CN110035603B - Method for preparing printed circuit embedded inductor - Google Patents
Method for preparing printed circuit embedded inductor Download PDFInfo
- Publication number
- CN110035603B CN110035603B CN201910337319.6A CN201910337319A CN110035603B CN 110035603 B CN110035603 B CN 110035603B CN 201910337319 A CN201910337319 A CN 201910337319A CN 110035603 B CN110035603 B CN 110035603B
- Authority
- CN
- China
- Prior art keywords
- printed circuit
- embedded inductor
- layer
- cobalt
- preparing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/16—Printed circuits incorporating printed electric components, e.g. printed resistor, capacitor, inductor
- H05K1/165—Printed circuits incorporating printed electric components, e.g. printed resistor, capacitor, inductor incorporating printed inductors
Abstract
A method for preparing a printed circuit embedded inductor belongs to the technical field of inductor preparation. The invention forms a metal seed layer and a graphical anti-corrosion layer on the surface of the medium in sequence, forms a metal conductor structure on the metal seed layer without the anti-corrosion layer, removes the graphical anti-corrosion layer and the metal seed layer covered under the graphical anti-corrosion layer as a sacrificial layer, and then deposits a magnetic film on the metal conductor structure, thereby realizing the manufacture of the printed circuit embedded inductor. The invention can realize the manufacture of the embedded inductor on any base material, so that the application of the embedded inductor element is more convenient and flexible; the inductance value of the manufactured product is improved remarkably, and the problem of uncontrollable inductance performance caused by manufacturing through holes on the magnetic conductive material is avoided; the preparation process is compatible with the production line of the printed circuit board, no additional process is needed, the investment of equipment and technology is reduced, the cost is reduced, and the industrial production is realized.
Description
Technical Field
The invention belongs to the technical field of inductor preparation, and particularly relates to a preparation method of a printed circuit embedded inductor.
Background
With the development of electronic devices toward miniaturization, functionalization and high integration, higher requirements are required to be put forward on various electronic components. The inductance element plays an important role in high-frequency and microwave frequency band signal transmission and processing as an important magnetic element, has been developed into a two-dimensional structure nowadays from an initial three-dimensional structure with the technical development, and is embedded inside a printed circuit board. The inductor embedded in the printed circuit board can not only meet the development trend of high integration level of an electronic system, but also realize minimum distance transmission of electric signals and improve the integrity of signal transmission. The technology of embedding inductance in printed circuit has become a current research hotspot.
Wangyue discloses a method for preparing a film inductor by forming an inductor circuit on monocrystalline silicon through magnetron sputtering of magnetic materials in 'organization structure and performance research of magnetron sputtering Co and CoTaZr films', wherein the whole inductor coil is formed by the magnetic materials, the cost for manufacturing an embedded inductor with the same inductance value is higher, and meanwhile, in an actual circuit, the mutual inductance among all turns of the inductor is stronger and the inductance performance is low. Kim et al, in the literature, "Thick-coil-buried inductors using patterned aluminum coils substrates", describe a method for manufacturing inductor coils by using groove metallization, in which grooves are manufactured according to coil requirements and then metal filling is performed, and the inductance value of the manufactured embedded inductor can only be improved by increasing the number of coils, which is not favorable for the miniaturization development of inductor elements. In order to increase the magnetic induction intensity of the electromagnet, a magnetic conductive substance is introduced into the magnetic circuit of the inductance coil, and the existence of the magnetic conductive substance can enhance the magnetic flux density (magnetic flux) of the magnetic circuit of the electromagnetic coil, reduce the inductance loss, further increase the electromagnetic induction intensity and be beneficial to realizing the miniaturization of an inductance structure. The technology of building a magnetically conductive material in a printed circuit embedded inductor has achieved a significant amount of development with the efforts of researchers. The invention discloses a method for manufacturing a printed circuit embedded inductor by etching a conductive coil with copper foil of a double-sided copper-clad substrate and then curing a magnetic composite material on the surface of the conductive coil to form a magnetic conductive substance in an inductor structure of a printed circuit board embedded technology and a manufacturing method thereof (application number is CN201610791943. X). However, the method has a complex process, and the substrate for manufacturing the embedded inductor is limited, so that the embedded inductor cannot be manufactured on any medium. With the widespread use of Surface Mount Technology (SMT) for electronic products, reliability problems may be caused by material mismatch when components are further integrated to construct a