Method and equipment for detecting defects of thin film transistor panelTechnical Field
The invention relates to a method and equipment for detecting defects of a thin film transistor panel, in particular to a method and equipment for detecting defects by scanning lines on the panel by a thermal imager.
Background
Currently, the panel industry in taiwan is mainly a Thin-Film Transistor (TFT) Liquid Crystal Display (LCD), which is formed by laminating a TFT panel and another color filter (color filter, CF), and then filling Liquid Crystal. The process includes a front-end Array (Array) process and a back-end Panel assembly (Cell) process, and during the manufacturing process of the TFT Panel (Panel), an electrical inspection apparatus must be used to detect the defects of the TFT Panel, so as to ensure the quality of the product.
Referring to fig. 1, a non-contact detection technique for defects of a TFT panel 10 is shown, in which a sensor head (sensor head)11 is used as a feeding electrode, and a voltage of about 500V (depending on the product and user settings) is applied to a circuit 12 by using an alternating current, and a distance DP of 150 μm to 100 μm is maintained between the sensor head 11 and the circuit 12, that is, air in the space is used as a medium, then a minute induced current is generated by using a capacitance principle, and after sensing its minute current, a signal is amplified by a non-contact receiving electrode 13 and an amplifier 14, so that a corresponding voltage can be output. When the signal change SC shown in fig. 2 is detected in the line 15, the position 20 of the Defect (Defect) having the Open or Short circuit (Short) in the line 15 is detected.
Referring to fig. 3, another contact detection technique for defects of a TFT panel 30 is shown, in which a Probe (Probe)31 on a Probe station (Prober) is used as a feeding electrode, and a Direct Current (DC) is used to apply a voltage of about 20V (depending on the product and the user setting) to a line 32, and the Probe 31 is in direct contact with the line 32 to sense the voltage or current of the line, and the signal is amplified by another Probe 33 as a receiving electrode and an amplifier 34. When the line 32 is detected to have the signal change SC as shown in fig. 4, it is the most normal practice to detect that the line 35 is the Defect (Defect) position 40 with the Open or Short circuit (Short).
Referring to fig. 5, another contact detection technique for defects of a TFT panel 50 is shown, in which a probe 51 is used as a feeding electrode and a voltage is applied to a line 52 by using an alternating current, the probe 51 and the line 52 are in direct contact, but a non-contact receiving electrode 53 and an amplifier 54 amplify signals at the receiving electrode portion instead.
However, the above three detection methods still have their insurmountable disadvantages, including: four types of defects, namely, a broken line and a short circuit defect of a peripheral circuit, a broken line and a short circuit defect of a drive IC circuit (GOA), a broken line and a short circuit defect of a pixel area circuit, and a defect of a micro broken line 63 of the circuits 61 and 62 shown in fig. 6, wherein the micro broken line 63 may be caused by impurities such as particles (particles), which originally belong to a part of a Pattern (Pattern), and is peeled and dropped by being cleaned by a cleaning machine, when a driving voltage V is applied to the circuits 61 and 62 (a dotted line DR indicates a current direction), the micro broken line 63 cannot be detected in a normal manner because a current still flows at the micro broken line 63 which is not interrupted but has a large piece of wire left but is not broken, but the micro broken line 63 may be immediately broken or broken by being driven by a too strong high voltage after a subsequent process or after being used for a long time by a user after being made into a product.
The four defects are not easily detected in the Array section, but usually are found only at the lighting site of the Cell section, but the defect can be detected at the lighting site of the Cell section, but the repair yield is low. Moreover, the broken line defect cannot be repaired at the Cell Repair station (Cell Repair), because the broken line defect can be repaired only at the Laser chemical vapor deposition (Laser CVD) section in the Array section, and the short-circuit defect can be repaired at the Cell Repair, but the success rate of the Cell Repair is lower than that of the Array section.
For this reason, how to solve the problem that the four defects are not easy to be detected in the Array section, after the inventor focuses on experiments, tests and researches, a method and an apparatus for detecting the defects of the thin film transistor panel are finally obtained, which not only effectively detect the four defects in the Array section, but also have the effect of improving the repair yield. That is, the present invention is directed to solve the problems of how to overcome the difficulty in detecting a disconnection or short defect of a line in an Array section, so that the disconnection or short defect of the line can be repaired in the Array section, how to overcome the problem that a location where the defect exists needs to be located, and how to overcome the problem that a location where the defect exists needs to be repaired according to a repair path.
