Bmmlcc with bleeder resistor and preparation method thereof

Abstract

The application provides a BME MLCC with a bleeder resistor and a preparation method thereof, and belongs to the technical field of patch components. A conductive paste is first coated on the surface of two opposite edge regions of one side of a substrate, first sintering is performed, and a conductive film layer is obtained; a resistor paste is second coated on the surface of the substrate, second sintering is performed, a resistor layer is formed, and a resistor is obtained; the resistor and the BME MLCC are bonded in a non-terminal electrode region by using an adhesive, the conductive film layer of the resistor is arranged opposite to the terminal electrode of the BME MLCC during the bonding, the terminal electrode and the conductive film layer are welded, and the BME MLCC with the bleeder resistor is obtained. The resistor and the capacitor are respectively manufactured, so that the product production qualified rate is improved, the resistor and the capacitor are bonded and welded after being manufactured, and thus the product performance requirements can be met, and the product manufacturing cost can be effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of surface mount components, and in particular to a BME MLCC with a bleeder resistor and its fabrication method. Background Technology

[0002] High-voltage capacitors used in electronic circuits need to be discharged after the power supply is cut off; otherwise, residual charge can damage the capacitor itself and even pose a risk of electric shock. There are many methods of discharge, but a commonly used method is resistor discharge. This involves connecting a resistor of a certain resistance value across the two electrodes of the capacitor to control the discharge rate and duration, thus protecting the capacitor.

[0003] BME MLCC (Base Metal Electrode Multi-Layer Ceramic Capacitors) refers to multilayer ceramic capacitors that use base metals, typically nickel or copper, as electrode materials. A related technology discloses a method for preparing BME MLCCs with bleed resistors at high temperatures. The BME MLCC prepared by this method includes a ceramic core, end electrodes disposed opposite each other on both sides of the ceramic core, a resistive layer disposed on the surface of the ceramic core between the two end electrodes, and two overlapping electrodes connected between the end of the resistive layer and the opposite end electrode. The overlapping electrodes and the resistive layer are sequentially sintered on the surface of the fired ceramic core, or vice versa. However, this method suffers from a low product yield. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a BME MLCC with a bleeder resistor and a method for its fabrication. The fabrication method of the present invention manufactures the resistor and capacitor separately, thereby improving the product yield.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for fabricating a BME MLCC with a bleeder resistor, comprising the following steps: A conductive paste is first coated on the surface of two opposite edge regions on one side of the substrate, and then a first sintering is performed to obtain a conductive film layer. A second resistive paste is coated on the surface of the substrate, and a second sintering is performed to form a resistive layer, thereby obtaining a resistor; the first coating and the second coating are located at different positions, and the conductive film layer and the resistive layer are in physical contact. The resistor and the BME MLCC are bonded together in the non-terminal electrode area using an adhesive. During bonding, the conductive film layer of the resistor is positioned opposite to the terminal electrode of the BME MLCC. The terminal electrode is then welded to the conductive film layer to obtain the BME MLCC with a bleed resistor.

[0006] Preferably, the substrate is made of alumina, beryllium oxide, or aluminum nitride.

[0007] Preferably, the adhesive is silicone or epoxy resin.

[0008] Preferably, the adhesive is applied by dot application.

[0009] Preferably, both the first and second sintering are carried out in air.

[0010] Preferably, the welding is tin soldering.

[0011] Preferably, the internal electrode of the BME MLCC is nickel, and the terminal electrode is copper.

[0012] Preferably, the conductor paste comprises a pure silver conductor paste.

[0013] Preferably, the resistive paste includes a ruthenium-based resistive paste.

[0014] The present invention also provides a BME MLCC with a bleeder resistor prepared by the preparation method described above. The BME MLCC with a bleeder resistor includes a resistor and a capacitor. The terminal electrodes of the resistor and the capacitor are welded together, and the non-electrode areas are bonded together with an adhesive.

