JPH06196555A - Ultraviolet ray irradiation system - Google Patents

Abstract

PURPOSE:To provide an ultraviolet ray irradiation system in which an optimal irradiation time can be set automatically depending on the degree of consumption of an ultraviolet lamp. CONSTITUTION:The system is operated idly under a state where no work is fed, and the illuminance of an ultraviolet lamp 12 is measured by means of an illuminance sensor 24. A main controller 31 calculates an ultraviolet irradiation time by dividing an accumulated quantity of light being set by a digital switch SW1 for setting an accumulated quantity of light by a measured illuminance. When the work W is irradiated with ultraviolet rays, a shutter 14 is opened for a time interval thus calculated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ring-shaped frame (work) for holding a semiconductor wafer via an ultraviolet-sensitive adhesive tape attached to the back surface of the semiconductor wafer.
On the other hand, the present invention relates to an ultraviolet irradiation device that irradiates ultraviolet rays.

[0002]

As is well known, during the semiconductor manufacturing process,
There is a dicing process for cutting a semiconductor wafer into chips. In this dicing process, as a method of supporting the semiconductor wafer, an adhesive tape larger than the semiconductor wafer is attached to the back surface of the semiconductor wafer, and the peripheral portion of the adhesive tape is attached to a ring-shaped frame, so that the semiconductor wafer There is something to support. Such a wafer support structure (hereinafter, also referred to as a work) is fixed, and a semiconductor wafer is cut by a cutter while leaving the adhesive tape. This method has the advantage that chips can be prevented from chipping or scattering, but the adhesive strength of the adhesive tape must be large in order to withstand the impact force during cutting.
However, on the other hand, in the die bonding process after the dicing process, the cut chips must be easily peeled from the adhesive tape, but there is a problem that the large adhesive force of the adhesive tape hinders chip peeling. .

Therefore, recently, an ultraviolet-sensitive adhesive tape having a property that its adhesive strength is reduced by irradiating with ultraviolet rays is used, and a semiconductor wafer is adhered and supported by such an adhesive tape to form a chip shape. If the work is irradiated with ultraviolet rays after the cutting, the above-mentioned problems can be solved.

The ultraviolet irradiating device for such an application covers a work with a cover, supplies an inert gas into the cover, and opens and closes a shutter interposed between the ultraviolet lamp and the work as irradiation time control means. The work is irradiated with ultraviolet rays for a predetermined time (for example, 5 seconds).

[0005]

However, the above-mentioned conventional ultraviolet irradiation device has the following problems. That is, since the illuminance of the new ultraviolet lamp is different from that of the old ultraviolet lamp, even if the work is irradiated with ultraviolet light for a certain period of time, the older the ultraviolet lamp is, the lower the integrated light amount is. The photopolymerization of the pressure sensitive adhesive of the UV sensitive pressure sensitive adhesive tape depends on the above-mentioned integrated light quantity, and thus the degree of photopolymerization of the pressure sensitive adhesive decreases as the UV lamp ages. Therefore, if you set the UV irradiation time based on a new UV lamp, when the UV lamp becomes old, insufficient polymerization of the adhesive will occur, and the adhesive strength of the adhesive will not decrease so much. There is a problem that it becomes difficult to peel off the chip in the bonding process. Also, in consideration of the decrease in illuminance of the ultraviolet lamp, if the ultraviolet irradiation time is set long beforehand, the irradiation time will be unnecessarily extended while the ultraviolet lamp is new.
As a result, another problem that the processing capacity of the device is lowered occurs.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an ultraviolet irradiation device capable of setting an optimum ultraviolet irradiation time in accordance with the degree of wear of the ultraviolet lamp. And

[0007]

The present invention has the following constitution in order to achieve such an object. Claim 1
The invention described in (1) is an ultraviolet irradiation device for irradiating a ring-shaped frame (work) holding the semiconductor wafer with ultraviolet rays through an ultraviolet-sensitive adhesive tape attached to the back surface of the semiconductor wafer. In, an ultraviolet lamp for irradiating the work with ultraviolet light, an illuminance sensor for measuring the illuminance of the ultraviolet lamp, an integrated light quantity setting device for setting the integrated light quantity of the ultraviolet light, and when the work is not flowing in an idle operation. In the illuminance of the ultraviolet lamp detected by the illuminance sensor, by dividing the set integrated light amount, irradiation time calculation means for calculating the irradiation time of the ultraviolet,
When the work is irradiated with ultraviolet rays, irradiation time control means for performing irradiation for the calculated irradiation time is provided.

