CN105006362A - Preparation method for thin-film capacitor with strippable substrate - Google Patents

Abstract

The invention discloses a method for preparing a film capacitor with a peelable substrate. The process steps are: ① Spin-coat a certain thickness of polyurethane glue layer on the substrate and cure it with ultraviolet light; ② Prepare the dielectric layer by sol-gel or sputtering method; ③ Prepare the electrode layer by sputtering method, and use Laser etching to obtain a patterned electrode layer; ④ Prepare in sequence according to the dielectric layer/electrode layer/dielectric layer/electrode layer, and prepare terminal electrodes at both ends of the long side of the capacitor to form a single layer of interdigitated structure or multilayer film capacitors; ⑤Put the above film capacitors into a resistance furnace and perform annealing treatment at a certain temperature to crystallize the dielectric layer and burn off the organic layer to realize the peeling of the film capacitor from the substrate. The invention can realize the peeling off of the device and the substrate without using corrosive substances such as acid or alkali, has the characteristics of simple process and easy industrialization, and is especially suitable for making various single-layer or multi-layer thin film components.

Description

A kind of film capacitor preparation method with peelable substrate

technical field

The invention belongs to the technical field of film component preparation, and relates to a method for preparing a film capacitor with a peelable substrate, in particular to a method for preparing a single-layer or multilayer film capacitor with a peelable substrate.

Background technique

With the development of electronic technology, after the development of semiconductor manufacturing technology from micron to nanometer stage, the integration level of chips has been greatly improved, and correspondingly higher requirements have been put forward for the components required for its matching. For example, the development of the field of mobile communication requires the core chip of the Intel central processing unit to be further reduced, so that the components, especially the chip multilayer ceramic capacitor (MLCC), face the following problems: the effective capacitance area available on the back of the substrate is greatly reduced, However, the demand for components has increased significantly; at the same time, the space for surface mounting is very limited. For these problems, Intel has proposed a solution using small surface mount or embedded passive components, requiring the multilayer ceramic capacitor (MLCC) used to be as small as possible without reducing the capacitance and reliability. .

In order to achieve the above goals, it is one of the trends in technology development to use thin-film methods to manufacture electronic components. At the same time, in order to further reduce the volume of the devices, it is necessary to peel off the thin-film devices from the substrate and directly mount them. The existing technology mainly adopts the method of manufacturing a metal sacrificial layer, that is, a layer of metal sacrificial layer is deposited on the substrate by a thin film method, and then the sacrificial layer is selectively etched with acid or alkali to obtain a strippable layer after the film or device is completed. The thin film of the substrate, but this method is for the thin film capacitor that uses barium titanate base material as medium and metal or non-metallic oxide as electrode, needs to protect the thin film material before removing sacrificial layer with selective etching solution, and While corroding the sacrificial layer, the dielectric layer and the electrode layer are likely to be partially corroded, which increases the difficulty of stripping the film from the substrate.

In order to improve the above deficiencies, the present invention adopts polyurethane organic material as the sacrificial layer between the substrate and the thin film, and burns off the organic layer while the thin film device is annealed to realize the peeling off of the thin film or device from the substrate. Compared with the method of the above-mentioned metal sacrificial layer, the use of acid or alkali solutions can be avoided, and the damage of acid or alkali to the dielectric layer and electrode layer can also be avoided, which has the characteristics of convenience and low cost.

Contents of the invention

The purpose of the present invention is to provide a preparation method of a film capacitor with a peelable substrate, by which the film capacitor can be peeled off quickly and at low cost from the substrate, the method can effectively reduce the volume of the film capacitor, and is convenient Mounting or embedding film capacitors in other places is conducive to improving the integration of chips or integrated circuits.

