JP6597323B2 - Ultraviolet treatment apparatus and ultraviolet treatment method - Google Patents

Description

  The present invention relates to an ultraviolet processing apparatus and an ultraviolet processing method for performing ultraviolet irradiation processing for irradiating a workpiece with ultraviolet rays.

As a wiring board for mounting a semiconductor element such as a semiconductor integrated circuit element, a multilayer wiring board in which insulating layers and conductive layers (wiring layers) are alternately stacked is known.
In the manufacturing process of a multilayer wiring board, an insulating layer or a conductive layer is obtained by drilling or laser processing a wiring board material (hereinafter simply referred to as “substrate”) in which an insulating layer is laminated on a conductive layer. There is a step of removing a part of the hole and forming a via hole. At this time, smears (residues) caused by the materials constituting the insulating layer and the conductive layer are generated on the bottom surface of the formed via hole. If the plating process is performed in the via hole with the smear still attached, a connection failure between the wiring layers is caused. Therefore, it is necessary to perform a desmear process for removing the smear.
As a via hole desmear treatment method, a method of irradiating a substrate with ultraviolet rays has been proposed. For example, Patent Document 1 discloses a desmear treatment method in which ultraviolet rays are irradiated to a substrate on which a via hole is formed in an atmosphere of a gas (processing gas) containing oxygen or ozone.

JP2015-41728A

In the technique described in Patent Document 1, the entire substrate is irradiated with ultraviolet rays. For this reason, the region where no via hole is formed is irradiated with ultraviolet rays, and the light utilization efficiency is lowered. Further, if the substrate surface on which no via hole is formed is excessively irradiated with ultraviolet rays, undesired ashing may occur on the substrate surface.
Therefore, an object of the present invention is to provide an ultraviolet treatment apparatus and an ultraviolet treatment method that can appropriately irradiate ultraviolet rays to an area that requires ultraviolet irradiation treatment to improve the light use efficiency.

In order to solve the above-described problems, an aspect of the ultraviolet processing apparatus according to the present invention includes a light source unit in which a plurality of ultraviolet light emitting elements are arranged in an array, an object to be processed, and a processing gas containing oxygen. A processing unit having a processing region irradiated with ultraviolet rays emitted from the light source unit in an atmosphere, a region specifying unit for specifying the processing region based on design data of the object to be processed, and the plurality of ultraviolet light emission A light source control unit that individually controls the output of the element and irradiates the processing region specified by the region specifying unit with ultraviolet rays, the object to be processed is a wiring board material, and the region specifying unit includes: Based on position data of via holes formed in the wiring board material included in the design data, an area in the wiring board material in which the via holes are formed is specified as the processing area.
Here, the “processing gas” is a gas for processing an object to be processed, and is a gas that obtains processing capability by being irradiated with ultraviolet rays. A typical example is oxygen. When oxygen is irradiated with ultraviolet rays, oxygen radicals (active species) and ozone are generated.
According to the ultraviolet ray processing apparatus of the present invention, an ultraviolet ray is appropriately irradiated to an area that requires an ultraviolet ray irradiation process using a light source unit in which a plurality of ultraviolet light emitting elements whose outputs can be individually controlled are arranged in an array. Therefore, the light use efficiency can be improved. In addition, since an area that requires ultraviolet irradiation processing is specified based on design data (for example, CAD data) of an object to be processed, appropriate ultraviolet irradiation processing is possible for objects to be processed of various designs (types). is there.

Further, only the region in which the via hole is formed can be specified as a region requiring the ultraviolet irradiation treatment and irradiated with ultraviolet rays. Thereby, the desmear process which removes the smear which arose on the bottom part surface etc. of a via hole in the manufacturing process of a wiring board can be performed. Further, the region where no via hole is formed can be prevented from being irradiated with ultraviolet rays, and undesired ashing can be prevented.

Furthermore, in the ultraviolet processing apparatus, a storage unit that stores the size data of the via hole and the irradiation condition of the ultraviolet ray with respect to the via hole in association with each other, and the via hole formed in the wiring board material included in the design data An irradiation condition determining unit that determines the irradiation condition of the processing region specified by the region specifying unit according to the size of the via hole, based on the size data of and the irradiation condition stored in the storage unit The light source control unit may irradiate the ultraviolet ray to the processing region specified by the region specifying unit under the irradiation condition determined by the irradiation condition determining unit.
As described above, since the ultraviolet irradiation condition is determined according to the size of the via hole, an appropriate ultraviolet irradiation process is performed for each via hole even when via holes having different sizes are formed in one wiring board material. It can be carried out.

In the ultraviolet processing apparatus, the via hole size data may include information on at least one of the shape, diameter, and depth of the via hole. When the size (shape, diameter, depth) of the via hole is different, the amount of smear generated in the via hole is also different, so that the ultraviolet irradiation conditions for appropriately performing the desmear process are also different. By including information on the shape, diameter, and depth in the size data of the via hole, an appropriate ultraviolet irradiation process can be performed for each via hole.
Furthermore, in the above-described ultraviolet processing apparatus, the irradiation condition may include information on at least one of the irradiation intensity and the irradiation time of the ultraviolet light. In this case, the amount of ultraviolet irradiation can be changed for each via hole. Therefore, it is possible to suppress the occurrence of insufficient desmear processing due to an insufficient amount of irradiation light and undesired ashing due to an excessive amount of irradiation light.

