Chip peeling method, chip peeling device, and chip manufacturing method

Abstract

According to the present invention, a plurality of chips obtained by dicing a wafer and an adhesive sheet affixed to the backs of the plurality of chips are contained in a container, a low-pressure atmosphere is created in the interior of the container by performing a vacuum process, the plurality of chips and the adhesive sheet are irradiated with UV rays from the back side inside the container in which the low-pressure atmosphere is maintained, the adhesive sheet is brought into contact with an uneven surface inside the container in which the low-pressure atmosphere is maintained, a gas is introduced into the space on the front side of the plurality of chips and the adhesive sheet while maintaining the low-pressure atmosphere in the space on the back side of the plurality of chips and the adhesive sheet, and the pressure difference between the space on the back side and the space on the front side presses and flexes the adhesive sheet against the uneven surface, thus partially peeling off the adhesive sheet from the plurality of chips.

Description

Chip peeling method, chip peeling device, and chip manufacturing method

[0001] The present invention relates to a chip peeling method, a chip peeling device, and a chip manufacturing method for peeling chips cut from a wafer of semiconductors, electronic components, or the like from an adhesive material.

[0002] In an automated process for dicing wafers of semiconductors, electronic components, etc., into chips and recovering them, it is necessary to stably peel multiple chips on the wafer from the adhesive sheet attached to the backside thereof, and to achieve this, it is particularly important to reduce the adhesiveness (low adhesion) of the adhesive sheet and to use a technique for partially peeling the chip-attached surface.As a method for peeling multiple chips on a wafer from the adhesive sheet attached to the backside thereof, Patent Document 1 discloses a chip peeling method in which ultraviolet light is irradiated onto an ultraviolet-absorbing sheet attached to a wafer holding frame, and the chips are sucked and peeled off from the ultraviolet-absorbing sheet. In this chip peeling method, an irradiation mask that exposes the portions corresponding to each chip on the ultraviolet absorbing sheet is covered from the back side of the ultraviolet absorbing sheet, and ultraviolet rays are irradiated from the irradiation mask side, the irradiated ultraviolet absorbing sheet is placed on a base having a plurality of uneven portions with peaks and valleys on the upper surface and to which negative pressure is applied, so that each chip is located at the top of the uneven portions, a pressing mask that presses against the street portions of the wafer on the ultraviolet absorbing sheet is covered from the front side of the ultraviolet absorbing sheet to expose each chip, and each chip is peeled off by suction while negative pressure is applied to each uneven portion of the base.

[0003] Furthermore, Patent Document 2 discloses a semiconductor wafer dicing method in which a semiconductor wafer is placed and fixed under an inert gas or vacuum, diced, and then ultraviolet light is irradiated from the backside of the dicing film to reduce the adhesive strength of the pressure-sensitive adhesive, and the dice are then removed.

[0004] Furthermore, Patent Document 3 discloses a method for using a semiconductor manufacturing apparatus in which an annular frame having a substrate with dicing grooves fixed to a first opening by an adhesive member is placed on a table having a plurality of first through holes penetrating in the vertical direction and a plurality of second through holes each provided between the plurality of first through holes and penetrating in the vertical direction, with the dicing groove being positioned above the second through holes, and a container provided below, the container having a second opening which has a second inner diameter larger than the first inner diameter of the first opening and can be tightly fitted to the annular frame, and a joint which can communicate between the outside and the inside of the container is placed on the annular frame so that the second opening is tightly fitted to the annular frame, and the plurality of first through holes are depressurized, the plurality of second through holes are depressurized, and the inside of the container is pressurized using the joint, thereby making it easier for the chips to peel off from the adhesive member (sheet).

[0005] Furthermore, Patent Document 4 discloses a method for manufacturing an adhesive-coated chip, in which a wafer and a die-bond adhesive layer are completely cut using a cutting device to form a chip, and then the fixing jig with the chip fixed thereto is transferred from the cutting device to a pick-up device, and the adhesive layer of the fixing jig is deformed on the pick-up device to pick up the chip together with the die-bond adhesive layer from the fixing jig. The fixing jig comprises an adhesive layer and a jig base having a plurality of protrusions on one side and a sidewall on the periphery of one side that is approximately the same height as the protrusions. The adhesive layer is laminated on the surface of the jig base having the protrusions. A compartment space is formed on the surface of the jig base having the protrusions by the adhesive layer, the protrusions, and the sidewall. The jig base has at least one through-hole that penetrates the compartment space with the outside. The adhesive layer is deformed by suctioning air from the compartment space through the through-hole.

[0006] Japanese Patent No. 4439773 Japanese Patent No. 2510416 Japanese Patent Laid-Open No. 2023-045873 Japanese Patent No. 5196838

[0007] The techniques disclosed in Patent Documents 1 to 4 are each effective in stabilizing chip peeling from adhesive sheets, and it is expected that combining these techniques will improve the stability of chip peeling. However, simply combining these techniques results in an increase in the size of the device, which necessitates a need to make the device more compact. Furthermore, the technical challenge is how to improve the stability of chip peeling while ensuring productivity.

[0008] However, from the viewpoint of the latter problem, Patent Document 1 describes that ultraviolet light is irradiated through an irradiation mask that exposes the portions on the ultraviolet absorbing sheet corresponding to each chip, but does not disclose anything about the atmosphere under which the ultraviolet absorbing sheet should be treated during and after ultraviolet light irradiation.

[0009] Furthermore, although Patent Document 2 describes the method of irradiating ultraviolet light onto a semiconductor wafer under an inert gas or vacuum to reduce the adhesive strength of a pressure-sensitive adhesive, it does not describe how to peel the chip from the adhesive sheet, much less discloses the atmosphere under which the chip should be treated after ultraviolet light irradiation.

[0010] Furthermore, Patent Document 3 describes that pressure is applied to the front side of the substrate and reduced pressure is applied to the back side via the through holes, thereby partially bending the adhesive member and promoting peeling, but it does not describe how ultraviolet irradiation is performed, and still less does it disclose what kind of atmosphere the substrate should be treated under during ultraviolet irradiation and the subsequent peeling.

[0011] Furthermore, Patent Document 4 describes that a jig base having a plurality of protrusions on one side is provided, at least one through-hole is formed in the jig base, and suction is applied through this through-hole to deform the adhesive layer, but it does not describe at all how to perform ultraviolet irradiation, and still less discloses what kind of atmosphere the substrate should be treated under during ultraviolet irradiation and the subsequent peeling.

[0012] Even when Patent Documents 1 to 4 are combined, there is still room for improvement in terms of increasing production efficiency while ensuring stable chip peeling, such as in what atmosphere the adhesive sheet should be placed in during and after ultraviolet irradiation to effectively carry out ultraviolet irradiation and chip peeling.

[0013] Therefore, an object of the present invention is to provide a chip peeling method that can effectively perform both ultraviolet irradiation and chip peeling, a compact chip peeling device that can effectively and efficiently perform both ultraviolet irradiation and chip peeling, and a chip manufacturing method.

[0014] Another object of the present invention is to provide a chip peeling method, a chip peeling device, and a chip manufacturing method that can perform sufficient ultraviolet irradiation and efficiently peel chips from an adhesive sheet.

[0015] According to the present invention, a chip peeling method is provided in which a plurality of chips obtained by dicing a wafer and an adhesive sheet attached to the back surfaces of the plurality of chips are placed in a container, the container is subjected to a suction process to create a low-pressure atmosphere inside, ultraviolet light is irradiated from the back surfaces of the plurality of chips and the adhesive sheet within the container maintained in a low-pressure atmosphere, the adhesive sheet is abutted against an uneven surface within the container maintained in a low-pressure atmosphere, gas is introduced into the front surface space of the plurality of chips and the adhesive sheet while maintaining a low-pressure atmosphere in the back surface space of the plurality of chips and the adhesive sheet, and the pressure difference between the back surface space and the front surface space causes the adhesive sheet to be pressed against the uneven surface and deflect, thereby partially peeling the adhesive sheet from the plurality of chips.

[0016] The interior of a container containing multiple chips and an adhesive sheet is evacuated to create a low-pressure atmosphere, and ultraviolet light is irradiated from the backside of the multiple chips and adhesive sheet. Because the container is in a low-pressure atmosphere during UV irradiation, the UV light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits UV curing (reduced adhesive strength), thereby efficiently reducing the adhesive strength of the adhesive sheet. Furthermore, the adhesive sheet is abutted against an uneven surface within a container continuously maintained in a low-pressure atmosphere. While the backside space of the multiple chips and adhesive sheet is maintained in a low-pressure atmosphere, gas is introduced into the frontside space. The pressure difference between the low-pressure atmosphere of the backside space and the gas pressure in the frontside space presses the adhesive sheet against the uneven surface, causing it to bend. This effectively peels the periphery of the chip and the peripheral portion of the chip center (hereinafter referred to as the periphery) from the adhesive sheet, resulting in a partially peeled state. In this way, the atmosphere around the adhesive sheet is maintained in a low-pressure atmosphere from UV irradiation to peeling, effectively maintaining the adhesive strength of the adhesive sheet in a reduced state. If these treatments are carried out in the same container, both the ultraviolet irradiation treatment and the chip peeling treatment can be carried out efficiently. In the present invention, the low-pressure atmosphere refers to an atmosphere below atmospheric pressure that has an oxygen concentration that does not inhibit the curing of the adhesive sheet by ultraviolet irradiation, and specifically, is preferably 100 Pa or less.

[0017] It is preferable to raise the plurality of chips and adhesive sheet in a container maintained in a low-pressure atmosphere and irradiate them with ultraviolet light from the backside, and then lower the plurality of chips and adhesive sheet in a container continuously maintained in a low-pressure atmosphere so that the adhesive sheet abuts against the uneven surface. Since ultraviolet light is irradiated from the backside of the raised adhesive sheet while the plurality of chips and adhesive sheet are raised, sufficient ultraviolet light is effectively irradiated onto the adhesive sheet. Then, the plurality of chips and adhesive sheet are lowered and the adhesive sheet abuts against the uneven surface, so that a peeling process can be effectively performed in which the peripheral portions of the chips are peeled off from the adhesive sheet to create a partially peeled state.

[0018] During ultraviolet irradiation, it is preferable to create a low-pressure atmosphere in the back-side space through a suction through-hole connected to the back-side space, and during partial peeling, to create a low-pressure atmosphere in the back-side space through the suction through-hole and introduce gas into the front-side space through an introduction through-hole connected to the front-side space.

[0019] It is also preferable to fix an ultraviolet irradiation source outside the wafer area, raise the multiple chips and adhesive sheet when irradiating ultraviolet light, and lower the multiple chips and adhesive sheet when partially peeling, so that the adhesive sheet comes into contact with the uneven surface.

[0020] During ultraviolet irradiation, it is also preferable to raise the multiple chips and adhesive sheet and move the ultraviolet irradiation light source into the wafer area, and during partial peeling, to move the irradiation light source out of the wafer area and lower the multiple chips and adhesive sheet so that the adhesive sheet abuts against the uneven surface.

[0021] During ultraviolet irradiation, it is also preferable to raise the multiple chips and adhesive sheet and guide ultraviolet light from an irradiation light source located outside the wafer area to irradiate the adhesive sheet, and during partial peeling, lower the multiple chips and adhesive sheet to abut the adhesive sheet against the uneven surface.

[0022] It is also preferable that the container is composed of a first container and a second container isolated from the first container via an opening and closing door, and that when irradiating ultraviolet light, the plurality of chips and adhesive sheet are placed in the first container, and ultraviolet light from an irradiation light source provided in the first container is irradiated onto the adhesive sheet, and when partially peeling, the plurality of chips and adhesive sheet are transferred into the second container and the adhesive sheet is abutted against the uneven surface.

