A leveling device for LTCC basic printing

Abstract

This utility model discloses a leveling device for LTCC substrate printing, belonging to the field of LTCC substrate manufacturing technology. It includes a stainless steel aluminum plate, a first sheet of Mylar paper, raw tape, PET film, a second sheet of Mylar paper, a vacuum plastic bag, a vacuum packaging machine, and a warm water press. Multiple sets of the first sheet of Mylar paper, raw tape, PET film, and second sheet of Mylar paper are stacked on the stainless steel aluminum plate, arranged from bottom to top. The vacuum plastic bag wraps the stainless steel aluminum plate and all the stacked first sheet of Mylar paper, raw tape, PET film, and second sheet of Mylar paper, ensuring a vacuum inside the bag. The vacuum packaging machine seals and evacuates the vacuum plastic bag, and the warm water press performs a warm water pressing operation on the vacuum plastic bag. This leveling device levels the raw tape, ensuring a good connection between the upper and lower layers at the through-hole locations within the LTCC substrate product. This increases product reliability, avoids incomplete through-hole connections in the LTCC substrate, improves the electrical connection reliability between the upper and lower layers of the LTCC substrate, and avoids the risk of product failure.

Description

Technical Field

[0001] This utility model relates to a leveling device for LTCC basic printing, belonging to the field of LTCC substrate technology. Background Technology

[0002] LTCC substrates are high-performance multilayer ceramic circuit boards, formed by simultaneously sintering ceramic materials and metal conductors at low temperatures (typically below 1000°C). They combine the excellent properties of ceramics with the ability to be integrated into multiple layers, making them widely used in high-frequency, high-reliability electronic devices.

[0003] Through-holes in a certain LTCC substrate product were discovered using CT, such as... Figure 1-2 As shown, there is a loose connection between the upper and lower layers at the through hole location of the product. This problem can also be visually observed after grinding. Loose connections in the through holes will cause the risk of open circuits between the upper and lower layers, resulting in poor reliability. If the product flows into the customer's store, it will cause the customer's product to fail. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a leveling device for LTCC basic printing, which can avoid the virtual connection of through holes in LTCC substrate, improve the electrical connection reliability between upper and lower layers of LTCC substrate, and avoid the risk of product failure.

[0005] The technical solution adopted by this utility model is as follows: A leveling device for LTCC basic printing includes a stainless steel aluminum plate, a first sheet of Mylar paper, raw tape, PET film, a second sheet of Mylar paper, a vacuum plastic bag, a vacuum packaging machine, and a warm water press. Multiple sets of the first sheet of Mylar paper, raw tape, PET film, and second sheet of Mylar paper are stacked on the stainless steel aluminum plate from bottom to top. The vacuum plastic bag wraps the stainless steel aluminum plate and all the first sheet of Mylar paper, raw tape, PET film, and second sheet of Mylar paper stacked on it, ensuring that the inside of the vacuum plastic bag is vacuum. The vacuum packaging machine is used to seal and vacuum the vacuum plastic bag. The warm water press is used to perform a warm water pressing operation on the vacuumed vacuum plastic bag.

[0006] Furthermore, the number of stacked Mylar paper, raw tape, PET film and second Mylar paper shall not exceed 20.

[0007] The beneficial effects of this utility model are as follows: Compared with the prior art, this utility model adds a leveling device to the printing process to level the raw tape. That is, after all the filling layers are filled, the raw tape after filling is leveled. After leveling, the silver paste at the position of the hole in the raw tape is completely pressed into the hole. After leveling, normal printing continues. This results in a good connection between the upper and lower layers inside the product, which increases the reliability of the product, avoids the through-hole connection of the LTCC substrate, improves the electrical connection reliability between the upper and lower layers of the LTCC substrate, and avoids the risk of product failure. Attached Figure Description

[0008] Figure 1 This is a diagram of the through-hole DPA of an existing LTCC substrate filled with silver paste;

[0009] Figure 2 This is a CT image of a silver paste-filled via on an existing LTCC substrate;

[0010] Figure 3 This is a diagram of the through-hole DPA of an LTCC substrate after the addition of a leveling process;

[0011] Figure 4 This is a CT image of the silver paste-filled vias of an LTCC substrate after the addition of a leveling process;

[0012] Figure 5 This is a schematic diagram of the leveling process;

