Wafer cutting pretreatment device

Abstract

The utility model relates to a wafer cutting pretreatment device, which comprises a material placing mechanism, a laser head moving mechanism, a connecting block, a laser head and a wafer monitoring mechanism, the material placing mechanism comprises a material placing disc, and a plurality of clamps are arranged on the outer wall of the material placing disc; the connecting block is connected with the laser head moving mechanism; the laser head and the wafer monitoring mechanism are connected to the bottom of the connecting block; and the laser head and a sensing head of the infrared thickness measurement sensing equipment face the material placing mechanism. The wafer thickness measuring device has the advantages that the thickness of the wafer laminating glue on the production line is detected one by one through the wafer monitoring mechanism, full inspection of the production line is achieved, uniformity of the thickness of the laminating glue of the target wafer before laser is ensured, direct contact with the surface of the wafer can be avoided due to the characteristic of non-contact induction thickness measurement of the infrared thickness measuring sensing equipment, and the production efficiency is improved. The risk of wafer damage is reduced; and the clamp positions the wafer on the material placing disc, so that the wafer is prevented from shaking due to external factors, and the thickness measurement error of infrared thickness measurement sensing equipment and the error of a laser position are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor packaging, in particular to a wafer cutting preprocessing device. Background Art

[0002] In the field of semiconductor packaging technology, wafers need to be cut. Since the overall size of the wafer is extremely small, in order to improve the cutting accuracy, especially for low-dielectric products, pre-treatment, namely laser treatment, is required before cutting to remove the metal on the cutting surface.

[0003] In order to prevent the laser energy from damaging the product surface, a layer of coating glue (mainly water and propylene glycol) needs to be applied to the surface of the wafer to protect the product before laser treatment. If the coating glue is applied normally, the surface of the wafer will be clean and pollution-free after washing. If the coating glue is applied unevenly, there will be pollution and silicon powder residue on the surface of the wafer after washing. Uneven coating of the wafer coating glue is an important factor affecting the quality of laser treatment.

[0004] The standard range of coating glue thickness is 0.5-1um, and the uniformity of coating glue thickness cannot be achieved by manual visual inspection. In order to ensure the uniformity of coating glue thickness of laser wafers, the coating quality is currently confirmed by manual sampling using testing equipment. Due to the low efficiency of thickness testing and low sampling frequency, missed inspections often occur, and abnormal thickness cannot be discovered in time. In addition, manual inspection increases the frequency of contact with the product, which can easily cause wafer scratches.

[0005] Therefore, there is a problem of poor laser quality caused by uneven wafer coating glue, which affects the wafer cutting yield. Utility Model Content

[0006] The utility model aims to provide a wafer cutting pre-processing device, which can confirm the uniformity of the coating glue and improve the laser quality.

[0007] In order to achieve the above-mentioned utility model object, the utility model provides a wafer cutting pre-processing device, including a material placing mechanism, a laser head moving mechanism, a connecting block, a laser head, and a wafer monitoring mechanism;

[0008] The material placement mechanism includes a material placement tray, and the outer wall of the material placement tray is provided with a plurality of clamps; the clamps include a fixing frame, a rotating shaft, a clamping plate, and a driving member; the fixing frame is provided with a connecting groove, a connecting rod is provided in the connecting groove, and the rotating shaft is coaxially connected with the connecting rod; the side edge of the clamping plate is fixed on the side wall of the rotating shaft; the driving member is connected with the connecting rod;

[0009] The connecting block is connected to the laser head moving mechanism, and the laser head and the wafer monitoring mechanism are connected to the bottom of the connecting block; the wafer monitoring mechanism includes an infrared thickness measuring sensor device, and the sensor heads of the laser head and the infrared thickness measuring sensor device are both facing the material placing mechanism.

[0010] Preferably, the outer wall of the material placing tray is provided with four clamps in a circular array.

[0011] Preferably, the placing tray is provided with a plurality of honeycomb through holes, and the honeycomb through holes are connected with ventilation pipes.

[0012] As a further improvement of the utility model, it also includes a movable frame and a movable shell, the laser head movable mechanism is connected to the top of the material placing mechanism through the movable frame, the connecting block is connected to the laser head movable mechanism through the movable shell, the movable frame is provided with a limiting rod, the movable shell is provided with a through hole, and the movable shell is connected to the limiting rod through the through hole.

[0013] Furthermore, two position sensors are provided on the top of the movable frame, a sensing rod is vertically provided on the top of the movable shell, and the sensing parts of the position sensors face downwards.