[0023] and a pressure-inducing inlet hole that penetrates the container and communicates with the front-side space of the plurality of chips and the adhesive sheet and is used to introduce gas into the front-side space. An irradiation light source is provided within the container for irradiating ultraviolet light onto the adhesive sheet. The suction means is configured to create a low-pressure atmosphere inside the container by suction through the suction through hole when ultraviolet light is irradiated by the irradiation light source, and to maintain the low-pressure atmosphere inside the container by suction through the suction through hole during partial peeling. The present invention also provides a chip peeling device that includes: a sealable container; support means that is disposed within the container and supports a plurality of chips by an adhesive sheet attached to the backside of the plurality of chips; a suction through hole that penetrates the container and communicates with the back-side space of the plurality of chips and the adhesive sheet and is used to create a low-pressure atmosphere in at least the back-side space; an introduction through hole that penetrates the container and communicates with the front-side space of the plurality of chips and the adhesive sheet and is used to introduce gas into the front-side space; an irradiation light source that is disposed within the container and irradiates ultraviolet light onto the adhesive sheet; and a suction means that is configured to create a low-pressure atmosphere inside the container by suction through the suction through hole when ultraviolet light is irradiated by the irradiation light source, and to maintain the low-pressure atmosphere inside the container by suction through the suction through hole during partial peeling. The present invention also provides a chip peeling device that includes: a sealable container;

[0024] The interior of a container containing multiple chips and an adhesive sheet is suctioned through a suction through-hole to create a low-pressure atmosphere, and ultraviolet light is irradiated from the backside of the adhesive sheet by an irradiation light source. Because ultraviolet light is irradiated from the backside of the adhesive sheet, sufficient ultraviolet light is effectively irradiated onto the adhesive sheet. Furthermore, since the container is maintained in a low-pressure atmosphere during irradiation, the ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits UV curing (reduced adhesive strength), thereby efficiently reducing the adhesive strength of the adhesive sheet. Furthermore, the adhesive sheet is abutted against an uneven surface within a container maintained in a continuous low-pressure atmosphere. While maintaining a low-pressure atmosphere in the backside space of the multiple chips and adhesive sheet, gas is introduced into the front-side space. The pressure difference between the low-pressure atmosphere in the backside space and the gas pressure in the front-side space presses the adhesive sheet against the uneven surface, causing it to bend. This effectively peels the peripheral edge of the chip from the adhesive sheet, resulting in a partially peeled state. In this way, the atmosphere around the adhesive sheet is maintained in a low-pressure atmosphere from the time of UV irradiation until peeling, effectively maintaining the adhesive strength of the adhesive sheet in a reduced state. If these processes are carried out in the same container, both the ultraviolet irradiation process and the chip peeling process can be carried out efficiently.

[0025] It is preferable that the support means further include a lifting means for lifting the multiple chips and adhesive sheet during ultraviolet irradiation, and for lowering the multiple chips and adhesive sheet to abut the adhesive sheet against the uneven surface during partial peeling. With the multiple chips and adhesive sheet elevated by the lifting means, ultraviolet light is irradiated from the backside of the multiple chips and adhesive sheet. Because ultraviolet light is irradiated from the backside of the elevated adhesive sheet, sufficient ultraviolet light is effectively irradiated onto the adhesive sheet. Then, the multiple chips and adhesive sheet are lowered, and the adhesive sheet is abutted against the uneven surface, so that a peeling process can be effectively performed in which the peripheral portions of the chips are peeled from the adhesive sheet to create a partially peeled state.

[0026] It is also preferable that the suction through-hole is configured to create a low-pressure atmosphere in the back-side space when ultraviolet rays are irradiated and to create a low-pressure atmosphere in the back-side space when partial peeling is performed, and that the introduction through-hole is configured to introduce gas into the front-side space when partial peeling is performed.

[0027] In this case, it is preferable that the irradiation light source is fixedly positioned outside the wafer area, and that the lifting means raises the multiple chips and adhesive sheet when ultraviolet light is irradiated, and that the lifting means lowers the multiple chips and adhesive sheet when partial peeling is performed.

[0028] In this case, it is also preferable that the device further includes a moving means capable of moving the irradiation light source between the inside and outside of the wafer area, and that during ultraviolet irradiation, the lifting means lifts the multiple chips and adhesive sheet while the moving means moves the irradiation light source into the wafer area, and during partial peeling, the moving means moves the irradiation light source out of the wafer area while the lifting means lowers the multiple chips and adhesive sheet.

[0029] Furthermore, in this case, it is also preferable that the device further includes a light-guiding means for guiding ultraviolet light from an irradiation light source located outside the wafer area to the adhesive sheet, and that the lifting means lifts the multiple chips and adhesive sheet when irradiating ultraviolet light, and that the lifting means lowers the multiple chips and adhesive sheet to abut against the uneven surface when partially peeling.

[0030] It is preferable that the upper surface of the light guide means is provided with an uneven surface that is ultraviolet-transmitting.

[0031] It is also preferable that the light guide means comprises an edge-light light guide plate.

[0032] It is also preferable that the container is composed of a first container and a second container isolated from the first container via an opening and closing door, and that when irradiating ultraviolet light, a plurality of chips and an adhesive sheet are placed in the first container and ultraviolet light from an irradiation light source is irradiated onto the adhesive sheet, and when partially peeling, the adhesive sheet transferred into the second container is abutted against the uneven surface.

[0033] According to the present invention, there is further provided a chip manufacturing method comprising: an element formation step of forming semiconductor elements or electronic component elements on a wafer; a dicing step of dicing the wafer and the adhesive sheet after attaching an adhesive sheet to the back surface of the wafer on which the semiconductor elements or electronic component elements have been fabricated by the element formation step; an ultraviolet irradiation step of accommodating the plurality of chips obtained by the dicing step and the adhesive sheet attached to the back surfaces of the plurality of chips in a sealable container and suctioning the container to create a low-pressure atmosphere inside the container, and irradiating ultraviolet light from the back surfaces of the plurality of chips and the adhesive sheet in the container maintained in a low-pressure atmosphere; a partial peeling step of, after the ultraviolet irradiation step, abutting the adhesive sheet against an uneven surface in the container maintained in a low-pressure atmosphere, and introducing gas into the front surface space of the plurality of chips and the adhesive sheet while maintaining the back surface space of the plurality of chips and the adhesive sheet in a low-pressure atmosphere, thereby pressing the adhesive sheet against the uneven surface and bending it due to the pressure difference between the back surface space and the front surface space, thereby partially peeling the adhesive sheet from the plurality of chips; and a recovery step of recovering the plurality of chips peeled in the partial peeling step.

[0034] In the ultraviolet irradiation process, the interior of a container containing multiple chips and an adhesive sheet is evacuated to create a low-pressure atmosphere, and ultraviolet light is irradiated from the backside of the multiple chips and the adhesive sheet. Because the container is in a low-pressure atmosphere during ultraviolet irradiation, the ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits UV curing (reduced adhesive strength), thereby efficiently reducing the adhesive strength of the adhesive sheet. Furthermore, in the partial peeling process, the adhesive sheet is abutted against an uneven surface within a container continuously maintained in a low-pressure atmosphere. While maintaining a low-pressure atmosphere in the backside space of the multiple chips and the adhesive sheet, gas is introduced into the frontside space. The pressure difference between the low-pressure atmosphere in the backside space and the gas pressure in the frontside space presses the adhesive sheet against the uneven surface, causing it to bend. This effectively peels the periphery of the chip and the peripheral portion near the center of the chip (hereinafter referred to as the periphery) from the adhesive sheet, achieving a partially peeled state. In this way, the atmosphere around the adhesive sheet is maintained in a low-pressure atmosphere from ultraviolet irradiation to peeling, effectively maintaining the adhesive strength of the adhesive sheet in a reduced state. If these processes are carried out in the same container, both the ultraviolet irradiation process and the chip peeling process can be carried out efficiently.

[0035] It is preferable that the ultraviolet irradiation step includes a step of raising the plurality of chips and adhesive sheet in a container maintained in a low-pressure atmosphere and irradiating ultraviolet light from the back side, and that the partial peeling step includes a step of lowering the plurality of chips and adhesive sheet in a container continuously maintained in a low-pressure atmosphere and abutting the adhesive sheet against the uneven surface.

[0036] It is also preferable that the ultraviolet irradiation process includes a process of creating a low-pressure atmosphere in the back-side space through a suction through-hole connected to the back-side space during ultraviolet irradiation, and that the partial peeling process includes a process of creating a low-pressure atmosphere in the back-side space through the suction through-hole during partial peeling, and introducing gas into the front-side space through an introduction through-hole connected to the front-side space.

[0037] It is also preferable that the ultraviolet irradiation process includes a step of fixing an ultraviolet irradiation source outside the wafer area and raising the multiple chips and adhesive sheet during ultraviolet irradiation, and that the partial peeling process includes a step of lowering the multiple chips and adhesive sheet during partial peeling to abut the adhesive sheet against the uneven surface.

[0038] It is also preferable that the ultraviolet irradiation process includes a step of raising the multiple chips and adhesive sheet during ultraviolet irradiation and moving the ultraviolet irradiation light source into the wafer area, and that the partial peeling process includes a step of moving the irradiation light source outside the wafer area during partial peeling and lowering the multiple chips and adhesive sheet to abut the adhesive sheet against the uneven surface.

[0039] It is also preferable that the ultraviolet irradiation process includes a step of raising the multiple chips and adhesive sheet during ultraviolet irradiation and guiding ultraviolet light from an irradiation light source located outside the wafer area to irradiate the adhesive sheet, and that the partial peeling process includes a step of lowering the multiple chips and adhesive sheet during partial peeling to abut the adhesive sheet against the uneven surface.

[0040] It is also preferable that the container is composed of a first container and a second container isolated from the first container via an opening / closing door, that the ultraviolet irradiation process includes a step of placing a plurality of chips and an adhesive sheet in the first container and irradiating the adhesive sheet with ultraviolet light from an irradiation light source provided in the first container, and that the partial peeling process includes a step of transferring the plurality of chips and adhesive sheet into the second container and abutting the adhesive sheet against the uneven surface during partial peeling.

[0041] According to the present invention, the container is kept in a low-pressure atmosphere during UV irradiation, allowing UV irradiation in an atmosphere with a low concentration of oxygen, which inhibits UV curing (reduced adhesive strength), thereby efficiently reducing the adhesive strength of the adhesive sheet. Furthermore, the adhesive sheet is placed in contact with an uneven surface within a container maintained in a continuous low-pressure atmosphere. While maintaining a low-pressure atmosphere in the backside space of the multiple chips and adhesive sheet, gas is introduced into the frontside space. The pressure difference between the low-pressure atmosphere in the backside space and the gas pressure in the frontside space presses the adhesive sheet against the uneven surface, causing it to bend. This effectively peels the peripheral edge of the chip from the adhesive sheet, resulting in a partially peeled state. Thus, the low-pressure atmosphere surrounding the adhesive sheet is maintained from UV irradiation to peeling, effectively maintaining the adhesive strength of the adhesive sheet in a reduced state. Furthermore, by performing these processes within the same container, both the UV irradiation process and the chip peeling process can be efficiently performed.