complete machine. The invention discloses a method for manufacturing a magnetic thin film pressing type blind hole electromagnetic induction multilayer printed circuit board (application number is CN201410285999.9), wherein a lamination method is adopted to manufacture a magnetic conductive substance, and then a guide blind hole is manufactured on the magnetic conductive substance to form a printed circuit embedded inductor. Chenjian et al in the document "an inductance core buries PCB technology in the assembling process" bury the magnetic conductive substance inside the printed circuit board wholly, construct the electrical coil through the metallized via hole, this method combines with the magnetic conductive substance through the via hole to get the embedded inductance of printed circuit with high inductance value, the process is complicated, with high costs, and need extra process when the assembly line production of printed circuit board, compatibility with PCB process is poor. The invention discloses a method for preparing a magnetic substance of an embedded inductor of a printed circuit board by directly chemically plating a layer of non-metallic alloy magnetic material on an inductor coil. The method has simple process and low production cost, and has obvious effect on improving the inductance value, but the nonmetal alloy obtained by the method not only serves as a conductor for transmitting and carrying electric signals, but also serves as a magnetic substance, and the nonmetal alloy with larger resistance value easily causes low inductance quality factor. Sugawa et al, in the literature, "carbon-iron/epoxy composite magnetic core for planar power inductor used in package-level power grid", and Van Johnson et al, in the literature, "design and performance study of Ni-Cu-Zn ferrite thin film for inductors", describe a method of improving the inductance value by covering the surface of an inductor with a magnetic composite material obtained by mixing ferrite and resin by screen printing. However, the adoption of the screen printing method has the defects that the thickness error exists in the process, so that the inductance value obtained by the same process has larger error, and the inductance performance cannot be controlled.
Disclosure of Invention
The invention provides a method for preparing a printed circuit embedded inductor, aiming at the problems of limited base material for manufacturing the embedded inductor, poor compatibility with a PCB (printed Circuit Board) process, uncontrollable inductive performance and the like in the prior art. In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
a method for preparing a printed circuit embedded inductor is characterized by comprising the following steps:
step 1: forming a metal seed layer on the surface of the dielectric layer;
step 2: covering the metal seed layer prepared in the step 1 with a patterned anti-corrosion layer by using a pattern transfer technology;
and step 3: growing a metal conductor layer on the metal seed layer without the coverage of the anti-corrosion layer;
and 4, step 4: removing the anti-corrosion layer and the metal seed layer covered by the anti-corrosion layer to prepare and obtain a conductor structure of the embedded inductor;
And 5: and (4) forming a magnetic thin film on the surface of the conductor structure prepared in the step (4).
Further, a step of browning treatment is further included before the step 5, so that a metal organic thin film layer is formed on the surface of the conductor structure of the embedded inductor.
Further, a sputtering process or an electroless plating process is adopted for forming the metal seed layer in the step 1.
Further, the electroless plating process includes the steps of cleaning, microetching, pre-dipping, activating and electroless plating.
Specifically, the metal seed layer formed in step 1 may be one of titanium copper sputtering, electroless copper plating, electroless tin plating, and electroless nickel plating.
Further, the patterned resist layer in the step 2 is designed according to the conductor structure of the embedded inductor, and the patterned resist layer and the conductor structure are complementary on the plane.
Further, the magnetic thin film in the step 5 is preferably a pure cobalt thin film or a non-metallic cobalt composite material.
Further, the method for forming the magnetic film in the step 5 is magnetron sputtering, electroplating or ink-jet printing.
As a specific embodiment, the specific operation of electroplating the cobalt film in step 5 is as follows: placing the conductor structure prepared in the step (4) in electroplating solution to prepare a pure cobalt film; the electroplating conditions were as follows: the pH value of the electroplating solution is 3-6, the electroplating temperature is 20-40 ℃, and the current density is 0.5-4A/dm 2Electroplating for 5-90 min; the electroplating solution comprises 20-300 g/L of cobalt salt, 1-2000 mg/L of first complexing agent, 1-200 mg/L of second complexing agent, 10-50 g/L of buffering agent, pH regulator and deionized water, wherein the first complexing agent comprises one or a mixture of more of glycine, alanine, valine, leucine, isoleucine, aspartic acid, glutamic acid, lysine and arginine, the second complexing agent comprises one or a mixture of two of sodium polydithio dipropane sulfonate and 3-mercapto-1-propane sulfonate, the cobalt salt is a composition of one or more of cobalt chloride, cobalt sulfate, cobalt acetate, cobalt nitrate and cobalt sulfamate, and the pH regulator is acid and/or sodium hydroxide corresponding to anions in the cobalt salt, the buffer is preferably boric acid.