Disclosure of Invention
The invention discloses a method for detecting defects of a Thin Film Transistor (TFT) panel, which comprises the steps of applying voltage to a circuit of the panel, wherein the circuit comprises a plurality of positions, scanning the positions by using a thermal imager to obtain a plurality of temperature image data of the positions, comparing the temperature image data with normal temperature image data to detect abnormal image data, and marking all the positions corresponding to the abnormal images as defective positions when the temperature of the corresponding positions represented by the abnormal image data is judged to be higher than a user set value so as to be beneficial to subsequent processes.
In addition, from the main technical point of view, the present invention also discloses a method for detecting defects of a Printed Circuit Board (PCB), comprising applying a voltage to a circuit of the PCB, wherein the circuit comprises a plurality of locations, scanning the plurality of locations of the circuit by a thermal imager to obtain a plurality of temperature image data corresponding to each of the plurality of locations, comparing each of the plurality of temperature image data corresponding to each of the plurality of locations with normal temperature image data to detect abnormal image data, and marking the location corresponding to the abnormal image as a defect location when the temperature of the specific location represented by the abnormal image data is higher than a user set value, so as to facilitate a subsequent process.
The present invention also discloses a method for detecting defects of a semiconductor, wherein the semiconductor has a circuit, and the circuit includes a plurality of locations, the method includes powering on the circuit, measuring the temperature of each location one by one to obtain a plurality of temperature image data of the plurality of locations, comparing each of the plurality of temperature image data with reference temperature image data to detect abnormal images, and when the difference between the temperature data of each abnormal image and the reference temperature is greater than a user set value, determining each location corresponding to the temperature data of each abnormal image as a defective location to facilitate subsequent processes.
The present invention may also be an apparatus for detecting whether a semiconductor has a circuit, wherein the circuit includes a plurality of positions, the apparatus includes a power-on component configured to power on the circuit, a measurement component configured to measure temperatures of the positions one by one to obtain temperature data of the positions, and a comparison component configured to compare the temperature data with reference temperature image data to detect an abnormal image, and when a difference between the temperature data of the abnormal image and the reference temperature is greater than a user setting value, determine that the position corresponding to the temperature data is a defective position, so as to facilitate a subsequent process.
Drawings
FIG. 1 is a side view of a known technique for non-contact detection of defects in a TFT panel;
FIG. 2 is a side view of the inspection technique of FIG. 1 in the presence of a defect;
FIG. 3 is a side view of a well-known contact detection technique for TFT panel defects;
FIG. 4 is a side view of the inspection technique of FIG. 3 in the presence of a defect;
FIG. 5 is a side view of a well-known hybrid contact and non-contact inspection technique for TFT panel defects;
FIG. 6 is a top view of a conventional TFT panel with normal wiring and wiring having a micro-disconnection defect;
FIG. 7 is a top view of peripheral circuits in the method for detecting defects in a Thin Film Transistor (TFT) panel according to the preferred embodiment of the present invention;
FIG. 8 is a top view of a defect existing between peripheral lines;
FIG. 9 is a top view of a repair path based on the coordinates of the defect location;
FIG. 10 is a photograph of a portion of the peripheral circuit having an abnormal image after being scanned by the thermal imager;
FIG. 11 is a top view of a thermal imager mounted on a gantry structure for scanning and movement.
Detailed Description
In order to make four well-known defects be detected in the Array section, the present invention provides the following method and apparatus for detecting defects in a Thin Film Transistor (TFT) panel.
Referring to fig. 3 and 7, a Thin Film Transistor (TFT) panel 30 and the peripheral circuits 71, 72 in the defect detection method thereof according to the preferred embodiment of the invention are shown, including a circuit (e.g., the peripheral circuits 71, 72) contacting the panel 30 by using a probe 31, and further applying a voltage to the circuit, the voltage being from a power-on element 301, wherein the circuit 72 includes a plurality of positions 721, 722, a Thermal imager 75 scans the plurality of positions 721, 722 to obtain a plurality of temperature image data of the plurality of positions 721, 722, and compares the plurality of temperature image data with normal temperature image data to detect abnormal image data, when it is determined that the temperature of the corresponding position (e.g., the position 722) represented by the abnormal image data is higher than a user set value, all the positions corresponding to the abnormal images are marked as defective positions (e.g., the position 722), so as to be beneficial to the subsequent process.