[0042] FIG. 1 is a cross-sectional view schematically showing the overall configuration of a first embodiment of a chip peeling device according to the present invention. FIG. 2 is a plan view and a partially enlarged view showing the overall configuration of the upper surface of a mounting table according to the first embodiment and a partial configuration thereof. FIG. 3 is a flowchart schematically showing the flow of processing steps according to the first embodiment. FIG. 4 is a cross-sectional view schematically showing the state of the chip peeling device in an ultraviolet irradiation processing step of the first embodiment. FIG. 5 is a cross-sectional view schematically showing the state of the chip peeling device in a partial peeling processing step of the first embodiment. FIG. 6 is a cross-sectional view schematically showing the state of the chip peeling device in a chip recovery processing step of the first embodiment. FIG. 7 is a cross-sectional view schematically showing the overall configuration of a second embodiment of a chip peeling device according to the present invention. FIG. 8 is a plan view and a partially enlarged view showing the overall configuration of the upper surface of a mounting table according to the second embodiment and a partial configuration thereof. FIG. 9 is a side cross-sectional view and a plan cross-sectional view schematically showing the configuration and operation form of a moving mechanism of an ultraviolet light source according to the second embodiment. FIG. 10 is a flowchart schematically showing the flow of processing steps according to the second embodiment. FIG. 11 is a cross-sectional view schematically showing the state of the chip peeling device in an ultraviolet irradiation processing step of the second embodiment. 1 is a cross-sectional view schematically showing the state of a chip peeling device in a chip recovery processing step of a second embodiment. FIG. 1 is a cross-sectional view schematically showing the overall configuration of a third embodiment of a chip peeling device of the present invention. FIG. 2 is a plan view and a partially enlarged view showing the overall configuration of the upper surface of a mounting table (edge-light light guide plate) of the third embodiment and a partial configuration thereof. FIG. 3 is a flowchart schematically showing the flow of processing steps of the third embodiment. FIG. 4 is a cross-sectional view schematically showing the state of a chip peeling device in an ultraviolet irradiation processing step of the third embodiment. FIG. 5 is a cross-sectional view schematically showing the state of a chip peeling device in a partial peeling processing step of the third embodiment. FIG. 6 is a cross-sectional view schematically showing the configuration of a mounting plate or edge-light light guide plate in modified embodiments of the first to third embodiments. FIG. 7 is a plan view and a partially enlarged view showing the overall configuration and a partial configuration thereof, and FIG. 8 is a cross-sectional view taken along line A-A of the upper surface of a mounting plate or edge-light light guide plate in modified embodiments of the first to third embodiments.Fig. 10 is a flowchart schematically showing the flow of processing steps in a fourth embodiment. Fig. 11 is a process explanatory diagram sequentially explaining, in side cross section and plan cross section, the state of the chip peeling device in each processing step of the fourth embodiment. Fig. 12 is a process explanatory diagram sequentially explaining, in side cross section and plan cross section, the state of the chip peeling device in each processing step of the fourth embodiment. Fig. 13 is a process explanatory diagram sequentially explaining, in side cross section and plan cross section, the state of the chip peeling device in each processing step of the fourth embodiment. Fig. 14 is a flowchart schematically showing the flow of processing steps in a chip manufacturing method of the present invention.

[0043] FIG. 1 shows a schematic diagram of the overall configuration of a first embodiment of a chip peeling device according to the present invention.

[0044] In FIG. 1 , 10 denotes a sealable container (chamber) for performing ultraviolet irradiation processing and partial chip peeling processing inside; 11 denotes a suction through-hole provided at the bottom of the container 10 for evacuating the inside of the container 10 or a part thereof to create a low-pressure atmosphere; 12 denotes an inlet through-hole provided at the top of the container 10 for introducing air or a gas such as an inert gas into the inside of the container 10; 13 denotes a plurality of chips obtained by, for example, dicing a semiconductor wafer; 14 denotes an adhesive sheet attached to the backside of the plurality of chips 13; 15 denotes a support ring (corresponding to the support means of the present invention) having an opening with a diameter larger than that of the wafer substrate and supporting the wafer substrate or the plurality of chips 13 and the adhesive sheet 14 attached to their backsides; 16 denotes an elevating mechanism (corresponding to the elevating means of the present invention) for raising and lowering the support ring 15 in the vertical direction; 17 denotes an ultraviolet light source (corresponding to the irradiation light source of the present invention) for irradiating ultraviolet light onto the adhesive sheet 14; and 18 denotes a mounting table for the support ring 15.

[0045] The upper surface of the mounting base 18 provided below the support ring 15 is provided with an uneven surface 18a, and when the support ring 15 is lowered, the lower surface of the adhesive sheet 14 abuts against the uneven surface 18a of the mounting base 18 and is supported by the convex portion.

[0046] FIG. 2 shows an enlarged view of the entire structure of the top surface of the mounting table 18 and a portion of the structure.

[0047] As shown in FIG. 2 , the uneven surface 18a formed on the top surface of the mounting table 18 is provided with a plurality of convex portions 18b and a plurality of concave portions 18c, and each of the concave portions 18c is provided with a plurality of through holes 18d that penetrate the mounting table 18 in the vertical direction. These through holes 18d are connected to the suction through holes 11. Note that the positions of the through holes 18d are not limited to the positions shown in the figure, as long as they are within the concave portions 18c. Furthermore, the shape of the convex portions 18b shown in the figure is merely an example, and various planar shapes, such as square, rectangular, or circular, may be used depending on the chip shape. Furthermore, the peripheral side surfaces of the convex portions 18b may be formed in a tapered shape.

[0048] As shown in Fig. 1, the suction through hole 11 is connected to a vacuum pump (not shown) via an exhaust valve (not shown), whereby, as necessary, the entire interior of the container 10 or a back-side space 19a (see Figs. 5 and 6) of the adhesive sheet 14 inside the container 10 is evacuated to a low-pressure atmosphere. The introduction through hole 12 is openable to the atmosphere via a valve (not shown), or is connected to a compressor or compressed gas cylinder (not shown) via a valve (not shown), whereby, as necessary, the entire interior of the container 10 or a front-side space 19b (see Figs. 5 and 6) of the adhesive sheet 14 inside the container 10 can be adjusted to a higher pressure atmosphere than the back-side space 19a when the back-side space 19a is in a low-pressure atmosphere state, such as an atmospheric pressure atmosphere or a pressurized atmosphere exceeding atmospheric pressure.

[0049] The ultraviolet light source 17 is composed of one or more lamps or LEDs capable of emitting ultraviolet light of a wavelength capable of reducing the adhesive strength of the adhesive sheet 14. Specifically, it is composed of a linear (straight tube) low-pressure discharge UV lamp or UV-LED, and in this embodiment, it is composed of four low-pressure discharge UV lamps or UV-LEDs fixedly arranged in an area outside the wafer area, which is the area of ​​the support ring 15. Although not shown, a reflector can be provided on the back of the ultraviolet light source 17 to appropriately set the light distribution of the ultraviolet light.

[0050] In this embodiment, the container 10 is configured so that it can be opened by dividing it into upper and lower halves at the position of the O-ring 10a, and can be closed in a sealed state by the O-ring 10a.

[0051] FIG. 3 shows a schematic flow of each processing step in this embodiment, and FIGS. 4 to 6 show a schematic state of the chip peeling device in each processing step.

[0052] A wafer substrate on which semiconductors or electronic components are formed is mounted on a support ring 15 having an opening with a diameter larger than that of the substrate by adhering an adhesive sheet 14 to the backside of the wafer substrate. The wafer substrate is then diced into multiple chips and cleaned. Thereafter, as shown in FIG. 1 , the support ring 15 is set in a predetermined position on an elevating mechanism 16 equipped with a support ring holder installed inside a container 10 (step S1). In the following description of this embodiment, the term "support ring 15" refers to a structure in which the adhesive sheet 14 and multiple diced chips are mounted.

[0053] Next, a vacuum pump (not shown) is operated to evacuate the entire interior of the container 10 to a low-pressure atmosphere through the suction through-hole 11 as shown by arrow A1 (FIG. 4) (step S2). At this time, the release valve of the introduction through-hole 12 is kept closed.

[0054] Next, the lifting mechanism 16 is operated to raise the support ring 15 upward (step S3), and ultraviolet irradiation of the adhesive sheet 14 from the ultraviolet light source 17, which is located in a fixed position, begins (step S4). This effectively irradiates the adhesive sheet 14 with ultraviolet light, reducing the adhesive strength of the adhesive sheet 14 around the chip and / or the bottom of the adhesive sheet 14. By providing a reflector on the back of the ultraviolet light source 17, the light distribution can be adjusted, allowing the ultraviolet light to be more effectively irradiated onto the adhesive sheet 14. Furthermore, during irradiation, the space around the adhesive sheet 14 remains in a low-pressure atmosphere, so that the ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits ultraviolet curing (reduced adhesive strength), thereby efficiently reducing the adhesive strength of the adhesive sheet 14. The exhaust process of step S2 continues during the lifting process of the lifting mechanism 16 in step S3 and the ultraviolet irradiation process in step S4. This prevents the presence of oxygen from inhibiting the reduction in adhesive strength due to ultraviolet curing of the adhesive sheet 14, and also simplifies control of the exhaust valve and vacuum pump associated with the suction through-hole 11. In addition, in step S1 above, if the support ring 15 is set in a predetermined position inside the container 10 at a position suitable for irradiating the adhesive sheet 14 with ultraviolet rays in step S4, the lifting process in step S3 above may be omitted.

[0055] Figure 4 shows a schematic diagram of the state of the chip peeling device during this ultraviolet irradiation process. As shown in Figure 4, because the support ring 15 is raised, even if the ultraviolet light source 17 is installed in a fixed position outside the wafer area, a sufficient amount of ultraviolet light can be irradiated onto the back surface of the adhesive sheet 14. If a reflector is installed behind the ultraviolet light source 17, a more sufficient amount of ultraviolet light can be irradiated onto the back surface of the adhesive sheet 14.

[0056] Thereafter, ultraviolet irradiation is terminated (step S5), and the lifting mechanism 16 is operated to lower the support ring 15, bringing the adhesive sheet 14 into contact with the uneven surface 18a of the mounting table 18 and supporting it with its convex portions (step S6). As a result, the adhesive sheet 14, support ring 15, lifting mechanism 16, and the inner wall of the container 10 form a back-side space 19a and a front-side space 19b for the plurality of chips 13 and adhesive sheet 14. The back-side space 19a is a sealed space except for the suction through-holes 11, and the front-side space 19b is a sealed space except for the introduction through-holes 12.

[0057] 5 schematically illustrates the state of the chip peeling apparatus in the next partial peeling process. As indicated by arrow A2 in FIG. 5 , the process of evacuating the backside space 19a through the suction through-holes 11 to create a low-pressure atmosphere continues (step S7). At the same time, the valve (not shown) of the inlet through-holes 12 is opened, and the frontside space 19b is filled with a gas, such as atmospheric air, through the inlet through-holes 12, as indicated by arrow A3 in FIG. 5 . The pressure difference between the backside space 19a and the frontside space 19b, which is generated by creating a state in which the internal pressure of the frontside space 19b is higher than that of the backside space 19a, causes the adhesive sheet 14 to be pressed against the uneven surface 18a of the mounting table 18 and deflect. As a result, the peripheral edges of the multiple chips 13 are efficiently peeled off from the adhesive sheet 14, resulting in a partial peeling state. The pressure in the surface-side space 19b at this time may be any value that generates a pressure difference that allows the adhesive sheet 14 to be pressed against the uneven surface 18a of the mounting table 18 and bend. However, by pressurizing the surface-side space 19b with air or inert gas from a compressor or compressed gas cylinder, the pressure difference increases, allowing the adhesive sheet 14 to bend more effectively. The rate (speed) of change in pressure in the surface-side space 19b is adjusted within a range that prevents damage to the chip 13 due to stress during peeling when the adhesive sheet 14 is pressed against the uneven surface 18a of the mounting table 18 and bends and deforms due to peeling. The exhaust process in step S7 is also performed during the ultraviolet irradiation termination process in step S5 and the lowering process of the lifting mechanism 16 in step S6. This prevents the presence of oxygen from inhibiting the adhesive strength of the adhesive sheet 14 from decreasing due to ultraviolet curing, and simplifies control of the exhaust valve and vacuum pump associated with the suction through-hole 11.

[0058] FIG. 6 schematically illustrates the state of the chip peeling device in the next chip recovery process. As indicated by arrow A4 in FIG. 6 , the exhaust valve is controlled to open the suction through-hole 11 to the atmosphere, and as indicated by arrow A5 in FIG. 6 , the inlet through-hole 12 is left open to the atmosphere. This causes the backside space 19a and the frontside space 19b to be at the same atmospheric pressure, and then the lifting mechanism 16 is operated to lift the support ring 15 (step S9). Next, the container 10 is opened, and the support ring 15 is removed from the container 10 (step S10). This allows the partially peeled chip 13 to be easily picked up. The support ring 15 may be directly recovered from the lifting mechanism 16, or a transfer means and a recovery section may be separately provided within the container 10, and the support ring 15 may be transferred from the lifting mechanism 16 to the recovery section by the transfer means. This configuration allows step S10 and step S1, in which the next support ring 15 to be processed is set, to be performed simultaneously, thereby improving process efficiency.