As a specific embodiment, the specific operation of magnetron sputtering the cobalt film in step 5 is as follows: and (4) completely covering the cobalt film on the surface of the printed circuit board obtained by the step (4) through a magnetron sputtering device, then covering a corrosion inhibitor on the surface of the conductor structure, etching to remove the cobalt film without the protection of the corrosion inhibitor, and finally removing the corrosion inhibitor to realize the manufacture of the magnetic thin film. The thickness of the magnetic cobalt film prepared by magnetron sputtering is preferably 0.1-1 μm.
As a specific embodiment, the specific operation of ink-jet printing the cobalt film in step 5 is as follows: processing the surface of the conductor structure or the surface of the conductor structure coated with the metal organic thin film layer by an ink-jet printing method in the step 4 to directly print the cobalt film composite material; the raw materials used for ink-jet printing comprise thermoplastic resin and cobalt particles, wherein the thermoplastic resin is any one of polylactic acid, polyethylene, polypropylene and polybutadiene, and the mass fraction of the cobalt particles is 60-90%.
Compared with the prior art, the invention has the following beneficial effects:
(1) the invention innovates the means of embedding the inductance structure (conductive coil) in the substrate, and further modifies the magnetic film on the surface of the inductance structure, thereby realizing the embedding of the inductance forming the magnetic film in the printed circuit board. Compared with the conventional subtractive method for manufacturing the conductive coil, the invention can realize the manufacture of the embedded inductor on any substrate, thereby avoiding the adverse effect caused by material mismatch when the SMT technology realizes the integration of components and parts, and enabling the embedded inductor element to be more convenient and flexible to apply.
(2) Compared with the existing lamination method, the method for preparing the embedded inductor of the printed circuit can punch holes before the conductor structure is formed, and realizes through holes (namely hole metallization) while forming a metal seed layer, thereby avoiding the problem of uncontrollable inductance performance caused by manufacturing the through holes on a magnetic core.
(3) The method for preparing the embedded inductor of the printed circuit is simple and controllable in process, can be compatible with a production line of a printed circuit board, does not need to add extra working procedures, reduces equipment and technology investment, is beneficial to reducing cost and realizes industrial production.
(4) The invention provides a method for preparing a printed circuit embedded inductor, which comprises the steps of forming a metal organic film on the surface of a conductor structure of the embedded inductor by performing brown oxidation treatment on the conductor structure, then depositing a magnetic film, and enabling an organic metal film to be used as a barrier layer of a copper conductor and the magnetic film of the embedded inductor by utilizing the relatively large resistance value of the metal organic film, so that the magnetic performance of the magnetic film is effectively exerted, and the effect of improving the inductance value of the embedded inductor is favorably realized.
(5) The invention provides a method for preparing a printed circuit embedded inductor, which adopts ink-jet printing, electroplating and magnetron sputtering to deposit a magnetic film, can overcome the defect of large inductance error in the traditional screen printing process under the same process, is beneficial to obtaining an inductance element with stable performance, improves the performance stability of a product and further realizes large-scale production and manufacturing.
Drawings
Fig. 1 is a schematic view of a manufacturing process of forming a magnetic thin film of a printed circuit embedded inductor based on a magnetron sputtering method according to embodiment 1 of the present invention, and a cross section is shown in the schematic view.
Fig. 2 is a schematic view of a manufacturing process of forming a magnetic thin film by a printed circuit embedded inductor based on an inkjet printing method according to embodiment 2 of the present invention, and the schematic view shows a cross section.
Fig. 3 is a schematic diagram of a manufacturing process of forming a magnetic thin film of a printed circuit embedded inductor based on an electroplating method according to embodiment 3 of the present invention, and the schematic diagram shows a cross section.
FIG. 4 is a cross-sectional metallographic image of a product obtained in example 1 of the present invention.
FIG. 5 is a cross-sectional metallographic image of a product obtained in example 2 of the present invention.
FIG. 6 is a cross-sectional metallographic image of a product obtained in example 3 of the present invention.
Fig. 7 is a microscopic topography of the plating surface of the printed circuit embedded inductor provided in example 3 of the present invention and comparative examples 1 and 2.