The technical scheme that the present invention solves the problems of the technologies described above is:

A method for preparing a thin film capacitor with a peelable substrate, comprising preparation of an adhesive layer, preparation of a dielectric layer, preparation of an electrode layer, preparation of a composite layer, and a stripping process, the process steps of which are:

① Adhesive layer preparation: Spin-coat a certain thickness of polyurethane adhesive layer on the substrate and cure it with ultraviolet light;

②Preparation of dielectric layer: The dielectric layer is prepared by sol-gel or sputtering method;

③ Electrode layer preparation: The electrode layer is prepared by sputtering, and the patterned electrode layer is obtained by laser etching;

④ Composite layer preparation: Then prepare in sequence according to the method of dielectric layer/electrode layer/dielectric layer/electrode layer, and prepare terminal electrodes at both ends of the long side of the capacitor to form a single-layer or multi-layer film capacitor with an interdigitated structure;

⑤ Peeling: Put the above-mentioned film capacitor into a resistance furnace, and perform annealing treatment at a certain temperature to crystallize the dielectric layer and burn off the organic layer, so as to realize the peeling of the film capacitor from the substrate.

The aforementioned substrates include alumina, quartz, silicon wafers, zirconia, and strontium titanate single wafers.

The above-mentioned electrode layer is a metal or non-metal inorganic oxide thin film material, including pure metals of Ni, Ag, Cu, Ti, Au or Pt or their composite metals and ITO, AZO, SnO ₂ oxides;

The dielectric layer mentioned above includes BaTiO ₃ and various dielectric film materials based on BaTiO ₃ , including inorganic non-metallic oxide films of PZT, X7R porcelain powder, Y5V porcelain powder, and X8R porcelain powder.

The dielectric layer mentioned above may be one layer or multiple layers.

The thickness of the polyurethane layer mentioned above is 0.2-5 μm, the thickness of a single layer of the electrode layer is 0.1-2 μm, and the thickness of a single layer of the dielectric layer is 0.2-3 μm.

The annealing temperature of the film capacitor mentioned above is 500-800° C., and the time is 15-120 minutes. the

Advantage and positive effect of the present invention:

1. The method adopts the polyurethane organic material as the sacrificial layer between the substrate and the film, and the organic layer can be removed during the annealing process of the film, thereby realizing the peeling off of the film and the substrate.

2. This method does not need to use acid or alkali solution in the whole stripping process, which can avoid the damage of acid or alkali solution to the dielectric layer and electrode layer.

3. Compared with the existing film stripping technology, the film capacitor prepared by peeling off the substrate has the advantages of low cost, simple process, and easy industrialization, and is especially suitable for thin film components, especially single-layer or multi-layer thin film components. Delamination on the substrate.

Description of drawings

Figure 1: Cross-sectional SEM image of a film capacitor after peeling off from the substrate.

Detailed ways

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples.

Example 1

A method for preparing a film capacitor with a peelable substrate, the specific implementation steps are as follows:

(1) A polyurethane layer with a thickness of 2.5 μm is coated on the alumina substrate by spin coating, and cured by ultraviolet light;

(2) Deposit a BaTiO ₃ dielectric film with a thickness of 3 μm by magnetron sputtering;

(3) Using the magnetron sputtering method, deposit an ITO electrode film layer with a thickness of 2 μm on the above-mentioned dielectric layer, and pattern the ITO electrode film to the capacitive electrode size of the 0201-sized MLCC by laser etching;

(4) The BaTiO ₃ dielectric film with a thickness of 3 μm and the ITO electrode film with a thickness of 2 μm are sequentially deposited by magnetron sputtering, and the ITO electrode layer is patterned according to the 0201 specification capacitor electrode staggered layer structure by laser etching, and the dielectric layer is repeated and electrode layer 3 times, and finally sputter Ag terminal electrodes at both ends of the long side of the capacitor to form a multilayer film capacitor with an interdigitated structure;

(5) Put the multilayer film capacitor above into a resistance furnace and anneal at 600°C for 30 minutes to peel off the film capacitor from the substrate. The SEM image of the film section after peeling is shown in Figure 1.