Further, in the above-described ultraviolet processing apparatus, the apparatus further includes a gas supply / exhaust unit for flowing the processing gas along the surface of the object to be processed, and the region specifying unit is configured such that the processing gas flowed by the gas supply / exhaust unit is A region before reaching the region where the object to be processed is held may be specified as the processing region. In this case, the processing gas that has been irradiated with ultraviolet rays to obtain the processing capability can be supplied to the region where the object to be processed is held. Therefore, it is possible to effectively perform the ultraviolet irradiation process on the object to be processed.
Furthermore, the ultraviolet processing apparatus may further include an alignment mechanism that aligns the light source unit and the object to be processed held in the processing unit. In this case, it is possible to easily and appropriately identify the ultraviolet light emitting element corresponding to the processing region specified based on the design data of the object to be processed, and reliably irradiate the processing region requiring the ultraviolet irradiation treatment with ultraviolet rays. can do.

In the ultraviolet processing apparatus, the light source unit may include the alignment mechanism, and the alignment mechanism may align the plurality of ultraviolet light emitting elements and the object to be processed. In this case, it is possible to reliably irradiate ultraviolet rays to a processing area in the object to be processed that requires ultraviolet irradiation processing.
One embodiment of the ultraviolet treatment method according to the present invention is generated from a light source unit in which a plurality of ultraviolet light emitting elements are arranged in an array in an atmosphere of a treatment gas containing oxygen based on design data of an object to be treated. a step of ultraviolet rays to identify the processing area to be irradiated with the outputs of the plurality of ultraviolet light emitting devices individually controlled, seen including and a step of irradiating ultraviolet rays on the identified the processing area, the treated object Is a wiring board material, and in the step of specifying the processing area, the area in which the via hole is formed in the wiring board material based on the position data of the via hole formed in the wiring board material included in the design data Is specified as the processing region.
As a result, it is possible to appropriately irradiate ultraviolet rays to a region requiring ultraviolet irradiation treatment, and to improve the light utilization efficiency. In addition, since an area that requires ultraviolet irradiation processing is specified based on design data (for example, CAD data) of an object to be processed, appropriate ultraviolet irradiation processing is possible for objects to be processed of various designs (types). is there.

  ADVANTAGE OF THE INVENTION According to this invention, an ultraviolet-ray can be irradiated appropriately to the area | region which needs an ultraviolet irradiation process, and the utilization efficiency of light can be improved.

It is a figure which shows the structural example of the ultraviolet-ray processing apparatus of this embodiment. It is a figure which shows the structural example of a light source. It is a structural example of an alignment mechanism. It is a figure explaining an ultraviolet irradiation process. It is a block diagram which shows the structure of a control part. It is a figure which shows a part of manufacturing process of a multilayer wiring board.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration example of an ultraviolet ray processing apparatus 100 according to the present embodiment. In the present embodiment, as an example of the ultraviolet ray processing apparatus 100, an application example to a photodesmear apparatus will be described. A photodesmear apparatus is an apparatus that removes smear in via holes formed in a substrate by irradiating the substrate heated to a certain temperature with ultraviolet rays in an atmosphere containing oxygen.
(Configuration of UV treatment equipment)
As shown in FIG. 1, the ultraviolet ray processing apparatus 100 includes a light irradiation unit 10 that is a light source unit, and a processing unit 20 that holds a substrate (workpiece) W that is an object to be processed. The light irradiation unit 10 stores therein a light source 11 that emits ultraviolet light (vacuum ultraviolet light) necessary for desmear processing, for example, a wavelength of 220 nm or less, preferably 190 nm or less, and the work W held by the processing unit 20 has a light source 11. Irradiate ultraviolet light from Here, the reason why the wavelength of ultraviolet rays emitted from the light source 11 is set to 220 nm or less is that when the wavelength of ultraviolet rays exceeds 220 nm, it becomes difficult to decompose and remove smears caused by organic substances such as resins. is there.

The light source 11 has a configuration in which small light emitting elements (ultraviolet light emitting elements) such as LEDs and LDs that emit ultraviolet light are arranged in an array so as to be as dense and vertically as possible, and a plurality of light emitting elements are selected. Those that can be controlled to be turned on can be used. FIG. 2 shows a configuration example of the light source 11. The light source 11 is a planar light emitter in which n light-emitting blocks 11 (1, 1) incorporating light-emitting diodes are arranged densely in the horizontal direction and m in the vertical direction. The numbers n and m to be arranged are determined from the size of a single element and a desired light emitting area. The size of the light source 11 may be a size that sufficiently covers the size of the work W, or may be smaller than the size of the work W. For example, the entire workpiece may be irradiated in four steps by using a light source having a size of 1/2 each of the workpiece W in length and width (a size of ¼ of the area of the workpiece). A power source (P / S) 31 for lighting control of each light emitting element is connected to the light emitting block of the light source 11. The power source 31 is controlled by the control unit 40 and individually controls the outputs of the plurality of light emitting elements that constitute the light source 11.
The light source 11 is not limited to a configuration in which small light-emitting elements such as LEDs and LDs are arranged, as long as the light source 11 can be controlled so as to emit ultraviolet rays locally. For example, in a plasma display panel, a large number of minute cells are formed in a vertical and horizontal plane, and each cell emits light by discharge. However, a light source applying this principle may be used. In this case, each cell corresponds to one light emitting element.