[0013] Figure 6 This is a schematic diagram of the leveling structure. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0015] like Figure 1-2 As shown, there is a loose connection between the upper and lower layers at the through-hole location of the product. This problem can also be visually observed after grinding. Loose connections in through-holes can cause open circuits between the upper and lower layers, resulting in poor reliability. If the product flows to the customer, it will cause product failure risk. To address this technical problem, embodiments 1-2 of this utility model provide a leveling structure for LTCC substrate printing and a method for manufacturing LTCC substrates. By adding a leveling process to the printing process, the loose connections in through-holes of LTCC substrates can be avoided, the electrical connection reliability between the upper and lower layers of the LTCC substrate can be improved, and the risk of product failure can be avoided.

[0016] Example 1: A leveling device for LTCC basic printing includes a stainless steel aluminum plate 1, a first sheet of Mylar paper 2, raw tape 3, PET film 4, a second sheet of Mylar paper 5, a vacuum plastic bag 6, a vacuum packaging machine, and a warm water press. Multiple sets of the first sheet of Mylar paper 2, raw tape 3, PET film 4, and second sheet of Mylar paper 5 are stacked on the stainless steel aluminum plate 1 from bottom to top. The vacuum plastic bag 6 wraps the stainless steel aluminum plate 1 and all the first sheet of Mylar paper 2, raw tape 3, PET film 4, and second sheet of Mylar paper 5 stacked on it, ensuring that the inside of the vacuum plastic bag 6 is vacuum. The vacuum packaging machine is used to seal and vacuum the vacuum plastic bag 6. The warm water press is used to perform a warm water pressing operation on the vacuumed vacuum plastic bag 6. The number of sets of the first sheet of Mylar paper 2, raw tape 3, PET film 4, and second sheet of Mylar paper 5 stacked is no more than 20.

[0017] Example 2: As Figure 3-6As shown, an LTCC substrate fabrication method includes the following steps:

[0018] S1. Ingredients: The powder is ball-milled to a particle size of 0.5-1μm. The ingredients, stirring speed and time are adjusted according to the different formulas of each product to achieve the slurry we need.

[0019] S2, Casting: The ball-milled ingredients are prepared into a slurry, and a casting technique is used to obtain a green ceramic tape with a thickness of 10-250μm;

[0020] S3. Cutting: Cut the green ceramic strip into green ceramic strips of various thicknesses, each 6 inches in diameter;

[0021] S4. Hole making: According to the pre-made hole making pattern, use a laser hole making machine to make holes on the green ceramic tape that needs to be made;

[0022] S5. Printing: The printing method is screen printing. The design graphic is prepared on film, and after exposure, the inductance is transferred to a 200-500 mesh steel wire mesh covered with photosensitive emulsion to form a printing fixture. The G layer, via layer, and surface layer of the LTCC substrate use 200-500 mesh. The photosensitive emulsion coating thickness is controlled as follows: 37μm~110μm; printing GAP value: 1mm~2mm; printing squeegee pressure: 0.05MPa~0.10MPa; squeegee step speed: 0.0 5m / s~0.10m / s; Print each layer of the design model onto the green ceramic tape of the corresponding thickness. The line width and G layer thickness error of the LTCC substrate are within 2μm. The thickness of the BOT layer and TOP layer of the LTCC substrate is 10-30μm. After all the filling layers are filled, a leveling operation is required. After the leveling operation, warm water pressure is applied and natural cooling is performed. The Mylar paper and the PET film on the non-green tape are removed in sequence to obtain the leveled green tape. Then, normal printing can be performed.

[0023] Specifically, the leveling operation steps are as follows:

[0024] S5.1 Clean the stainless steel aluminum plate and Mylar paper with lint-free paper and alcohol;

[0025] S5.2 The first sheet of Mylar paper is placed in the center of the stainless steel aluminum plate;

[0026] S5.3 The raw tape is overlapped on the Mylar paper, with the side of the raw tape with the holes filled facing up;

[0027] S5.4 The oily side of the PET film covers the raw conveyor belt;

[0028] S5.5 Place the second Mylar paper in the center on top of the PET film;

[0029] S5.6 Repeat S5.2-5.5, stacking the strips in the following order: first Mylar paper → raw tape → PET film → second Mylar paper. No more than 20 raw tapes should be placed on each stainless steel aluminum plate.

