Reinforced detection method and system for internal structure of multilayer ceramic capacitor

Abstract

A strengthening detection method for the internal structure of a multilayer ceramic capacitor comprises the following steps: placing a plurality of batches of multilayer ceramic capacitors to be detected into temperature regulation and control equipment, and carrying out temperature change circulation by utilizing the temperature regulation and control equipment, when at least one of the to-be-tested multilayer ceramic capacitors has a special electrical characteristic, the temperature change cycle excites the special electrical characteristic; after the temperature change cycle is executed, standing the to-be-tested laminated ceramic capacitor in the temperature regulation and control equipment; and inspecting a plurality of electrical characteristic items for each of the to-be-inspected multilayer ceramic capacitors by using the electrical measurement device to distinguish at least one good product from the to-be-inspected multilayer ceramic capacitors, the at least one good product having no special electrical characteristic. Therefore, hidden special electrical characteristics possibly existing in the multilayer ceramic capacitor can be excited in advance, and the yield of the multilayer ceramic capacitor with a relatively good electrical distribution level is further improved.

Description

Technical Field

[0001] The present disclosure relates to a method and system for detecting multilayer ceramic capacitors, and more particularly to an enhanced detection method and system for detecting multilayer ceramic capacitors with special internal structures. Background Art

[0002] Multi-layer ceramic capacitor (MLCC), also known as chip capacitor, is a capacitor with ceramic as dielectric. It is composed of two or more layers of alternating ceramic layers and metal layers. It has the advantages of easy chipization, small size, large capacitance, suitable for mass production, low price, good frequency characteristics and high stability. It can be directly soldered on the circuit board, so it is widely used in various electronic products.

[0003] However, the internal structure of multilayer ceramic capacitors may change during the manufacturing process such as screen printing, cutting, sintering, etc., or a more special internal structure may be produced due to changes in process and materials. Specifically, multilayer ceramic capacitors with special internal structures may make their electrical characteristics behave like good products (i.e., have a better electrical distribution level). Therefore, electrical quality testing or thermal shock testing alone cannot accurately detect multilayer ceramic capacitors with special internal structures, and therefore cannot ensure that all shipped multilayer ceramic capacitors have a better electrical distribution level. Summary of the invention

[0004] Therefore, the object of the present invention is to provide a method for strengthening the detection of the internal structure of a multilayer ceramic capacitor, which is applicable to a system for strengthening the detection of the internal structure of a multilayer ceramic capacitor, and includes: performing a special internal structure excitation step and using an electrical property measurement device to perform an electrical property quality measurement step. The special internal structure excitation step includes: placing multiple batches of multilayer ceramic capacitors to be inspected into a temperature control device, and using the temperature control device to perform at least one temperature change cycle, wherein at least one temperature change cycle corresponds to a special electrical characteristic, and when at least one of those batches of multilayer ceramic capacitors to be inspected has a special electrical characteristic, at least one temperature change cycle excites the special electrical characteristic; and after performing at least one temperature change cycle, the batches of multilayer ceramic capacitors to be inspected in the temperature control device are left stationary. The electrical property quality measurement step includes: performing a plurality of electrical property characteristic item inspections on each of those batches of multilayer ceramic capacitors to be inspected, so as to distinguish at least one good product from those batches of multilayer ceramic capacitors to be inspected, wherein at least one good product does not have a special electrical characteristic.

[0005] According to an embodiment of the present disclosure, the method further includes a thermal shock sampling inspection step using a thermal shock inspection device. The thermal shock sampling inspection step includes: receiving at least one good product separated from the multilayer ceramic capacitors to be inspected in the electrical quality measurement step; and performing a thermal shock sampling inspection on at least one good product in the multilayer ceramic capacitors to be inspected to conduct a secondary inspection of at least one good product in the multilayer ceramic capacitors to be inspected.

[0006] According to an embodiment of the present disclosure, a temperature range of at least one temperature change cycle is between 25 degrees and 150 degrees.