According to a second aspect of the present invention, an ultraviolet lamp similar to that of the first aspect, an illuminance sensor, and an integrated light quantity setting device are provided, and the illuminance sensor detects when the work is irradiated with ultraviolet rays. By using the illuminance of the ultraviolet lamp, the integrated light amount calculation means for calculating the integrated light amount at every predetermined time after the irradiation is started, and the integrated light amount calculated by the integrated light amount calculation means, by the integrated light amount setting device. And a control means for ending the irradiation when the set integrated light quantity is exceeded.

[0009]

The operation of the present invention is as follows. That is,
According to the first aspect of the present invention, every time the predetermined number of works are subjected to the ultraviolet irradiation processing, the work is run without idling, and the illuminance sensor measures the illuminance of the ultraviolet lamp at that time. Then, the irradiation time of ultraviolet rays is calculated by dividing the integrated light quantity of ultraviolet rays preset by the integrated light quantity setting device by the measured illuminance. The irradiation time control means performs irradiation for the calculated irradiation time when the work is irradiated with ultraviolet rays.

According to the second aspect of the invention, the illuminance of the ultraviolet lamp is measured while the work is being irradiated with the ultraviolet light. Then, using the measured illuminance, the integrated light amount is calculated every predetermined time after the irradiation is started. The irradiation time control means ends the irradiation when the calculated integrated light amount exceeds a preset integrated light amount.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a mechanical portion of an embodiment of an ultraviolet irradiation device according to the present invention,
FIG. 2 is an external perspective view of a work to be processed. The work W is one in which an ultraviolet-sensitive adhesive tape 2 larger than the semiconductor wafer 1 is attached to the back surface of the semiconductor wafer 1, and the outer peripheral portion of this adhesive tape 2 is attached to the ring-shaped frame 3.

The ultraviolet irradiating device for irradiating the work W with ultraviolet light is composed of a work receiving part A for carrying in the work W from a device (for example, a dicing device) on the hand side (not shown), an ultraviolet irradiation processing part B, and a processing part. It is composed of a work discharge unit C for discharging the waste work W'to a processing device (for example, a stocker device for storing the processed work W'in a required cassette or a die bonding device) on the lower side (not shown). .

The work receiving portion A is provided with a receiving belt 4 along a line and a work placing table 6 on which a work W is placed and which is raised and lowered by an air cylinder 5. The work discharge unit C has a discharge belt 7 along the line.
And a work table 9 that is moved up and down by the air cylinder 8.

The ultraviolet irradiation processing section B is a ring-shaped work support base 1 for receiving the frame portion of the work W.
0, a cylindrical housing 11 that accommodates the same, an ultraviolet lamp 12 that is disposed below the cylindrical housing 11 and irradiates the lower surface of the work W with ultraviolet rays, an ultraviolet bundle tube 13, a shutter 14, a shutter drive motor 15, and the like. There is.
Further, as shown in FIG. 3, an illuminance sensor 24 for measuring the illuminance of ultraviolet rays is provided in the housing 11. Further, a traverse mechanism 16 for adsorbing and transporting the work W from the work receiving section A to the ultraviolet irradiation processing section B and from the ultraviolet irradiation processing section B to the work discharging section C is provided.

The traverse mechanism 16 includes two sets of work suction mechanisms 19, which are moved up and down by air cylinders 17, 18.
A guide frame 2 in which a movable frame 21 having 20 at both ends is arranged in the line direction by an air cylinder 22.
It is configured to move forward and backward along 3
One suction mechanism 19 supplies the work W of the work receiving section A to the ultraviolet irradiation processing section B, and at the same time, the other suction mechanism 20 sends out the processed work W ′ of the ultraviolet irradiation processing section B to the work discharging section C. Has become.

