Improvement method for chip bonding in stacking and sintering process of chip capacitor ceramic substrates

Abstract

The invention discloses an improvement method for chip bonding in the stacking and sintering process of chip capacitor ceramic substrates, and belongs to the technical field of electronic components. The improvement method comprises the following steps of: preparing one or more of zirconium oxide powder, aluminum oxide powder, glass powder and starch according to a set proportion, and fully and uniformly mixing to prepare anti-sticking powder; dipping an anti-sticking powder medium by using an anti-sticking powder coating tool to coat the surface of the ceramic green body sheet back and forth, so that a layer of uniform anti-sticking powder is adsorbed on the surface of the ceramic green body sheet; stacking a plurality of ceramic green sheets with a layer of uniform isolation powder adsorbed on the surface according to a process design requirement; the multiple stacked ceramic green body pieces are placed in a high-temperature sintering furnace to be sintered according to a set sintering technology; and separating the ceramic substrate subjected to high-temperature sintering to obtain the high-performance ceramic substrate for the chip capacitor. The problems that in the stacking sintering process, bonding and separation are difficult, the surface of the ceramic substrate is uneven, and the quality consistency is poor are solved. The method is widely applied to the manufacturing technology of electronic component ceramic substrates.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic components, and further relates to the technical field of ceramic substrates, and specifically to a method for improving chip capacitor ceramic substrate adhesion during stacking and sintering. Background Art

[0002] Driven by the booming development of the information age and the artificial intelligence industry, communication technologies such as 4G and 5G are being updated faster and faster, and the requirements for miniaturization, chip-based and high-frequency electronic components are becoming more urgent. As one of the three major passive electronic components (resistors, capacitors and inductors), the market demand for capacitors, especially chip capacitors, has shown explosive growth in recent years. The global market size is about US$18 billion, and chip capacitors account for more than 25% of the market share. High-performance dielectric ceramic substrates for chip capacitors, hereinafter referred to as ceramic substrates, as the core functional layer materials of components, directly determine product performance indicators and product quality.

[0003] Usually, ceramic substrates for chip capacitors are sintered by stacking multiple pieces during the sintering process, and isolation powder is used as a medium to isolate the green sheets, provide a debinding channel for the green sheets, and prevent the substrate from sticking during sintering. However, conventional green sheets are coated with isolation powder using a dry powder sprayer, which is prone to pipe blockage and cumbersome operation during operation, and the amount of isolation powder sprayed is unstable and uneven. After multiple pieces of ceramic substrates are stacked and sintered, serious problems such as sticking and difficulty in separation are prone to occur, and the surface of the ceramic substrate is uneven and has poor flatness. Therefore, it is very challenging to use a cost-effective and simple method to evenly distribute the isolation powder on the surface of the green sheet, solve the problem of ceramic substrate stacking and sintering, and improve the flatness of the product surface.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The technical problem to be solved by the present invention is to solve the problems of sticking, difficult separation, uneven surface of ceramic substrates, poor quality consistency, etc. in the existing powder spraying process of multiple ceramic green sheets stacked sintering technology.

[0006] To this end, the present invention provides a method for improving chip capacitor ceramic substrate sticking during stacking and sintering, comprising the following method: Preparation of isolation powder: Use one or more of zirconium oxide powder, aluminum oxide powder, glass powder and starch, prepare them according to a set ratio and mix them thoroughly to prepare isolation powder, which is used as an isolation medium when multiple green ceramic sheets are stacked.

[0007] Dip the powder coating tool into the powder coating medium and apply it back and forth on the surface of the ceramic green sheet, so that the surface of the ceramic green sheet absorbs a uniform layer of powder coating.

[0008] Multiple pieces stacking: The ceramic green sheets with a uniform layer of powder adsorbed on the surface are stacked in multiple pieces according to the process design requirements.

[0009] High temperature sintering: Place multiple stacked ceramic green sheets in a high temperature sintering furnace and sinter them according to the set sintering process.

[0010] Substrate separation: Separate the ceramic substrate after high-temperature sintering to obtain a high-performance ceramic substrate for chip capacitors.

[0011] Compared with the traditional green sheet using a sprayer to separate powder, the present invention is based on the improvement of the chip capacitor using a ceramic substrate separation powder sintering method, the ceramic green sheet separation powder tool is optimized, and the green sheet surface can be adsorbed with a thin layer of separation powder by using a simple-to-operate, low-cost tool. After the ceramic green sheet is stacked and sintered, the substrates can be well separated, reducing the problem of sticking, while improving the surface flatness of the ceramic substrate, and the improvement effect is obvious. The substrates made by sintering will not have sticking phenomenon, the substrates can be well separated, and the substrate surface flatness is very good.

[0012] The method can be widely used in the manufacturing technology of ceramic substrates of electronic components. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the surface condition of a ceramic substrate in the prior art.