[0007] According to an embodiment of the present disclosure, the method further includes a manual sampling step. The manual sampling step includes: receiving at least one good product separated from the batches of multilayer ceramic capacitors to be inspected in the electrical quality measurement step; and performing a random inspection on the good products in the batches of multilayer ceramic capacitors to be inspected to conduct a secondary inspection of the good products in the batches of multilayer ceramic capacitors to be inspected.

[0008] According to an embodiment of the present disclosure, the special electrical characteristics include a special loss angle and a special insulation resistance.

[0009] According to an embodiment of the present disclosure, the electrical characteristic inspection includes capacitance tolerance specification, loss angle, withstand voltage and insulation resistance.

[0010] Another object of the present invention is to provide an enhanced detection system for the internal structure of multilayer ceramic capacitors, comprising: a temperature control device and an electrical property measurement device. The temperature control device is configured to perform at least one temperature change cycle on multiple batches of multilayer ceramic capacitors to be inspected, wherein at least one temperature change cycle corresponds to a special electrical characteristic, and when at least one of those batches of multilayer ceramic capacitors to be inspected has a special electrical characteristic, at least one temperature change cycle excites the special electrical characteristic. The electrical property measurement device is configured to perform multiple electrical characteristic item detection on each of those batches of multilayer ceramic capacitors to be inspected, so as to distinguish at least one good product from those batches of multilayer ceramic capacitors to be inspected, wherein at least one good product does not have a special electrical characteristic.

[0011] According to an embodiment of the present disclosure, the system further comprises: a thermal shock inspection device configured to perform a thermal shock spot check inspection on at least one good product in the multilayer ceramic capacitor area to be inspected, so as to conduct a secondary inspection on at least one good product in the multilayer ceramic capacitor area to be inspected.

[0012] According to an embodiment of the present disclosure, a temperature range of at least one temperature change cycle is between 25 degrees and 150 degrees.

[0013] According to an embodiment of the present disclosure, the special electrical characteristics include a special loss angle and a special insulation resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to make the above and other objects, features, advantages and embodiments of the present invention more understandable, the attached drawings are described as follows:

[0015] Figure 1 A schematic diagram illustrating a system for strengthening the internal structure of a multilayer ceramic capacitor according to an embodiment of the present invention;

[0016] Figure 2 A schematic diagram illustrating a method for strengthening the internal structure of a multilayer ceramic capacitor according to an embodiment of the present invention;

[0017] Figure 3 According to an embodiment of the present invention, a schematic diagram is drawn showing the change of the loss angle (electrical characteristic) of a good sample and a bad sample after being stimulated; and

[0018] Figure 4 According to an embodiment of the present invention, a schematic diagram is shown showing changes in insulation resistance (electrical characteristics) of good and bad samples after being stimulated. DETAILED DESCRIPTION

[0019] The following is a detailed discussion of the embodiments of the present invention. However, it is to be understood that the embodiments provide many applicable concepts that can be implemented in a variety of specific contexts. The embodiments discussed and disclosed are for illustration only and are not intended to limit the scope of the present invention.

[0020] Please refer to Figure 1 , which is a schematic diagram of an enhanced detection system 100 for the internal structure of a multilayer ceramic capacitor according to an embodiment of the present invention. The enhanced detection system 100 for the internal structure of a multilayer ceramic capacitor includes a temperature control device 110, an electrical property measurement device 120, a thermal shock test device 130, and a program control system 140. The enhanced detection system 100 for the internal structure of a multilayer ceramic capacitor can be used to detect the special internal structure of a multilayer ceramic capacitor. Before the electrical property measurement device 120 measures the electrical quality of the multilayer ceramic capacitor, the temperature control device 110 is used to pre-stimulate the hidden special electrical characteristics that may exist in the multilayer ceramic capacitor to avoid the situation where the electrical quality measurement result of the multilayer ceramic capacitor is good, but its internal structure is actually special, thereby improving the yield of multilayer ceramic capacitors with a better electrical distribution level. In addition, the thermal shock test device 130 performs a spot check on the good products after the electrical property measurement device 120 has been inspected to conduct a secondary inspection of the good products of the multilayer ceramic capacitor.