Example 2

A method for preparing a film capacitor with a peelable substrate, the specific implementation steps are as follows:

(1) A polyurethane layer with a thickness of 1.5 μm is coated on the alumina substrate by spin coating, and cured by ultraviolet light;

(2) Prepare a sol with a metal ion concentration of 0.5 mol/L with butyl titanate, barium acetate, glacial acetic acid, acetylacetone, etc., and prepare a 2 μm BaTiO ₃ dielectric film on the above polyurethane layer by means of homogenization;

(3) Using the magnetron sputtering method, deposit an Ag electrode thin film layer with a thickness of 0.2 μm on the above dielectric layer, and pattern the Ag electrode thin film to the capacitive electrode size of an MLCC with a size of 0201 by laser etching;

(4) Using the above-mentioned sol-gel method to sequentially prepare a BaTiO ₃ dielectric film with a thickness of 0.5 μm and an Ag electrode film with a thickness of 0.2 μm, and laser etch to pattern the Ag electrode layer according to the 0201 capacitor electrode staggered structure, and repeat The dielectric layer and the electrode layer are 30 times, and finally the terminal electrodes of Ag are sputtered at both ends of the long side of the capacitor to form a multilayer film capacitor with an interdigitated structure;

(5) Put the above-mentioned multilayer film capacitor into a resistance furnace, and anneal at 550°C for 60 minutes to realize the peeling of the film capacitor from the substrate.

Example 3

A method for preparing a film capacitor with a peelable substrate, the specific implementation steps are as follows:

(1) A polyurethane layer with a thickness of 0.5 μm is coated on the quartz substrate by spin coating, and cured by ultraviolet light;

(2) Prepare a sol with a metal ion concentration of 0.8 mol/L with butyl titanate, zirconium acetate, lead acetate, glacial acetic acid, acetylacetone, etc., and prepare a 3 μm PZT dielectric film on the above polyurethane layer by means of homogenization;

(3) Using the magnetron sputtering method, deposit a Cu electrode film layer with a thickness of 2 μm on the above-mentioned dielectric layer, and pattern the Cu electrode film to the capacitive electrode size of the 0402-sized MLCC by laser etching;

(4) The PZT dielectric film with a thickness of 3 μm and the Cu electrode film with a thickness of 2 μm were sequentially prepared by the above-mentioned sol-gel method, and the Cu electrode layer was patterned according to the 0402 capacitor electrode staggered structure by laser etching, and the dielectric layer and the The electrode layer is 50 times, and finally the terminal electrodes of Ag are sputtered at both ends of the long side of the capacitor to form a multilayer film capacitor with an interdigitated structure;

(5) Put the multilayer film capacitor above into a resistance furnace, and anneal at 500°C for 40 minutes to realize the peeling of the film capacitor from the substrate.

Example 4

A method for preparing a film capacitor with a peelable substrate, the specific implementation steps are as follows:

(1) Coat a layer of polyurethane with a thickness of 3 μm on the silicon substrate by spin coating, and cure it by ultraviolet light;

(2) The X7R dielectric film with a thickness of 2 μm is deposited by magnetron sputtering;

(3) Using the magnetron sputtering method, deposit a Pt electrode film layer with a thickness of 0.1 μm on the above-mentioned dielectric layer, and pattern the Pt electrode film into the capacitive electrode size of an MLCC with a size of 0201 by laser etching;

(4) The X7R dielectric film with a thickness of 1.0 μm and the Pt electrode film with a thickness of 0.1 μm are sequentially deposited by magnetron sputtering, and the Pt electrode layer is patterned according to the 0201 specification capacitor electrode staggered layer structure by laser etching, and the dielectric layer is repeated. layer and electrode layer 100 times, and finally sputter Ag terminal electrodes at both ends of the long side of the capacitor to form a multilayer film capacitor with an interdigitated structure;

(5) Put the above-mentioned multilayer film capacitor into a resistance furnace, and anneal at 800°C for 50 minutes to realize the peeling of the film capacitor from the substrate.

