Method and device for detecting in situ the quality of the conductive adhesive bonding of a quartz wafer

Abstract

The application discloses a method and device for detecting the conductive glue bonding quality of a quartz wafer in situ, and the method comprises the following steps: a, determining a testable area on the wafer; b, inputting an image recognition system with a teaching module to accurately identify the testable area; c, testing the test area of the wafer electrode with a probe, and reading the resistance value, that is, the on-resistance value of the conductive glue; and d, displaying and storing the resistance value obtained by the test into a database for data analysis and product tracing. The application realizes real-time and effective control of the quartz resonator processing technology and quality by monitoring the conductive glue bonding quality of a quartz resonator in a pre-processing stage, and achieves the purposes of improving product yield and avoiding waste of production resources.

Description

Technical Field

[0001] This invention relates to the field of quartz crystal manufacturing technology, and in particular to a method and apparatus for on-site testing of the bonding quality of conductive adhesive on quartz wafers during the quartz crystal production process. Background Technology

[0002] With the rapid development of electronic information technology, fields such as aerospace, navigation, communication, and measurement and control are placing increasingly higher demands on the short-term stability, long-term stability, and reliability of frequency sources. As a core component of high-precision frequency sources, high-stability quartz crystals require extremely low fault tolerance, thus their reliability is receiving increasing attention.

[0003] Currently, quartz crystal manufacturers are striving to control the quality of raw materials and auxiliary materials during production, including the purity of quartz materials, the material of the base and spring contacts, cleaning solvents, and conductive adhesives. They are also paying closer attention to process control, such as the cleaning time and method of the wafers, the amount of conductive adhesive, curing time, and curing temperature, to ensure a high yield rate. In the production of quartz resonators, the control of the pre-processing stage plays a decisive role. The dispensing process, as a key node in quartz resonator manufacturing, directly affects the resonator's resistance, electrostatic capacitance, and other key indicators, as well as its electrical performance throughout its lifespan. However, due to the lack of effective testing methods in the pre-processing stage, the resistance, DLD, and other indicators of the resonator are generally only tested after processing is complete. The disadvantage of this method is that it cannot promptly eliminate potential problems during the resonator processing, leading to a low final product yield and wasted production resources. Summary of the Invention

[0004] This invention provides a method and apparatus for on-site testing of the bonding quality of conductive adhesive on quartz wafers. The aim is to achieve real-time and effective control over the processing technology and quality of quartz resonators by monitoring the bonding quality of conductive adhesive in the pre-processing stage of quartz resonators, thereby improving product yield and avoiding waste of production resources.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for on-site testing of the bonding quality of conductive adhesive on quartz wafers involves testing the bonding quality of the conductive adhesive after the adhesive application and curing processes are completed during the production of quartz resonators. The method includes the following steps:

[0007] a. Based on the size, frequency, and other information of the workpiece being tested, the core energy region of the wafer oscillation is determined using the oscillation energy range formula. Then, combined with empirical values, the core energy region of the wafer oscillation is avoided, and the testable area on the wafer is determined.

[0008] b. Based on the determined testable area of ​​the wafer, the vertex of the upper right (or lower right) angle between the spring and the electrode is taken as the positioning origin. The teaching module is used to input it into the image recognition module system to accurately identify the testable area.

[0009] c. Use probes to test the testable areas of the wafer electrodes, and read the resistance value through a digital bridge, which is the on-resistance value of the conductive adhesive;

[0010] d. Display and store the resistance values ​​obtained from the test into the database for analysis of the conductive adhesive bonding quality of the workpiece and traceability of the product. Workpieces that do not meet the requirements are reworked or scrapped, while qualified workpieces enter the next processing step.

[0011] In the above method for on-site testing of the bonding quality of conductive adhesive on quartz wafers, in step a, the core energy region of the oscillation of the workpiece being tested is a region with a diameter of d. a The formula for calculating the circular region is: , where d a Where is the diameter of the core energy region, n is the overtone order (n=1,3,5…), h is the wafer thickness, and R is the coating radius on the wafer.

[0012] In the above-mentioned method for on-site testing of the bonding quality of conductive adhesive on quartz wafers, in step a, there are two testable areas on the wafer, on the front and back sides respectively. The testable areas are described as follows: starting from the center of the wafer, outside the core energy region of the wafer oscillation, and within the beveled area of ​​the coating. If the wafer has a beveled edge, the beveled area should be avoided.

[0013] In the above-mentioned method for on-site testing of the bonding quality of conductive adhesive on quartz wafers, in step c, the resistance value is tested by a digital bridge. The actual test point is between the crystal lead and the wafer electrode, and the resistance measured between the two points is the conductivity resistance of the conductive adhesive.