Fig. 8 shows inductance values of printed circuit embedded inductors provided by different electroplating systems.
Detailed Description
In order to make the technical solutions and principles of the present invention more clear to those skilled in the art, the following detailed description is made with reference to the accompanying drawings and specific examples, where the following examples are illustrative of the printed circuit embedded inductor with a surface modified magnetic cobalt film, but it should be clear to those skilled in the art that the present invention is not limited to the printed circuit embedded inductor with a surface modified magnetic cobalt film, and the method is applicable to the fabrication of any printed circuit embedded inductor with a modified magnetic thin film.
Example 1:
a printed circuit embedded inductor and a method for forming a magnetic film on the surface thereof are disclosed, the implementation flow is shown in figure 1, and the specific implementation steps are as follows:
(1) forming a metal seed layer
a. Cleaning: preparing an acidic deoiling liquid consisting of 5 volume percent of sulfuric acid, 5 volume percent of OP emulsion and deionized water; soaking a 4cm x 5cm epoxy resin substrate in 50 ℃ acid degreasing liquid for 3min, carrying out ultrasonic treatment for 1min to remove oil stains on the surface, and washing the epoxy resin substrate with deionized water to remove degreasing liquid attached to the surface after finishing the degreasing treatment;
b. micro-etching: preparing microetching solution consisting of 5 volume percent of sulfuric acid, 50g/L of sodium persulfate and deionized water; b, carrying out ultrasonic treatment on the epoxy resin substrate obtained after the treatment in the step a in a microetching solution at 25 ℃ for 2min to change the surface into a rough structure with unevenness and ensure that a coating is tightly combined with the surface, and washing the epoxy resin substrate with deionized water to remove the microetching solution attached to the surface after the microetching treatment is finished;
c. pre-dipping: preparing a pre-immersion liquid consisting of 5% sulfuric acid and deionized water by volume percentage; b, soaking the epoxy resin substrate obtained after the treatment in the step b in a pre-immersion liquid at 25 ℃ for 1min, adjusting the acid-base property of an adhesion solution on the surface of the epoxy resin substrate, and maintaining the acidity of the activation tank;
d. And (3) activation: preparing an activation solution consisting of 60mg/L palladium chloride, 5% sulfuric acid by volume percentage concentration and deionized water by using metal; c, soaking the epoxy resin substrate obtained after the treatment in the step c in a pre-immersion liquid at 25 ℃ for 5min, and depositing required catalytic seed crystals on the surface of the epoxy resin substrate;
e. manufacturing a metal seed layer: preparing copper plating solution consisting of 25g/L of copper chloride, 20g/L of copper sulfate, 4g/L of formaldehyde, 20g/L of ethylene diamine tetraacetic acid disodium salt, 10g/L of potassium sodium tartrate, 15g/L of sodium hydroxide and deionized water; d, soaking the epoxy resin substrate obtained after the treatment of the step d in a copper plating solution at 35 ℃ for 5min to complete the chemical copper plating process to form a metal seed layer;
(2) forming a patterned resist layer
Covering the surface of a metal seed layer obtained by chemical copper plating with a resist of a negative image inductance coil pattern;
(3) filling metal
Preparing copper plating solution consisting of 75g/L copper sulfate, 220g/L concentrated sulfuric acid, 60mg/L chloride ions and deionized water; electroplating the epoxy resin substrate obtained after the treatment of the step (2) in electroplating solution at 25 ℃ for 60min, wherein the current density is 2A/dm2, and partially filling a metal seed layer without being covered by a corrosion inhibitor to form a metal conductor layer;
(4) etching metal seed and resist layers
Preparing an etching solution consisting of 100g/L of copper chloride, 100g/L of ammonia chloride, 600g/L of ammonia water and deionized water; removing the resist covering the surface of the printed circuit board, soaking the printed circuit board in the etching solution for 30s, and etching off the metal seed layer area outside the embedded inductance coil protected by the resist to form the embedded inductance coil;
(5) browning treatment
Preparing a browning solution consisting of 95g/L sulfuric acid, 4g/L water-soluble methoxylated polyethylene glycol, 25mg/L sodium chloride, 150mg/L copper sulfate, 8g/L benzotriazole, 20g/L hydrogen peroxide and deionized water; soaking the formed embedded inductor in a browning liquid at 35 ℃ for 60s to form a metal organic film on the surface of the conductor structure;
(6) forming magnetic cobalt film on surface of embedded inductor
a. Performing magnetron sputtering on the surface of the embedded inductor obtained in the step (5) by adopting a metal Co target with the purity of 99.95%, wherein the sputtering power is 200W, the sputtering time is 5min, and the working air pressure is 0.4 Pa;
b. covering a corrosion inhibitor on the surface of the embedded inductance coil, then soaking the printed circuit board in the etching solution prepared in the step (4) for 10s, etching off the cobalt film without the protection of the corrosion inhibitor, and finally removing the corrosion inhibitor to obtain the printed circuit embedded inductance with the magnetic cobalt film deposited on the surface.
