Circuit structure for detecting open circuit test of touch screen
By adding high resistance to the touch screen circuit breaker test circuit structure to form a high resistance loop, the problem of difficulty in accurately detecting bilateral traces and single-sided disconnection in the prior art is solved, and higher detection accuracy and lower production costs are achieved.
Patent Information
- Application Number
- CN202421730623.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-22
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-07-22
AI Technical Summary
When performing touch screen circuit breaking tests, it is difficult to accurately detect unilateral disconnections of bilateral lines, resulting in misjudgment of defective products as good products, increasing production costs and reducing process yields.
A circuit structure is designed, by adding a high resistance in the first single-sided TX region and the second single-sided TX region of the test FPC, a circuit loop is several times higher than the single-sided resistance of the left and right lines, thereby significantly increasing the adjacent deviation and capacitance difference during electrical performance testing.
This circuit structure significantly improves the detection accuracy of unilateral disconnected products, and the differences in adjacent deviations and capacitance values change significantly, which can effectively avoid misjudging bad products as good products, reduce production costs and improve process yields.
Smart Images
Figure CN223038107U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a circuit structure, in particular to a circuit structure for detecting the open - circuit test of a touch screen. Background Art
[0002] Before the touch screen is bonded to the FPC, a dummy piezoelectric test needs to be carried out to prevent defective electrical products from flowing into the next process. The dummy piezoelectric test mainly tests whether the sensor is open - circuited or short - circuited after the FPC is connected to the touch screen.
[0003] Currently, the conventional touch - screen routing designs include several routing methods such as 1T1R, 2T1R, 2T2R, 1T2R, etc. Different IC brands have different requirements for routing designs. Among them, the routing designs suitable for narrow - bezel and commonly used are 1T1R and 2T1R. Among them, since 2T1R is a double - side routing, when the product is subjected to the dummy piezoelectric test, the pins in the bonding area of 2T1R are in contact with the pins on the FPC of the dummy piezoelectric test fixture to achieve connection and conduction. In this way, the electrical function of the product can be tested using the electrical test procedure.
[0004] However, it is found in actual tests that the double - side routing 2T has two single - side resistors R1 and R2. The resistances of R1 and R2 are both relatively small, approximately between 0.5 and 2 KΩ. When one side of the single - side is disconnected, the adjacent deviation and capacitance value difference during the dummy piezoelectric test are not very large. Therefore, it is very difficult to control the open - circuit products using the normal adjacent deviation range and capacitance value range during the dummy piezoelectric test, which easily misjudges the defective products with single - side open - circuit as qualified products, increasing the production cost of the subsequent process and reducing the actual process yield. Summary of the Utility Model
[0005] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a circuit structure for detecting the open - circuit test of a touch screen, which can conveniently and accurately judge whether the product is qualified, reduce costs and improve the process yield.
[0006] To achieve the above object, the technical solution adopted by the utility model is: a circuit structure for detecting the open - circuit test of a touch screen, including:
[0007] A test FPC, which has a touch IC therein. The test FPC is provided with an RX single - side area, and symmetrically - structured first single - side TX area and second single - side TX area are arranged on both sides of the RX single - side area; wherein, the first single - side TX area and the second single - side TX area are respectively composed of a plurality of first pin channels and second pin channels;
[0008] Sensor, which has multiple TX channels inside; among them, each of the first pin channels forms a left loop with the corresponding TX channel and the touch IC through the left line, and the second pin channel corresponding to the first pin channel, the TX channel forming the left loop with the first pin channel, and the touch IC form a right loop through the right trace. The left loop and the right loop form a complete loop;
[0009] The first high resistance and the second high resistance are respectively arranged on the first pin channel and the second pin channel, and the resistance values of the first high resistance and the second high resistance are the same; among them, the resistance values of the first high resistance and the second high resistance are in the range of 1 - 15 KV.
[0010] Furthermore, multiple first high resistances and multiple second high resistances are arranged in a multi - row staggered horizontal manner on the first pin channel and the second pin channel.
[0011] Furthermore, the first high resistance is a near - end high resistance, and the second high resistance is a far - end high resistance.
[0012] Furthermore, the first single - side TX area and the second single - side TX area respectively include multiple first pin channels and multiple second pin channels arranged in parallel from left to right; the left - most first pin channel in the first single - side TX area, the TX channel in the Sensor, and the touch IC form a left - hand loop through the left trace, and the right - most second pin channel in the second single - side TX area, the TX channel connected to the first pin channel, and the touch IC form a right - hand loop through the right trace.