[0014] The above-mentioned method for on-site testing of the bonding quality of conductive adhesive on quartz wafers includes, in step d, information in the database including: production batch number, base model, base manufacturer, wafer cleaning conditions, adhesive curing process, adhesive curing equipment, etc.

[0015] A device for on-site testing of the bonding quality of conductive adhesive on quartz wafers includes a workbench and, mounted on the workbench, a teaching module, an image recognition module, a test position alignment module, a test probe module, a rotating platform module, a digital bridge, a computer, and a software system; wherein:

[0016] The teaching module is used to input the calculated and determined test range into the image recognition module system;

[0017] An image recognition module is used to accurately identify testable areas on wafer electrodes;

[0018] The test position alignment module is used to accurately align the test position according to the image recognition.

[0019] Test probe module, a unit used for direct contact with the testable area;

[0020] A rotating platform module is used to rotate a wafer to the other side after testing on one side.

[0021] A digital bridge is used to test the on-resistance of conductive adhesive.

[0022] Computer and software systems are used to receive feedback signals from various modules and to drive and coordinate the actions of these modules.

[0023] The above-mentioned device for on-site testing of the bonding quality of conductive adhesive on quartz wafers includes a test position alignment module comprising an X-axis and Z-axis adjustment assembly and a Y-axis adjustment assembly. Both the X-axis and Z-axis adjustment assembly and the Y-axis adjustment assembly are motor-driven lead screw and nut transmission assemblies, with the nut moving along the lead screw axis. The Y-axis adjustment assembly is mounted on the nut of the X-axis and Z-axis adjustment assembly.

[0024] In the aforementioned device for on-site testing of the bonding quality of conductive adhesive on quartz wafers, both the image recognition module and the test probe module are mounted on the nut of the Y-axis adjustment assembly. The Y-axis motor drives the lead screw nut transmission assembly to move the image recognition module and the test probe module closer to or further away from the workpiece being tested.

[0025] The aforementioned device for on-site testing of the bonding quality of conductive adhesive on quartz wafers has two sets of spring probes arranged in parallel on the test probe module.

[0026] The aforementioned device for on-site testing of the bonding quality of conductive adhesive on quartz wafers includes a rotating platform module equipped with a rotating motor and a rotating table. The output shaft of the rotating motor is connected to the rotating table, and the workpiece to be tested is mounted on the rotating table.

[0027] This invention provides a method for on-site testing of the bonding quality of conductive adhesive on quartz wafers. It can determine the bonding quality of conductive adhesive by testing its conduction resistance online. This method can monitor the quality of raw materials and the execution of processing technology in the early stages of quartz resonator processing in a timely manner. Furthermore, it can analyze real-time statistical data to facilitate timely identification and handling of quality problems in the workpiece during processing, thereby improving product yield and avoiding waste of production resources.

[0028] The present invention also provides a device for on-site detection of the bonding quality of conductive adhesive on quartz wafers. It provides equipment support for quality control of the dispensing process in the pre-processing stage of quartz resonators, thereby ensuring timely judgment and handling of quality problems existing in the workpiece during the processing. Attached Figure Description

[0029] Figure 1 This is a flowchart of a method for on-site testing of the bonding quality of conductive adhesive on quartz wafers;

[0030] Figure 2 This is a schematic diagram of the structure of the workpiece being inspected;

[0031] Figure 3 yes Figure 2 Side view;

[0032] Figure 4 This is a schematic diagram of a device for on-site testing of the bonding quality of conductive adhesive on quartz wafers.

[0033] The labels in the diagram represent:

[0034] 1 is the workpiece to be tested, 1-1 is the testable area, 1-2 is the core energy region of the crystal oscillation, 1-3 is the chamfered area, and 1-4 is the crystal lead.

[0035] 2 is the teaching module; 3 is the image recognition module; 4 is the Y-axis adjustment component; 5 is the X-axis and Z-axis adjustment component; 6 is the digital bridge; 7 is the computer and software system; 8 is the rotary platform module; 9 is the test probe module; 10 is the workbench. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0037] See Figure 1 , Figure 2 , Figure 3 , Figure 4 This invention provides a method for on-site testing of the bonding quality of conductive adhesive on quartz wafers. The method involves testing the bonding quality of the conductive adhesive after the adhesive application and curing processes are completed during the production of quartz resonators. The method includes the following steps:

[0038] a. Based on the size, frequency, and other information of the workpiece 1 under test, the core energy region 1-2 of the wafer oscillation is determined using the formula for the oscillation energy range of the wafer. Since the oscillation of the wafer is mainly concentrated in the core energy region during normal operation, damage to this region (quartz body and coating) will directly affect the product quality. Therefore, this region needs to be avoided during testing. This invention determines the oscillation core energy region for each type of wafer under test according to the following formula and with reference to different processes and empirical values. The core energy region range of the oscillation of the workpiece 1 under test is a diameter of d. a The formula for calculating the circular region is: , where d aLet be the diameter of the core energy region, n be the overtone order (n=1,3,5…), h be the wafer thickness, and R be the coating radius on the wafer. The test area must meet two conditions: 1) it must be a non-oscillating core energy region; 2) the region must have a coating. Based on these conditions, there are two testable regions 1-1 on the wafer, located on the front and back sides respectively. Typically, the testable region is described as the coating extending from the wafer center, outside the core energy region 1-2 of the wafer oscillation, and within the chamfered region 1-3. If the wafer has a chamfered edge, the chamfered region 1-3 should be avoided.

[0039] b. Based on the testable area 1-1 of the wafer determined in step a, take the vertex of the upper right (or lower right) angle between the spring and the electrode as the positioning origin, and input it into the image recognition module 3 system through the teaching module 2 to accurately identify the testable area 1-1;

[0040] c. Start the test. Clamp the workpiece 1 to be tested and place it on the rotating platform module 8. Start the image recognition module 3 and the alignment module. Through the X-axis and Z-axis adjustment components 5 and the Y-axis adjustment component 4, make the probe of the test probe module 9 contact the test area of ​​the wafer electrode. Since the actual test point is between the crystal lead 1-4 and the wafer electrode, and since both the crystal lead and the wafer electrode are metals and good conductors, ignore the slight impedance generated by them. The resistance measured between the two points of the crystal lead 1-4 and the wafer electrode is the conduction resistance of the conductive adhesive. The resistance value can be read through the digital bridge 6 to complete the single-sided test of the workpiece. Then the rotating platform module 8 rotates 180° to test the other side of the workpiece 1. The resistance values ​​read twice are the conduction resistance values ​​of the conductive adhesive.

[0041] d. Display and store the resistance values ​​obtained from the test into the database for analysis of the conductive adhesive bonding quality of the workpiece and traceability of the product. Workpieces that do not meet the requirements are reworked or scrapped, while qualified workpieces enter the next processing step. To achieve product traceability, the information in the database also includes: production batch number, base model, base manufacturer, wafer cleaning conditions, adhesive curing process, adhesive curing equipment, etc.

[0042] See Figure 4 The present invention also provides an apparatus for on-site testing of the bonding quality of conductive adhesive on quartz wafers, used to perform the above-mentioned testing of the bonding quality of conductive adhesive on quartz wafers. It includes a workbench 10 and, mounted on the workbench 10, a teaching module 2, an image recognition module 3, a test position alignment module, a test probe module 9, a rotating platform module 8, a digital bridge 6, and a computer and software system 7; wherein:

[0043] Teaching module 2 is used to input the calculated and determined test range into the image recognition module 3 system;

[0044] Image recognition module 3 is used to accurately identify the testable area 1-1 on the wafer electrode;

[0045] The test position alignment module is used to perform precise alignment according to the test position identified by the image. It includes X-axis and Z-axis adjustment components 5 and Y-axis adjustment components 4. Both X-axis and Z-axis adjustment components 5 and Y-axis adjustment components 4 are motor-driven lead screw and nut transmission components. Under the drive of the motor, the lead screw rotates and the nut moves along the lead screw axis. The Y-axis adjustment component is installed on the nut of the X-axis and Z-axis adjustment components 5.

[0046] The test probe module 9 is a unit used to directly contact the testable area 1-1. Both the image recognition module 3 and the test probe module 9 are mounted on the nut of the Y-axis adjustment component 4. Two sets of spring probes are arranged in parallel on the test probe module 9. The two sets of spring probes of the image recognition module 3 and the test probe module 9 are driven by the Y-axis motor to move the lead screw nut transmission component to approach or move away from the workpiece 1 being tested.

[0047] The rotating platform module 8 is used to rotate the wafer to the other side after testing one side. The rotating platform module 8 is equipped with a rotating motor and a rotating table. The output shaft of the rotating motor is connected to the rotating table, and the workpiece 1 to be tested is installed on the rotating table.

[0048] Digital bridge 6 is used to test the on-resistance value of conductive adhesive;

[0049] The computer and software system 7 is used to receive feedback signals from each module and drive and coordinate the actions of the aforementioned modules.