  The light irradiation unit 10 includes a box-shaped casing 12 having a window 17 made of quartz glass or the like that transmits ultraviolet light, for example. The light source 11 is disposed on the light source support 18 inside the casing 12. The inside of the casing 12 is maintained in an inert gas atmosphere by supplying an inert gas such as nitrogen gas, for example. A cooling mechanism including a water cooling pipe 13 and a chiller 32 for cooling the light emitting element is provided above (back side) the light source 11 in the light irradiation unit 10. The water cooling pipe 13 is connected to a chiller 32, and for example, circulating cooling water is flowed through the inside.

The light irradiation unit 10 includes an alignment camera 14 that detects the position of the alignment mark formed on the workpiece W, and the alignment camera is supported on the light source support 18 in the same manner as the light source 11. At least two alignment cameras 14 are provided. The position information of the alignment mark detected by the alignment camera 14 is sent to the control unit 40.
The processing unit 20 includes a stage 21 that sucks and holds the workpiece W that performs an ultraviolet irradiation process (desmear process). The stage 21 is arranged to face the window portion of the light irradiation unit 10. For example, a suction hole (not shown) is formed in the stage 21 to suck the workpiece W. The stage 21 is made of, for example, an aluminum material in order to ensure the flatness and the accuracy of the suction holes.

An outer peripheral groove 21 a is formed on the outer peripheral portion of the surface of the stage 21. Since the O-ring 22 is sandwiched between the outer peripheral groove 21a and the window portion of the light irradiation unit 10, the light irradiation unit 10 and the processing unit 20 are assembled in an airtight manner.
The stage 21 incorporates a heater 23 that heats the work area together with the work W on which the work W is placed and irradiated with ultraviolet rays from the light irradiation unit 10. As the heater 23, for example, a heating mechanism such as a sheath heater or a cartridge heater can be used. The heater 23 is connected to a heater controller (not shown) that controls the heating temperature of the processing region to a predetermined set temperature.
An air supply path 24 for supplying a processing gas (processing gas) for performing a desmear process to the processing region is formed at one side edge (right side in FIG. 1) of the stage 21. A gas supply unit 33 is connected to the air supply path 24 via a valve 33a. The operation of the gas supply unit 33 is controlled by the control unit 40. Further, an exhaust passage 25 for exhausting the processing gas including the exhaust gas after the desmear process to the outside of the stage part 21 is formed at the other side edge part of the stage 21 (left side in FIG. 1). An exhaust apparatus (not shown) is connected to the exhaust path 25 via a valve 33b.

  Here, as the processing gas, for example, oxygen, ozone, a mixed gas of oxygen, ozone, or water vapor, a gas obtained by mixing an inert gas or the like with these gases, or the like can be considered. The processing gas is supplied to the processing region through the air supply path 24 and discharged to the outside of the stage section 21 through the exhaust path 25 while the work W is irradiated with the ultraviolet rays from the light irradiation unit 10. The That is, the processing gas flows from the right to the left in FIG. 1 through the processing region between the window of the light irradiation unit 10 and the workpiece W. That is, the air supply path 24, the exhaust path 25, and the gas supply section 33 constitute a gas supply / exhaust section that allows the processing gas to flow along the surface of the workpiece W.

Further, the light irradiator 10 is provided with a light source support 18 in the X direction (left and right direction in FIG. 1), Y direction (perpendicular to the plane of FIG. 1), and θ direction (around the Z axis perpendicular to the XY plane). A light source moving mechanism 35 that is movable in the rotation direction is attached via an arm 36. The operation of the light source unit moving mechanism 35 is controlled by the control unit 40.
As shown in FIG. 3, the light source unit moving mechanism 35 includes an X-direction moving mechanism 35a that can move the light source support 18 in the X direction and a Y-direction moving mechanism 35b that can move the light source support 18 in the Y direction. It is configured to include. The arm 36 includes an arm 36a attached to the X-direction moving mechanism 35a and an arm 36b attached to the Y-direction moving mechanism 35b. The light source unit moving mechanism 35 may include a θ-direction moving mechanism (not shown) separately from the X-direction moving mechanism 35a and the Y-direction moving mechanism 35b, or may be configured as the X-direction moving mechanism 35a or the Y-direction. The light source support 18 may be rotationally moved in the θ direction by the moving mechanism 35b. For example, when the light source support 18 is rotated in the θ direction by the X direction moving mechanism 35a, the X direction moving mechanism 35a includes two arms extending in the X direction, and the two arms are mutually connected in the X direction. The light source support 18 may be rotated in the θ direction by advancing and retracting in the reverse direction.

  The processing unit 20 is provided with a processing unit moving mechanism 34 that can move the processing unit 20 in the Z direction (vertical direction in FIG. 1). The operation of the processing unit moving mechanism 34 is controlled by the control unit 40. When the processing unit 20 is lowered by the processing unit moving mechanism 34, a gap is formed between the light irradiation unit 10 and the processing unit 20, and the workpiece W is taken in and out of the processing unit 20 using this gap. Is possible. When performing the desmear process, the processing unit 20 is raised by the processing unit moving mechanism 34, and the O-ring 22 comes into contact with the window unit of the light irradiation unit 10. Thereby, the space of the processing unit 20 on the stage 21 on which the workpiece W is placed is sealed.