[0030] S5.7. Place the stainless steel and aluminum sheets together in a bag, vacuum seal for 50 seconds, and heat seal for 2.5-3 seconds at a low temperature. See the work instruction diagram. Figure 5 See the stacking diagram. Figure 6 .

[0031] The leveling device for LTCC substrate printing includes a stainless steel aluminum plate 1, a first Mylar paper 2, raw tape 3, PET film 4, and a second Mylar paper 5. Multiple sets of the first Mylar paper 2, raw tape 3, PET film 4, and second Mylar paper 5 are stacked on the stainless steel aluminum plate 1 from bottom to top. A vacuum bag is wrapped around the stainless steel aluminum plate 1 and the multiple sets of the first Mylar paper 2, raw tape 3, PET film 4, and second Mylar paper 5. A vacuum plastic bag 6 is wrapped around the stainless steel aluminum plate 1 and all the first Mylar paper 2, raw tape 3, PET film 4, and second Mylar paper 5 stacked on it, ensuring that the inside of the vacuum plastic bag 6 is vacuum. A vacuum packaging machine is used to seal and vacuum the vacuum plastic bag 6. A warm water press is used to perform a warm water press operation on the vacuumed vacuum plastic bag 6. The number of sets of the first Mylar paper 2, raw tape 3, PET film 4, and second Mylar paper 5 stacked is no more than 20.

[0032] The function of Mylar paper is: because Mylar paper is relatively hard and has a smooth surface, it has the function of flattening and supporting flatness. The function of PET film is to protect the production tape from damage. Stainless steel and aluminum plates have a smooth surface and high hardness, and provide support.

[0033] The leveling structure performs a leveling operation on all the filler layers of the raw tape in the printing process. After leveling, the silver paste at the position of the filler hole in the raw tape is completely pressed into the hole. The LTCC substrate produced after leveling has a good connection between the upper and lower layers at the filler hole, which increases the reliability of the product, avoids the through-hole connection of the LTCC substrate, improves the electrical connection reliability between the upper and lower layers of the LTCC substrate, and avoids the risk of product failure.

[0034] The temperature and pressure are determined according to the temperature and pressure curves for time, pressure, and temperature in the table below.

[0035]

[0036] S6. Lamination: The printed ceramic tapes are laminated in the design order using a fully automatic alignment and lamination machine.

[0037] S7. Isostatic pressing: The laminated diaphragm is subjected to final pressing using isostatic pressing; maximum isostatic pressing temperature: (60~90)℃; holding time: (200~1000)s; holding pressure: (3000~8000)psi, forming a Bar block. The pressure can be adjusted according to the actual situation for different materials and products.

[0038] S8. Cutting: Divide the Bar block into sections and cut according to the cutting lines of the designed product. The cutting accuracy is ±0.1mm.

[0039] S9. Debinding and sintering: Surface electrode products are sintered in one process, while products without surface electrodes are sintered after debinding. They are sintered into semi-finished products according to their respective debinding and sintering curves.

[0040] S10. Chamfering: Select different chamfering parameters and chamfering media according to the product material and product size, and achieve a certain chamfering radius according to the standard.

[0041] S11, Silvering and Burning: Apply silver to the silvered surface according to the design, and make sure to reach a certain silvering size. After applying silver, burn it as required.

[0042] S12, Electroplating: Applying the required metal to the sintered product through chemical plating or electroplating to ultimately form the product.

[0043] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A planarization device for LTCC base printing, characterized in that, The system includes a stainless steel aluminum plate, a first sheet of Mylar paper, raw tape, PET film, a second sheet of Mylar paper, a vacuum plastic bag, a vacuum packaging machine, and a warm water press. Multiple sets of the first sheet of Mylar paper, raw tape, PET film, and second sheet of Mylar paper are stacked on the stainless steel aluminum plate from bottom to top. The vacuum plastic bag wraps the stainless steel aluminum plate and all the first sheet of Mylar paper, raw tape, PET film, and second sheet of Mylar paper stacked on it, ensuring that the inside of the vacuum plastic bag is vacuum. The vacuum packaging machine is used to seal and vacuum the vacuum plastic bag, and the warm water press is used to perform a warm water pressing operation on the vacuumed vacuum plastic bag.

2. A levelling device for LTCC base printing according to claim 1, characterised in that, The number of stacks of the first Mylar paper, raw tape, PET film and the second Mylar should not exceed 20.

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