Glue dispensing device and glue dispensing height calibration method

Abstract

The invention relates to the technical field of wafer dispensing, and specifically provides a dispensing device for wafer dispensing, comprising a moving unit, a dispensing unit arranged at an output end of the moving unit, and a platform unit located below the dispensing unit and used for carrying wafers; the moving unit comprises a second moving part and a third moving part; the dispensing unit comprises a needle and a non-contact distance meter, and a contact sensing element is arranged on the platform unit; the second moving part drives the non-contact distance meter and the third moving part to move to a zero position in the direction where the contact sensing element is located, and then the third moving part drives the needle to move toward the contact sensing element, contacts the contact sensing element and triggers it, and at the same time, the non-contact distance meter measures the deformation amount generated by the pressure on the contact point between the contact sensing element and the needle; in addition, a dispensing height calibration method is disclosed, which solves the problem of inaccurate dispensing height measurement due to the deformation amount of the sensor.

Description

Technical Field

[0001] The present application relates to the field of glue dispensing technology, and in particular to a glue dispensing device and a glue dispensing height calibration method. Background Art

[0002] Dispensing technology is widely used in electronics, lighting, automotive and other industries. It can be used for bonding, infusion, coating, sealing or filling in product processes. In actual production, different products have huge differences in size, shape, material and other aspects. Therefore, the needle of the dispensing machine needs to be calibrated, maintained or replaced regularly.

[0003] Especially when performing high-precision dispensing, the flatness of the product surface will also affect the dispensing accuracy and quality, so the dispensing needs to be calibrated according to the different flatness of the product surface. However, in the prior art, the dispensing head is usually used to press the sensor to a certain depth, and then slowly lift the dispensing head to find the moment when the trigger signal disappears. This solution has extremely high requirements on the sensor sensitivity and is easy to damage the needle, and ultimately cannot accurately measure and calibrate. Summary of the invention

[0004] The present invention provides a glue dispensing device and a glue dispensing height calibration method to solve the technical problem in the prior art that the glue dispensing height measurement is inaccurate due to the deformation of the sensor.

[0005] To solve the above problems, the technical solution adopted by the present invention is:

[0006] The invention provides a dispensing device for dispensing wafers, comprising a moving unit, a dispensing unit arranged at an output end of the moving unit, and a platform unit located below the dispensing unit and used for carrying wafers; the moving unit comprises a second moving part and a third moving part; the dispensing unit comprises a needle head and a non-contact distance meter, and a contact sensing element is arranged on the platform unit; the second moving part drives the non-contact distance meter and the third moving part to move to a zero position in the direction where the contact sensing element is located, and then the third moving part drives the needle head to move toward the contact sensing element, contacts the contact sensing element and triggers it, and at the same time, the non-contact distance meter measures the deformation amount generated by the pressure on the contact point between the contact sensing element and the needle head.

[0007] Furthermore, the non-contact distance meter includes a transmitting end and a receiving end, and the needle is arranged between the transmitting end and the receiving end.

[0008] Furthermore, the mobile unit includes a gantry, a first mobile part fixed on the gantry, a second mobile part connected to the output end of the first mobile part, a third mobile part connected to the output end of the second mobile part, and a fourth mobile part is provided on both sides of the third mobile part. The first mobile part can drive the dispensing unit and the second mobile part, the third mobile part, and the fourth mobile part to move horizontally, the second mobile part drives the third mobile part, the fourth mobile part and the dispensing unit to move vertically, the third mobile part drives the valve body and the needle to move vertically, and the fourth mobile part drives the dispensing unit to move longitudinally.

[0009] Furthermore, the dispensing units are divided into two or more groups.

[0010] Furthermore, the platform unit includes a carrier for placing wafers and a test table, and the test table is provided with a test section and a cleaning section; the contact sensing element is located in the test section.

[0011] Furthermore, the testing part further comprises a testing area for testing the amount of glue and a glue dispensing area. Furthermore, the surfaces of the carrier and the testing platform are both provided with a fluorine coating.