The ultraviolet irradiation device configured as described above is provided with a control system for automatically setting the ultraviolet irradiation time as shown in FIG. UV lamp drive controller 30
Is ON / OFF of the lighting signal a from the main controller 31.
The ultraviolet lamp 12 is turned on / off according to OFF, and the shutter driving motor 15 is rotated in the reverse direction according to ON / OFF of the shutter opening / closing signal b from the main controller 31 to open the shutter 14 for a predetermined time. The ultraviolet lamp drive controller 30 and the main controller 31 correspond to the shutter drive controller in the present invention.

The main controller 31 has a function of calculating the ultraviolet irradiation time as will be described later and corresponds to the irradiation time calculating means in the present invention. The main controller 31 includes a CPU 32 that executes processing according to an operation program stored in the memory 33, an input interface 34, and an output interface 35. The input interface 34 includes an integrated light amount setting digital switch SW1 and an illuminance correction digital switch S for setting the integrated light amount according to the ultraviolet sensitive adhesive tape 2.
W2, A / D converter 26, irradiation time upper limit setting timer 3
8, a shutter open sensor 36 that detects that the shutter 14 has been opened, a shutter close sensor 37 that detects that the shutter 14 has been closed, etc. are respectively connected.

The illuminance correction digital switch SW described above
2 is provided for correcting the measured value because a difference occurs between the actual illuminance of ultraviolet rays and the measured value depending on the mounting position of the illuminance sensor 24. However, due to the above difference, the integrated light amount setting digital switch S
The integrated light amount may be set in consideration of the integrated light amount set by W1, and in this case, the illuminance correction digital switch S
It is not necessary to provide W2.

The irradiation time upper limit setting timer 38 is a timer in which the upper limit of the ultraviolet irradiation time is set and which starts time measurement by the timer start signal c from the main controller 31, and the ultraviolet irradiation time calculated by the main controller 31. If the time exceeds the set time, it times out and notifies the life of the ultraviolet lamp 12.

On the output interface 35 of the main controller 31, a buzzer 39 which emits an alarm sound when the irradiation time upper limit setting timer 38 times out, and a 7-segment code display of the state of the apparatus when the alarm sound is emitted The LED 40 and the like are connected.

The illuminance meter 25 inputs the signal from the illuminance sensor 24 to obtain the illuminance of ultraviolet rays. The analog signal of the UV illuminance obtained by the illuminometer 25 is A / D
After being converted into a digital signal by the converter 26, it is sent to the main controller 31.

Next, with reference to the flow charts shown in FIGS. 4 and 5, the operation of the apparatus of the embodiment, particularly the automatic setting operation of the ultraviolet irradiation time will be described. FIG. 4 is a flowchart for calculating the irradiation time, and FIG. 5 is an operation flowchart for ultraviolet irradiation.

Referring to FIG. Main controller 31
The CPU 32 monitors the number of processed workpieces W (step S1), and the number of processed workpieces is a prescribed number (for example, 100).
When the number of sheets reaches, the acceptance of the work W is interrupted, and the apparatus is idled for illuminance measurement (step S2). Then, the illuminance measurement value of the ultraviolet lamp 12 measured by the illuminance sensor 24 and the illuminance meter 25 is taken into the main controller 31 via the A / D converter 26 (step S).
3). Based on this illuminance measurement value, the CPU 32 calculates the irradiation time by the following formula (step S4). Irradiation time = Set accumulated light quantity / (Illuminance measurement value x Set correction value) In the above formula, the set integrated light quantity is the value set by the integrated light quantity setting digital switch SW1, and the set correction value is the illuminance correction digital switch SW2. It is the set value. As is clear from the above equation, the irradiation time becomes longer as the ultraviolet lamp 12 becomes old and the illuminance decreases.

When the irradiation time is calculated, it is confirmed whether the irradiation time is within the normal range (step S5).
This is because the integrated light amount and the correction value are set by the operator, and therefore human error may occur. If the irradiation time is within the normal range, the process is terminated, while if the irradiation time is abnormal, an error display (buzzer 39
The alarm sound is generated by and the corresponding error code is displayed by the 7-segment LED 40).

When the irradiation time is calculated as described above, the work W is irradiated with ultraviolet rays as follows based on the calculated irradiation time. Hereinafter, description will be made with reference to FIG.