[0015] This invention provides a method for fabricating a BME MLCC with a bleed resistor, comprising the following steps: firstly coating a conductive paste onto the surface of two opposite edge regions on one side of a substrate, and performing a first sintering to obtain a conductive film layer; secondly coating a resistive paste onto the surface of the substrate, and performing a second sintering to form a resistive layer to obtain a resistor; wherein the first and second coatings are applied at different positions, and the conductive film layer and the resistive layer are in physical contact; the resistor and the BME MLCC are bonded together in a non-terminal electrode region using an adhesive, wherein the conductive film layer of the resistor is positioned opposite to the terminal electrode of the BME MLCC during bonding, and the terminal electrode is welded to the conductive film layer to obtain the BME MLCC with a bleed resistor.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention manufactures resistors and capacitors separately, increasing the yield rate of resistors and thus improving the overall product yield. After manufacturing, the resistors and capacitors are bonded and welded together. This satisfies product performance requirements while effectively reducing manufacturing costs. Data from the embodiments show that the yield rate of resistors using this invention reaches 100%, and the yield rate of BME MLCCs with bleeder resistors reaches 98%.

[0017] Furthermore, the resistive paste of the present invention includes a ruthenium-based resistive paste, which can be co-sintered with the conductor paste, thereby improving production efficiency and further reducing product manufacturing costs.

[0018] Furthermore, the present invention specifies that both the first and second sintering are carried out in air, avoiding the production of resistors under a protective atmosphere. Since ruthenium has multiple valence states, the unstable valence of ruthenium-based resistor paste during sintering under a protective atmosphere can easily cause fluctuations in resistance value, thus ensuring the stability of sintering and further improving the yield of BME MLCCs with bleed resistors.

[0019] The present invention also provides a BME MLCC with a bleeder resistor prepared by the preparation method described above. The BME MLCC with a bleeder resistor of the present invention has a wide production process window, and the resistance value can be arbitrarily adjusted between 10MΩ and 10GΩ as needed. Attached Figure Description

[0020] Figure 1 This is a schematic diagram showing the positions of the resistive paste and the conductive paste on the substrate surface; Figure 2 This is a schematic diagram of the external shape of a BME MLCC according to one embodiment; Figure 3 This is a schematic diagram of the external shape of a BME MLCC with a bleeder resistor according to one embodiment. Detailed Implementation

[0021] This invention provides a method for fabricating a BME MLCC with a bleeder resistor, comprising the following steps: A conductive paste is first coated on the surface of two opposite edge regions on one side of the substrate, and a first sintering is performed to obtain a conductive film layer. A second resistive paste is coated on the surface of the substrate, and a second sintering is performed to form a resistive layer, thereby obtaining a resistor; the first coating and the second coating are located at different positions, and the conductive film layer and the resistive layer are in physical contact. The resistor and the BME MLCC are bonded together in the non-terminal electrode area using an adhesive. During bonding, the conductive film layer of the resistor is positioned opposite to the terminal electrode of the BME MLCC. The terminal electrode is then welded to the conductive film layer to obtain the BME MLCC with a bleed resistor.

[0022] The present invention first coats a conductive paste on the surface of two opposite edge regions on one side of a substrate, and performs a first sintering to obtain a conductive film layer.

[0023] In this invention, the substrate is preferably made of alumina, beryllium oxide, or aluminum nitride. This invention does not impose any special limitations on the size of the substrate.

[0024] In this invention, the conductor paste preferably comprises a pure silver conductor paste.

[0025] In this invention, the temperature of the first sintering is preferably 850~900℃, specifically 850, 880 or 900℃, and the holding time is preferably 10min.

[0026] In this invention, the first sintering is preferably carried out in an air atmosphere.

[0027] In this invention, a second resistive paste is coated on the surface of the substrate, and a second sintering is performed to form a resistive layer, thereby obtaining a resistor; the first coating and the second coating are located at different positions, and the conductive film layer and the resistive layer are in physical contact.

[0028] In this invention, the second coating is preferably applied to the central region of the substrate.

[0029] In this invention, the second sintering temperature is preferably 850~900℃, specifically 850, 880 or 900℃, and the holding time is preferably 10min.

[0030] In this invention, the second sintering is preferably carried out in an air atmosphere, and it is not necessary to prepare the resistive layer in a protective atmosphere. Since ruthenium has many valence states, the instability of the valence of ruthenium-based resistive paste during sintering in a protective atmosphere is avoided, which can easily cause fluctuations in resistance value. This ensures the stability of sintering, thereby improving the yield of the resistive layer and the yield of BME MLCC with bleeder resistor.

[0031] In this invention, the resistance value of the resistive layer is preferably 400MΩ~1000MΩ.

[0032] In this invention, the resistive paste preferably includes a ruthenium-based resistive paste. The specific composition of the ruthenium-based resistive paste is not particularly limited; any type well-known to those skilled in the art can be used, such as ruthenium oxide-based resistive paste. When the resistive paste preferably includes a ruthenium-based resistive paste, the second sintering and the second sintering are performed simultaneously. That is, after coating the resistive paste and the conductor paste onto the surface of the substrate respectively, co-sintering is performed, improving production efficiency and further reducing product manufacturing costs.