(Substrate structure)
In the present embodiment, the workpiece W that is a processing target of the ultraviolet ray processing apparatus 100 is an intermediate wiring board material in the middle of manufacturing a multilayer wiring board for mounting a semiconductor element such as a semiconductor integrated circuit element. The multilayer wiring board is formed, for example, by laminating a conductive layer (wiring layer) and an insulating layer on a core substrate. The core substrate can be made of, for example, glass epoxy resin. As a material constituting the conductive layer (wiring layer), for example, copper, nickel, gold or the like can be used.
The insulating layer can be made of, for example, a resin containing a particulate filler made of an inorganic substance. As such a resin, for example, an epoxy resin, a bismaleimide triazine resin, a polyimide resin, a polyester resin, or the like can be used. Moreover, as a material which comprises a granular filler, a silica, an alumina, mica, a silicate, barium sulfate, magnesium hydroxide, a titanium oxide etc. can be used, for example.

In a multilayer wiring board, a via hole extending through one or a plurality of insulating layers in the thickness direction is formed in order to electrically connect one wiring layer and another wiring layer. In the manufacturing process of the multilayer wiring board, as shown in FIG. 4, a part of the insulating layer 61 is removed by, for example, laser processing the wiring board material in which the insulating layer 61 and the wiring layer 62 are laminated. As a result, a via hole VH is formed. As a laser processing method, a method using a CO ₂ laser, a method using a UV laser, or the like can be used. Note that the method of forming the via hole VH is not limited to laser processing, and for example, drill processing may be used.

When the via hole VH is formed in this way, the material constituting the insulating layer 61 and the wiring layer 62 is formed in the bottom region of the via hole VH, the surface of the inner wall surface (side wall), and the peripheral region of the via hole VH on the surface of the insulating layer 61. The resulting smear (residue) S adheres. If the plating process is performed in the via hole VH with the smear S still adhered, connection failure between wiring layers may be caused. Therefore, a desmear process for removing smear S attached to the via hole VH is performed on the wiring board material (work W) in which the via hole VH is formed.
When the workpiece W is placed on the stage 21 shown in FIG. 1, the workpiece W is placed so that the opening of the via hole VH faces the light irradiation unit 10, that is, the smear S is irradiated with ultraviolet rays from the light source 11. Is done. In the present embodiment, the control unit 40 individually controls the lighting of the plurality of light emitting elements constituting the light source 11, and irradiates only the region where the via hole VH is formed with ultraviolet UV as shown in FIG. To remove smear S.

(Configuration of control unit)
As shown in FIG. 1, the control unit 40 is connected to an integrated system management unit 200 such as a factory where the ultraviolet ray processing apparatus 100 is installed. The control unit 40 receives design data (for example, CAD / CAM data) of the work W from the integrated system management unit 200. The design data includes position data and size data of via holes formed in the workpiece W. The design data is also sent to another apparatus, for example, a laser processing apparatus that forms a via hole, and is used to form a via hole in the workpiece W.
FIG. 5 is a block diagram illustrating a specific configuration of the control unit 40.
The control unit 40 includes a design data input unit 41, a data conversion unit 42, a light amount input unit 43, a storage unit 44, a comparison calculation unit 45, and a light source lighting control unit 46. The design data input unit 41 inputs the design data of the work W from the integrated system management unit 200 and outputs the input design data to the data conversion unit 42. Based on the design data input from the design data input unit 41, the data conversion unit 42 converts the position data where the via hole is formed into ultraviolet irradiation position data, and the converted ultraviolet irradiation position data is sent to the light source lighting control unit 46. Output. The data conversion unit 42 outputs via hole size data included in the design data input from the design data input unit 41 to the comparison calculation unit 45.

  The light amount input unit 43 inputs via hole size data and light amount data input by the user of the ultraviolet processing apparatus 100, and stores them in the storage unit 44 in association with each other. Here, the size data of the via hole includes data on the shape (aspect ratio), diameter, and depth of the via hole. The light amount data is data indicating the irradiation conditions of ultraviolet rays, and includes the irradiation intensity and irradiation time of ultraviolet rays. This light quantity data is obtained in advance through experiments or the like. The set of the via hole size data and the light amount data may be directly input by the user to the control unit 40 as indicated by the solid line in FIG. 5, or the total system management unit 200 as indicated by the broken line in FIG. You may input via.

The comparison calculation unit 45 refers to the storage unit 44 and acquires light amount data corresponding to the via hole size data input from the data conversion unit 42. Then, the comparison calculation unit 45 outputs the acquired light amount data to the light source lighting control unit 46.
The light source lighting control unit 46 turns on the light emitting element of the light source 11 at the corresponding position based on the ultraviolet irradiation position data input from the data conversion unit 42. At this time, the light source lighting control unit 46 controls the amount of light emitted from the light source 11 based on the light amount data (irradiation intensity, irradiation time) input from the comparison calculation unit 45. Thereby, only the area | region in which the via hole was formed on the workpiece | work W is irradiated with the ultraviolet-ray of the light quantity according to the size of a via hole, and a desmear process is carried out.
In FIG. 5, the design data input unit 41 and the data conversion unit 42 correspond to a region specifying unit that specifies a processing region irradiated with ultraviolet rays in the processing unit 20, and the comparison calculation unit 45 corresponds to the size of the via hole. The light source lighting control unit 46 and the power supply 31 individually control the outputs of the plurality of ultraviolet light emitting elements and correspond to the light source control unit that irradiates the processing region with ultraviolet rays. ing.