[0014] Furthermore, the position sensor is provided with a connecting piece, the connecting piece is provided with a connecting hole, the top of the movable frame is provided with an adjusting slot, and the fastener passes through the connecting hole and the adjusting slot to detachably fix the position sensor to the top of the movable frame.

[0015] Furthermore, it also includes a frame, the movable frame is connected to the top of the material placing mechanism through the frame, and the frame is provided with an indicator light.

[0016] As a further improvement of the utility model, the wafer monitoring mechanism also includes a camera device.

[0017] The wafer cutting pre-processing device of the utility model places the wafer on the material placing tray and positions it by the clamp; then the laser head and the wafer monitoring mechanism are moved to the top of the wafer by the laser head moving mechanism, and the infrared thickness sensor device absorbs the surface of propylene glycol (the main component of the film coating glue) through the infrared light and scatters the spectrum of a specific frequency. The content of propylene glycol is determined by detecting the peak position and intensity of the absorption spectrum, thereby measuring the thickness of the wafer film coating glue, confirming whether the wafer film coating glue is evenly distributed, and transmitting the test results to the terminal computer. The standard range of coating glue thickness is 0.5-1um. If the coating thickness is lower than 0.5um or higher than 1um, the computer will determine that the thickness is unqualified. Only wafers with coating thickness that meets the standard can be processed subsequently. After the terminal computer receives the information that the standard has been met, it immediately turns off the infrared thickness measuring sensor equipment to prevent it from being damaged during the laser process. The laser head then performs laser processing on the wafer to remove the surface metal of the wafer cutting path to improve the subsequent wafer cutting accuracy. After the processing is completed, the laser head and wafer monitoring mechanism are reset through the laser head moving mechanism.

[0018] Compared with the prior art, the wafer cutting pretreatment device of the utility model has the following advantages:

[0019] (1) The wafer monitoring mechanism detects the thickness of the wafer coating glue on the production line one by one, realizing full inspection of the production line and ensuring the uniformity of the coating glue thickness of the target wafer before laser irradiation. The non-contact sensing thickness measurement feature of the infrared thickness sensor equipment can avoid direct contact with the wafer surface, reducing the risk of wafer damage;

[0020] (2) The fixture positions the wafer on the tray to prevent the wafer from shaking due to external factors, thereby reducing the thickness measurement error of the infrared thickness sensor equipment and the error of the laser position. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of the wafer cutting pre-processing device of the utility model;

[0022] Figure 2 This is a schematic diagram of the structure of the wafer cutting pre-processing device of the utility model;

[0023] Figure 3 It is a schematic diagram of the structure of the material placing mechanism;

[0024] Figure 4 is a schematic diagram of the fixture structure;

[0025] Figure 5 It is a schematic diagram of honeycomb through-hole connection;

[0026] Figure 6 This is a schematic diagram of the position sensor connection. DETAILED DESCRIPTION

[0027] The specific implementation of the utility model is further described in detail below with reference to the accompanying drawings.

[0028] like Figure 1-2 As shown, the wafer cutting pre-processing device of the utility model includes a material placing mechanism 1, a laser head moving mechanism 2, a connecting block 3, a laser head 4, and a wafer monitoring mechanism 5;

[0029] like Figure 3 As shown, the material placing mechanism 1 comprises a material placing tray 11, and a plurality of clamps 12 are provided on the outer wall of the material placing tray 11; Figure 4 As shown, the clamp 12 includes a fixing frame 13, a rotating shaft 14, a clamping plate 16, and a driving member 17; the fixing frame 13 is provided with a connecting groove 131, a connecting rod 15 is provided in the connecting groove 131, and the rotating shaft 14 is coaxially connected with the connecting rod 15; the side edge of the clamping plate 16 is fixed on the side wall of the rotating shaft 14; the driving member 17 is connected with the connecting rod 15;

[0030] The driving member 17 can be an existing motor, which drives the connecting rod 15 to rotate, so that the rotating shaft 14 connected thereto rotates. Since on the automated production line, the wafer 8 is transferred in the vertical direction by a robot arm. Before placing the wafer 8, the initial state of the clamp 16 is a vertical state, which provides space for the material tray 11 to discharge the material, and avoids the clamp 16 interfering with the material discharge of the robot arm in the vertical direction; after placing the wafer 8, the clamp 16 turns to the material tray 11 along with the rotating shaft 14, and the clamp 16 is in a horizontal lying state, and the wafer 8 is clamped between the clamp 16 and the material tray 11 to position the wafer 8, so as to avoid the wafer 8 from moving on the material tray 11 during subsequent processing, which affects the cutting quality of the wafer 8.