[0059] Furthermore, in the first embodiment, the series of steps S1 to S10 is performed for a single support ring 15, but a stocker containing a plurality of support rings 15 may be set in step S1, in which the support ring 15 is set at a predetermined position inside the container 10. In this case, in step S1, a transfer means for transferring the support rings 15 is installed inside the container 10, and the support rings 15 in the stocker are transferred and set by this transfer means to the support ring holders of the lifting means 16, and steps S2 to S9 are performed. The support rings 15 that have been subjected to the partial peeling process are stored by this transfer means in the stocker or a separate recovery stocker for recovering processed products. Thereafter, the processes from step S1 to step S9 are similarly repeated for the next untreated support ring 15. When the series of partial peeling processes has been completed for all of the support rings 15 in the stocker, the container 10 is opened, and the support rings 15 together with the stocker are removed from the container 10.

[0060] As described above, according to the first embodiment, the interior of the container 10 is maintained in a low-pressure atmosphere, and the plurality of chips 13 and the adhesive sheet 14 are elevated and ultraviolet light is irradiated from the backside of the adhesive sheet 14. Because ultraviolet light is irradiated from the backside of the elevated adhesive sheet 14, sufficient ultraviolet light is effectively irradiated onto the adhesive sheet 14. Furthermore, since the container 10 is in a low-pressure atmosphere during irradiation, ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits ultraviolet curing (reduction in adhesive strength), thereby efficiently reducing the adhesive strength of the adhesive sheet 14. Furthermore, the adhesive sheet 14 is brought into contact with the uneven surface 18a of the mounting table 18, gas is introduced into the front-side space 19b, and the back-side space 19a is maintained in a low-pressure atmosphere. As a result, the pressure difference between the low-pressure atmospheres of the back-side space 19a and the front-side space 19b presses the adhesive sheet 14 against the uneven surface 18a, causing it to bend, thereby enabling the chips 13 to be effectively peeled from the adhesive sheet 14. During this peeling process, the entire container 10 or the backside space 19a is in a low-pressure atmosphere, so ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits ultraviolet curing (reduction in adhesive strength), and the adhesive strength of the adhesive sheet 14 is efficiently reduced. Furthermore, by configuring the suction through-hole 11 to be shared by both step S2, in which the entire container 10 is evacuated to a low-pressure atmosphere, and step S7, in which the process of evacuating the backside space 19a to a low-pressure atmosphere in the partial peeling process is continued, these processes are performed within the same container 10, so that both the ultraviolet light irradiation process and the chip peeling process can be performed efficiently.

[0061] FIG. 7 shows a schematic diagram of the overall configuration of a second embodiment of the chip peeling device according to the present invention.

[0062] In FIG. 7, 110 is a sealable container (chamber) for carrying out ultraviolet irradiation treatment and partial chip peeling treatment inside, 111 is a suction through-hole provided in the bottom of the container 110 for exhausting the inside of the container 110 or a part thereof to create a low-pressure atmosphere, 112 is an introduction through-hole provided in the top of the container 110 for introducing air or a gas such as an inert gas into the inside of the container 110, 113 is a plurality of chips obtained by dicing a semiconductor wafer, for example, 114 is an adhesive sheet attached to the backside of the plurality of chips 113, and 115 is a hole having a diameter smaller than the diameter of the wafer substrate. The support ring (corresponding to the support means of the present invention) has a large diameter opening and supports a wafer substrate or multiple chips 113 with an adhesive sheet 114 attached to the back surface thereof, 116 indicates a lifting mechanism (corresponding to the lifting means of the present invention) that raises and lowers the support ring 115 in the vertical direction, 117 indicates an ultraviolet light source (corresponding to the irradiation light source of the present invention) for irradiating ultraviolet light onto the adhesive sheet 114, 118 indicates a mounting table for the support ring 115, and 120 indicates a moving mechanism (corresponding to the moving means of the present invention) that can move the ultraviolet light source 117 inside and outside the wafer area.

[0063] The upper surface of the mounting base 118 provided below the support ring 115 is provided with an uneven surface 118a, and when the support ring 115 is lowered, the lower surface of the adhesive sheet 114 abuts against the uneven surface 118a of the mounting base 118 and is supported by the convex portion.

[0064] FIG. 8 shows a schematic diagram of the top surface of the mounting table 118 .

[0065] As shown in FIG. 8 , the uneven surface 118a formed on the top surface of the mounting table 118 is provided with a plurality of convex portions 118b and a plurality of concave portions 118c, and each of the concave portions 118c is provided with a plurality of through holes 118d that penetrate the mounting table 118 in the vertical direction. These through holes 118d are connected to the suction through holes 111. Note that the positions of the through holes 118d are not limited to the positions shown in the figure, as long as they are within the concave portions 118c. Furthermore, the shape of the convex portions 118b shown in the figure is merely an example, and various planar shapes, such as square, rectangular, or circular, may be used depending on the chip shape. Furthermore, the peripheral side surfaces of the convex portions 118b may be tapered.

[0066] FIG. 9 schematically illustrates an exemplary configuration of the moving mechanism 120. FIGS. 9A and 9B show a side cross section and a plan cross section of the ultraviolet light source 117 in a state where it is turned off outside the wafer area, FIGS. 9C and 9D show a side cross section and a plan cross section of the ultraviolet light source 117 in a state where it is turned on and sliding from outside the wafer area toward inside the wafer area, within the wafer area, or from inside the wafer area toward outside the wafer area, and FIGS. 9E and 9F show a side cross section and a plan cross section of the ultraviolet light source 117 in a state where it is turned off outside the wafer area. In the exemplary configuration of FIG. 9, the structures of the ultraviolet light source 117 and the moving mechanism 120 are different from those shown in FIGS. 7 and 11 to 13, but are functionally the same.

[0067] As shown in FIG. 9 , the movement mechanism for the ultraviolet light source 117 includes a pair of rails 121 extending horizontally (left and right in FIG. 9 ) within the container 110, and a moving frame 122 connected at both ends to the pair of rails 121 and sliding along the pair of rails 121, and the ultraviolet light source 117, which is configured as a linear (straight tube) low-pressure discharge UV lamp or UV-LED, is attached to the moving frame 122.

[0068] 9(C) and 9(D), the ultraviolet light source 117 is turned on, and the movable frame 122 to which the ultraviolet light source 117 is attached slides along the rail 121, thereby irradiating the adhesive sheet 114 with ultraviolet light. With the ultraviolet light source 117 turned on, the movable frame 122 (ultraviolet light source 117) may be configured to reciprocate multiple times within the wafer area to irradiate ultraviolet light, or to reciprocate only once to irradiate ultraviolet light. Alternatively, the movable frame 122 (ultraviolet light source 117) may be configured to stop in the center and irradiate ultraviolet light without reciprocating within the wafer area. Which configuration is used is determined depending on the light distribution of ultraviolet light from the ultraviolet light source 117. If the light distribution from the ultraviolet light source 117 has a wide angle, it is desirable to stop in the center and irradiate, and if the light distribution has a narrow angle, it is desirable to irradiate with a reciprocating movement.

[0069] As shown in Fig. 7, the suction through hole 111 is connected to a vacuum pump (not shown) via an exhaust valve (not shown), whereby, as necessary, the entire interior of the container 110 or a back-side space 119a (see Figs. 12 and 13) of the adhesive sheet 114 inside the container 110 is evacuated to a low-pressure atmosphere. The introduction through hole 112 is openable to the atmosphere via a valve (not shown), or is connected to a compressor or compressed gas cylinder (not shown) via a valve (not shown), whereby, as necessary, the entire interior of the container 110 or a front-side space 119b (see Figs. 12 and 13) of the adhesive sheet 114 inside the container 110 can be adjusted to a pressure atmosphere higher than that of the back-side space 119a when the back-side space 119a is in a low-pressure atmosphere state, such as an atmospheric pressure atmosphere or a pressurized atmosphere exceeding atmospheric pressure.

[0070] The ultraviolet light source 117 is composed of one or more lamps or LEDs capable of emitting ultraviolet light of a wavelength capable of reducing the adhesive strength of the adhesive sheet 114. Specifically, as described above, it is composed of a linear (straight tube) low-pressure discharge UV lamp or UV-LED, and in this embodiment, it is composed of a low-pressure discharge UV lamp or UV-LED that is arranged so as to be movable between the inside and outside of the wafer area by a movement mechanism. The ultraviolet light source 117 may also be configured to emit light from a surface light source (UV-LED array) that covers the wafer area.

[0071] In this embodiment, the container 110 is configured so that it can be opened by dividing it into upper and lower halves at the position of the O-ring 110a, and can be closed in a sealed state by the O-ring 110a.

[0072] FIG. 10 shows a schematic flow of each processing step in this embodiment, and FIGS. 11 to 13 show a schematic state of the chip peeling device in each processing step.

[0073] A wafer substrate on which semiconductors or electronic components are formed is attached to a support ring 115 having an opening with a diameter larger than that of the substrate by adhering an adhesive sheet 114 to the backside of the wafer substrate. The wafer substrate is then diced into multiple chips and cleaned. Thereafter, as shown in FIG. 7 , the support ring 115 is set in a predetermined position on an elevating mechanism 116 equipped with a support ring holder installed inside the container 110 (step S11). In the following description of this embodiment, the term "support ring 115" refers to a structure in which the adhesive sheet 114 and multiple diced chips are attached.

[0074] Next, a vacuum pump (not shown) is operated to evacuate the entire interior of the container 110 to a low-pressure atmosphere through the suction through-hole 111 as shown by arrow A1 (FIG. 11) (step S12). At this time, the release valve of the introduction through-hole 112 is kept closed.

[0075] Next, the lifting mechanism 116 is operated to raise the support ring 115 upward (step S13). Next, ultraviolet light irradiation from the ultraviolet light source 117 to the adhesive sheet 114 begins (step S14), and the moving mechanism 120 slides the ultraviolet light source 117 into the wafer area, which is the area below the adhesive sheet 114 (step S15). The moving mechanism 120 then slides the ultraviolet light source 117 to an area outside the wafer area (step S16), and ultraviolet irradiation ends (step S17). As described above, the sliding movement of the ultraviolet light source 117 may be configured so that the ultraviolet light source 117 reciprocates within the wafer area multiple times, reciprocates only once, or stops in the center of the wafer area. Note that if the support ring 115 is set in a predetermined position within the container 110 in step S12 and is already set in a position suitable for ultraviolet irradiation of the adhesive sheet 114 in step S14, the raising process in step S13 may be omitted.

[0076] 11 and 9C and 9D schematically illustrate the state of the chip peeling apparatus during this ultraviolet irradiation process. As shown in these figures, the ultraviolet light source 117 slides into the wafer area directly below the raised support ring 115, allowing a sufficient amount of ultraviolet light to be irradiated onto the backside of the adhesive sheet 114. This significantly reduces the adhesive strength of the adhesive sheet 114 around the chip and / or the bottom of the adhesive sheet 114. Furthermore, during this irradiation, the space around the adhesive sheet 114 remains in a low-pressure atmosphere, so that ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits ultraviolet curing (reduced adhesive strength), thereby efficiently reducing the adhesive strength of the adhesive sheet 114. The exhaust process in step S12 continues during the process of raising the lifting mechanism 116 in step S13, the process of starting ultraviolet light irradiation in step S14, the process of moving the ultraviolet light source 117 into the wafer area in step S15, the process of moving the ultraviolet light source 117 out of the wafer area in step S16, and the process of terminating ultraviolet light irradiation in step S17. As a result, the adhesive strength of the adhesive sheet 114 can be maintained at a reduced level, since the decrease in adhesive strength due to ultraviolet curing of the adhesive sheet 114 can be prevented from being inhibited by the presence of oxygen, and further, control of the exhaust valve and vacuum pump associated with the suction through-hole 111 is simplified.