(Manufacturing process)
FIG. 6 is a diagram showing a part of the manufacturing process of the multilayer wiring board.
The ultraviolet ray processing apparatus 100 performs a desmear process on the wiring board material (work W) subjected to laser via processing by the laser processing apparatus. Here, the laser via processing is performed based on design data (CAD / CAM data) held in the CAD data storage 201 included in the integrated system management unit 200. The workpiece W that has been subjected to laser via processing is conveyed to the ultraviolet processing apparatus 100. At this time, the processing unit 20 of the ultraviolet processing apparatus 100 is lowered by the processing unit moving mechanism 34. Then, the workpiece W is transferred from the outside of the processing unit 20 into the processing unit 20 and placed on the stage 21. The workpiece W is held on the stage 21 by vacuum suction or the like. At this time, the integrated system management unit 200 transmits design data (CAD / CAM data) of the workpiece W to be desmeared to the control unit 40 of the ultraviolet ray processing apparatus 100.

When the workpiece W is placed on the stage 21, the vacuum pump connected to the stage 21 operates, and the workpiece W is sucked and fixed on the stage 21. The processing unit 20 is raised by the processing unit moving mechanism 34, and the O-ring 22 comes into contact with the lower surface of the light irradiation unit 10 to seal the space of the processing unit 20. Then, the control unit 40 operates the gas supply unit 33 to supply the processing gas into the processing unit 20.
The supply of the processing gas may be continuous or intermittent. If the amount necessary for the oxidative decomposition of the resin is supplied, the decomposition reaction will not be reduced due to the lack of oxidizing agent.

Next, the alignment cameras 14a to 14d provided on the light source support 18 shown in FIG. 3 detect the alignment marks Ma to Md formed on the workpiece W, respectively, and position information of the detected alignment cameras 14a to 14d is detected. It transmits to the control part 40. Based on the positional information of the alignment marks Ma to Md of the workpiece W acquired from the alignment cameras 14a to 14d, the control unit 40 sends a movement signal to the light source unit moving mechanism 35 so that the position of the light source 11 matches the position of the workpiece W. Send to. Based on this movement signal, the light source unit moving mechanism 35 moves the light source support 18 in the XYθ directions. In addition, the control part 40 shall memorize | store the positional information on each light emitting element of the light source 11. FIG. The alignment cameras 14a to 14d and the light source unit moving mechanism 35 constitute an alignment mechanism.
In the ultraviolet irradiation device 100 of the present embodiment, a sealing mechanism is necessary for the stage 21 in order to seal the supply gas, and the stage 21 cannot be moved after the sealing portion comes into contact with the window portion 17. This is because when the stage 21 is moved, the sealing material is deformed and the supply gas leaks.

(Position data of the light source block to be lit)
When the alignment between the workpiece W and the light source 11 is completed, the control unit 40 then turns on the light source 11 and starts desmear processing. Specifically, the control unit 40 sends the design data of the workpiece W captured by the design data input unit 41 in FIG. 5 to the data conversion unit 42. As described above, the design data includes the position data of the via hole indicating where the via hole is formed in the work W. The data converter 42 extracts via hole position data from the via hole design data, and converts the via hole position data into ultraviolet irradiation position data indicating which position of the individual light emitting elements constituting the light source 11 corresponds to. The ultraviolet irradiation position data is sent to the light source lighting control unit 46.

(Light intensity data of the light source block to be lit)
The data converter 42 extracts via hole size data from the via hole design data, and sends the extracted size data to the comparison operation unit 45. Based on the size data of the via hole, the comparison calculation unit 45 calls the light amount data associated therewith from the storage unit 44. Then, light amount data corresponding to the size of the called via hole is sent to the light source lighting control unit 46.
More specifically, the necessary light amount data corresponding to the basic via size can be obtained in advance by experiments.

For example, a glass epoxy substrate on which a 25 μm insulating film having a blind via hole having a diameter of 100 μm opened by a laser processing apparatus is formed is irradiated with ultraviolet rays having a work surface illuminance (not the bottom of the via but the top surface of the via) of 100 mW / cm ² . Irradiate for an appropriate time to decompose smear. Then, ultraviolet rays are irradiated until the copper surface at the bottom of the via is visible, and the residual smear is visually confirmed using SEM / EDX (scanning electron microscope / energy dispersive X-ray spectroscopy) (a Cu surface appears so that it can be understood well). .) By this method, EDX can quantitatively analyze the element with high accuracy in the central portion of the via having an opening of about 100 μm. The reason is that the opening diameter of the via is sufficiently large for the electron beam and characteristic X-ray detectors. When C (carbon amount) at the bottom of the via is quantitatively analyzed, the amount of carbon relative to copper decreases, and saturation occurs at a certain point. This irradiation amount is obtained in advance by experiments.
It is extremely difficult to measure the amount of smear at the bottom edge of the via, but it can be calculated based on the analysis value at the center. For example, in the case of a blind via hole having an opening diameter of 100 μm, when it is necessary to irradiate 100 seconds to remove smear at the center of the via bottom, the time required for the edge portion of the via bottom is 85 based on Table 1. It can be seen that /57=1.49 times as long, that is, 149 seconds.