The CPU 32 is the housing 1 shown in FIG.
Whether or not the work W has been loaded into the housing 1 is monitored by looking at the detection signal of an optical sensor (not shown) installed in the housing 11 (step S11).
When the work W is carried in, the inside of the housing 11 is replaced with nitrogen gas (step S12), and then the shutter opening / closing signal b is turned on to open the shutter 14 (step S13). At this time, the CPU 32 monitors whether or not the shutter open sensor 36 is turned on (step S14). If the shutter open sensor 36 is not turned on within a predetermined time, the shutter 14 is turned on. It is determined that an abnormality has occurred in the display and an error is displayed (step S15).

When the shutter open sensor 36 is turned on, the timer start signal c is turned on and the irradiation time upper limit setting timer 38 is started (step S1).
6). Then, the soft timer realized by the program of the main controller 31 is used to monitor the time from the opening of the shutter 14 (step S17), and when the previously calculated irradiation time has elapsed, the shutter opening / closing signal The shutter 14 is closed by turning off b (step S18). The CPU 32 monitors whether the shutter close sensor 37 is turned on (step S19). If the shutter close sensor 37 is not turned on within a predetermined time, the shutter 1 is released.
It is judged that an abnormality has occurred in 4 and an error is displayed.

On the other hand, the CPU 32 monitors the time-up signal d of the irradiation time upper limit setting timer 38 while the shutter 14 is open, and the irradiation time upper limit setting timer 38 times up before the irradiation time elapses. In other words, in other words, if the irradiation time is longer than the set upper limit value, it is determined that the life of the ultraviolet lamp 12 has expired, and an alarm prompting the replacement of the ultraviolet lamp 12 (alarm sound by the buzzer 39). Is generated, and the 7-segment LED 40 indicating the life of the ultraviolet lamp 12 is displayed).

<Second Embodiment> In the first embodiment described above,
The illuminance of the ultraviolet lamp 12 was measured in a dry operation state in which the work W was not carried into the apparatus, and the ultraviolet irradiation time was determined based on the measured illuminance value. In the second embodiment, the integrated light amount is obtained by measuring the illuminance at regular intervals while irradiating the work W with ultraviolet rays, and the shutter 14 is closed when the integrated light amount exceeds a preset value. ing. The configuration of each part of the device is the same as that of the first embodiment, and therefore the description thereof is omitted here. However, the CPU 32 in the embodiment corresponds to the integrated light amount calculation means in the invention described in claim 2.

The operation will be described below with reference to the flow chart shown in FIG. Steps S31 to S36
Is the same as steps S11 to S16 in the operation flow of the first embodiment shown in FIG. That is,
When the work W is carried into the housing 11, the inside of the housing 11 is purged with nitrogen, and then the shutter 14 is opened, and it is confirmed whether the shutter 14 is operating normally. The setting timer 38 is started.

After the irradiation time upper limit setting timer 38 is started, the illuminance measurement value is fetched at regular intervals (for example, every 0.1 seconds) (step S37), and the shutter 1
The cumulative light amount after opening 4 is sequentially calculated (step S
38). Specifically, as shown in FIG. 7, the average value of two continuously measured illuminance values and the sampling interval (here, 0.1 second) are sequentially multiplied, and the values are added. The cumulative light amount is obtained by going. Figure 7
The shaded area in the inside corresponds to the integrated light amount of ultraviolet rays from when the shutter 14 is opened to when the shutter 14 is closed.

In step S39, the integrated light amount obtained at each sampling interval is compared with the integrated light amount value preset by the integrated light amount setting digital switch SW1. If the obtained integrated light amount exceeds the set value, Shutter 1
4 is closed (step S40). Then, after confirming that the shutter close sensor 37 is in the ON state, the process returns to step S31, and the shutter close sensor 37
If is not turned on, an error display is displayed.

On the other hand, if it is determined in step S39 that the integrated light amount is smaller than the set value, it is determined whether the irradiation time upper limit setting timer 38 has timed up (step S43). When the irradiation time upper limit setting timer 38 times out, the ultraviolet lamp 12 has reached the end of its life, and therefore an alarm is issued to prompt replacement of the ultraviolet lamp 12.
Further, until the irradiation time upper limit setting timer 38 times out, the process returns to step S37 to capture the illuminance measurement value at the next sampling timing.