The circuit can be a peripheral circuit, a drive IC circuit or a pixel area circuit, and the position with the defect has a broken line defect, a short circuit defect or a micro broken line defect. The normal temperature image data corresponds to the user set value, and the drive IC circuit is manufactured by adopting a Gate Driver on Array (GOA) technology.
Referring to fig. 8, there is shown a defect 84, 85 between peripheral lines 81, 82, 83. Referring to fig. 9, an operator marks coordinates of the defect locations, where the coordinates are used for positioning the subsequent processes and drawing repair paths 91 and 92 (as shown by the dotted line range in the figure), and the detection method further includes performing Laser (Laser) repair on the defect locations according to the repair paths 91 and 92. Referring to fig. 10, it is a photograph of an image of a peripheral circuit scanned by the thermal imager 75, and there is a white key-shaped protruding circuit on the right side, and the surrounding is red, which means that the temperature of the circuit at the position is abnormal.
Referring to fig. 11, two thermal imagers 111 are mounted on the gantry structure 110, a product 112 (shown by a dotted line in the figure) is mounted on a working platform 113, a probe can contact a circuit of the product 112, a left arrow and a right arrow of an X-axis stroke (Stage X) are directions in which the thermal imagers 111 scan right and move left, a mounting manner of the probe (Prober)114 is determined according to a circuit design of the product, a microscope (Micro Scope)115 is mounted on a left side, a focusing Alignment Camera (Alignment Camera)116 is mounted on an upper right side and a lower right side, and a left double arrow and a right double arrow in the figure respectively indicate moving directions of related devices.
The design concept of the invention is to utilize the thermal effect of the current: when free electrons flow, atoms (referring to nuclei and electrons bound thereto) do not move, but vibrate back and forth at fixed lattice positions. When electrons collide with atoms in the flowing process, the kinetic energy of the electrons is reduced, and the vibration of the atoms is intensified, so that the temperature of a wire is increased, and the thermal effect of current is realized.
In addition, the principle of resistance is: the free electrons slow down in velocity due to collisions, as if the water flow were slowed by resistance against an obstruction, we call the wire resistive. Also, ohm's law is: in 1826 ohm german scholars (1789-1854) found that the voltage across the conductor is proportional to the current flowing through it, a relationship known as ohm's law. The unit of resistance is called ohm (ohm, symbol Ω), 1 ohm-1 volt/ampere, or 1 Ω -1V/a. U ═ IR. From an energy point of view, the heat energy generated when current flows through the conductor is actually converted from electrical energy. If the resistance of a conductor is R, the electrical power P of said conductor due to the electrical energy consumed by the passage of current can be expressed as follows, using ohm's law: p ═ I2And R is IU. As can be seen from the above equation, the heat energy generated by passing the same current through conductors of different resistances is proportional to the resistance.
The invention utilizes the principle to apply voltage (the voltage is adjusted according to the resistance value of each product circuit) on the peripheral circuit of the TFT panel, so that the circuit generates heat energy. The normal circuit and the abnormal circuit will generate the difference in heat energy due to the resistance difference, so the defect position is captured by using the difference.
The detection method of the defect of the Printed Circuit Board (PCB) is also suitable for the printed circuit board, and comprises the steps of applying voltage to a circuit of the circuit board, wherein the circuit comprises a plurality of positions, scanning the positions of the circuit by using a thermal imager (such as a position with the reference number of 75 in fig. 7) to obtain a plurality of corresponding temperature image data of the positions, comparing the corresponding temperature image data with normal temperature image data to detect abnormal image data, and marking the position corresponding to the abnormal image as a defect position when the temperature of the specific position represented by the abnormal image data is higher than a user set value so as to be beneficial to subsequent processes.
As viewed from another practicable viewpoint, the present invention is also a defect detection method for a semiconductor (e.g., TFT panel 30), wherein the semiconductor has lines, such as peripheral lines 71, 72, and line 72 includes a plurality of locations 721, 722, the method includes energizing the line 72, measuring the temperature at each of the locations one by one (e.g., as measured by scanning with a thermal imager 75), to obtain a plurality of temperature imagery data for the plurality of locations 721, 722, and comparing each of the plurality of temperature image data with the reference temperature image data to detect an abnormal image, when the difference between the temperature data of each abnormal image and the reference temperature is greater than a user set value, each position (for example, the position 722) corresponding to the temperature data of each abnormal image is determined as a defect position, so as to be beneficial to performing subsequent processes. Of course, the detecting method may further include scanning with the thermal imager 75 to measure the temperature of each of the positions, wherein the reference temperature image data is normal temperature image data.