[0012] Furthermore, the carrier and the test bench are separate.

[0013] Furthermore, the conveying unit includes a first conveying part, a second conveying part and a third conveying part. The first conveying part drives the carrier and the test bench to move longitudinally, the second conveying part drives the carrier to rotate, and the third conveying part lifts the wafer vertically.

[0014] In addition, a dispensing height calibration method is also disclosed, comprising the following steps:

[0015] a. The second moving part drives the dispensing unit downward vertically to move the non-contact distance meter to the first safety position;

[0016] b. The second moving part drives the non-contact distance meter to continue to move to the zero position vertically;

[0017] c. The third moving part drives the needle and the valve body to move vertically, and contacts the sensing plane of the contact sensing element until it is triggered. The third moving part is immediately paused, and the system records the movement displacement of the third moving part as L1;

[0018] d. The non-contact distance meter measures the deformation amount caused by the pressure on the contact point between the contact sensing element and the needle, and the system records the deformation amount as L2;

[0019] e. The third moving part drives the needle to rise vertically and move to the second safety position; the system obtains the relative height between the non-contact rangefinder and the sensing plane of the contact sensing element when the non-contact rangefinder is at the zero position from the difference between L1 and L2, thereby determining the relative height between the needle and the sensing plane of the contact sensing element.

[0020] Furthermore, when the front end of the needle touches the surface of the contact sensing element, the light spot emitted by the emitting end is arranged obliquely relative to the front end of the needle.

[0021] Furthermore, the straight-line distance from the center of the light spot to the center of the needle is greater than half of the dispensing line width.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention provides a dispensing device and a dispensing height calibration method. Through the cooperation of a second moving part, a third moving part, a non-contact distance meter, a needle head and a contact sensing part, when the non-contact distance meter is at a zero value, the deformation of the triggering surface of the needle head when the contact sensor is triggered is detected, and the difference between the displacement distance of the needle head and the dispensing plane at the initial position when the non-contact distance meter is at the zero position is obtained, so that after calibration, the needle head can be driven by the third moving part to move down a distance of L1-L2-L3 (L3 is the dispensing height), so that the needle head can be accurately located at the optimal dispensing position, and high-precision dispensing can be achieved for different dispensing planes while protecting the needle head from damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution proposed in the present invention, a detailed description is given below in combination with embodiments and drawings. It should be understood that the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, these drawings can be changed under the concept of the present invention.

[0025] Figure 1 An assembly stereogram of an embodiment of a glue dispensing device provided by the present invention;

[0026] Figure 2 An assembly stereogram of an embodiment of a dispensing unit provided by the present invention;

[0027] Figure 3 An assembly perspective view of an embodiment of a platform unit provided by the present invention.

[0028] 1. Gantry; 11. Moving unit; 111. First moving part; 112. Second moving part; 113. Third moving part; 114. Fourth moving part; 12. Glue dispensing unit; 121. Valve body; 122. Needle; 123. Non-contact distance meter; 1231. Transmitter; 1232. Receiving end; 2. Transport unit; 21. First transport part; 22. Second transport part; 23. Third transport part; 3. Platform unit; 31. Carrier; 32. Test bench; 321. Cleaning part; 3211. Wiping area; 322. Test part; 3221. Contact sensing element; 3222. Glue dispensing area; 3223. Test area. DETAILED DESCRIPTION

[0029] Please also read Figure 1 In this embodiment, the present invention provides a dispensing device for dispensing wafers, including a gantry 1, the gantry 1 is made of marble and fixed on a lower frame, and a moving unit 11 is provided on the gantry 1. When the moving unit 11 moves, the marble gantry 1 plays a stabilizing role. A dispensing unit 12 is provided at the output end of the moving unit 11, and the moving unit 11 drives the dispensing unit 12 to perform horizontal, longitudinal and two-stage vertical movements; a platform unit 3 for carrying wafers is provided below the dispensing unit 12, and a conveying unit 2 for conveying wafers to the dispensing position is provided below the platform unit 3, and the conveying unit 2 drives the platform unit 3 to perform longitudinal, vertical and rotational movements.