[0031] Preferably, four clamps 12 are provided in a circular array on the outer wall of the material tray 11. The four-point wafer fixing method has a better positioning effect on the wafer 8.

[0032] like Figure 5 As shown, the material tray 11 is provided with a plurality of honeycomb through holes 111, and the honeycomb through holes 111 are connected to a vent pipe 112. Airflow is generated in each honeycomb through hole 111 through the vent pipe 112, so that negative pressure is generated on the upper surface of the material tray 11, and the target cut wafer 8 is adsorbed on the material tray 11, and the clamp 12 is used to further ensure that the wafer 8 is laid flat on the material tray 11, so as to prevent the extremely small wafer 8 from being affected by the jitter of the production line equipment and being offset on the material tray 11.

[0033] The connecting block 3 is connected to the laser head moving mechanism 2. The laser head moving mechanism 2 can be an existing ball screw assembly. By connecting a motor, the motor drives the screw to rotate forward and reverse, thereby driving the connecting block 3 connected thereto to move back and forth.

[0034] The laser head 4 and the wafer monitoring mechanism 5 are connected to the bottom of the connecting block 3 ; the wafer monitoring mechanism 5 includes an infrared thickness measuring sensor device 51 , and the sensor heads of the laser head 4 and the infrared thickness measuring sensor device 51 are both facing the material placing mechanism 1 .

[0035] The wafer cutting pretreatment device of the utility model places the wafer 8 on the material placing tray 11 and positions it by the clamp 12; then the laser head 4 and the wafer monitoring mechanism 5 are moved to the top of the wafer 8 by the laser head moving mechanism 2, and the infrared thickness sensor device 51 absorbs the infrared light through the surface of propylene glycol (the main component of the coating glue) and scatters the spectrum of a specific frequency. The content of propylene glycol is determined by detecting the peak position and intensity of the absorption spectrum, thereby measuring the thickness of the wafer coating glue, confirming whether the wafer coating glue is evenly distributed, and transmitting the test results to the terminal computer. The standard range of the coating glue thickness is 0.5-1um. If the coating thickness is lower than 0.5um or higher than 1um, the computer will determine that the thickness is unqualified. Only wafers with coating thickness that meets the standard can be processed subsequently. After the terminal computer receives the information that the standard has been met, it immediately turns off the infrared thickness measuring sensor device 51 to prevent it from being damaged during the laser process. Then the laser head 4 starts laser processing on the wafer 8 to remove the surface metal of the wafer cutting path to improve the subsequent wafer cutting accuracy. After the processing is completed, the laser head 4 and the wafer monitoring mechanism 5 are reset through the laser head moving mechanism 2.

[0036] The wafer cutting pre-processing device of the utility model also includes a moving frame 21 and a moving shell 31. The laser head moving mechanism 2 is connected to the upper part of the material placing mechanism 1 through the moving frame 21. The connecting block 3 is connected to the laser head moving mechanism 2 through the moving shell 31. The moving frame 21 is provided with a limiting rod 23. The moving shell 31 is provided with a through hole 311. The moving shell 31 is connected to the limiting rod 23 through the through hole 311. Under the action of the laser head moving mechanism 2, the moving shell 31 moves back and forth along the limiting rod 23. The limiting rod 23 plays a limiting role, improves the movement stability of the connecting block 3 and the wafer monitoring mechanism 5 below, and avoids the laser head 4 from shaking when the connecting block 3 moves due to the excessive overall mass of the laser head 4 and the wafer monitoring mechanism 5, thereby affecting the laser quality.

[0037] Two position sensors 6 are provided on the top of the mobile frame 21. Figure 6 As shown, a sensing rod 32 is vertically arranged on the top of the moving shell 31, and the sensing part of the position sensor 6 faces downward.

[0038] The two position sensors 6 are respectively installed at the head and tail ends of the moving travel range of the laser head 4 and the wafer monitoring mechanism 5. The position sensor 6 is an existing photoelectric sensor. When the sensing rod 32 moves to the sensing position of the position sensor 6, the position sensor 6 converts the induced light signal into an electrical signal and transmits it to the terminal computer, so that the terminal obtains the moving position information of the moving shell 31 (that is, the laser head 4 and the wafer monitoring mechanism 5). When the position sensor 6 senses the sensing rod 32, the computer issues a command to stop the operation of the laser head moving mechanism 2, thereby improving the controllability of the movement of the laser head 4 and the wafer monitoring mechanism 5.