The cross-sectional metallographic graph of the cobalt-plated film on the surface of the embedded inductor coil obtained in this example is shown in fig. 4, and the inductance value is improved by 15% compared with the embedded inductor before the magnetic thin film is not deposited.
Example 2:
a printed circuit embedded inductor and a method for forming a magnetic film on the surface thereof are disclosed, the implementation flow is shown in figure 2, and the specific implementation steps are as follows:
(1) forming a metal seed layer
a. Cleaning: preparing an acidic deoiling liquid consisting of 5 volume percent of sulfuric acid, 5 volume percent of OP emulsion and deionized water; soaking a 4cm x 5cm epoxy resin substrate in 50 ℃ acid degreasing liquid for 3min, carrying out ultrasonic treatment for 1min to remove oil stains on the surface, and washing the epoxy resin substrate with deionized water to remove degreasing liquid attached to the surface after finishing the degreasing treatment;
b. micro-etching: preparing microetching solution consisting of 5 volume percent of sulfuric acid, 50g/L of sodium persulfate and deionized water; b, carrying out ultrasonic treatment on the epoxy resin substrate obtained after the treatment in the step a in a microetching solution at 25 ℃ for 2min to change the surface into a rough structure with unevenness and ensure that a coating is tightly combined with the surface, and washing the epoxy resin substrate with deionized water to remove the microetching solution attached to the surface after the microetching treatment is finished;
c. Pre-dipping: preparing a pre-immersion liquid consisting of 5% sulfuric acid and deionized water by volume percentage; b, soaking the epoxy resin substrate obtained after the treatment in the step b in a pre-immersion liquid at 25 ℃ for 1min, adjusting the acid-base property of an adhesion solution on the surface of the epoxy resin substrate, and maintaining the acidity of the activation tank;
d. and (3) activation: preparing an activation solution consisting of 60mg/L palladium chloride, 5% sulfuric acid by volume percentage concentration and deionized water by using metal; c, soaking the epoxy resin substrate obtained after the treatment in the step c in a pre-immersion liquid at 25 ℃ for 5min, and depositing required catalytic seed crystals on the surface of the epoxy resin substrate;
e. manufacturing a metal seed layer: preparing copper plating solution consisting of 25g/L of copper chloride, 20g/L of copper sulfate, 4g/L of formaldehyde, 20g/L of ethylene diamine tetraacetic acid disodium salt, 10g/L of potassium sodium tartrate, 15g/L of sodium hydroxide and deionized water; d, soaking the epoxy resin substrate obtained after the treatment of the step d in a copper plating solution at 35 ℃ for 5min to complete the chemical copper plating process to form a metal seed layer;
(2) forming a patterned resist layer
Covering the surface of a metal seed layer obtained by chemical copper plating with a resist of a negative image inductance coil pattern;
(3) filling metal
Preparing copper plating solution consisting of 75g/L copper sulfate, 220g/L concentrated sulfuric acid, 60mg/L chloride ions and deionized water; electroplating the epoxy resin substrate obtained after the treatment of the step (2) in electroplating solution at 25 ℃ for 60min, wherein the current density is 2A/dm2, and partially filling a metal seed layer without being covered by a corrosion inhibitor to form a metal conductor layer;
(4) Etching metal seed and resist layers
Preparing an etching solution consisting of 100g/L of copper chloride, 100g/L of ammonia chloride, 600g/L of ammonia water and deionized water; removing the resist covering the surface of the printed circuit board, soaking the printed circuit board in the etching solution for 30s, and etching off the metal seed layer area outside the embedded inductance coil protected by the resist to form the embedded inductance coil;
(5) browning treatment
Preparing a browning solution consisting of 95g/L sulfuric acid, 4g/L water-soluble methoxylated polyethylene glycol, 25mg/L sodium chloride, 150mg/L copper sulfate, 8g/L benzotriazole, 20g/L hydrogen peroxide and deionized water; soaking the formed embedded inductor in a browning liquid at 35 ℃ for 60s to form a metal organic film on the surface of the conductor structure;
(6) forming magnetic cobalt film on surface of embedded inductor
a. Drying polylactic acid in a 50 ℃ oven for 12h, mixing the polylactic acid with 90% cobalt particles by mass percent, and blending the mixed materials by using a torque rheometer to obtain a magnetic composite wire capable of performing ink-jet printing;
b. and (b) forming a magnetic cobalt film on the surface of the embedded inductor by using the magnetic composite wire in the step (a) through an ink-jet printer to obtain the printed circuit embedded inductor with the magnetic cobalt film deposited on the surface.