In addition, the numerical value of Table 1 makes substrate surface illumination intensity 100%.
As shown in Table 1, since the arrival rate decreases as the via opening diameter decreases, the irradiation time increases.
In this manner, the light source lighting control unit 46 outputs a signal for lighting the light emitting element at the position corresponding to the via hole formed in the workpiece W under the condition of the light amount (irradiation intensity, irradiation time) according to the size of the via hole. Send to power supply 31. Based on the signal transmitted from the light source lighting control unit 46, the power supply 31 lights only the light emitting elements above the position where the via hole is formed.
Thereby, ultraviolet rays are irradiated only to the area | region in which the via hole of the workpiece | work W is formed, and a desmear process is made. When the desmear process of the workpiece W is completed, the control unit 40 controls the power supply 31 to stop the ultraviolet irradiation of the light source 11 and also controls the gas supply unit 33 to stop the supply of the processing gas to the processing unit 20. To do. Next, the control unit 40 lowers the processing unit 20 by the processing unit moving mechanism 34. The workpiece W after the desmear process is removed from the stage 21 and carried out of the processing unit 20.

The work W after the desmear process is conveyed to an ultrasonic cleaning apparatus, and subjected to an ultrasonic vibration process (ultrasonic cleaning (US cleaning) process) as a physical vibration process. The frequency of ultrasonic waves in the ultrasonic vibration treatment is preferably 20 kHz or more and 70 kHz or less, for example. This is because if the frequency of the ultrasonic wave exceeds 70 kHz, it is difficult to break off smears caused by inorganic substances and remove them from the wiring board material.
In such ultrasonic vibration processing, a liquid such as water and a gas such as air can be used as the ultrasonic vibration medium.
More specifically, when water is used as the vibration medium, the ultrasonic vibration treatment can be performed by immersing the wiring board material in, for example, water and ultrasonically vibrating the water in this state. . When a liquid is used as the ultrasonic vibration medium, the processing time of the ultrasonic vibration processing is, for example, 10 seconds to 600 seconds.

When air is used as the vibration medium, ultrasonic vibration treatment can be performed by spraying compressed air on the wiring board material while ultrasonically vibrating the compressed air. Here, it is preferable that the pressure of compressed air is 0.2 Mpa or more, for example. Moreover, the processing time of the ultrasonic vibration processing by compressed air is, for example, 5 seconds to 60 seconds.
The ultraviolet irradiation treatment process and the physical vibration treatment process may be performed once in this order, but the ultraviolet irradiation treatment process and the physical vibration treatment process are preferably performed alternately. Here, the number of repetitions of the ultraviolet irradiation treatment step and the physical vibration treatment step is appropriately set in consideration of the ultraviolet irradiation time in each ultraviolet irradiation treatment step, and is, for example, 1 to 5 times.

  As described above, ozone and active oxygen are generated by irradiating a treatment gas containing oxygen with ultraviolet light having a wavelength of 220 nm or less in the ultraviolet irradiation treatment, and the smear S caused by the organic substance is decomposed by ozone or active oxygen. Gasified. As a result, most of the smear S caused by the organic substance is removed. At this time, the smear S caused by the inorganic substance is exposed by removing the smear S caused by the organic substance, and further becomes brittle when irradiated with ultraviolet rays.

By applying physical vibration treatment in this state, the smear S caused by the exposed inorganic substance and the remaining part of the smear S caused by the organic substance are destroyed and removed by the mechanical action due to the vibration. Alternatively, a slight gap is generated between smears due to the shrinkage of smears S caused by inorganic substances and the difference in thermal expansion that occurs when each smear S is irradiated with ultraviolet rays. The substrate is separated from the wiring board material by a physical vibration treatment. As a result, the smear S caused by the inorganic substance and the smear S caused by the organic substance are completely removed from the wiring board material.
Thus, according to the photo desmear process which performs an ultraviolet irradiation process and a physical vibration process, a desmear process can be performed without using the chemical | medical agent which requires a waste liquid process. Note that processing information related to the photo desmear process is stored in the irradiation data storage 202 provided in the integrated system management unit 200.

When the photo desmear process is completed, a process of removing the protective film by a mask peeler device is performed as necessary, and then a process of forming a seed layer on the surface of the workpiece W is performed. Thereafter, after a resist is applied on the seed layer, a resist pattern is formed on the seed layer through an exposure process and a development process. Then, after the plating layer is formed from the via hole to the opening of the resist pattern, the resist is peeled off, and the seed layer is removed (seed etching) using the plating layer as a mask.
As described above, the ultraviolet ray processing apparatus 100 according to the present embodiment is relatively small and requires ultraviolet ray irradiation processing by the light source 11 in which the light emitting elements that can be switched on and off independently are arranged in a matrix. Only a necessary amount of light (intensity, time) can be irradiated to the spot.

  On the other hand, in an ultraviolet processing apparatus (desmear processing apparatus) using an ultraviolet lamp such as an excimer lamp as a light source, it is assumed that the entire substrate on which via holes are formed is irradiated with ultraviolet rays. The reason for irradiating the entire substrate with ultraviolet rays in the desmear processing apparatus is as follows. The substrate has a region where a via hole is formed and a region where a via hole is not formed. The positions of these regions differ depending on the design of a circuit pattern formed on the substrate. If the entire substrate is irradiated with ultraviolet rays, processing can be performed regardless of the position of the region where the via hole is formed. That is, the desmear process can be performed on substrates of various designs (types).