[0014] Figure 2 Schematic diagram of the surface condition of the ceramic substrate of the present invention. DETAILED DESCRIPTION

[0015] like Figure 1 As shown, the method for improving chip capacitor ceramic substrate sticking during stacking and sintering is specifically implemented as follows: Case 1: The particle size of the isolation powder is above 100 meshes, and is fully mixed in the proportion of 35% zirconium oxide powder, 15% aluminum oxide powder, 10% glass powder and 40% starch. The ceramic green sheets are neatly placed on the operating table, and the roller tool is used to dip the isolation powder medium and roll back and forth on the surface of the ceramic green sheets, so that the surface of the placed ceramic green sheets can adsorb a thin and uniform layer of isolation powder, and then the ceramic green sheets adsorbed with isolation powder are stacked on the support plate using zirconium oxide plates, and finally placed in a high-temperature sintering furnace for sintering, the temperature is set to 1300 ° C, the insulation time is 2h, and the sintering process of the ceramic substrate is completed. After sintering, the ceramic substrates are easily separated, and the surface flatness of the ceramic substrates is very high. After multiple batches of verification, the qualified rate of ceramic substrates is above 92%.

[0016] Table 1 Sintering qualification rate of powder-coated substrates using roller tool Serial number batch Number of inputs Number of qualified Pass rate Warpage 1 SY1# 4300 3977 92.5% ≤0.2% 2 SY2# 4500 4230 94.0% ≤0.2% 3 SY3# 4400 4100 93.2% ≤0.2% 4 SY4# 4300 3986 92.7% ≤0.2% Case 2: The particle size of the isolation powder is above 100 meshes, and is fully mixed in the proportion of 35% zirconium oxide powder, 10% aluminum oxide powder, 10% glass powder and 45% starch. The ceramic green sheets are neatly placed on the operating table, and a soft brush tool is used to dip the isolation powder medium and brush it back and forth on the surface of the ceramic green sheet, so that the surface of the ceramic green sheet can adsorb a layer of uniform isolation powder, and then the ceramic green sheet adsorbed with isolation powder is stacked on the support plate using a zirconium oxide plate, and finally placed in a high-temperature sintering furnace for sintering, the temperature is set to 1310 ° C, the insulation time is 2h, and the sintering process of the ceramic substrate is completed. After sintering, the ceramic substrates are easily separated, and the surface flatness of the ceramic substrates is very high. After multiple batches of verification, the qualified rate of ceramic substrates is above 88%.

[0017] Table 2 Sintering qualification rate of powder-coated substrates using a soft brush tool Serial number batch Number of inputs Number of qualified Pass rate Warpage 1 SY1# 4000 3560 89.0% ≤0.2% 2 SY2# 4200 3654 87.0% ≤0.2% 3 SY3# 4000 3480 87.0% ≤0.2% 4 SY4# 4100 3616 88.2% ≤0.2% Figure 1 This is a picture of the surface of the ceramic substrate where the sticking problem occurs during sintering with powder in the traditional method. Figure 2 The effect diagram of the substrate surface after sintering the ceramic substrate to improve the powder adhesion of the present invention is shown. The comparison shows that the substrates made by sintering will not stick to each other, the substrates can be well separated, and the surface flatness of the substrates is very good.

[0018] Finally, it should be noted that the above embodiments are merely examples for the purpose of clear explanation. The present invention includes but is not limited to the above embodiments. It is not necessary and impossible to list all implementation methods exhaustively. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. All implementation methods that meet the requirements of the present invention belong to the protection scope of the present invention.

Claims

1. A method for improving chip capacitor ceramic substrate sticking during stacking and sintering, characterized in that: The following methods are included: Preparation of isolation powder: one or more of zirconium oxide powder, aluminum oxide powder, glass powder and starch are prepared in a set ratio and fully mixed to prepare isolation powder, which is used as an isolation medium when multiple green ceramic sheets are stacked; Powder coating: Use a powder coating tool to dip the powder coating medium and apply it back and forth on the surface of the ceramic green sheet, so that the surface of the ceramic green sheet absorbs a uniform layer of powder coating; Multiple pieces stacking: The ceramic green sheets with a uniform layer of powder adsorbed on the surface are stacked in multiple pieces according to the process design requirements; High temperature sintering: Place the stacked ceramic green sheets in a high temperature sintering furnace and sinter them according to the set sintering process; Substrate separation: Separate the ceramic substrate after high-temperature sintering to obtain a high-performance ceramic substrate for chip capacitors.

2. The method for improving chip capacitor ceramic substrate sticking during stacking and sintering as claimed in claim 1, characterized in that: The particle size of the isolation powder is above 100 meshes.

3. The method for improving chip capacitor ceramic substrate sticking during stacking and sintering as claimed in claim 1, characterized in that: The powder-isolating shoe coating tool is a roller.

4. The method for improving chip capacitor ceramic substrate sticking during stacking and sintering as claimed in claim 1, characterized in that: The shoe powder coating tool is a soft-bristled brush.

5. The method for improving chip capacitor ceramic substrate sticking during stacking and sintering as claimed in claim 1, characterized in that: The ratio of the isolation powder is 30%-50% zirconium oxide powder, 10%-30% aluminum oxide powder, 10%-30% glass powder and 20%-40% starch.

6. The method for improving chip capacitor ceramic substrate sticking during stacking and sintering as claimed in claim 1, characterized in that: The ceramic green body with good adsorption and anti-sticking powder adopts zirconia plates as multiple stacked firing plates.

7. The method for improving chip capacitor ceramic substrate sticking during stacking and sintering as claimed in claim 1, characterized in that: The sintering temperature of the high-temperature sintering is 1300° C.±30° C., and the heat preservation time is 1 h to 3 h.

8. The method for improving chip capacitor ceramic substrate sticking during sintering process as claimed in claim 1, characterized in that: The warpage of the ceramic substrate is ≤0.2%.

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