[0033] In this invention, the first coating and the second coating are preferably printed, and this invention does not have any special limitations on the printing process.

[0034] Figure 1 This is a schematic diagram showing the positions of the resistive paste and the conductive paste on the substrate surface. The conductive paste is located on two opposite edge areas on one side of the substrate, and the resistive paste is located in the middle of the substrate, ensuring that the conductive film layer and the resistive layer are in physical contact after sintering.

[0035] This invention uses an adhesive to bond the resistor and the BME MLCC (capacitor) in the non-terminal electrode area. During bonding, the conductive film layer of the resistor is positioned opposite to the terminal electrode of the BME MLCC. The terminal electrode is then welded to the conductive film layer (which serves as the terminal electrode of the resistor) to obtain the BME MLCC with a bleed resistor. Preferably, the BME MLCC is bonded to the resistor after an adhesive is applied to the surface of the non-terminal electrode position, and the terminal electrode of the BME MLCC is welded to the conductive film layer of the resistor to obtain the BME MLCC with bleed resistor.

[0036] In this invention, the internal electrode of the BME MLCC is preferably nickel, and the terminal electrode is preferably copper.

[0037] In this invention, the dielectric material of the BME MLCC is preferably barium titanate or barium titanate-based ceramic material.

[0038] The present invention does not impose any special limitation on the BME MLCC, and any BME MLCC well known to those skilled in the art can be used. Figure 2 This is a schematic diagram of the external shape of a BME MLCC according to one embodiment.

[0039] In this invention, the adhesive is preferably silicone or epoxy resin.

[0040] In this invention, the adhesive is preferably applied by dot application.

[0041] In this invention, the process of applying the adhesive preferably includes curing, and the curing time is preferably 1 to 24 hours, specifically 1, 6, 12, 18 or 24 hours. The temperature is preferably room temperature, i.e. no additional heating or cooling is required.

[0042] In this invention, the welding is preferably tin soldering.

[0043] In this invention, solder pads are preferably attached to the end electrode positions of the BME MLCC before the soldering is performed.

[0044] In a specific embodiment of the present invention, it is preferable to apply silicone gel to the surface of the non-terminal electrode position of the BME MLCC, and at the same time attach solder sheets to the terminal electrode position, and attach the resistor to the BME MLCC in the direction of terminal electrode to terminal electrode, and cure at room temperature for 1~24h.

[0045] In this invention, the welding is preferably performed in a reflow oven to complete the welding of the capacitor and the substrate.

[0046] The present invention also provides a BME MLCC with a bleeder resistor prepared by the preparation method described above. The BME MLCC with a bleeder resistor includes a resistor and a capacitor. The terminal electrodes of the resistor and the capacitor are welded together, and the non-electrode areas are bonded together with an adhesive.

[0047] In this invention, the resistance value of the BME MLCC with bleeder is preferably 10MΩ~10GΩ.

[0048] Figure 3 This is a schematic diagram of the external shape of a BME MLCC with a bleeder resistor according to one embodiment.

[0049] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0050] In this invention, the yield rate refers to the ratio of the input quantity to the output quantity of the product in each step.

[0051] Example 1 Fabricating a BME MLCC with a bleeder resistor includes the following steps: Step 1: Print pure silver conductor paste on an alumina substrate, and then fire it in air at 850°C for 10 minutes to form a continuous conductive film layer. Step 2: Print ruthenium-based resistive paste onto the alumina substrate with the conductive film layer formed, and then fire it in air at 850°C for 10 minutes to form a resistive layer, thus obtaining the resistor; a schematic diagram of the positions of the resistive paste and the conductive paste on the substrate surface is shown below. Figure 1 As shown; the yield rate of the resistors is 100%; Step 3: Apply silicone sealant to the surface of the non-terminal electrode area of ​​the BME MLCC, and simultaneously attach solder pads at the terminal electrode positions. Attach the resistor from Step 2 to the BME MLCC with the terminal electrode facing each other, and cure at room temperature for 12 hours to obtain the assembly; the BME MLCC uses nickel as the inner electrode and copper as the two side terminal electrodes. Step 4: Place the assembled components from Step 3 into a reflow oven for soldering to obtain the BME MLCC with a bleed resistor, as shown in the figure. Figure 3 As shown, the yield rate is 97%.