[0030] Please also read Figure 2 In this embodiment, the dispensing unit 12 includes a needle 122 for dispensing, a valve body 121 that drives the needle 122 to move, and a non-contact distance meter 123 for measuring the distance. The non-contact distance meter 123 includes a transmitting end 1231 and a receiving end 1232. The needle 122 is arranged between the transmitting end 1231 and the receiving end 1232. The distances from the needle 122 to the transmitting end 1231 and the receiving end 1232 are the same. The transmitting end 1231 transmits to the measuring position, and is reflected from the measuring position to the receiving end 1232 to form a three-point measurement. The non-contact distance meter 123 can be a three-point laser sensor.

[0031] The moving unit 11 includes a first moving part 111 fixed on the gantry 1, a second moving part 112 connected to the output end of the first moving part 111, a third moving part 113 connected to the output end of the second moving part 112, and a fourth moving part 114 is provided on both sides of the third moving part 113. The first moving part 111 can drive the dispensing unit 12 and the second moving part 112, the third moving part 113, and the fourth moving part 114 to move horizontally, the second moving part 112 drives the third moving part 113, the fourth moving part 114 and the dispensing unit 12 to move vertically, the third moving part 113 drives the valve body 121 and the needle 122 to move vertically, and the fourth moving part 114 drives the dispensing unit 12 to move longitudinally. The first moving part 111 is mainly used to move the dispensing device to the top of the platform. The non-contact distance meter 123 is fixed on the second moving part 112. The second moving part 112 is mainly used to move the non-contact distance meter 123 to the first safety position and the zero position and then reset it again. The valve body 121 and the needle 122 are fixed on the third moving part 113. After the valve body 121 and the needle 122 move vertically synchronously with the non-contact distance meter 123 through the second moving part 112, they move vertically again through the third moving part 113, move to the contact sensing element 3221 to be triggered, and reset after being triggered, which is the above-mentioned two-stage vertical movement. There are more than two dispensing units 12. After more than two sets of valve bodies 121 and needles 122 are installed, there is still a front-to-back spacing between the more than two sets of valve bodies 121 and needles 122, that is, between the needles 122 and the needles 122. At this time, the fourth movable part 114 can be used to adjust the needles 122 and the needles 122 to be on the same horizontal line, so that multiple heads can be dispensed at the same time to improve efficiency.

[0032] Please also read Figure 3In this embodiment, the platform unit 3 includes a carrier 31 for placing wafers and a test table 32. The carrier 31 and the test table 32 are split to prevent the static electricity of the test table 32 from affecting the dispensing of wafers on the carrier 31, and the test table 32 can be placed toward the switch door for ease of operation; both the carrier 31 and the test table 32 are fluorine-plated, which can be anti-static and corrosion-resistant; a cleaning section 321 and a testing section 322 are provided on the test table 32, and the testing section 322 includes a contact sensor 3221, a testing area 3223 for testing the amount of glue, and a glue dispensing area 3222. The cleaning section 321 includes a wiping area 3211 for wiping the needle 122, and the glue amount can be measured in the testing area 3223. Test, dispense glue in the glue dispensing area 3222, observe the glue dispensing shape test, etc., and determine whether the cooperation between the valve body 121 and the needle 122 reaches the glue dispensing accuracy before officially performing the glue dispensing work; when the needle 122 performs the glue dispensing work for a period of time, according to the different glue characteristics, glue will solidify at the front end of the needle 122, and the front end of the needle 122 can be wiped through the wiping area 3211, otherwise the glue dispensing amount will be affected, and the glue dispensing accuracy cannot be achieved. The wiping method can be a friction method of moving the needle 122 left and right, or a dust-free cloth can be tightly wrapped around the front end of the needle 122 and pulled down without damaging the needle 122, so as to ensure the cleanliness of the needle 122 during glue dispensing.