[0013] Due to the application of the above - mentioned technical solution, the present utility model has the following advantages compared with the prior art:
[0014] The circuit structure of the present utility model for detecting the open - circuit test of the touch screen adds the first high resistance and the second high resistance in the first pin channel in the first single - side TX area and the second pin channel in the second single - side TX area, which are several times higher than the single - side resistance of the left line and the right line. In this way, when testing the electrical properties of single - side broken - wire products, the changes in adjacent deviation values and capacitance differences are both very obvious, so that it is easy to detect defective products with single - side broken wires, meeting the actual usage requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The following further describes the technical solution of the present utility model with reference to the drawings:
[0016] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;
[0017] Figure 2 isFigure 1 Enlarged view of part A in
[0018] Figure 3 is Figure 1 Enlarged view of part B in
[0019] Figure 4 Schematic diagram of the distribution of the first high - resistance in the first pin channel in an embodiment of the present utility model;
[0020] Figure 5 Partial equivalent distribution diagram of the first high - resistance and the second high - resistance in the circuit structure when there are 46 TX channels in an embodiment of the present utility model;
[0021] Figure 6 Data comparison table of the adjacent deviation value changes between the present utility model and the prior art;
[0022] Figure 7 Curve comparison diagram of the capacitance value difference changes between the present utility model and the prior art;
[0023] Wherein: Test FPC1, Sensor2, left - hand line 3, right - hand trace 4, first high - resistance 5, second high - resistance 6, RX single - side area 11, first single - side TX area 12, second single - side TX area 13, first pin channel 120, second pin channel 130. Specific implementation mode
[0024] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of this application.
[0025] The present utility model provides a circuit structure for detecting the open - circuit test of a touch screen, so as to solve the problem in the prior art that when false piezoelectric measurement is performed, defective products with unilateral wire breakage are easily misjudged as good products, which increases the production cost of subsequent processes and reduces the process yield.
[0026] For the sake of easy understanding, the specific process in the embodiments of this application is described below. Please refer to Figures 1 to 4, a circuit structure for detecting open - circuit tests of a touch screen in an embodiment of the present application, includes a test FPC1, a Sensor2, a first high - resistance 5, and a second high - resistance 6; a touch - control IC is provided in the test FPC1, an RX single - side area 11 is provided on the test FPC1, and a first single - side TX area 12 and a second single - side TX area 13 with symmetrically arranged structures are provided on both sides of the RX single - side area 11; wherein, the first single - side TX area 12 and the second single - side TX area 13 are respectively composed of a plurality of first pin channels 120 and second pin channels 130.
[0027] The Sensor2 has a plurality of TX channels; wherein, each of the first pin channels 120 forms a left - hand loop with the corresponding TX channel and the touch - control IC through a left - hand line 3, and the second pin channel 130 corresponding to the first pin channel 120, the TX channel forming the left - hand loop with the first pin channel 120, and the touch - control IC form a right - hand loop through a right - hand trace 4. The left - hand loop and the right - hand loop form a complete loop.
[0028] The first high - resistance 5 and the second high - resistance 6 are respectively arranged in the first pin channel 120 and the second pin channel 130, and the resistance values of the first high - resistance 5 and the second high - resistance 6 are the same; the resistance values of the first high - resistance 5 and the second high - resistance 6 are in the range of 1 - 15 KV.
[0029] The circuit structure for detecting open - circuit tests of a touch screen of the present utility model adds the first high - resistance 5 and the second high - resistance 6 with resistance values several times higher than the single - side resistance of the left - hand line and the right - hand line in the first pin channel 120 and the second pin channel 130. In this way, when electrically testing single - side broken - line products, the changes in adjacent deviation values and capacitance differences are both obvious, so that defective products with single - side broken lines can be easily detected.
[0030] The Sensor2 has a plurality of TX channels. In this embodiment, it includes a plurality of TX1 channels, TX2 channels... TXn channels, where n is an integer greater than 1.
[0031] Specifically, in this embodiment, the first single - side TX area 12 and the second single - side TX area 13 respectively include a plurality of first pin channels 120 and a plurality of second pin channels 130 arranged in parallel from left to right. The left - most first pin channel 120, TX1 channel, and touch - control IC in the first single - side TX area 12 form a left - hand loop through a left - hand trace, and the right - most second pin channel 130 in the second single - side TX area 13, the TX1 channel, and the touch - control IC form a right - hand loop through a right - hand trace. The left - hand loop and the right - hand loop form a complete test loop; by analogy, a plurality of test loops with the same structure are included in this circuit structure.
[0032] Secondly, in the left circuit of this embodiment, that is, the left trace 3 conducts the touch IC, the first pin channel 120, and the TX1 channel to form a single-sided resistor R1; similarly, in the right circuit, the right trace 4 conducts the touch IC, the second pin channel 130, and the TX1 channel to form a single-sided resistor R2; among them, the values of R1 and R2 corresponding to each TX channel are not equal.
[0033] Furthermore, the first high resistor 5 is a proximal high resistor, and the second high resistor 6 is a distal high resistor. In this embodiment, a high resistor is set as R3, and the second high resistor is set as R4. The number of R3 and R4 high resistors is determined by the number of TX channels of sensor2. One proximal high resistor R3 and one distal high resistor R4 need to be added for each TX channel.