[0077] Next, the lifting mechanism 116 is operated to lower the support ring 115, and the adhesive sheet 114 is brought into contact with the uneven surface 118a of the mounting table 118 and supported by the convex portions (step S18). As a result, a back side space 119a and a front side space 119b for the plurality of chips 113 and adhesive sheet 114 are formed by the adhesive sheet 114, the support ring 115, the lifting mechanism 116, and the inner wall of the container 110. The back side space 119a is a sealed space except for the suction through-holes 111, and the front side space 119b is a sealed space except for the introduction through-holes 112.

[0078] 12 schematically illustrates the state of the chip peeling apparatus in the next partial peeling process. As indicated by arrow A2 in FIG. 12 , the process of evacuating the backside space 119a through the suction through-hole 111 to create a low-pressure atmosphere continues (step S19). At the same time, by opening a valve (not shown), a gas such as air is filled into the frontside space 119b through the inlet through-hole 112 as indicated by arrow A3 in FIG. 12 . The pressure difference between the backside space 119a and the frontside space 119b, which are low-pressure atmospheres created by creating a higher internal pressure in the frontside space 119b than in the backside space 119a, causes the adhesive sheet 114 to be pressed against the uneven surface 118a of the mounting table 118 and bend. As a result, the peripheral edges of the multiple chips 113 are efficiently peeled off from the adhesive sheet 114, resulting in a partial peeling state. The pressure in the front-side space 119b at this time may be any value that can generate a pressure difference that allows the adhesive sheet 114 to be pressed against the uneven surface 118a of the mounting table 118 and bend, but by pressurizing the front-side space 119b with air or inert gas from a compressor or compressed gas cylinder, the pressure difference increases and the adhesive sheet 114 can be bent more effectively. Furthermore, the rate of change (speed) of the pressure in the front-side space 119b is adjusted within a range that does not damage the chip 113 due to stress during peeling when the adhesive sheet 114 is pressed against the uneven surface 118a of the mounting table 118 and bends and deforms due to peeling. Note that the exhaust process in step S12 is continued during the ultraviolet irradiation termination process in step S17 and the lowering process of the lifting mechanism 116 in step S18. This prevents the adhesive strength of the adhesive sheet 114 from decreasing due to ultraviolet curing due to the presence of oxygen, thereby maintaining the adhesive strength of the adhesive sheet 114 at a reduced level, and further simplifies the control of the exhaust valve and vacuum pump associated with the suction through-hole 111.

[0079] FIG. 13 schematically illustrates the state of the chip peeling device in the next chip recovery process. As indicated by arrow A4 in FIG. 13 , the exhaust valve is controlled to open the suction through-hole 111 to the atmosphere, and as indicated by arrow A5 in FIG. 13 , the inlet through-hole 112 is left open to the atmosphere. This causes the backside space 119a and the frontside space 119b to be at the same atmospheric pressure, and then the lifting mechanism 116 is operated to lift the support ring 115 (step S21). Next, the container 110 is opened, and the support ring 115 is removed from the container 110 (step S22). This allows the partially peeled chip 113 to be easily picked up. The support ring 115 may be directly recovered from the lifting mechanism 116, or a transfer means and a recovery section may be separately provided within the container 110, and the support ring 115 may be transferred from the lifting mechanism 116 to the recovery section by the transfer means. This configuration allows step S22 and step S11, in which the support ring 115 to be processed next is set, to be carried out simultaneously, thereby improving the efficiency of the process.

[0080] Furthermore, in the second embodiment described above, the above series of steps S11 to S22 are performed using a single support ring 115, but in step S11, in which the support ring 115 is set at a predetermined position inside the container 110, a stocker containing multiple support rings 115 may be set. In this case, in step S11, a transfer means for transferring the support rings 115 is installed in the container 110, and this transfer means is used to transfer and set the support rings 115 in the stocker to the support ring holding section of the lifting means 116, and steps S12 to S21 are executed. This transfer means then stores the support rings 115 that have been partially peeled into the stocker or a separate recovery stocker for recovering processed products. Thereafter, the processes from step S11 to step S21 are repeated in the same manner for the next unprocessed support ring 115, and when the series of partial peeling processes has been completed for all of the support rings 115 in the stocker, the container 110 is opened, and the support rings 115 together with the stocker are removed from the container 110.

[0081] As described above, according to the second embodiment, the interior of the container 110 is maintained in a low-pressure atmosphere, and the plurality of chips 113 and adhesive sheet 114 are raised. Furthermore, the ultraviolet light source 117 is slid into the wafer area, and ultraviolet light is irradiated from the backside of the adhesive sheet 114. Because the ultraviolet light source 117 is slid into the wafer area to irradiate ultraviolet light, sufficient ultraviolet light is effectively irradiated onto the adhesive sheet 114. Furthermore, since the container 110 is continuously maintained in a low-pressure atmosphere during irradiation, ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits ultraviolet curing (reduction in adhesive strength), and the adhesive strength of the adhesive sheet 114 is efficiently reduced. Furthermore, the adhesive sheet 114 is abutted against the uneven surface 118a of the mounting table 118, and gas at or above atmospheric pressure is introduced into the front-side space 119b, while the back-side space 119a is maintained in a low-pressure atmosphere. As a result, the pressure difference between the back-side space 119a, which is a low-pressure atmosphere, and the front-side space 119b, which is atmospheric pressure or pressurized, pressurizes the adhesive sheet 114 against the uneven surface 118a, causing it to bend, thereby effectively peeling the chip 113 from the adhesive sheet 114. During this peeling process, the entire container 110 or the back-side space 119a is in a low-pressure atmosphere, so ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits ultraviolet curing (reduction in adhesive strength), and the adhesive strength of the adhesive sheet 114 is efficiently reduced. Furthermore, the suction through-hole 111 is configured to be shared by both step S12, in which the entire container 110 is evacuated to a low-pressure atmosphere, and step S17, in which the process of evacuating the back-side space 119a to a low-pressure atmosphere in the partial peeling process is continued. Since these processes are performed within the same container 110, both the ultraviolet light irradiation process and the chip peeling process can be performed efficiently.

[0082] FIG. 14 shows a schematic diagram of the overall configuration of a third embodiment of a chip peeling device according to the present invention.

[0083] In FIG. 14, 210 is a sealable container (chamber) for carrying out ultraviolet irradiation treatment and partial chip peeling treatment inside, 211 is a suction through-hole provided in the bottom of the container 210 for exhausting the inside of the container 210 or a part thereof to create a low-pressure atmosphere, 212 is an introduction through-hole provided in the top of the container 210 for introducing air or a gas such as an inert gas into the inside of the container 210, 213 is a plurality of chips obtained by dicing a semiconductor wafer, for example, 214 is an adhesive sheet attached to the backside of the plurality of chips 213, 215 is a diameter of the wafer substrate, The support ring (corresponding to the support means of the present invention) has a large diameter opening and supports a wafer substrate or multiple chips 213 with an adhesive sheet 214 attached to the back surface thereof, 216 is a lifting mechanism (corresponding to the lifting means of the present invention) that raises and lowers the support ring 215 in the vertical direction, 217 is an ultraviolet light source (corresponding to the irradiation light source of the present invention) that is provided at a fixed position outside the wafer area and generates ultraviolet rays, and 218 is an edge-light light guide plate that guides ultraviolet rays from the ultraviolet light source 217 to the adhesive sheet 214 and also serves as a mounting base for the support ring 215.

[0084] The edge-light light guide plate 218, which is provided below the support ring 215, has an uneven surface 218a on its upper surface. When the support ring 215 is lowered, the lower surface of the adhesive sheet 214 abuts against the uneven surface 218a of the edge-light light guide plate 218 and is supported by the convex portions. The edge-light light guide plate 218 in this embodiment is formed by adhering a UV-transmitting member having an uneven surface 218a to the upper surface of a commercially available flat light guide (light guide). If feasible, an edge-light light guide plate 218 having an integrally formed uneven surface 218a on its upper surface may also be used. A microlens array may also be used as the UV-transmitting member having the uneven surface 218a. The use of a microlens array provides both the function of providing an uneven surface for partially peeling off the adhesive sheet 214 and the function of uniformly irradiating UV light.

[0085] FIG. 15 shows a schematic configuration of the upper surface of this edge-light light guide plate 218 .

[0086] As shown in FIG. 15 , the uneven surface 218a formed on the top surface of the mounting base 218 is provided with a plurality of convex portions 218b and a plurality of concave portions 218c, and each of the concave portions 218c is provided with a plurality of through holes 218d that penetrate the edge-light light guide plate 218 in the vertical direction. These through holes 218d are connected to the suction through holes 211. The positions of the through holes 218d are not limited to the positions shown in the figure, as long as they are within the concave portions 218c. Furthermore, the shape of the convex portions 218b shown in the figure is merely an example, and various planar shapes, such as square, rectangular, or circular, may be used depending on the chip shape. Furthermore, the peripheral side surfaces of the convex portions 218b may be tapered.

[0087] As shown in Fig. 14, the suction through-hole 211 is connected to a vacuum pump (not shown) via an exhaust valve (not shown), whereby, as necessary, the entire interior of the container 210 or a back-side space 219a (see Fig. 18) of the adhesive sheet 214 inside the container 210 is evacuated to a low-pressure atmosphere. The introduction through-hole 212 is openable to the atmosphere via a valve (not shown), or is connected to a compressor or compressed gas cylinder (not shown) via a valve (not shown), whereby, as necessary, the entire interior of the container 210 or a front-side space 219b (see Fig. 18) of the adhesive sheet 214 inside the container 210 can be adjusted to a higher pressure atmosphere than the back-side space 219a when the back-side space 219a is in a low-pressure atmosphere state, such as an atmospheric pressure atmosphere or a pressurized atmosphere exceeding atmospheric pressure.

[0088] The ultraviolet light source 217 is composed of one or more lamps or LEDs capable of emitting ultraviolet light of a wavelength capable of reducing the adhesive strength of the adhesive sheet 214. Specifically, it is composed of a linear (straight tube) low-pressure discharge UV lamp or UV-LED, and in this embodiment, it is composed of UV-LEDs fixedly disposed on both sides (left and right ends in FIG. 14 ) of the edge light light guide plate 218 or around the edge light light guide plate 218.

[0089] In this embodiment, the container 210 is configured so that it can be opened by dividing it into upper and lower halves at the position of the O-ring 210a, and can be closed in a sealed state by the O-ring 210a.

[0090] FIG. 16 shows a schematic flow of each processing step in this embodiment, and FIGS. 17 and 18 show a schematic state of the chip peeling device in each processing step.

[0091] A wafer substrate on which semiconductors or electronic components are formed is attached to a support ring 215 having an opening with a diameter larger than that of the substrate by adhering an adhesive sheet 214 to the backside of the wafer substrate. The wafer substrate is then diced into multiple chips and cleaned. Thereafter, as shown in FIG. 14 , the support ring 215 is set in a predetermined position on an elevating mechanism 216 equipped with a support ring holder installed inside the container 210 (step S31). In the following description of this embodiment, the term "support ring 215" refers to a structure in which the adhesive sheet 214 and multiple diced chips are attached.

[0092] Next, a vacuum pump (not shown) is operated to evacuate the entire interior of the container 210 to a low-pressure atmosphere through the suction through-hole 211 as shown by arrow A1 (FIGS. 14 and 17) (step S32). At this time, the release valve of the introduction through-hole 212 is kept closed.