[0033] The mobile unit 11 includes a first conveying part 21, a second conveying part 22 and a third conveying part 23. The first conveying part 21 will drive the carrier 31 and the test table 32 to move longitudinally. When loading the wafer, the third conveying part 23 will lift the carrier 31 and the test table 32 vertically to receive the wafer, which plays a buffering role to prevent the wafer from being damaged when it is directly placed on the carrier 31. After the wafer loading is completed, the carrier 31 and the test table 32 are moved to the bottom of the dispensing unit 12; the needle 122 is aligned with the dispensing position, and the second conveying part 22 drives the carrier 31 to rotate. After the dispensing is completed, the third conveying part 23 will vertically lower the wafer for unloading. When unloading, the material fork is inserted into the middle gap between the wafer and the third conveying part 23 to ensure that the unloading action is completed quickly without damaging the finished product.

[0034] In this embodiment, a method for calibrating dispensing height is disclosed, comprising:

[0035] a. The second moving part 112 drives the dispensing unit 12 to descend vertically (i.e., in the direction of the contact sensing element 3221), and moves the non-contact distance meter 123 to the first safety position; it should be noted that the first safety position is a preset position where the non-contact distance meter 123 is located above the contact sensing element 3221 and does not interfere with other components, and is within the measuring range of the non-contact distance meter 123.

[0036] b. The second movable part 112 drives the non-contact distance meter 123 to move to the zero position in the vertical direction; wherein, the method for determining the zero position may be: the second movable part 112 drives the non-contact distance meter 123 to move down to a position within its sensing range, within which a distance S may be preset, and when the second movable part 112 drives the non-contact distance meter 123 to move down, the non-contact distance meter 123 detects the triggering surface of the contact sensing element 3221 and continues to measure the distance until the test distance reaches S, and the position of the second movable part 112 is defined as the zero position or the zero position of the non-contact distance meter 123.

[0037] c. The third moving portion 113 drives the needle 122 and the valve body 121 to start moving vertically toward the triggering surface of the contact sensing element 3221;

[0038] d. until the contact sensing element 3221 is triggered; at this time, the distance moved by the third moving part 113 is read, and the distance is defined as L1; the non-contact distance meter measures the deformation of the surface of the contact sensing element 3221, and the deformation is defined as L2.

[0039] e. The third moving part 113 drives the needle 122 and the valve body 121 to rise vertically and move to the second safety position. It should be noted that the second safety position is a preset position where the needle 122 is above the contact sensor 3221 and does not interfere with other components.

[0040] f. The controller calculates that the zero position of the needle 122 is when the non-contact rangefinder 123 reaches the zero position, and the third movable part 113 drives the needle 122 to move down a distance of L1-L2, at which time the position of the needle 122 is the zero position height of the needle 122; the preset dispensing height is L4, and the third movable part 113 drives the needle 122 to move down a distance of L1-L2-L3, at which time the position of the needle 122 is the dispensing height of the needle 122.

[0041] Specifically, in this embodiment, the first moving part 111 moves the dispensing device to the top of the platform, at which time the needle 122 is located above the contact sensing element 3221, and the non-contact distance meter 123 is moved to the zero position by the second moving part 112. At this time, the non-contact distance meter 123 displays zero; next, the second moving part 112 keeps the non-contact distance meter 123 at the zero position, and the third moving part 113 drives the needle 122 to move to the zero position. When the valve body 121 moves to the trigger sensing position of the contact sensing element 3221 and the contact sensing element 3221 has a contact signal, the third moving part 113 is immediately suspended, and the system records the movement amount of the third moving part 113 as L1. Since the contact sensing element 3221 has high sensitivity and a certain elasticity on its surface, when the front end of the needle 122 presses against the contact sensing element 3221, the surface of the contact sensing element 3221 is elastically deformed or slightly moved downward by the downward pressure applied by the needle 122. The non-contact distance meter 123 can calculate the change of the contact sensing element 3221 through the distance S collected when it is in the zero position and the distance S1 collected after the trigger. The shape L2 is S1-S, and the system records this parameter as L2. At this time, by calculating the difference between L1 and L2, it can be concluded that when the non-contact distance meter 123 is at the zero point, the distance between the initial position of the needle 122 and the zero position is L1-L2. That is to say, when the non-contact distance meter 123 is at the zero point, the third moving part 113 drives the needle 122 to move down from the initial position by a distance of L1-L2. At this time, the position of the needle 122 is the zero position height of the needle 122; the preset dispensing height is L3, and the third moving part 113 drives the needle 122 to move down by a distance of L1-L2-L3. At this time, the position of the needle 122 is the dispensing height of the needle 122. In order to ensure the accuracy of dispensing, the above steps ae need to be performed once before each dispensing, and then dispensing can be started.