[0039] The position sensor 6 is provided with a connecting piece 61, the connecting piece 61 is provided with a connecting hole 62, the top of the mobile frame 21 is provided with an adjusting slot 22, the fastener 63 can be a bolt and nut assembly, and the fastener 63 passes through the connecting hole 62 and the adjusting slot 22 to detachably fix the position sensor 6 on the top of the mobile frame 21. Different installation positions of the adjusting slot 22 can be selected through the fastener 63, so as to adjust the positions of the two position sensors 6, thereby changing the moving stroke of the laser head 4 and the wafer monitoring mechanism 5.

[0040] The wafer cutting pre-processing device of the utility model also includes a frame 7, and the mobile frame 21 is connected to the top of the material placement mechanism 1 through the frame 7. The frame 7 is provided with an indicator light 71. If the thickness of the wafer coating glue detected by the infrared thickness sensing device 51 is uneven, the computer displays that the wafer thickness does not meet the standard, the indicator light 71 lights up red, and the operator immediately takes action; if the thickness of the wafer coating glue detected by the infrared thickness sensing device 51 is uniform, the computer displays that the wafer thickness meets the standard, the indicator light 71 lights up green, and the operator performs the next laser work. The setting of the indicator light 71 can facilitate the operator to timely and intuitively understand the results of the measured wafer coating glue thickness, especially for wafers that do not meet the standard, so that they can be quickly processed.

[0041] The wafer monitoring mechanism 5 also includes a camera device 52. Since the size of the wafer 8 is generally small and its thickness is 100-780um, and the laser depth of the laser head 4 is only 10-20um, it cannot be observed by the naked eye. The camera device 52 can take real-time photos of the status of the wafer 8 on the loading tray 11 and transmit the image to the computer screen, and the operator can intuitively observe the status of the wafer 8 through the screen.

[0042] The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the described embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention, and these equivalent modifications or substitutions are all within the scope defined by the claims of this application.

Claims

1. A wafer cutting pre-processing device, characterized in that: It includes a material placement mechanism, a laser head moving mechanism, a connecting block, a laser head, and a wafer monitoring mechanism; The material placement mechanism includes a material placement tray, and the outer wall of the material placement tray is provided with a plurality of clamps; the clamps include a fixing frame, a rotating shaft, a clamping plate, and a driving member; the fixing frame is provided with a connecting groove, a connecting rod is provided in the connecting groove, and the rotating shaft is coaxially connected with the connecting rod; the side edge of the clamping plate is fixed on the side wall of the rotating shaft; the driving member is connected with the connecting rod; The connecting block is connected to the laser head moving mechanism, and the laser head and the wafer monitoring mechanism are connected to the bottom of the connecting block; the wafer monitoring mechanism includes an infrared thickness measuring sensor device, and the sensor heads of the laser head and the infrared thickness measuring sensor device are both facing the material placing mechanism.

2. The wafer cutting pre-processing device according to claim 1, characterized in that: The outer wall of the material placing tray is provided with four clamps in a circular array.

3. The wafer cutting pre-processing device according to claim 1, characterized in that: The material placing tray is provided with a plurality of honeycomb through holes, and the honeycomb through holes are connected with ventilation pipes.

4. The wafer cutting pre-processing device according to claim 1, characterized in that: It also includes a moving frame and a moving shell, the laser head moving mechanism is connected to the top of the material placement mechanism through the moving frame, the connecting block is connected to the laser head moving mechanism through the moving shell, the moving frame is provided with a limiting rod, the moving shell is provided with a through hole, and the moving shell is connected to the limiting rod through the through hole.

5. The wafer cutting pre-processing device according to claim 4, characterized in that: Two position sensors are arranged on the top of the movable frame, a sensing rod is arranged vertically on the top of the movable shell, and the sensing parts of the position sensors face downwards.

6. The wafer cutting pre-processing device according to claim 5, characterized in that: The position sensor is provided with a connecting piece, the connecting piece is provided with a connecting hole, the top of the moving frame is provided with an adjusting slot, and a fastener passes through the connecting hole and the adjusting slot to detachably fix the position sensor on the top of the moving frame.

7. The wafer cutting pre-processing device according to claim 4, characterized in that: It also includes a frame, through which the movable frame is connected above the material placing mechanism, and the frame is provided with an indicator light.

8. The wafer cutting pre-processing device according to claim 1, characterized in that: The wafer monitoring mechanism also includes a camera device.

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