  However, the following problems can be considered with respect to the method of irradiating the entire substrate with light. Originally, it is not necessary to irradiate ultraviolet rays in a region where a via hole is not formed on the substrate. Therefore, if the desmear processing apparatus is configured to irradiate the entire substrate with ultraviolet rays, the region where no via holes are formed is irradiated with ultraviolet rays, and the light utilization efficiency decreases. In particular, in recent years, the size of substrates has increased, and when the area of a region where via holes are formed in a large substrate is small, the light utilization efficiency is significantly reduced. Furthermore, if the region where no via hole is formed is excessively irradiated with ultraviolet rays, undesired ashing may occur on the surface.

  In addition, the size (shape, diameter, depth) of via holes formed in one substrate may vary from one type to many. If the size of the via hole is different, the amount of smear generated in the via hole is also different, so that the processing conditions (the amount of irradiated ultraviolet light) for appropriately performing the desmear process are also different. However, in the case of a configuration in which the entire substrate is irradiated with ultraviolet rays, it is difficult to change processing conditions depending on the location of the substrate. In this way, when there are multiple sizes of via holes on a single substrate, the entire substrate is irradiated by adjusting the processing conditions to the via hole with the largest amount of light necessary for processing so that there is no remaining under-processed via hole. Become. For this reason, an area in which the amount of UV irradiation is always excessive is generated.

On the other hand, in the present embodiment, the ultraviolet ray processing apparatus 100 can irradiate ultraviolet rays only to the region where the via hole is formed, so that the light utilization efficiency can be increased. As a result, the lifetime of the light source 11 can be extended. Moreover, since the ultraviolet-ray processing apparatus 100 can prevent an ultraviolet-ray being irradiated to the area | region in which the via hole is not formed, it can prevent undesired ashing.
In the case of a general exposure apparatus, the optical system is fixed. Then, an exposure part and a non-exposure part are formed on the work using a mask pattern, light is blocked by a shutter, the work is moved, and then the shutter is opened to perform exposure. Next, the shutter is closed and the stage is moved so as to be aligned with the next exposure area of the workpiece. Next, the operation of opening the shutter is repeated in order to perform exposure. During the period from exposure to exposure, the light source is turned on, and light control is only blocked by a mask, so that only a very small amount of light is actually used for resist exposure. In other words, the work can be irradiated with light only where it is necessary, but the power of light is also used in unnecessary areas.

On the other hand, in this embodiment, since the outputs of the plurality of light emitting elements constituting the light source 11 are individually controlled, it is possible to prevent light power from being used in unnecessary portions and to improve the light use efficiency. Can be raised.
Furthermore, the ultraviolet ray processing apparatus 100 can irradiate a necessary region with ultraviolet rays having a necessary light amount in accordance with the size of the via hole. Therefore, even if via holes of different sizes are formed on a single substrate, it is possible to irradiate each via hole with ultraviolet rays having an appropriate amount of light. As a result, it is possible to prevent a region that emits more light than necessary.

  The ultraviolet ray processing apparatus 100 acquires design data (CAD / CAM data) including position data and size data of via holes formed in the workpiece W, and acquires position data where via holes are formed based on the acquired design data. Convert to UV irradiation position data. And the ultraviolet-ray processing apparatus 100 makes the light emitting element of the position corresponding to the light source 11 light based on the converted ultraviolet irradiation position data. In this way, by using the design data of the workpiece W, the position where the via hole is formed, that is, the position where the ultraviolet irradiation process is necessary is determined even when the position where the via hole is formed for each workpiece W is different. Can be identified appropriately.

In addition, by using the light source 11 in which a plurality of light emitting elements whose outputs can be individually controlled are arranged in an array, it is possible to easily perform lighting control for selectively emitting light only at a necessary portion. Therefore, it is possible to irradiate ultraviolet rays only on necessary portions without using a mask or the like, for example. In addition, since the minimum necessary ultraviolet ray can be irradiated, the cooling mechanism of the light source 11 can be reduced.
Furthermore, when the ultraviolet ray processing apparatus 100 irradiates the region where the via hole is formed with the ultraviolet ray, the ultraviolet ray processing device 100 irradiates the ultraviolet ray with a light amount corresponding to the size of the via hole. The ultraviolet ray processing apparatus 100 stores an appropriate amount of light (irradiation intensity or irradiation time) obtained in advance through experiments or the like with respect to the size (diameter, depth, shape, etc.) of the via hole in association with the size data of the via hole. The light quantity corresponding to the size of the via hole is acquired based on the size data of the via hole included in the acquired design data. Thus, by using the design data of the workpiece W, the size of the via hole formed in the workpiece W can be properly grasped. Therefore, for example, when via holes having different diameters are mixedly mounted on one workpiece W, or CO ₂ vias formed using a CO ₂ laser and laser vias formed using a UV laser are mixedly mounted. Even if it exists, an ultraviolet irradiation process can be performed on the process conditions suitable for each via hole, respectively.

  Further, the ultraviolet ray processing apparatus 100 includes an alignment mechanism for aligning the light source 11 and the workpiece W. Specifically, the ultraviolet ray processing apparatus 100 reads the position of the workpiece W by detecting the alignment mark M formed on the workpiece W by the alignment camera 14 provided in the light irradiation unit 10. Then, the ultraviolet ray processing apparatus 100 moves the light source 11 relative to the workpiece W in accordance with the amount of positional deviation of the workpiece W with respect to the light source 11, and aligns the light source 11 and the workpiece W. As described above, when alignment of the light source 11 and the workpiece W is performed by the alignment mechanism, the lighting control of the light beam 11 is performed based on the ultraviolet irradiation position data calculated based on the design data of the workpiece W. Furthermore, it is possible to appropriately irradiate the desired position with ultraviolet rays.