[0042] This method can prevent the dispensing from being affected by changes in the flatness of the wafer and the carrier 31, so that the needle 122 is at an accurate height each time the dispensing starts.

[0043] Of course, it should also be noted that, in the present embodiment, the trigger surface of the contact sensing element 3221 is set to be on the same horizontal plane as the dispensing plane of the wafer (the horizontal height difference between the trigger surface and the dispensing plane is within the error range, such as ±0.5mm). From this, it can be concluded that when the non-contact distance meter 123 is at the zero position, the relative height of the needle 122 from the dispensing plane is L1-L2. Then, each time the second moving part 112 drives the non-contact distance meter 123 to be at the zero position, the third moving part 113 drives the needle 122 to move down a distance of L1-L2. It is considered that the height difference between the lower end of the needle 122 and the dispensing plane of the wafer is zero (that is, zero within the height difference error range that meets the design requirements). Then, according to the set dispensing height L3, the third moving part 113 drives the needle 122 to move down a distance of L1-L2-L3. At this time, the needle 122 is located at the best dispensing position, thereby performing precise dispensing.

[0044] In addition, considering the error caused by the deformation of the contact sensor 3221, each time the needle 122, the valve body 121 is replaced or the related structural parts are adjusted, recalibration is performed after the machine is turned on and off to eliminate the error caused by it.

[0045] In addition, considering that the non-contact rangefinder 123 may be interfered with by the needle 122 when measuring, in this embodiment, when the front end of the needle 122 touches the surface of the contact sensing element 3221, the light spot emitted by the transmitting end 1231 is offset by a set distance relative to the front end of the needle 122. If the setting overlaps, the needle 122 will block the light spot emitted by the transmitting end 1231, and then the receiving end 1232 will not be able to receive the reflected light signal, and the measurement will not be achieved. In addition, it should be noted that because the transmitting end 1231 The emitted light spot and the drawn glue dispensing line width both have a radius. When the center of the light spot is too close to the center of the glue dispensing line width, the light spot will be blocked. Therefore, it is necessary to set the straight-line distance from the center of the light spot emitted by the transmitting end 1231 to the center of the front end of the needle 122 to be greater than half of the glue dispensing line width. For example, if the glue dispensing line width is 0.6mm and the glue dispensing radius is 0.3mm, that is, the straight-line distance from the center of the light spot to the glue dispensing center is greater than 0.3mm, and the offset distance from the center of the light spot to the glue dispensing center is greater than 0.43mm, in order to ensure reliable distance measurement and thus ensure glue dispensing accuracy.