[0093] Next, as shown in FIG. 17 , the lifting mechanism 216 is operated to raise the support ring 215 upward (step S33), and ultraviolet light irradiation is initiated from the ultraviolet light sources 217 arranged around the edge-light light guide plate 218 (step S34). The ultraviolet light from the ultraviolet light sources 217 passes through the edge-light light guide plate 218 and is irradiated onto the back surface of the adhesive sheet 214. This effectively irradiates the adhesive sheet 214 with sufficient ultraviolet light, reducing the adhesive strength of the adhesive sheet 214 around the chip and / or the bottom of the adhesive sheet 214. Furthermore, during this irradiation, the space around the adhesive sheet 214 remains in a low-pressure atmosphere, so that ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits ultraviolet curing (reduced adhesive strength), and the adhesive strength of the adhesive sheet 214 is efficiently reduced. The exhaust process in step S32 is also continuously performed during the lifting process of the lifting mechanism 216 in step S33 and the start of the ultraviolet light irradiation process in step S34. This prevents the adhesive strength of adhesive sheet 214 from being reduced by UV curing due to the presence of oxygen, and also simplifies control of the exhaust valve and vacuum pump associated with suction through-hole 211. Note that, at the time when support ring 215 is set at a predetermined position inside container 210 in step S31, if the support ring is set at a position suitable for UV irradiation of adhesive sheet 214 in step S34, the raising process in step S33 may be omitted.

[0094] Thereafter, ultraviolet irradiation is terminated (step S35), and the lifting mechanism 216 is operated to lower the support ring 215, bringing the adhesive sheet 214 into contact with the uneven surface 218a of the edge-light light guide plate 218 and supporting it with the convex portions (step S36). As a result, as shown in Fig. 18, a back-side space 219a and a front-side space 219b for the plurality of chips 213 and adhesive sheet 214 are formed by the adhesive sheet 214, the support ring 215, the lifting mechanism 216, and the inner wall of the container 210. The back-side space 219a is a sealed space except for the suction through-holes 211, and the front-side space 219b is a sealed space except for the introduction through-holes 212.

[0095] As shown by arrow A2 in Fig. 18 , the process of evacuating the rear-side space 219a through the suction through-hole 211 to create a low-pressure atmosphere continues (step S37). At the same time, by opening a valve (not shown), a gas such as the atmosphere is filled into the front-side space 219b through the introduction through-hole 212 as shown by arrow A3 in Fig. 18 . In this way, the pressure difference between the rear-side space 219a and the front-side space 219b, which are low-pressure atmospheres generated by making the internal pressure of the front-side space 219b higher than that of the rear-side space 219a, causes the adhesive sheet 214 to be pressed against the uneven surface 218a of the edge-light light guide plate 218 and to bend. As a result, the peripheral portions of the multiple chips 213 are efficiently peeled off from the adhesive sheet 214, resulting in a partially peeled state. The pressure in the surface-side space 219b at this time may be any value that generates a pressure difference that allows the adhesive sheet 214 to be pressed against the uneven surface 218a of the mounting table 218 and bend. However, by pressurizing the surface-side space 219b with air or inert gas from a compressor or compressed gas cylinder, the pressure difference increases, allowing the adhesive sheet 214 to bend more effectively. The rate (speed) of change in pressure in the surface-side space 219b is adjusted within a range that prevents damage to the chip 213 due to stress during peeling when the adhesive sheet 214 is pressed against the uneven surface 218a of the mounting table 218 and bends and deforms due to peeling. The exhaust process in step S37 is also performed during the ultraviolet irradiation termination process in step S35 and the lowering process of the lifting mechanism 216 in step S36. This prevents the presence of oxygen from inhibiting the adhesive strength of the adhesive sheet 214 from decreasing due to ultraviolet curing, and simplifies control of the exhaust valve and vacuum pump associated with the suction through-hole 211.

[0096] Thereafter, the exhaust valve is controlled to open the suction through-hole 211 to the atmosphere, while the introduction through-hole 212 is left open to the atmosphere. This brings the backside space 219a and the frontside space 219b to the same atmospheric pressure, and then the lifting mechanism 216 is operated to lift the support ring 215 (step S39). Next, the container 210 is opened, and the support ring 215 is removed from the container 210 (step S40). This allows the partially peeled chip 213 to be easily picked up. The support ring 215 may be directly removed from the lifting mechanism 216, or a transfer means and a recovery unit may be separately provided within the container 210, and the support ring 215 may be transferred from the lifting mechanism 216 to the recovery unit by the transfer means. This configuration allows step S40 and step S31, in which the next support ring 215 to be processed is set, to be performed simultaneously, thereby improving process efficiency.

[0097] Furthermore, in the third embodiment described above, the series of steps S31 to S40 described above are performed using a single support ring 215, but in step S31, in which the support ring 115 is set at a predetermined position inside the container 210, a stocker containing multiple support rings 215 may be set. In this case, in step S31, a transfer means for transferring the support rings 215 is installed in the container 210, and this transfer means is used to transfer and set the support rings 215 in the stocker to the support ring holding section of the lifting means 216, and steps S32 to S39 are executed. This transfer means stores the support rings 215 that have been partially peeled into the stocker or a separate recovery stocker for recovering processed products, and thereafter, the processes from step S31 to step S39 are similarly repeated for the next unprocessed support ring 215. When the series of partial peeling processes has been completed for all of the support rings 215 in the stocker, the container 210 is opened, and the support rings 215 together with the stocker are removed from the container 210.

[0098] As described above, according to the third embodiment, the interior of the container 210 is maintained in a low-pressure atmosphere, and the plurality of chips 213 and the adhesive sheet 214 are raised, and ultraviolet light is irradiated onto the back surface of the adhesive sheet 214 via the edge-light light guide plate 218. Because ultraviolet light is irradiated onto the back surface of the raised adhesive sheet 214 via the edge-light light guide plate 218, sufficient ultraviolet light is effectively irradiated onto the adhesive sheet 214. Furthermore, since the container 210 is maintained in a low-pressure atmosphere during irradiation, ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits ultraviolet curing (reduction in adhesive strength), and the adhesive strength of the adhesive sheet 214 is efficiently reduced. Furthermore, the adhesive sheet 214 is brought into contact with the uneven surface 218a of the edge-light light guide plate 218, and a gas at or above atmospheric pressure is introduced into the front-side space 219b, while the back-side space 219a is maintained in a low-pressure atmosphere. As a result, the pressure difference between the back-side space 219a, which is a low-pressure atmosphere, and the front-side space 219b, which is atmospheric pressure or pressurized, pressurizes the adhesive sheet 214 against the uneven surface 218a, causing it to bend, thereby effectively peeling the chip 213 from the adhesive sheet 214. During this peeling process, the entire container 210 or the back-side space 219a is in a low-pressure atmosphere, so ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits ultraviolet curing (reduced adhesive strength), and the adhesive strength of the adhesive sheet 214 is efficiently reduced. Furthermore, the suction through-hole 211 is configured to be shared by both step S32, in which the entire container 210 is evacuated to a low-pressure atmosphere, and step S37, in which the process of evacuating the back-side space 219a to a low-pressure atmosphere in the partial peeling process is continued. Since these processes are performed within the same container 210, both the ultraviolet light irradiation process and the chip peeling process can be performed efficiently.

[0099] Fig. 19 shows a schematic cross-sectional view of the configuration of a mounting plate or edge-light light guide plate in a modified version of the first to third embodiments, and Fig. 20 shows an enlarged view of the overall configuration of the top surface of the mounting plate or edge-light light guide plate in this modified version, as well as a partial configuration thereof. Fig. 20(A) shows an enlarged view of the overall configuration of the top surface and a partial configuration thereof, and Fig. 20(B) shows the cross section taken along line A-A thereof.

[0100] In the first to third embodiments described above, through holes that pass through the mounting plate or edge-light light guide plate are provided in the recesses of the recessed surface, but in this modified embodiment, as shown in Figures 19 and 20, a recessed surface 318a is formed on the upper surface of a mounting plate or edge-light light guide plate 318, with a plurality of protrusions 318b and a plurality of recesses 318c, and a plurality of first through holes 318d that pass through the mounting plate or edge-light light guide plate 318 in the vertical direction are provided in each of the recesses 318c, and further, a plurality of second through holes 318e that pass through the mounting plate or edge-light light guide plate 318 in the vertical direction are provided in each of the protrusions 318b. These first through holes 318d and second through holes 318e are in communication with the suction through hole 311. The first through-hole 318d is provided to evacuate the entire container or the space behind the adhesive sheet of the container to create a low-pressure atmosphere. The second through-hole 318e is provided to suction-fix the adhesive sheet on which the chip is mounted to the top surface of the convex portion 318b. This fixes the adhesive sheet corresponding to the inner region of the chip, making it easier to peel the adhesive sheet near the periphery of the chip when deformation is caused by suction through the first through-hole 318d. Even if the second through-hole 318e is not provided, the chip periphery can be peeled by suction through the first through-hole 318d. However, providing the second through-hole 318e allows for more accurate peeling. The position of the first through-hole 318d is not limited to the illustrated position as long as it is within the concave portion 318c. The illustrated shape of the convex portion 318b is merely an example, and various planar shapes, such as square, rectangular, or circular, may be used depending on the chip shape. Furthermore, the peripheral side surface of the protrusion 318b may be tapered.

[0101] As a further modification of the third embodiment described above, a light diffusing layer may be formed on the front or rear surface of the mounting plate or edge light guide plate, thereby improving the degree of diffusion of the irradiated ultraviolet light.

[0102] FIG. 21 shows a schematic diagram of the overall configuration of a fourth embodiment of the chip peeling device of the present invention, with (A) a side cross section and (B) a plan cross section, FIG. 22 shows a schematic diagram of the flow of the processing steps of this embodiment, and FIGS. 23 to 25 show the state of the chip peeling device in each processing step of this embodiment.

[0103] In FIG. 21, 410a denotes a sealable first container for carrying out ultraviolet irradiation treatment therein, 410b denotes a sealable second container provided adjacent to the first container 410a for carrying out partial peeling treatment of chips, 421 denotes a partition wall separating the first container 410a and the second container 410b, 422 denotes an opening / closing door provided on the partition wall 421 and opening to allow communication between the first container 410a and the second container 410b, 417 denotes an ultraviolet light source fixedly disposed inside the first container 410a, and 423 denotes a support ring 415 for supporting a plurality of chips and an adhesive sheet, which is disposed between the first container 410a and the second container 410b. The support ring 415 has an opening 424 that moves the support ring 415 horizontally and vertically (raising and lowering) within the second container 410b, a first suction through-hole 411a provided in the lower part of the first container 410a for evacuating the inside of the first container 410a to create a low-pressure atmosphere, a second suction through-hole 411b provided in the lower part of the second container 410b for evacuating the inside or a part of the second container 410b to create a low-pressure atmosphere, and an introduction mechanism 412 provided in the upper part of the second container 410b for introducing air or pressurized gas into the inside of the second container 410b. As in the first to third embodiments, multiple chips are obtained by dicing a semiconductor wafer, for example, and adhesive sheets are attached to the backsides of the multiple chips. The support ring 415 has an opening 424 that is larger in diameter than the diameter of the wafer substrate and supports the wafer substrate or the multiple chips and the adhesive sheets attached to their backsides.

[0104] A mounting base 418 for support ring 415 is disposed at a lower position inside second container 410b, at the position of second suction through-hole 411b. An uneven surface 418a is provided on the upper surface of mounting base 418, and when support ring 415 is lowered to the position of mounting base 418, the lower surface of the adhesive sheet comes into contact with uneven surface 418a of mounting base 418 and is supported by the convex portions.

[0105] The configuration of the uneven surface 418a provided on the upper surface of the mounting table 418 is the same as the configuration shown in FIG. 2, FIG. 8, FIG. 15 or FIG.

[0106] The wafer transfer device 423 includes a gripper 423a that grips a plurality of chips, an adhesive sheet, and a support ring 415 (hereinafter referred to as a wafer) that supports them, and an arm 423b that is connected to the tip of the gripper 423a and extends and retracts to horizontally move the gripper 423a. The arm 423b is configured to transfer wafers between the first container 410a and the second container 410b by extending and retracting. That is, the device is configured to perform the process of transferring a wafer set on a first tray 424a inside the second container 410b to a position above the ultraviolet light source 417 of the first container 410a, and the process of transferring a wafer positioned above the ultraviolet light source 417 of the first container 410a into the second container 410b and setting it on the second tray 424b.

