrangement of the connection bumps is formed, the connection bumps are assisted. Without borrowing, the fluid of the underfill material can easily spread between the semiconductor device and the surface of the printed wiring board 72. If such an underfill material injection hole 85 is not used, the spread of the fluid is significantly inhibited as the distance between the semiconductor device and the surface of the printed wiring board 72 is reduced.

Regardless of which underfill method is employed, it is desirable that plasma irradiation be applied to the planned underfill material application area 102 defined on the surface of the printed wiring board 101, for example, as shown in FIG. By such plasma irradiation, dirt attached to the surface of the printed wiring board 101 can be removed, and the wettability of the surface of the printed wiring board 101 can be improved. If the wettability is improved in this way, the fluid 10 of the underfill material
3 can easily spread along the surface of the printed wiring board 101. If a large surface force is secured around the planned application area 102 as compared with the surface tension of the fluid 103, the fluid 103 can be reliably prevented from spreading beyond the application area 102. Become. The expected application area 102 may be defined based on the outline shape of the semiconductor device 104 mounted on the printed wiring board 101.

1 is a diagram schematically showing an overall configuration of an underfill device for a semiconductor device according to a first embodiment of the present invention. It is an expanded sectional view of an underfill material filling syringe. It is a partially expanded sectional view which shows roughly the attachment with which the front-end | tip of an underfill material filling syringe is mounted | worn. It is a figure which shows roughly the structure of a printed wiring board and a semiconductor device. It is process drawing which shows roughly the underfill method implement | achieved with the underfill apparatus for semiconductor devices which concerns on 1st Embodiment. It is process drawing which shows roughly the mounting method of the semiconductor device with respect to a printed wiring board. It is a conceptual diagram which shows roughly the function of an irradiation window. 1 is a diagram schematically showing an overall configuration of a mounting apparatus according to an embodiment of the present invention. It is process drawing which shows schematically the mounting method of the semiconductor device implement | achieved with the mounting apparatus. It is a figure which shows schematically the structure of the semiconductor device which concerns on other embodiment. It is process drawing which shows roughly the isolation | separation method of the semiconductor device which concerns on one Embodiment of this invention. It is a figure which shows schematically the whole structure of the underfill apparatus for semiconductor devices which concerns on 2nd Embodiment of this invention. It is process drawing which shows roughly the underfill method implement | achieved with the underfill apparatus for semiconductor devices which concerns on 2nd Embodiment. It is a top view which shows roughly the structure of the printed wiring board applied to the underfill method implement | achieved with the underfill apparatus for semiconductor devices which concerns on 2nd Embodiment. It is a top view which shows the concept of the printed wiring board to which plasma irradiation was given.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Underfill apparatus for semiconductor devices, 11 Printed wiring board, 12 Processing table, 13 Support head, 14 Positioning mechanism, 15 Underfill material filling syringe, 16
Dispenser, 18 light source, 19 mask member, 21 nozzle, 22 container, 26 transmission window, 27 attachment, 32 semiconductor device, 35 fluid of ultraviolet curable resin (reactive curable resin), 44 ultrasonic head, 53 thin film tape 57 Semiconductor device 58 Flange 59 Step surface 61 Wafer 62 Notch 64 Notch 71
Underfill device for semiconductor device, 72 printed wiring board, 74 support head, 76
Light source, 79 dispenser, 82 semiconductor device, 85 underfill material injection hole, 88
Ultraviolet curable resin (photo curable resin) fluid, 91 overfilled underfill material injection hole, 92
Depleted side underfill material injection hole, 93 substrate body, 94 application planned area, 95 conductive input / output pad, 96 overdense area, 97 depopulated area, 101 printed wiring board, 102 application planned area, W1 first groove width, W2 No. 1 2 groove width.

Claims (14)

  Prior to mounting the semiconductor device on the surface of the printed wiring board, a process of supplying a fluid of a reactive curable resin from the nozzle toward the surface of the printed wiring board, and when a predetermined amount of the fluid is ejected, the nozzle And a step of increasing the viscosity of the fluid inside. A method for underfilling a semiconductor device, comprising:   Prior to mounting the semiconductor device on the surface of the printed wiring board, a step of supplying a fluid of a photo-curing resin from the nozzle toward the surface of the printed wiring board, and when a predetermined amount of the fluid is ejected, And a step of irradiating the fluid with a light beam from the formed transmission window.   A light-impermeable nozzle, a light-impermeable container that is connected to a base end of the nozzle and is filled with a fluid of a photocurable resin, and a transmission window formed in the nozzle. Underfill material filled syringe.   A light-impermeable nozzle, a light-impermeable container that is connected to the base end of the nozzle and filled with a fluid of photo-curing resin, a cylindrical attachment connected to the tip of the nozzle, and an attachment An underfill material-filled syringe comprising a transmissive window formed.   A processing table, a support head that faces the processing table, a positioning mechanism that is connected to the support head and causes the support head to move toward the ejection position, and a dispenser that is connected to the support head and supplies pressure toward the support head And a light source for irradiating a light beam toward an irradiation area defined between the support head at the ejection position and the processing table.   6. The underfill device for a semiconductor device according to claim 5, further comprising a mask member that blocks the light beam directed toward the processing table.   A process of irradiating the downward surface of the printed wiring board with light while holding the semiconductor device covering the underfill material injection hole formed in the printed wiring board, and the printed wiring during the light irradiation And a step of supplying a fluid of a photo-curing resin from the upward surface side of the substrate to the underfill material injection hole.   A support head positioned at the ejection position; a dispenser connected to the support head for supplying pressure toward the support head; and disposed below the support head positioned at the ejection position to emit light upward. An underfill device for a semiconductor device, comprising: a light source for irradiation.   Overflowing in the board body in the overfilled area of the conductive I / O pads arranged in the area where the underfill material is to be applied on the surface of the board body and the conductive I / O pads specified in the area where the underfill material is to be applied The under-filled side is formed in the board body in the depopulated area of the side underfill material injection hole and the conductive I / O pad specified in the area where the underfill material is to be applied, and is formed larger than the overfilled side underfill material injection hole A printed wiring board comprising an underfill material charging hole.   A pretreatment method for underfill, characterized in that plasma irradiation is performed on an underfill material application area defined on a surface of a printed wiring board.   A step of supplying a fluid of a reactive curable resin to the surface of the printed wiring board; a step of mounting a semiconductor device on the surface of the printed wiring board to which the fluid of the reactive curable resin is supplied; and A method for mounting a semiconductor device, comprising: a step of contacting an ultrasonic head; and a step of curing a fluid of a reactive curable resin.   12. The method of mounting a semiconductor device according to claim 11, wherein a thin film film is disposed between the semiconductor device and the ultrasonic head when the ultrasonic head is brought into contact. .   12. The semiconductor device mounting method according to claim 11, wherein a flange is formed on the outer periphery of the semiconductor device so that a stepped surface faces the surface of the printed wiring board.   When cutting out a semiconductor device from a wafer, the method includes a step of making a notch with a first groove width in the wafer, and a step of cutting the semiconductor device along the notch by a notch with a second groove width smaller than the first groove width. Semiconductor device isolation method.

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