[0046] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0047] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] The above is a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for calibrating the dispensing height of a dispensing device, used for dispensing on wafers, characterized in that: The invention comprises a moving unit (11), a dispensing unit (12) arranged at the output end of the moving unit (11), and a platform unit (3) located below the dispensing unit (12) and used for carrying a wafer; the moving unit (11) comprises a second moving part (112) and a third moving part (113); the dispensing unit (12) comprises a needle (122) and a non-contact distance meter (123); a contact sensing element (3221) is arranged on the platform unit (3); the second moving part (112) drives the non-contact distance meter (123) to move the needle (122) and the non-contact distance meter (123); After the contact distance meter (123) and the third moving part (113) move to a zero position in the direction of the contact sensing element (3221), the third moving part (113) drives the needle head (122) to move toward the contact sensing element (3221) to contact the contact sensing element (3221) until it is triggered, and at the same time, the non-contact distance meter (123) measures the deformation amount generated by the pressure on the contact point between the contact sensing element (3221) and the needle head (122); The following steps are also included: a. the second moving part (112) drives the dispensing unit (12) to descend vertically, and moves the non-contact distance meter (123) to a first safety position; b. the second moving part (112) drives the non-contact distance meter (123) to continue moving to the zero position in the vertical direction; c. The third movable part (113) drives the needle (122) and the valve body (121) to move vertically, and contacts the sensing plane of the contact sensing element (3221) until it is triggered. The third movable part (113) is immediately paused, and the system records the movement displacement of the third movable part (113) as L1; d. the non-contact distance meter (123) measures the deformation amount generated by the pressure on the contact point between the contact sensing element (3221) and the needle (122), and the system records the deformation amount as L2; e. The third moving part (113) drives the needle head (122) to rise vertically and move to the second safety position; the system obtains the relative height between the non-contact distance meter (123) and the sensing plane of the contact sensing element (3221) when the non-contact distance meter (123) is at the zero position from the difference between L1 and L2, thereby determining the relative height between the needle head (122) and the sensing plane of the contact sensing element (3221).

2. The method for calibrating the dispensing height of a dispensing device according to claim 1, characterized in that: The non-contact distance meter (123) comprises a transmitting end (1231) and a receiving end (1232), and the needle head (122) is arranged between the transmitting end (1231) and the receiving end (1232).

3. The method for calibrating the dispensing height of a dispensing device according to claim 1, characterized in that: The moving unit (11) comprises a gantry (1), a first moving part (111) fixed on the gantry (1), a second moving part (112) connected to an output end of the first moving part (111), a third moving part (113) connected to an output end of the second moving part (112), and fourth moving parts (114) are arranged on both sides of the third moving part (113); the first moving part (111) can drive the dispensing unit (12) and the second moving part (112), the third moving part (113), and the fourth moving part (114) to perform lateral movement; the second moving part (112) drives the third moving part (113), the fourth moving part (114), and the dispensing unit (12) to perform vertical movement; the third moving part (113) drives the valve body (121) and the needle (122) to perform vertical movement; and the fourth moving part (114) drives the dispensing unit (12) to perform longitudinal movement.

4. The method for calibrating the dispensing height of a dispensing device according to claim 3, characterized in that: The dispensing units (12) are in groups of two or more.

5. The method for calibrating the dispensing height of a dispensing device according to claim 1, characterized in that: The platform unit (3) comprises a carrier (31) for placing wafers and a test table (32); the test table (32) is provided with a test section (322) and a cleaning section (321); the contact-type sensing element (3221) is located in the test section (322).

6. The method for calibrating the dispensing height of a dispensing device according to claim 5, characterized in that: The testing portion (322) further comprises a testing area (3223) for testing the amount of glue and a glue dispensing area (3222).

7. The method for calibrating the dispensing height of a dispensing device according to claim 5, characterized in that: The surfaces of the carrier (31) and the test platform (32) are both provided with a fluorine coating.

8. The method for calibrating the dispensing height of a dispensing device according to any one of claims 5 to 7, characterized in that: The carrier (31) and the test bench (32) are separate.

9. The method for calibrating the dispensing height of a dispensing device according to claim 8, characterized in that: The invention also comprises a transport unit (2), wherein the transport unit (2) comprises a first transport part (21), a second transport part (22) and a third transport part (23), wherein the first transport part (21) drives the carrier (31) and the test table (32) to move longitudinally, the second transport part (22) drives the carrier (31) to rotate, and the third transport part (23) lifts the wafer vertically.

10. The method for calibrating the dispensing height of a dispensing device according to claim 2, characterized in that: When the front end of the needle (122) touches the surface of the contact-type sensing element (3221), the light spot emitted by the emitting end (1231) is arranged obliquely relative to the front end of the needle (122).

11. The method for calibrating the dispensing height of a dispensing device according to claim 10, characterized in that: The straight-line distance from the center of the light spot to the center of the needle (122) is greater than half the glue dispensing line width.

Images