The present invention may also be an apparatus for detecting whether a semiconductor (e.g., a TFT panel 30) has a defect, wherein the semiconductor has a circuit (e.g., a peripheral circuit 71, 72), and the circuit 72 includes a plurality of locations 721, 722, the apparatus includes a power-on component 301 for powering on the circuit 72, a measuring component (e.g., a thermal imager 75) for measuring the temperature of each of the locations one by one to obtain temperature data of each of the locations 721, 722, and a comparing component (e.g., an application software, not shown) for comparing each of the temperature data with reference temperature image data to detect abnormal images, and when the difference between the temperature data of each of the abnormal images and the reference temperature is greater than a user-set value, determining each of the locations (e.g., the locations 722) corresponding to each of the temperature data as a defect location, so as to be beneficial to the subsequent process.
Examples
1. A method for detecting defects of a Thin Film Transistor (TFT) panel comprises the steps of applying voltage to a circuit of the panel, wherein the circuit comprises a plurality of positions, scanning the positions by a thermal imager to obtain a plurality of temperature image data of the positions, comparing the temperature image data with normal temperature image data to detect abnormal image data, and marking all the positions corresponding to the abnormal images as defective positions when the temperature of the corresponding positions represented by the abnormal image data is judged to be higher than a user set value so as to be beneficial to subsequent processes.
2. The detection method of embodiment 1, further comprising contacting the line with a probe to apply the voltage.
3. The inspection method according to embodiment 1 or 2, wherein the locations where defects exist have coordinates used for positioning and planning repair paths for the subsequent processes.
4. The inspection method as in any embodiments 1-3, further comprising laser repairing the defect location according to the repair path.
5. The detecting method as claimed in any embodiment 1-4, wherein the circuit is a peripheral circuit, a driving IC circuit or a pixel area circuit, and the defect location has a disconnection defect, a short circuit defect or a micro-disconnection defect.
6. The detecting method as claimed in any one of embodiments 1 to 5, wherein the normal temperature image data corresponds to the user setting value, and the driving IC circuit is fabricated by using gate driver on array (GOA) technology.
7. A method for detecting defects of a Printed Circuit Board (PCB) comprises the steps of applying voltage to a circuit of the circuit board, wherein the circuit comprises a plurality of positions, scanning the plurality of positions of the circuit by a thermal imager to obtain a plurality of corresponding temperature image data of the plurality of positions, comparing the plurality of corresponding temperature image data with normal temperature image data to detect abnormal image data, and marking the position corresponding to the abnormal image as a defect position when the temperature of the specific position represented by the abnormal image data is higher than a user set value so as to be beneficial to subsequent processes.
8. A defect detection method of a semiconductor is provided, wherein the semiconductor is provided with a circuit, the circuit comprises a plurality of positions, the method comprises the steps of electrifying the circuit, measuring the temperature of each position one by one to obtain a plurality of temperature image data of the positions, comparing each temperature image data with reference temperature image data to detect abnormal images, and judging each position corresponding to the temperature data of each abnormal image as a defect position when the difference between the temperature data of each abnormal image and the reference temperature is larger than a user set value so as to be beneficial to subsequent processes.
9. The detecting method according to embodiment 8, further comprising measuring a temperature at each of the locations by scanning with a thermal imager, wherein the reference temperature image data is normal temperature image data.
10. An apparatus for detecting whether a semiconductor has a circuit, wherein the circuit comprises a plurality of positions, the apparatus comprises a power-on component for powering on the circuit, a measuring component for measuring the temperature of each position one by one to obtain the temperature data of each position, and a comparing component for comparing each temperature data with reference temperature image data to detect abnormal images, and when the difference between the temperature data of each abnormal image and the reference temperature is greater than a user set value, each position corresponding to each temperature data is judged to be a defect position, so as to be beneficial to subsequent processes.
In summary, the present invention can obtain the image data with abnormal temperature on the energized line by scanning the plurality of positions with the thermal imager in a new design, and the applied coordinate analysis mode of the defect position can indeed achieve the efficacy of positioning and planning the repair path for the subsequent process. Accordingly, various modifications may occur to those skilled in the art without departing from the scope of the appended claims.