[0021] In an embodiment of the present invention, the temperature control device 110 is used to perform a temperature change cycle on the multilayer ceramic capacitor, thereby stimulating the special internal structure that may exist in the multilayer ceramic capacitor. The temperature control device 110 can be a high and low temperature test machine, an oven, an oven, an environmental testing equipment, etc., or any device or equipment that can control the temperature to perform a temperature change cycle, and the present invention is not limited thereto. In some embodiments of the present invention, the temperature control device 110 can be filled with nitrogen during the heating process to provide an oxidation-free baking space to ensure that the multilayer ceramic capacitor will not oxidize.

[0022] In an embodiment of the present invention, the electrical property measuring device 120 is used to measure the electrical quality of the multilayer ceramic capacitor to distinguish good products (i.e., having a better electrical property distribution level) and defective products (i.e., having a weaker electrical property distribution level) in the multilayer ceramic capacitor. Specifically, the electrical property measuring device 120 can be used to measure multiple electrical characteristics of the multilayer ceramic capacitor, including withstand voltage, capacitance tolerance, insulation resistance IR (insulation resistance; IR), loss factor Tan D (dissipation factor; DF), etc., but the present invention is not limited to this. The electrical property measuring device 120 can be a single device with the above-mentioned multiple electrical property measurement functions, or it can be composed of multiple instruments, such as a megger, an insulation resistance tester, an inductance, capacitance and resistance meter (LCR) tester, an impedance analyzer, and other instruments for measuring related electrical characteristics.

[0023] In the embodiment of the present invention, the thermal shock test device 130 is used to randomly test the multilayer ceramic capacitors that have been tested as good products by the electrical measurement device 120. The thermal shock test device 130 can provide an instantaneous high temperature shock to randomly test whether the multilayer ceramic capacitors that have been tested as good products can withstand chemical changes or physical damage in the shortest time.

[0024] In an embodiment of the present invention, the program control system 140 is used to monitor and receive relevant information and measurement results provided by the temperature control device 110, the electrical property measurement device 120 and the thermal shock test device 130. The program control system 140 can be a personal computer, a laptop computer, a server, a distributed computer, a cloud server, an industrial computer, or any electronic device with a computing function, etc., and the present invention is not limited thereto. The temperature control device 110, the electrical property measurement device 120 and the thermal shock test device 130 can be connected to the program control system 140 by any wired or wireless communication method.

[0025] Please refer to Figure 2, which is a schematic diagram illustrating an enhanced detection method 200 for the internal structure of a multilayer ceramic capacitor according to an embodiment of the present invention. The enhanced detection method 200 for the internal structure of a multilayer ceramic capacitor includes a special internal structure excitation step 210, an electrical quality measurement step 220, and a spot check inspection step 230. Among them, the special internal structure excitation step 210 includes steps 211 and 212; the electrical quality measurement step 220 includes steps 221 and 222; and the spot check inspection step 230 includes steps 231 to 234. In an embodiment of the present invention, the enhanced detection method 200 for the internal structure of a multilayer ceramic capacitor can be performed by Figure 1 The enhanced detection system 100 for the internal structure of the multilayer ceramic capacitor shown in the figure can be implemented, or can be implemented by a similar architecture that can achieve similar functions. Figure 3 Strengthening detection method of internal structure of multilayer ceramic capacitors Figure 1 The following will describe an enhanced detection system 100 for the internal structure of a multilayer ceramic capacitor.