[0107] The horizontal / vertical moving device 424 is provided inside the second container 410b and is configured to horizontally slide a first tray 424a on which new wafers are set and a second tray 424b on which irradiated wafers are set after ultraviolet irradiation along rails 424c. The horizontal / vertical moving device 424 is further configured to vertically raise and lower the second tray 424b.

[0108] 21 , the first suction through-hole 411 a and the second suction through-hole 411 b are connected to a vacuum pump (not shown) via an exhaust valve (not shown), whereby the entire first container 410 a, the entire second container 410 b, or the space on the back side of the wafer inside the second container 410 b is evacuated to a low-pressure atmosphere as needed. The introduction through-hole 412 is openable to the atmosphere via a valve (not shown), or is connected to a compressor or compressed gas cylinder (not shown) via a valve (not shown), whereby the entire second container 410 b or the space on the front side of the wafer inside the second container 410 b can be adjusted to a pressure atmosphere higher than that of the space on the back side of the wafer, such as an atmospheric pressure atmosphere or a pressurized atmosphere exceeding atmospheric pressure, when the space on the back side of the wafer is in a low-pressure atmosphere state.

[0109] The ultraviolet light source 417 is composed of a plurality of lamps or LEDs capable of emitting ultraviolet light of a wavelength capable of reducing the adhesive strength of the adhesive sheet on the wafer. Specifically, it is composed of low-pressure discharge UV lamps or UV-LEDs in a linear (straight tube), annular, flat, or other shape, and in this embodiment, it is composed of low-pressure discharge UV lamps or UV-LEDs fixedly disposed below the wafer in the first container 410a. Although not shown, a reflector can be provided on the back of the ultraviolet light source 417 to appropriately set the light distribution of the ultraviolet light.

[0110] FIG. 22 shows a schematic flow of each processing step in this embodiment, and FIGS. 23 to 25 show a schematic state of the chip peeling device in each processing step.

[0111] A wafer substrate on which semiconductors or electronic components are formed is attached to a support ring 415 (wafer) having an opening with a diameter larger than that of the substrate by adhering an adhesive sheet to the backside of the wafer substrate. The wafer substrate is then diced into a plurality of chips and cleaned.

[0112] Thereafter, the process shown in FIG. 22 begins. In the following description, a wafer that has not undergone either UV irradiation or partial peeling is referred to as a new wafer 425. First, the new wafer 425 is placed on a first tray 424a inside the second container 410b (step S51). In this step S51, a vacuum pump (not shown) is operated to maintain the entire interior of the first container 410a at a low pressure (hereinafter, this state or operation will be referred to as "depressurized") through the first suction through-hole 411a. The release valve of the inlet through-hole 412 is then opened, and the second container 210b is placed at atmospheric pressure (hereinafter, this state will be referred to as "normal pressure"). FIG. 23A shows the state of the chip peeling device during this process.

[0113] Next, a vacuum pump (not shown) is operated to reduce the pressure in the second container 410b through the second suction through-hole 411b (step S52). Before this step, the release valve of the introduction through-hole 412 is closed. Figure 23(B) shows the state of the chip peeling device in this step.

[0114] Next, the opening / closing door 422 is opened, and the wafer transfer device 423 is operated to transfer the new wafer 425 placed on the first tray 424a of the second container 410b to a position above the ultraviolet light source 417 inside the first container 410a (step S53). Figures 23(C) to 23(E) show the states of the chip peeling device in these steps.

[0115] Next, the open / close door 422 is closed, and ultraviolet light irradiation from the ultraviolet light source 417 to the wafer begins (step S54). Figure 23(F) shows the state of the chip peeling device during this process. Because the ultraviolet light source 417 is fixedly positioned directly below the wafer, sufficient ultraviolet light is effectively irradiated onto the adhesive sheet on the wafer, reducing the adhesive strength of the adhesive sheet around the chip and / or the bottom of the adhesive sheet. Furthermore, during this irradiation, the space around the wafer remains in a low-pressure atmosphere, so the ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits UV curing (reduced adhesive strength), thereby efficiently reducing the adhesive strength of the adhesive sheet. The decompression process for the second container 410b is continuously performed between the ultraviolet light irradiation in steps S52 to S54 (between Figures 23(B) to 23(F)) as a preparation step for the partial peeling process (step S61), which will be described later. This simplifies the control of the exhaust valve and vacuum pump associated with the second suction through-hole 411b. Furthermore, the decompression process of the first container 410a is continuously performed throughout all the process steps, i.e., from step S51 to step S61 (between FIGS. 23A and 25C). This prevents the adhesive sheet from losing its adhesive strength due to UV curing from being inhibited by the presence of oxygen, and also simplifies the control of the exhaust valve and vacuum pump associated with the first suction through-hole 411a.

[0116] Next, the second suction through-hole 411b is closed, and the release valve of the introduction through-hole 412 is opened to bring the entire second container 410b to atmospheric pressure (step S55). In this case, ultraviolet light is continuously irradiated onto the wafer from the ultraviolet light source 417. Figure 24(A) shows the state of the chip peeling apparatus in this step.

[0117] Next, the next new wafer 425 is set on the first tray 424a inside the second container 410b (step S56). In this case, the ultraviolet light source 417 continues to irradiate the wafer with ultraviolet light until the set time has elapsed. Figure 24(B) shows the state of the chip peeling device during this process.

[0118] Next, a vacuum pump (not shown) is operated to reduce the pressure in the second container 410b through the second suction through-hole 411b to the same degree of vacuum as that in the first container 410a, and the second tray 424b is moved to the operating position of the gripper 423a of the wafer transfer device 423 (step S57). At this time, the release valve of the introduction through-hole 412 is kept closed. In this case, ultraviolet light irradiation from the ultraviolet light source 417 to the wafer continues until the set time has elapsed. Figure 24(C) shows the state of the chip peeling device in this process.

[0119] Thereafter, the ultraviolet irradiation is terminated, the door 422 is opened, and the wafer transfer device 423 is operated to transfer the wafer after ultraviolet irradiation processing to the second tray 424b inside the second container 410b (step S58). The wafer after ultraviolet irradiation is designated as irradiated wafer 425'. Figure 24(D) shows the state of the chip peeling device in this process.

[0120] Next, the horizontal / vertical moving device 424 is operated to move the second tray 424b carrying the irradiated wafer 425' above the mounting table 418, and slide the first tray 424a carrying the next new wafer 425 to the operating position of the gripper 423a of the wafer transfer device 423 (step S59). Figure 24(E) shows the state of the chip peeling device in this step.

[0121] Next, the wafer transfer device 423 is operated to transfer the new wafer 425 to a position above the ultraviolet light source 417 inside the first container 410a, and the horizontal / vertical transfer device 424 is operated to lower the second tray 424b so that the adhesive sheet of the irradiated wafer 425' abuts against the uneven surface 418a of the mounting table 418 and is supported by the convex portions (step S60). Figures 24(F) and 25(A) show the state of the chip peeling device in these steps.

[0122] Next, the open / close door 422 is closed, and ultraviolet irradiation of the wafer from the ultraviolet light source 417 begins in the first container 410a, while a partial peeling process of the plurality of chips on the irradiated wafer 425' from the adhesive sheet is performed in the second container 410b (step S61). In this partial peeling process, as in the first to third embodiments, a backside space and a frontside space are formed for the plurality of chips and the adhesive sheet, and the backside space is reduced in pressure by suction through the second suction through-hole 411b, while the frontside space is brought to a normal pressure state (atmospheric pressure or a pressurized state exceeding atmospheric pressure) by opening the valve of the introduction through-hole 412. Due to the pressure difference between the reduced-pressure backside space and the normal-pressure frontside space, the adhesive sheet is pressed against the uneven surface 418a of the mounting table 418 and bent, resulting in a partially peeled wafer in which the peripheral portions of the plurality of chips are efficiently peeled from the adhesive sheet. In the following description, a wafer for which the peeling process has been completed will be referred to as a peeled-processed wafer 425". The pressure in the front surface side space at this time needs only to generate a pressure difference that allows the adhesive sheet to be pressed against the uneven surface 418a of the mounting table 418 and to bend; by pressurizing the front surface side space with air or inert gas from a compressor or compressed gas cylinder, the pressure difference increases and the adhesive sheet can be bent more effectively. Furthermore, the rate of change (speed) of the pressure in the front surface side space is adjusted within a range that does not damage the chips due to stress during peeling when the adhesive sheet is pressed against the uneven surface 418a of the mounting table 418 and bends, causing peeling deformation. Figure 25(B) shows the state of the chip peeling device in this process.

[0123] Next, the entire second container 410b is brought to atmospheric pressure, the peeled wafer 425'' is collected from the second tray 424b (step S62), and a new wafer 425 is set on the first tray 424a as needed. FIG. 25C shows the state of the chip peeling device in this step. In this case, ultraviolet light may be irradiated from the ultraviolet light source 417 onto the new wafer 425 inside the first container 410a.

[0124] Thereafter, it is determined whether or not there is a new wafer to be processed (step S63), and if it is determined that there is a new wafer (YES), the process returns to step S57 (the state of FIG. 24C) and the processes of steps S57 to S63 are repeated. If it is determined that there is no new wafer (NO) in step S63, and if there is a wafer that is being irradiated with ultraviolet rays or has already been irradiated with ultraviolet rays, the wafer is subjected to partial peeling processing, and then all the processes of the fourth embodiment are terminated.

[0125] As described above, the fourth embodiment includes a first container 410a for performing an ultraviolet irradiation process and a second container 410b for performing a chip partial peeling process. The first container 410a is always maintained in a low-pressure atmosphere, and ultraviolet light is irradiated from the backside of the adhesive sheet. Because ultraviolet light is irradiated from the backside of the adhesive sheet, sufficient ultraviolet light is effectively irradiated onto the adhesive sheet. Furthermore, since the first container 410a maintains a low-pressure atmosphere during irradiation, ultraviolet light is irradiated in an atmosphere with a low concentration of oxygen, which inhibits ultraviolet curing (reduced adhesive strength), thereby efficiently reducing the adhesive strength of the adhesive sheet. Furthermore, within the second container 410b, the adhesive sheet is supported by the convex portions in contact with the uneven surface 418a of the mounting table 418, and gas is introduced into the front-side space, while the back-side space is maintained in a low-pressure atmosphere. As a result, the pressure difference between the low-pressure atmosphere of the backside space and the frontside space presses the adhesive sheet against the uneven surface 418a, causing it to bend, so that the peripheral edge of the chip can be effectively peeled off from the adhesive sheet to create a partially peeled state. Furthermore, because the ultraviolet irradiation treatment and the partial chip peeling treatment are performed in separate adjacent containers, both treatments can be performed simultaneously in parallel, improving treatment efficiency.

[0126] FIG. 26 shows a schematic flow of the processing steps of the chip manufacturing method of the present invention, and each processing step of the chip manufacturing method of the present invention will be described below with reference to FIG.

[0127] First, a large number of semiconductor elements or electronic component elements are formed on a wafer (step S71). These semiconductor elements or electronic component elements are formed using known processes. For example, in the formation of semiconductor elements, an oxide film or a nitride film is formed on a silicon wafer, followed by application of a photoresist, exposure, and development to form an etching mask, followed by etching and resist removal, followed by filling with an insulating film, planarization, formation of gate electrode patterns and source / drain regions, ion implantation, followed by formation of contacts and trenches, and then formation of wiring.

[0128] Next, an adhesive sheet is attached to the backside of the semiconductor wafer thus formed, and dicing is carried out to dice it into individual chips (step S72).

[0129] Thereafter, as explained in the first to fourth embodiments, the plurality of chips obtained by dicing and the adhesive sheet attached to the backside of the plurality of chips are placed in a sealable container and subjected to suction processing to create a low-pressure atmosphere inside the container, and ultraviolet light is irradiated from the backside of the plurality of chips and the adhesive sheet inside the container maintained in a low-pressure atmosphere (step S73). This ultraviolet light irradiation step may be performed by any of the methods of the first to fourth embodiments.