Example 5

A method for preparing a film capacitor with a peelable substrate, the specific implementation steps are as follows:

(1) A polyurethane layer with a thickness of 5 μm is coated on the zirconia substrate by spin coating, and cured by ultraviolet light;

(2) A Y5V dielectric film with a thickness of 2 μm is deposited by magnetron sputtering;

(3) Using the magnetron sputtering method, deposit a Pt/Ti electrode film layer with a thickness of 0.5 μm (the thickness of the Ti layer is 20nm) on the above dielectric layer, and pattern the Pt/Ti electrode film by laser etching Capacitive electrode size of 0603 size MLCC;

(4) The Y5V dielectric film with a thickness of 2 μm and the Pt/Ti electrode film with a thickness of 0.5 μm were sequentially deposited by magnetron sputtering, and the Pt/Ti electrode layer was patterned according to the 0603 capacitor electrode staggered layer structure by laser etching. And repeat the dielectric layer and the electrode layer 50 times, and finally sputter Ag terminal electrodes at both ends of the long side of the capacitor to form a multilayer film capacitor with an interdigitated structure;

(5) Put the above-mentioned multilayer film capacitor into a resistance furnace, and anneal at 500°C for 120 minutes to realize the peeling of the film capacitor from the substrate.

Example 6

A method for preparing a film capacitor with a peelable substrate, the specific implementation steps are as follows:

(1) A polyurethane layer with a thickness of 0.2 μm is coated on the strontium titanate single wafer substrate by spin coating, and cured by ultraviolet light;

(2) Using butyl titanate, zirconium acetate, strontium acetate, barium acetate, glacial acetic acid, acetylacetone, etc. as raw materials, prepare a sol with a metal ion concentration of 0.6mol/L according to the formula of X8R porcelain powder, and mix it in the above Prepare a 0.2μm X8R dielectric film on the polyurethane layer;

(3) Using the magnetron sputtering method, deposit an ITO electrode film layer with a thickness of 0.2 μm on the above dielectric layer, and pattern the ITO electrode film to the capacitive electrode size of the 0402-sized MLCC by laser etching;

(4) Using the above-mentioned sol-gel method to sequentially prepare the X8R dielectric film with a thickness of 0.2 μm and the ITO electrode film with a thickness of 0.2 μm, and laser etch to pattern the ITO electrode layer according to the capacitor electrode staggered structure of the 0402 specification, and repeat the dielectric layer and electrode layer 30 times, and finally sputter Ag terminal electrodes at both ends of the long side of the capacitor to form a multilayer film capacitor with an interdigitated structure;

(5) Put the above-mentioned multilayer film capacitor into a resistance furnace, and anneal at 620°C for 70 minutes to realize the peeling of the film capacitor from the substrate.

Example 7

A method for preparing a film capacitor with a peelable substrate, the specific implementation steps are as follows:

(1) A polyurethane layer with a thickness of 0.5 μm is coated on the quartz substrate by spin coating, and cured by ultraviolet light;

(2) A sol with a metal ion concentration of 1.0 mol/L was prepared with butyl titanate, barium acetate, glacial acetic acid, acetylacetone, etc., and a 2.5 μm BaTiO ₃ dielectric film was prepared on the above polyurethane layer by means of homogenization;

(3) Using the magnetron sputtering method, deposit an ITO/Au composite electrode thin film layer with a thickness of 0.3 μm on the above dielectric layer (where the thickness of the Au electrode layer is 0.1 μm), and the ITO/Au electrode is etched by laser etching. Thin film patterned to the capacitive electrode size of 0603 size MLCC;

(4) Prepare a BaTiO ₃ dielectric film with a thickness of 2.5 μm and an ITO/Au electrode film with a thickness of 0.3 μm in sequence by the above-mentioned sol-gel method, and pattern the ITO/Au electrode layer according to the 0603 capacitor electrode staggered layer structure by laser etching and repeat the dielectric layer and electrode layer 10 times, and finally sputter Ag terminal electrodes at both ends of the long side of the capacitor to form a multilayer film capacitor with an interdigitated structure;

(5) Put the above-mentioned multilayer film capacitor into a resistance furnace, and anneal at 750°C for 15 minutes to realize the peeling of the film capacitor from the substrate.