[0034] In this way, the resistance formed by the left trace is R1 + R3, and the resistance formed by the right trace is R2 + R4. By analogy, TX2, TX45, TX46, etc. respectively have corresponding R1 + R3 and R2 + R4. The resistance values of R3 and R4 can be between 1 and 15 KV. In principle, the resistance value of R3 needs to be consistent with that of R4. Its equivalent structure is as Figure 5 shown.
[0035] In this way, the resistance corresponding to a certain channel is RAD = (R1 + R3) * (R2 + R4) / [(R1 + R3) + (R2 + R4)]. When a certain side is broken, it can be observed that the adjacent deviation value changes greatly, so as to facilitate detecting whether the product is broken.
[0036] Furthermore, since the high resistor has a certain size, welding the high resistors on the FPC wiring by the method of component mounting on the same level is likely to cause the high resistors to overlap or squeeze each other. Therefore, in this embodiment, the high resistors are arranged in a multi-row staggered horizontal arrangement form, such as Figure 4 shown as a two-row staggered horizontal arrangement, that is, the first and third high resistors are on the first horizontal line, and the second and fourth high resistors are on the second horizontal line, and so on.
[0037] Of course, a three-row staggered horizontal arrangement can also be adopted, that is, the first high resistor, the fourth high resistor, and the seventh high resistor are on the first horizontal line, the second high resistor, the fifth high resistor, and the eighth high resistor are on the second horizontal line, the third high resistor, the sixth high resistor, and the ninth high resistor are on the third horizontal line, and so on; the way of staggered horizontal arrangement of high resistors includes but is not limited to the above several ways.
[0038] In actual use, a product with 40 TX channels is compared with the existing test structure.
[0039] For the differential change of adjacent deviation, the proximal resistance R1 and the distal resistance R2 of the TX1 channel to the TX40 channel are between 10.87 KΩ and 11.77 KΩ, and the total resistance R is between 5.46 KΩ and 5.87 KΩ. When there is a single-side break, the adjacent deviation measured by the electrical test program is between 0.638 and 0.71, and the change in adjacent deviation is obvious.
[0040] The comparison of the adjacent deviation differences between the prior art and this circuit structure is as Figure 6 shown. It can be seen that when the single-side break product is subjected to the false pressing test, the adjacent deviation of this utility model is 3.5 to 12 times that of the adjacent deviation of the conventional design circuit. The change in adjacent deviation is large and has exceeded the adjacent deviation range normally controlled by the electrical test program, and the defective products with single-side break can be easily detected.
[0041] For the differential change of capacitance value, the OK capacitance values of the TX1 channel to the TX40 channel measured by the electrical test program for normal samples are between 1390 and 1520. When there is a single-side break, the NG capacitance values of the TX1 channel to the TX40 channel measured by the electrical test program for abnormal samples are between 901 and 988. The capacitance difference between the OK capacitance value and the NG capacitance value is between 489 and 540, and the change in capacitance value is obvious.
[0042] The comparison of the capacitance differences between the prior art and this circuit structure is as Figure 7 shown. It can be seen that when the single-side break product is subjected to the false pressing test, the adjacent deviation of this utility model is 6 to 10 times that of the adjacent deviation of the conventional design circuit. The change in capacitance value is large and has exceeded the capacitance range normally controlled by the electrical test program, and the defective products with single-side break can be easily detected.
[0043] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A circuit structure for detecting a touch screen circuit break test, characterized in that: include: A test FPC, wherein the test FPC has a touch IC, and an RX single-sided area is provided on the test FPC, and a first single-sided TX area and a second single-sided TX area are symmetrically arranged on both sides of the RX single-sided area; wherein the first single-sided TX area and the second single-sided TX area are respectively composed of a plurality of first pin channels and a second pin channel; Sensor, wherein the Sensor has a plurality of TX channels; wherein each of the first pin channels and the corresponding TX channel and the touch IC form a left loop through a left line, and the second pin channel corresponding to the first pin channel, the TX channel forming the left loop with the first pin channel, and the touch IC form a right loop through a right line, and the left loop and the right loop form a complete loop; The first high resistor and the second high resistor are respectively arranged in the first pin channel and the second pin channel, and the resistance values of the first high resistor and the second high resistor are the same; wherein the resistance values of the first high resistor and the second high resistor are between 1 and 15 KV.
2. The circuit structure for detecting a touch screen disconnection test according to claim 1, characterized in that: The plurality of first high resistors and the plurality of second high resistors are arranged horizontally in a plurality of rows and staggered in the first pin channel and the second pin channel.
3. The circuit structure for detecting a touch screen disconnection test according to claim 1, characterized in that: The first high resistor is a near high resistor, and the second high resistor is a far high resistor.
4. The circuit structure for detecting a touch screen disconnection test according to claim 1, characterized in that: The first unilateral TX area and the second unilateral TX area respectively include a plurality of first pin channels and a plurality of second pin channels arranged in parallel from left to right; the leftmost first pin channel in the first unilateral TX area, the TX channel in the Sensor and the touch IC form a left loop through the left routing, and the rightmost second pin channel in the second unilateral TX area, the TX channel connected to the first pin channel and the touch IC form a right loop through the right routing.