[0026] In the special internal structure excitation step 210, step 211 is first performed to perform a temperature change cycle on the multilayer ceramic capacitor to be inspected. For some multilayer ceramic capacitors with special internal structures, the electrical characteristics measured by the electrical measurement device 120 may appear to be the same as normal electrical characteristics (i.e., have a better electrical distribution level). Therefore, before the electrical quality inspection of the multilayer ceramic capacitor to be inspected, the multilayer ceramic capacitor will be subjected to a temperature change cycle to excite the possible special electrical characteristics of the multilayer ceramic capacitor to be inspected, and then inspect the true electrical characteristics. In some embodiments, the temperature change cycle is between about 25°C and about 150°C, wherein the temperature is increased from 25°C to 150°C, and then the temperature is reduced from 150°C to 35°C to complete a temperature change cycle. In some embodiments, the temperature change cycle is increased from 25°C to at least 35°C, and then the temperature is reduced from 35°C to 25°C. In some cases, the temperature variation cycle is limited by the temperature specification of the MLCC to be tested, so when the temperature is too high (eg, greater than 150° C.), the MLCC to be tested may be oxidized.

[0027] Then, step 212 is performed to allow the multilayer ceramic capacitor to be tested to stand. After step 211 is performed to excite the multilayer ceramic capacitor to be tested, step 212 is performed to allow the multilayer ceramic capacitor to be tested to stand for a period of time so that the multilayer ceramic capacitor to be tested is relatively stable, and the subsequent electrical characteristic measurement results will also be relatively accurate. In some embodiments, the multilayer ceramic capacitor to be tested is allowed to stand for about 12 hours. In some embodiments, the multilayer ceramic capacitor to be tested is allowed to stand for no more than about 96 hours to prevent the electrical characteristics of the multilayer ceramic capacitor to be tested from returning to the state before being excited.

[0028] Figure 3The schematic diagram further shows the change of loss angle Tan D (electrical characteristics) of good samples and defective samples after stimulation, wherein the dotted line O is the specification standard of loss angle Tan D (i.e., loss angle Tan D = 0.001), the solid line A is the good sample of multilayer ceramic capacitors, and the solid line B is the defective sample of multilayer ceramic capacitors. It can be found that the good sample of multilayer ceramic capacitors (solid line A) is maintained within the specification standard before and after stimulation (i.e., loss angle Tan D ≤ 0.001), which is in line with the real good product (i.e., having a better electrical distribution level); while the defective sample of multilayer ceramic capacitors (solid line B) is within the specification standard before stimulation, but after stimulation, it is revealed that it is actually a special electrical characteristic (i.e., loss angle Tan D ≤ 0.001), and is actually a defective product (i.e., having a weaker electrical distribution level). In addition, the special electrical characteristics of multilayer ceramic capacitors can only be detected within 96 hours after stimulation. After that, the multilayer ceramic capacitors with special internal structures will return to being the same as good products. Therefore, it is necessary to conduct electrical quality inspections on multilayer ceramic capacitors within this period of time to accurately distinguish genuine good products.

[0029] Figure 4 The schematic diagram of the change of insulation resistance IR (electrical characteristics) of good samples and defective samples after stimulation is further drawn, wherein the dotted line O is the specification standard of insulation resistance IR (i.e., insulation resistance IR=50G), the solid line A is the good sample of multilayer ceramic capacitors, and the solid line B is the defective sample of multilayer ceramic capacitors. It can be found that the good sample of multilayer ceramic capacitors (solid line A) is maintained within the specification standard before and after stimulation (i.e., insulation resistance IR≥50G), which is in line with the real good product (i.e., having a better electrical distribution level), while the defective sample of multilayer ceramic capacitors (solid line B) is within the specification standard before stimulation, but after stimulation, it is revealed that it is actually a special electrical characteristic (i.e., insulation resistance IR≤50G), and is actually a defective product (i.e., having a weaker electrical distribution level). In addition, the special electrical characteristics of multilayer ceramic capacitors can only be detected within 96 hours after stimulation. After that, the multilayer ceramic capacitors with special internal structures will return to being the same as good products. Therefore, it is necessary to conduct electrical quality inspections on multilayer ceramic capacitors within this period of time to accurately distinguish genuine good products.

[0030] Therefore, according to the special internal structure excitation step 210, the potential hidden special electrical characteristics of the multilayer ceramic capacitor can be pre-excited to avoid the situation where the electrical quality measurement result of the multilayer ceramic capacitor is normal but its internal structure is actually special.