The cross-sectional metallographic graph of the cobalt-plated film on the surface of the embedded inductor coil obtained in this example is shown in fig. 5, and the inductance value is improved by 10% to 20% compared with the embedded inductor before the magnetic thin film is not deposited.
Example 3:
a printed circuit embedded inductor and a method for forming a magnetic film on the surface thereof are disclosed, the implementation flow is shown in figure 3, and the specific implementation steps are as follows:
(1) forming a metal seed layer
a. Cleaning: preparing an acidic deoiling liquid consisting of 5 volume percent of sulfuric acid, 5 volume percent of OP emulsion and deionized water; soaking a 4cm x 5cm epoxy resin substrate in 50 ℃ acid degreasing liquid for 3min, carrying out ultrasonic treatment for 1min to remove oil stains on the surface, and washing the epoxy resin substrate with deionized water to remove degreasing liquid attached to the surface after finishing the degreasing treatment;
b. micro-etching: preparing microetching solution consisting of 5 volume percent of sulfuric acid, 50g/L of sodium persulfate and deionized water; b, carrying out ultrasonic treatment on the epoxy resin substrate obtained after the treatment in the step a in a microetching solution at 25 ℃ for 2min to change the surface into a rough structure with unevenness and ensure that a coating is tightly combined with the surface, and washing the epoxy resin substrate with deionized water to remove the microetching solution attached to the surface after the microetching treatment is finished;
c. pre-dipping: preparing a pre-immersion liquid consisting of 5% sulfuric acid and deionized water by volume percentage; b, soaking the epoxy resin substrate obtained after the treatment in the step b in a pre-immersion liquid at 25 ℃ for 1min, adjusting the acid-base property of an adhesion solution on the surface of the epoxy resin substrate, and maintaining the acidity of the activation tank;
d. And (3) activation: preparing an activation solution consisting of 60mg/L palladium chloride, 5% sulfuric acid by volume percentage concentration and deionized water by using metal; c, soaking the epoxy resin substrate obtained after the treatment in the step c in a pre-immersion liquid at 25 ℃ for 5min, and depositing required catalytic seed crystals on the surface of the epoxy resin substrate;
e. manufacturing a metal seed layer: preparing copper plating solution consisting of 25g/L of copper chloride, 20g/L of copper sulfate, 4g/L of formaldehyde, 20g/L of ethylene diamine tetraacetic acid disodium salt, 10g/L of potassium sodium tartrate, 15g/L of sodium hydroxide and deionized water; d, soaking the epoxy resin substrate obtained after the treatment of the step d in a copper plating solution at 35 ℃ for 5min to complete the chemical copper plating process to form a metal seed layer;
(2) forming a patterned resist layer
Covering the surface of a metal seed layer obtained by chemical copper plating with a resist of a negative image inductance coil pattern;
(3) filling metal
Preparing copper plating solution consisting of 75g/L copper sulfate, 220g/L concentrated sulfuric acid, 60mg/L chloride ions and deionized water; electroplating the epoxy resin substrate obtained after the treatment of the step (2) in electroplating solution at 25 ℃ for 60min, wherein the current density is 2A/dm2, and partially filling a metal seed layer without being covered by a corrosion inhibitor to form a metal conductor layer;
(4) etching metal seed and resist layers
Preparing an etching solution consisting of 100g/L of copper chloride, 100g/L of ammonia chloride, 600g/L of ammonia water and deionized water; removing the resist covering the surface of the printed circuit board, soaking the printed circuit board in the etching solution for 30s, and etching off the metal seed layer area outside the embedded inductance coil protected by the resist to form the embedded inductance coil;
(5) browning treatment
Preparing a browning solution consisting of 95g/L sulfuric acid, 4g/L water-soluble methoxylated polyethylene glycol, 25mg/L sodium chloride, 150mg/L copper sulfate, 8g/L benzotriazole, 20g/L hydrogen peroxide and deionized water; soaking the formed embedded inductor in a browning liquid at 35 ℃ for 60s to form a metal organic film on the surface of the conductor structure;