[0130] Next, as explained in the first to fourth embodiments, an adhesive sheet is brought into contact with the uneven surface in a container maintained in a low-pressure atmosphere, and while the back-side space of the plurality of chips and adhesive sheet is maintained in a low-pressure atmosphere, gas is introduced into the front-side space of the plurality of chips and adhesive sheet, causing the pressure difference between the back-side space and the front-side space to press the adhesive sheet against the uneven surface and bend, thereby partially peeling the adhesive sheet from the plurality of chips (step S74). This partial peeling step may be performed by any of the methods of the first to fourth embodiments.

[0131] Next, the peeled chips are collected from the container (step S75).

[0132] Thereafter, the collected chip is fixed to a lead frame, wire-bonded, and then molded (step S76), thereby manufacturing a semiconductor chip (chip).

[0133] The effects of this chip manufacturing method are the same as those of the first to fourth embodiments, and therefore a description thereof will be omitted.

[0134] The above-described embodiments are merely illustrative of the present invention and are not limiting, and the present invention can be embodied in various other modified and altered forms. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

[0135] The present invention can be used in a chip peeling process when manufacturing semiconductor elements or electronic component elements.

[0136] 10, 110, 210 Container 10a, 110a, 210a O-ring 11, 111, 211, 311 Suction through-hole 12, 112, 212 Introduction through-hole 13, 113, 213 Tip 14, 114, 214 Adhesive sheet 15, 115, 215, 415 Support ring 16, 116, 216 Elevation mechanism 17, 117, 217, 417 Ultraviolet light source 18, 118, 218, 318, 418 Mounting table 18a, 118a, 218a, 318a, 418a Uneven surface 18b, 118b, 218b, 318b Convex portion 18c, 118c, 218c, 318c Concave portion 18d, 118d, 218d, 318d, 318e Through-holes 19a, 119a, 219a Back surface side space 19b, 119b, 219b Front surface side space 120 Moving mechanism 121, 424c Rail 410a First container 410b Second container 411a First suction through-hole 411b Second suction through-hole 412 Introducing mechanism 421 Partition wall 422 Opening and closing door 423 Wafer transfer device 423a Gripper 423b Arm 424 Horizontal and vertical moving device 424a First tray 424b Second tray 425 New wafer 425′ Irradiated wafer 425″ Separation-processed wafer

Claims

1. A chip peeling method comprising: placing a plurality of chips obtained by dicing a wafer and an adhesive sheet attached to the backside of the plurality of chips in a container; suctioning the container to create a low-pressure atmosphere inside the container; irradiating ultraviolet light from the backside of the plurality of chips and the adhesive sheet within the container while maintaining the low-pressure atmosphere; abutting the adhesive sheet against an uneven surface within the container while maintaining the low-pressure atmosphere; introducing gas into the space on the front side of the plurality of chips and the adhesive sheet while maintaining a low-pressure atmosphere; and pressing the adhesive sheet against the uneven surface and deflecting it due to the pressure difference between the backside space and the frontside space, thereby partially peeling the adhesive sheet from the plurality of chips.

2. A chip peeling method as described in claim 1, characterized in that the plurality of chips and the adhesive sheet are raised within the container maintained in a low-pressure atmosphere and ultraviolet light is irradiated from the back side, and the plurality of chips and the adhesive sheet are lowered within the container continuously maintained in a low-pressure atmosphere and the adhesive sheet is brought into contact with the uneven surface.

3. A chip peeling method as described in claim 1, characterized in that during the ultraviolet irradiation, the back side space is made into a low-pressure atmosphere through a suction through-hole connected to the back side space, and during the partial peeling, the back side space is made into a low-pressure atmosphere through the suction through-hole and gas is introduced into the front side space through an introduction through-hole connected to the front side space.

4. A chip peeling method as described in claim 2, characterized in that the ultraviolet irradiation light source is fixedly positioned outside the wafer area, the multiple chips and the adhesive sheet are raised when the ultraviolet light is irradiated, and the multiple chips and the adhesive sheet are lowered when the partial peeling is performed, so that the adhesive sheet abuts against the uneven surface.

5. A chip peeling method as described in claim 2, characterized in that, during the ultraviolet irradiation, the plurality of chips and the adhesive sheet are raised and the ultraviolet irradiation light source is moved into the wafer area, and during the partial peeling, the irradiation light source is moved out of the wafer area and the plurality of chips and the adhesive sheet are lowered so that the adhesive sheet abuts against the uneven surface.

6. A chip peeling method as described in claim 2, characterized in that, during the ultraviolet irradiation, the plurality of chips and the adhesive sheet are raised and ultraviolet light is guided from an irradiation light source located outside the wafer area to irradiate the adhesive sheet, and during the partial peeling, the plurality of chips and the adhesive sheet are lowered so that the adhesive sheet abuts against the uneven surface.

7. The chip peeling method described in claim 1, characterized in that the container is composed of a first container and a second container isolated from the first container via an opening and closing door, and when irradiating ultraviolet light, the multiple chips and the adhesive sheet are placed in the first container, and ultraviolet light from an irradiation light source provided in the first container is irradiated onto the adhesive sheet, and when partially peeling, the multiple chips and the adhesive sheet are transferred into the second container and the adhesive sheet is abutted against the uneven surface.

8. A chip peeling device comprising: a sealable container; support means disposed within the container and supporting a plurality of chips by an adhesive sheet affixed to the backside of the plurality of chips; suction holes penetrating the container and communicating with the backside space of the plurality of chips and the adhesive sheet, for creating a low-pressure atmosphere in at least the backside space; introduction holes penetrating the container and communicating with the frontside space of the plurality of chips and the adhesive sheet, for introducing gas into the frontside space; an irradiation light source disposed within the container for irradiating the adhesive sheet with ultraviolet light; suction means configured to create a low-pressure atmosphere inside the container by suctioning through the suction holes when ultraviolet light is irradiated by the irradiation light source, and to maintain a low-pressure atmosphere inside the container by suctioning through the suction holes during partial peeling; and an uneven surface against which the plurality of chips and the adhesive sheet come into contact during partial peeling, and which presses and bends the abutting adhesive sheet due to the pressure difference between the low-pressure atmosphere in the backside space and the gas pressure in the frontside space, thereby causing partial peeling.

9. A chip peeling device as described in claim 8, further comprising a lifting means for the support means, which raises the plurality of chips and the adhesive sheet when irradiating ultraviolet rays, and lowers the plurality of chips and the adhesive sheet when partially peeling, so that the adhesive sheet abuts against the uneven surface.

10. A chip peeling device as described in claim 8, characterized in that the suction through-hole is configured to create a low-pressure atmosphere in the back side space during ultraviolet irradiation and to create a low-pressure atmosphere in the back side space during partial peeling, and the introduction through-hole is configured to introduce gas into the front side space during partial peeling.

11. The chip peeling device described in claim 9, characterized in that the irradiation light source is fixedly positioned outside the wafer area, the lifting means lifts the multiple chips and the adhesive sheet when irradiating ultraviolet rays, and the lifting means lowers the multiple chips and the adhesive sheet when partially peeling.

12. The chip peeling device of claim 9, further comprising a moving means capable of moving the irradiation light source between the inside and outside of the wafer area, wherein, during the ultraviolet irradiation, the lifting means raises the plurality of chips and the adhesive sheet while the moving means moves the irradiation light source into the wafer area, and during the partial peeling, the moving means moves the irradiation light source out of the wafer area while lowering the plurality of chips and the adhesive sheet.

13. A chip peeling device as described in claim 9, further comprising a light guiding means for guiding ultraviolet light from the irradiation light source located outside the wafer area to the adhesive sheet, wherein the lifting means lifts the plurality of chips and the adhesive sheet when irradiating the ultraviolet light, and the lifting means lowers the plurality of chips and the adhesive sheet to abut against the uneven surface when partially peeling.

14. The chip peeling device according to claim 13, wherein the uneven surface having ultraviolet light transmittance is provided on the upper surface of the light guiding means.

15. The chip peeling device according to claim 14, wherein the light guide means comprises an edge-light light guide plate.

16. The chip peeling device described in claim 8, characterized in that the container is composed of a first container and a second container isolated from the first container via an opening and closing door, and during the ultraviolet irradiation, the plurality of chips and the adhesive sheet are placed in the first container and ultraviolet light from an irradiation light source provided in the first container is irradiated onto the adhesive sheet, and during the partial peeling, the adhesive sheet transferred into the second container is abutted against the uneven surface.

17. An element forming process for forming semiconductor elements or electronic component elements on a wafer; a dicing process for dicing the wafer and the adhesive sheet after adhering an adhesive sheet to the backside of the wafer on which the semiconductor elements or electronic component elements have been fabricated by the element forming process; and an ultraviolet irradiation process for irradiating ultraviolet light from the backside of the chips and the adhesive sheet inside the container maintained in a low-pressure atmosphere by storing the chips obtained by the dicing process and the adhesive sheet attached to the backside of the chips in a sealable container and suctioning the container. a partial peeling process in which, after the ultraviolet irradiation process, the adhesive sheet is abutted against an uneven surface in the container maintained in a low-pressure atmosphere, and while maintaining the back-side space of the plurality of chips and the adhesive sheet in a low-pressure atmosphere, gas is introduced into the front-side space of the plurality of chips and the adhesive sheet, thereby pressing the adhesive sheet against the uneven surface and bending it due to the pressure difference between the back-side space and the front-side space, thereby partially peeling the adhesive sheet from the plurality of chips; and a recovery process in which the plurality of chips peeled by the partial peeling process are recovered.

18. A chip manufacturing method as described in claim 17, characterized in that the ultraviolet irradiation process includes a step of raising the plurality of chips and the adhesive sheet in the container maintained in a low-pressure atmosphere and irradiating ultraviolet light from the back side, and the partial peeling process includes a step of lowering the plurality of chips and the adhesive sheet in the container maintained continuously in a low-pressure atmosphere and abutting the adhesive sheet against the uneven surface.

19. A chip manufacturing method as described in claim 17, characterized in that the ultraviolet irradiation process includes a process of creating a low-pressure atmosphere in the back-side space through a suction through-hole connected to the back-side space during the ultraviolet irradiation, and the partial peeling process includes a process of creating a low-pressure atmosphere in the back-side space through the suction through-hole during the partial peeling, and introducing gas into the front-side space through an introduction through-hole connected to the front-side space.

20. A chip manufacturing method as described in claim 18, characterized in that the ultraviolet irradiation process includes a step of fixing and positioning the ultraviolet irradiation source outside the wafer area and raising the multiple chips and the adhesive sheet during the ultraviolet irradiation, and the partial peeling process includes a step of lowering the multiple chips and the adhesive sheet during the partial peeling to abut the adhesive sheet against the uneven surface.

21. A chip manufacturing method as described in claim 18, characterized in that the ultraviolet irradiation process includes a step of raising the plurality of chips and the adhesive sheet while irradiating the ultraviolet rays and moving the ultraviolet irradiation light source into the wafer area, and the partial peeling process includes a step of moving the irradiation light source outside the wafer area while partially peeling and lowering the plurality of chips and the adhesive sheet so that the adhesive sheet abuts against the uneven surface.

22. A chip manufacturing method as described in claim 18, characterized in that the ultraviolet irradiation process includes a step of raising the plurality of chips and the adhesive sheet and guiding ultraviolet light from an irradiation light source located outside the wafer area to irradiate the adhesive sheet with ultraviolet light, and the partial peeling process includes a step of lowering the plurality of chips and the adhesive sheet during the partial peeling so that the adhesive sheet abuts against the uneven surface.

23. The chip manufacturing method described in claim 17, characterized in that the container is composed of a first container and a second container isolated from the first container via an opening and closing door, the ultraviolet irradiation process includes a step of placing the plurality of chips and the adhesive sheet in the first container and irradiating the adhesive sheet with ultraviolet light from an irradiation light source provided in the first container, and the partial peeling process includes a step of transferring the plurality of chips and the adhesive sheet into the second container and abutting the adhesive sheet against the uneven surface during the partial peeling.

Images