[0052] Example 2 Fabricating a BME MLCC with a bleeder resistor includes the following steps: Step 1: Print pure silver conductor paste on an aluminum nitride substrate, and then fire it in air at 880°C for 10 minutes to form a continuous conductive film layer. Step 2: Print ruthenium-based resistive paste onto the aluminum nitride substrate with the conductive film layer formed, and then fire it in air at 850°C for 10 minutes to form a resistive layer, thus obtaining the resistor; a schematic diagram of the positions of the resistive paste and conductor paste on the substrate surface is shown below. Figure 1 As shown; the yield rate of the resistors is 100%; Step 3: Apply silicone rubber to the surface of the non-terminal electrode area of ​​the BME MLCC, and simultaneously attach solder pads at the terminal electrode positions. Attach the resistor from Step 2 to the BME MLCC with the terminal electrode facing each other, and cure at room temperature for 1 hour to obtain the assembly; the BME MLCC uses nickel as the inner electrode and copper as the two side terminal electrodes. Step 4: Place the assembled components from Step 3 into a reflow oven for soldering to obtain the BME MLCC with a bleed resistor, with a yield rate of 96%.

[0053] Example 3 Fabricating a BME MLCC with a bleeder resistor includes the following steps: Step 1: Print pure silver conductor paste and ruthenium-based resistor paste onto an aluminum nitride substrate, then co-sinter them in air at 880°C for 10 minutes to form a continuous conductive film layer and resistive layer, thus obtaining the resistor; a schematic diagram of the positions of the resistive paste and conductor paste on the substrate surface is shown below. Figure 1 As shown; the yield rate of the resistors is 95%; Step 2: Apply epoxy resin to the surface of the non-terminal electrode area of ​​the BME MLCC, and simultaneously attach solder pads at the terminal electrode positions. Attach the resistor from Step 1 to the BME MLCC with the terminal electrode facing each other, and cure at room temperature for 16 hours to obtain the assembly; the BME MLCC uses nickel as the inner electrode and copper as the two side terminal electrodes. Step 3: Place the assembled components from Step 2 into a reflow oven for soldering to obtain the BME MLCC with a bleed resistor, with a yield rate of 98%.

[0054] The resistance value of the BME MLCC with bleeder obtained in Examples 1-3 can be adjusted arbitrarily between 10MΩ and 10GΩ as needed.

[0055] Comparative Example 1 BME MLCCs with bleed resistors were prepared according to the method in Example 1 of CN 118213196 A, with a yield of 55%.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for fabricating a BME MLCC with a bleeder resistor, characterized in that, Includes the following steps: A conductive paste is first coated on the surface of two opposite edge regions on one side of the substrate, and then a first sintering is performed to obtain a conductive film layer. A second resistive paste is coated on the surface of the substrate, and a second sintering is performed to form a resistive layer, thereby obtaining a resistor. The first coating and the second coating are applied at different locations, and the conductive film layer and the resistive layer are in physical contact. The resistor and the BME MLCC are bonded together in the non-terminal electrode area using an adhesive. During bonding, the conductive film layer of the resistor is positioned opposite to the terminal electrode of the BME MLCC. The terminal electrode is then welded to the conductive film layer to obtain the BME MLCC with a bleed resistor.

2. The preparation method according to claim 1, characterized in that, The substrate is made of alumina, beryllium oxide, or aluminum nitride.

3. The preparation method according to claim 1, characterized in that, The adhesive is silicone or epoxy resin.

4. The preparation method according to claim 1 or 3, characterized in that, The adhesive is applied by dot application.

5. The preparation method according to claim 1, characterized in that, Both the first and second sintering processes were carried out in air.

6. The preparation method according to claim 1, characterized in that, The welding is tin soldering.

7. The preparation method according to claim 1, characterized in that, The internal electrode of the BME MLCC is nickel, and the terminal electrode is copper.

8. The preparation method according to claim 1, characterized in that, The conductor paste includes a pure silver conductor paste.

9. The preparation method according to claim 1, characterized in that, The resistive paste includes ruthenium-based resistive paste.

10. The BME MLCC with a bleeder resistor prepared by the preparation method according to any one of claims 1 to 9, characterized in that, The BME MLCC with a bleed resistor includes a resistor and a capacitor, with the terminal electrodes of the resistor and capacitor welded together and the non-electrode areas bonded together with an adhesive.

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