[0031] Please continue to refer to Figure 2, and then enter the electrical quality measurement step 220. In the electrical quality measurement step 220, firstly, step 221 is performed to inspect the electrical characteristics of the multilayer ceramic capacitor to be inspected. In some embodiments, the electrical characteristics inspection includes inspecting the withstand voltage, capacitance tolerance specification, insulation resistance IR and loss angle Tan D of the multilayer ceramic capacitor to be inspected, but the present invention is not limited thereto.

[0032] Then, step 222 is performed to distinguish good products from the multilayer ceramic capacitors to be inspected. After performing step 221, good products and defective products are distinguished according to the results of the inspection of the electrical characteristic items. In some embodiments, the loss angle Tan D ≥ 0.001 is an electrical defective product, and the loss angle Tan D ≤ 0.001 is an electrical good product. In some embodiments, the insulation resistance IR ≤ 50G (set parameter) is an electrical defective product, and the insulation resistance IR ≥ 50G (set parameter) is an electrical good product. It should be understood that the loss angle Tan D and the insulation resistance IR may have different specification judgment standards according to the different specifications of the multilayer ceramic capacitors to be inspected.

[0033] Please continue to refer to Figure 3 , and then enter the spot check inspection step 230. In the spot check inspection step 230, firstly, step 231 is performed to perform a spot check inspection on the good products in the multilayer ceramic capacitor area to be inspected, and then step 232 is performed to determine whether the good products in the multilayer ceramic capacitor area to be inspected are truly good products. In some embodiments, a spot check inspection can be performed manually to confirm twice whether the good products in the multilayer ceramic capacitor area to be inspected are truly good products. In some embodiments, a spot check inspection can be performed by the thermal shock inspection device 130 to confirm twice whether the good products in the multilayer ceramic capacitor area to be inspected are truly good products. In an embodiment of the present invention, if the multilayer ceramic capacitor to be inspected is determined to be a truly good product, step 233 is performed to perform subsequent processes, production, etc.; if the multilayer ceramic capacitor to be inspected is determined to be a defective product, step 234 is performed to reprocess the multilayer ceramic capacitor to be inspected, and return to the special internal structure excitation step 210 to perform the enhanced detection method 200 of the internal structure of the multilayer ceramic capacitor again. In some embodiments, reprocessing the MLCC to be inspected includes reducing product specifications so that special electrical characteristics of the MLCC to be inspected can be inspected in the electrical quality measurement step 220 .

[0034] The enhanced detection method and system of the internal structure of multilayer ceramic capacitors according to the present invention are suitable for inspecting the special internal structure or electrical characteristics of multilayer ceramic capacitors, using temperature control equipment to pre-stimulate the potential hidden special electrical characteristics of multilayer ceramic capacitors, and then using electrical measurement equipment to inspect the electrical characteristics to distinguish good products from bad products, and finally using a thermal shock inspection device or manual methods to spot check and inspect good multilayer ceramic capacitors to improve the yield of good multilayer ceramic capacitors. In summary, the enhanced detection method and system of the internal structure of multilayer ceramic capacitors according to the present invention can inspect the special internal structure of multilayer ceramic capacitors, ensuring that the shipped multilayer ceramic capacitors all have a good electrical distribution level.

[0035] Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Any technician in this technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the following claims.

[0036]

Explanation of symbols

[0037] 100: Strengthen the detection system

[0038] 110: Temperature control equipment

[0039] 120: Electrical measurement equipment

[0040] 130: Thermal shock test device

[0041] 140: Program Control System

[0042] 200: Strengthening detection methods

[0043] 210: Special internal structure excitation step

[0044] 211,212: Steps

[0045] 220: Electrical quality measurement steps

[0046] 221,222: Steps

[0047] 230: Spot check inspection steps

[0048] 231,232,233,234: Steps

[0049] O: Dashed line

[0050] A,B: solid line

[0051] Tan D: Loss angle

[0052] IR: Insulation resistance.