Example 8

A method for preparing a film capacitor with a peelable substrate, the specific implementation steps are as follows:

(1) Coat a layer of polyurethane with a thickness of 0.8 μm on the silicon substrate by spin coating, and cure it by ultraviolet light;

(2) A PZT dielectric film with a thickness of 2.5 μm was deposited by magnetron sputtering;

(3) Using the magnetron sputtering method, a Ni electrode film layer with a thickness of 0.3 μm is deposited on the above dielectric layer, and the Ni electrode film is patterned into the capacitive electrode size of the 0402-sized MLCC by laser etching;

(4) A PZT dielectric film with a thickness of 1.8 μm and a Ni electrode film with a thickness of 0.3 μm were sequentially deposited by magnetron sputtering, and the Ni electrode layer was patterned according to the 0402 specification capacitor electrode staggered layer structure by laser etching, and the dielectric was repeated. layer and electrode layer 10 times, and finally sputter Ag terminal electrodes at both ends of the long side of the capacitor to form a multilayer film capacitor with an interdigitated structure;

(5) Put the above-mentioned multilayer film capacitor into a resistance furnace, and anneal at 580° C. for 35 minutes to realize the peeling of the film capacitor from the substrate.

Claims (7)

1. a film capacitor preparation method for peelable substrate, is characterized in that: comprise the preparation of organic glue-line, dielectric layer preparation, the preparation of electrode layer, composite bed preparation, stripping process, its processing step is:

1. glue-line preparation: the certain thickness polyurethane glue-line of spin coating on substrate, and with ultraviolet light polymerization;

2. dielectric layer preparation: adopt collosol and gel or sputtering method to prepare dielectric layer;

3. electrode layer preparation: adopt sputtering method to prepare electrode layer, and utilize laser ablation to obtain patterned electrodes layer;

4. composite bed preparation: prepare successively by the mode of dielectric layer/electrode layer/dielectric layer/electrode layer, and prepare termination electrode at the two ends on the long limit of capacitor, forms the single or multiple lift film capacitor of interdigital structure;

5. peel off: above-mentioned film capacitor is put into resistance furnace, carries out annealing in process in uniform temperature, make dielectric layer crystallization and burn organic layer, realize film capacitor from the stripping substrate.

2. the film capacitor preparation method of a kind of peelable substrate according to claim 1, is characterized in that: described substrate comprises aluminium oxide, quartz, silicon chip, zirconia, strontium titanate monocrystal sheet.

3. the film capacitor preparation method of a kind of peelable substrate according to claim 1, it is characterized in that: described electrode layer is metal or nonmetallic inorganic oxide film material, comprise the simple metal of Ni, Ag, Cu, Ti, Au or Pt or its composition metal and ITO, AZO, SnO ₂conductive oxide.

4. the film capacitor preparation method of a kind of peelable substrate according to claim 1, is characterized in that: described dielectric layer comprises with BaTiO ₃and with BaTiO ₃for all kinds of dielectric film materials of base, comprise the inorganic non-metallic sull of PZT, X7R porcelain powder, Y5V porcelain powder, X8R porcelain powder.

5. the film capacitor preparation method of a kind of peelable substrate according to claim 1, it is characterized in that: described dielectric layer can be one deck, also can be multilayer.

6. the film capacitor preparation method of a kind of peelable substrate according to claim 1, it is characterized in that: the thickness of described polyamine lipid layer is 0.2 ~ 5 μm, the thickness of the individual layer of described electrode layer is 0.1 ~ 2 μm, and the thickness in monolayer of described dielectric layer is 0.2 ~ 3 μm.

7. the film capacitor preparation method of a kind of peelable substrate according to claim 1, it is characterized in that: described film capacitor annealing temperature is 500 ~ 800 DEG C, the time is 15 ~ 120 minutes.