In the second embodiment, the illuminance is measured and the integrated light quantity is calculated every time one work W is processed, but the illuminance of the ultraviolet lamp 12 does not change so rapidly. The illuminance measurement and the integrated light amount calculation may be performed every time the number of the works W is appropriately processed.

Further, in the present invention, the illuminance is measured and the integrated light amount is calculated, but the integrated light amount may be measured using an integrated photometer.

[0036]

As is apparent from the above description, according to the invention described in claim 1, the ultraviolet irradiation time is determined based on the ultraviolet illuminance measured during the idle operation when the work is not flowing, and According to the second aspect of the present invention, the integrated light amount is calculated based on the ultraviolet illuminance measured at regular intervals while irradiating the work with the ultraviolet light, and the integrated light amount is compared with a predetermined set value. By doing so, the ultraviolet irradiation time is indirectly determined. Therefore, according to any of the first and second aspects of the invention, it is possible to irradiate the ultraviolet light for an optimum time depending on the degree of wear of the ultraviolet lamp. It can be done without causing insufficient irradiation of ultraviolet rays, and
There is no need to irradiate UV light unnecessarily to reduce the operating efficiency of the equipment.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a mechanical section of an apparatus according to an embodiment.

FIG. 2 is an external perspective view of a work.

FIG. 3 is a block diagram of a control system related to automatic setting of ultraviolet irradiation time.

FIG. 4 is a flowchart for calculating an ultraviolet irradiation time in the first embodiment.

FIG. 5 is a flowchart of an ultraviolet irradiation operation of the first embodiment.

FIG. 6 is a flowchart of an ultraviolet irradiation operation of the second embodiment.

FIG. 7 is an explanatory diagram of an integrated light amount calculation method in the second embodiment.

[Explanation of symbols]

 W ... Work 1 ... Semiconductor wafer 2 ... UV sensitive adhesive tape 3 ... Ring frame 12 ... UV lamp 12 30 ... UV lamp drive control unit 31 ... Main controller 36 ... Shutter open sensor 38 ... Irradiation time upper limit setting timer SW1 ... Integration Light intensity setting digital switch

Front page continuation (72) Inventor Toshiyuki Sekito 1-2-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Co., Ltd. (72) Inventor Matsuo Kanbara 1-21-2 Shihohozumi, Ibaraki-shi, Osaka Nitto Denko Stock In-house (72) Inventor Saburo Miyamoto 1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Seiki Co., Ltd.

Claims (2)

[Claims] 1. A ring-shaped frame (hereinafter, referred to as a work) holding the semiconductor wafer is irradiated with ultraviolet rays through an ultraviolet-sensitive adhesive tape attached to the back surface of the semiconductor wafer. In the ultraviolet irradiation device, an ultraviolet lamp that irradiates the work with ultraviolet light, an illuminance sensor that measures the illuminance of the ultraviolet lamp, an integrated light quantity setting device for setting the integrated light quantity of the ultraviolet light, and the work is not flowing. Irradiation time calculation means for calculating the irradiation time of ultraviolet rays by dividing the set integrated light quantity by the illuminance of the ultraviolet lamp detected by the illuminance sensor during idling, and the above-mentioned calculation when irradiating the work with ultraviolet rays. An irradiation time control means for performing irradiation for a specified irradiation time, and an ultraviolet irradiation device. 2. A ring-shaped frame (hereinafter, referred to as a work) holding the semiconductor wafer is irradiated with ultraviolet rays through an ultraviolet-sensitive adhesive tape attached to the back surface of the semiconductor wafer. In the ultraviolet irradiation device, an ultraviolet lamp for irradiating the work with ultraviolet light, an illuminance sensor for measuring the illuminance of the ultraviolet lamp, an integrated light quantity setting device for setting the integrated light quantity of the ultraviolet light, and the irradiation of the work with the ultraviolet light. When using the illuminance of the ultraviolet lamp detected by the illuminance sensor, the integrated light amount calculation means for calculating the integrated light amount at every predetermined time from the start of irradiation, and the integrated light amount calculated by the integrated light amount calculation means,
An ultraviolet irradiation device comprising: a control unit that terminates irradiation when the integrated light amount set by the integrated light amount setting device is exceeded.