Claims

1. A method for strengthening the detection of the internal structure of a multilayer ceramic capacitor, applicable to a system for strengthening the detection of the internal structure of a multilayer ceramic capacitor, characterized in that: The enhanced detection method comprises: Perform special internal structure excitation steps, including: Placing a plurality of batches of multilayer ceramic capacitors to be inspected into a temperature control device, and using the temperature control device to perform at least one temperature change cycle, wherein the at least one temperature change cycle corresponds to a special electrical characteristic, and when at least one of the plurality of batches of multilayer ceramic capacitors to be inspected has the special electrical characteristic, the at least one temperature change cycle excites the special electrical characteristic; as well as After performing the at least one temperature change cycle, leaving the batches of multilayer ceramic capacitors to be inspected in the temperature control device at rest; as well as The electrical property quality measurement step is performed using an electrical property measurement device, wherein the electrical property quality measurement step comprises: A plurality of electrical characteristic items are inspected for each of the plurality of batches of multilayer ceramic capacitors to be inspected, so as to distinguish at least one good product from the plurality of batches of multilayer ceramic capacitors to be inspected, wherein the at least one good product does not have the special electrical characteristic.

2. The method according to claim 1, characterized in that Also includes: A thermal shock sampling inspection step is performed using a thermal shock inspection device, and the thermal shock sampling inspection step comprises: receiving the at least one good product separated from the plurality of batches of multilayer ceramic capacitors to be inspected in the electrical quality measurement step; as well as A thermal shock spot check is performed on the at least one good product in the plurality of batches of multilayer ceramic capacitors to be inspected, so as to conduct a secondary inspection on the at least one good product in the plurality of batches of multilayer ceramic capacitors to be inspected.

3. The method according to claim 1, characterized in that The temperature range of the at least one temperature change cycle is between 25 degrees and 150 degrees.

4. The method according to claim 1, characterized in that: Also includes: Manual sampling steps include: receiving the at least one good product separated from the plurality of batches of multilayer ceramic capacitors to be inspected in the electrical quality measurement step; as well as A spot check is performed on the plurality of batches of good products in the multilayer ceramic capacitor area to be inspected, so as to conduct a secondary inspection on the plurality of batches of good products in the multilayer ceramic capacitor area to be inspected.

5. The method according to claim 1, characterized in that: The special electrical characteristics include a special loss angle and a special insulation resistance.

6. The method according to claim 1, characterized in that The electrical characteristic inspection items include capacitance value tolerance specifications, loss angle, withstand voltage and insulation resistance.

7. A system for strengthening the detection of the internal structure of a multilayer ceramic capacitor, characterized in that: The enhanced detection system comprises: A temperature control device, configured to perform at least one temperature change cycle on multiple batches of multilayer ceramic capacitors to be inspected, wherein the at least one temperature change cycle corresponds to a special electrical characteristic, and when at least one of the multiple batches of multilayer ceramic capacitors to be inspected has the special electrical characteristic, the at least one temperature change cycle excites the special electrical characteristic; as well as The electrical property measuring equipment is configured to perform a plurality of electrical property characteristic tests on each of the plurality of batches of multilayer ceramic capacitors to be inspected, so as to distinguish at least one good product from the plurality of batches of multilayer ceramic capacitors to be inspected, wherein the at least one good product does not have the special electrical property characteristic.

8. The system according to claim 7, characterized in that Also includes: The thermal shock inspection device is configured to perform a thermal shock spot check inspection on the at least one good product in the plurality of batches of multilayer ceramic capacitors to be inspected, so as to conduct a secondary inspection on the at least one good product in the plurality of batches of multilayer ceramic capacitors to be inspected.

9. The system according to claim 7, characterized in that The temperature range of the at least one temperature change cycle is between 25 degrees and 150 degrees.

10. The system according to claim 7, characterized in that The special electrical characteristics include a special loss angle and a special insulation resistance.

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