(Modification)
In the above embodiment, the case where the light source support 18 is moved in the XYθ direction in the alignment of the light source 11 and the workpiece W has been described. However, the processing unit 20 or the stage 21 is moved in the XYθ direction to move the light source 11 with the light source 11. You may align with the workpiece | work W. FIG. Further, in this alignment, a high-accuracy alignment performed by detecting an alignment mark formed on the workpiece W is shown as an example. However, a method may be employed in which the workpiece W is pressed against a plurality of pins provided on the stage 21 to perform alignment.
Moreover, although the said embodiment demonstrated the case where the area | region in which the via hole was formed was made into the required area | region of an ultraviolet irradiation process, it is not limited to this. For example, the necessary region for the ultraviolet irradiation treatment may be the surface of the workpiece W other than the via hole, or a region outside the workpiece W (for example, preparation before the processing gas reaches the region where the workpiece W is held) Region) or a combination thereof.

When the necessary region for the ultraviolet irradiation treatment includes a region where a via hole is formed and a surface of the workpiece W where no via hole is formed, the surface of the workpiece W where no via hole is formed has a dose (impact) different from that of the via hole. You may irradiate with an ultraviolet-ray. That is, the entire work W may be a necessary region for the ultraviolet irradiation process, and the amount of ultraviolet irradiation light may be changed between the region where the via hole is formed and the region where the via hole is not formed. Thereby, the via cleanness and the roughness adjustment of the surface of the workpiece W can be controlled separately.
Further, in the above embodiment, an abnormality detection unit that detects an abnormality of the light source 11 may be provided. When the abnormality detection unit detects that the light source 11 has a non-light emitting portion, the light source 11 may be shifted by the light source moving mechanism 35 to perform the ultraviolet irradiation process using the normal light emitting portion. In this case, process redundancy can be realized, and replacement and maintenance of the light source 11 can be reduced.

  DESCRIPTION OF SYMBOLS 10 ... Light irradiation part, 11 ... Light source, 14 ... Alignment camera, 18 ... Light source support body, 20 ... Processing part, 21 ... Stage, 31 ... Power supply, 33 ... Gas supply part, 34 ... Processing part moving mechanism, 35 ... Light source Part moving mechanism, 40 ... control part, 100 ... ultraviolet ray processing device, 200 ... general system management part, S ... smear, VH ... via hole

Claims (8)

A light source unit in which a plurality of ultraviolet light emitting elements are arranged in an array;
A processing unit having a processing region in which an object to be processed is held and irradiated with ultraviolet rays emitted from the light source unit in an atmosphere of a processing gas containing oxygen;
An area specifying unit for specifying the processing area based on design data of the object to be processed;
A light source control unit that individually controls outputs of the plurality of ultraviolet light emitting elements and irradiates the processing region specified by the region specifying unit with ultraviolet rays ;
The object to be processed is a wiring board material,
The region specifying unit specifies, as the processing region, a region where the via hole is formed in the wiring board material based on position data of a via hole formed in the wiring board material included in the design data. UV treatment equipment. A storage unit for storing the size data of the via hole and the irradiation condition of the ultraviolet ray for the via hole in association with each other;
The irradiation condition of the processing region specified by the region specifying unit based on the size data of the via hole formed in the wiring board material included in the design data and the irradiation condition stored in the storage unit And an irradiation condition determination unit that determines according to the size of the via hole,
The ultraviolet light processing according to claim 1 , wherein the light source control unit irradiates the processing region specified by the region specifying unit with the ultraviolet ray under the irradiation condition determined by the irradiation condition determination unit. apparatus. The ultraviolet ray processing apparatus according to claim 2 , wherein the size data of the via hole includes information on at least one of a shape, a diameter, and a depth of the via hole. The irradiation conditions, ultraviolet processing apparatus according to claim 2 or 3, characterized in that it comprises at least one information on the irradiation intensity and irradiation time of the ultraviolet. A gas supply / exhaust section for flowing the processing gas along the surface of the object to be processed;
The region specifying unit specifies, as the processing region, a region before the processing gas flowed by the gas supply / discharge unit reaches the region where the object to be processed is held. 5. The ultraviolet ray processing apparatus according to any one of items 1 to 4 . UV treatment device according to any one of claims 1 to 5, further comprising an alignment mechanism for aligning said treated object held in the processing unit and the light source unit. The light source unit has the alignment mechanism;
The ultraviolet alignment apparatus according to claim 6 , wherein the alignment mechanism aligns the plurality of ultraviolet light emitting elements and the object to be processed. Based on the design data of the object to be processed, a step of identifying a processing region irradiated with ultraviolet rays emitted from a light source unit in which a plurality of ultraviolet light emitting elements are arranged in an array in an atmosphere of a processing gas containing oxygen;
Wherein the plurality of the output of the ultraviolet light emitting element is individually controlled, seen including and a step of irradiating ultraviolet rays on the identified said processing region,
The object to be processed is a wiring board material,
In the step of specifying the processing region, the region where the via hole is formed in the wiring board material is specified as the processing region based on position data of a via hole formed in the wiring board material included in the design data. An ultraviolet treatment method characterized by the above.

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