Claims

1. A method for on-site testing of the bonding quality of conductive adhesive on quartz wafers, wherein the testing is performed using an on-site testing device for conductive adhesive bonding on quartz wafers, comprising a workbench (10) and a teaching module (2), an image recognition module (3), a test position alignment module, a test probe module (9), a rotating platform module (8), a digital bridge (6), a computer and software system (7) mounted on the workbench (10), wherein the test probe module (9) has two sets of spring probes arranged in parallel; Its features are: After the adhesive application and curing processes are completed during the production of quartz resonators, the quality of the conductive adhesive bonding is inspected, including the following steps: a. Based on the size and frequency of the workpiece (1) being tested, the core energy region of the wafer oscillation (1-2) is determined using the wafer oscillation energy range formula. The testable area on the wafer (1-1) is determined by avoiding the core energy region of the wafer oscillation (1-2). The core energy region of the oscillation of the workpiece (1) being tested is a region with a diameter of d. a The formula for calculating the circular region is: , where d a Where is the diameter of the core energy region, n is the overtone order (n=1,3,5…), h is the wafer thickness, and R is the coating radius on the wafer. b. Based on the determined testable area of ​​the wafer (1-1), take the vertex of the upper right or lower right angle between the spring and the wafer electrode as the positioning origin, and input it into the image recognition module (3) system through the teaching module (2) to accurately identify the testable area (1-1). c. Use a probe to test the testable area (1-1) of the chip, and read the resistance value through a digital bridge, which is the conduction resistance value of the conductive adhesive; The resistance value is tested by digital bridge (6). The actual test points are the crystal lead (1-4) and the wafer electrode. The resistance measured between the two points is the conduction resistance of the conductive adhesive. d. Display and store the resistance values ​​obtained from the test into the database for analysis of the conductive adhesive bonding quality of the workpiece and traceability of the product. Workpieces that do not meet the requirements are reworked or scrapped, while qualified workpieces enter the next processing step.

2. The method for on-site testing of the bonding quality of conductive adhesive on quartz wafers according to claim 1, characterized in that: In step a, there are two testable areas (1-1) on the wafer, on the front and back sides of the wafer respectively. The testable area (1-1) is described as the coating outside the core energy region (1-2) of the wafer oscillation, starting from the center of the wafer, and inside the chamfered area (1-3). If the wafer has a chamfered edge, the chamfered area (1-3) is avoided.

3. The method for on-site testing of the bonding quality of conductive adhesive on quartz wafers according to claim 1, characterized in that: In step d, the information in the database includes: production batch number, base model, base manufacturer, wafer cleaning conditions, adhesive curing process, and adhesive curing equipment.

4. The method for on-site testing of the bonding quality of conductive adhesive on quartz wafers according to claim 1, characterized in that: in, The teaching module (2) is used to input the calculated and determined test range into the image recognition module (3) system; The image recognition module (3) is used to accurately identify the testable area (1-1) on the wafer electrode. The test position alignment module is used to perform precise alignment according to the test position identified by the image; The rotating platform module (8) is used to rotate the wafer to the other side after testing one side of the wafer; The test probe module (9) is a unit used to directly contact the testable area (1-1); The digital bridge (6) is used to test the on-resistance value of the conductive adhesive; The computer and software system (7) is used to receive feedback signals from each module and drive and coordinate the actions of each module.

5. The method for on-site testing of the bonding quality of conductive adhesive on quartz wafers according to claim 4, characterized in that: The test position alignment module includes an X-axis and Z-axis adjustment assembly (5) and a Y-axis adjustment assembly (4). The X-axis and Z-axis adjustment assembly (5) and the Y-axis adjustment assembly (4) are both motor-driven lead screw and nut transmission assemblies. The nut moves along the lead screw axis. The Y-axis adjustment assembly is installed on the nut of the X-axis and Z-axis adjustment assembly (5).

6. The method for on-site testing of the bonding quality of conductive adhesive on quartz wafers according to claim 4, characterized in that: The image recognition module (3) and the test probe module (9) are both installed on the nut of the Y-axis adjustment assembly (4). The Y-axis motor drives the lead screw nut transmission assembly to move the image recognition module (3) and the test probe module (9) closer to or further away from the workpiece (1) being tested.

7. The method for on-site testing of the bonding quality of conductive adhesive on quartz wafers according to claim 4, characterized in that: The rotating platform module (8) is equipped with a rotating motor and a rotating table. The output shaft of the rotating motor is connected to the rotating table, and the workpiece (1) to be inspected is installed on the rotating table.

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