(6) forming magnetic cobalt film on surface of embedded inductor
a. Preparing a solution consisting of 28g/L of cobalt sulfate heptahydrate, 30g/L of boric acid, 30mg/L of glycine, 20mg/L of 3-mercapto-1-propane sodium sulfonate and deionized water, and adjusting the pH value to 4.0 by using dilute sulfuric acid and sodium hydroxide to obtain electroplating solution; electroplating the embedded inductor obtained in the step (5) as a cathode and the metal titanium mesh as an anode in electroplating solution at 25 ℃ for 30min, wherein the current density is 2A/dm2, and the air stirring flow is 1L/min;
b. and (b) quickly taking out the embedded inductor obtained after the treatment in the step (a) from the electroplating solution after the electroplating is finished, washing the embedded inductor with deionized water for 1-3 min, then washing the embedded inductor with absolute ethyl alcohol for 0.5-2 min, and finally drying the embedded inductor with cold air to obtain the printed circuit embedded inductor with the magnetic cobalt film deposited on the surface.
The cross-sectional metallographic image of the cobalt-plated film on the surface of the embedded inductor obtained in this example is shown in fig. 6, and the microscopic topographic image of the plated layer is shown in fig. 7 c. Compared with the embedded inductor before the magnetic film is not deposited, the inductance value is improved by 11 percent.
Comparative example 1:
a method for preparing a printed circuit embedded inductor comprises the following specific implementation steps:
(1) forming a metal seed layer
a. Cleaning: preparing an acidic deoiling liquid consisting of 5 volume percent of sulfuric acid, 5 volume percent of OP emulsion and deionized water; soaking a 4cm x 5cm epoxy resin substrate in 50 ℃ acid degreasing liquid for 3min, carrying out ultrasonic treatment for 1min to remove oil stains on the surface, and washing the epoxy resin substrate with deionized water to remove degreasing liquid attached to the surface after finishing the degreasing treatment;
b. micro-etching: preparing microetching solution consisting of 5 volume percent of sulfuric acid, 50g/L of sodium persulfate and deionized water; b, carrying out ultrasonic treatment on the epoxy resin substrate obtained after the treatment in the step a in a microetching solution at 25 ℃ for 2min to change the surface into a rough structure with unevenness and ensure that a coating is tightly combined with the surface, and washing the epoxy resin substrate with deionized water to remove the microetching solution attached to the surface after the microetching treatment is finished;
c. Pre-dipping: preparing a pre-immersion liquid consisting of 5% sulfuric acid and deionized water by volume percentage; b, soaking the epoxy resin substrate obtained after the treatment in the step b in a pre-immersion liquid at 25 ℃ for 1min, adjusting the acid-base property of an adhesion solution on the surface of the epoxy resin substrate, and maintaining the acidity of the activation tank;
d. and (3) activation: preparing an activation solution consisting of 60mg/L palladium chloride, 5% sulfuric acid by volume percentage concentration and deionized water by using metal; c, soaking the epoxy resin substrate obtained after the treatment in the step c in a pre-immersion liquid at 25 ℃ for 5min, and depositing required catalytic seed crystals on the surface of the epoxy resin substrate;
e. manufacturing a metal seed layer: preparing copper plating solution consisting of 25g/L of copper chloride, 20g/L of copper sulfate, 4g/L of formaldehyde, 20g/L of ethylene diamine tetraacetic acid disodium salt, 10g/L of potassium sodium tartrate, 15g/L of sodium hydroxide and deionized water; d, soaking the epoxy resin substrate obtained after the treatment of the step d in a copper plating solution at 35 ℃ for 5min to complete the chemical copper plating process to form a metal seed layer;
(2) forming a patterned resist layer
Covering the surface of a metal seed layer obtained by chemical copper plating with a resist of a negative image inductance coil pattern;
(3) filling metal
Preparing copper plating solution consisting of 75g/L copper sulfate, 220g/L concentrated sulfuric acid, 60mg/L chloride ions and deionized water; electroplating the epoxy resin substrate treated in the step f in 25 ℃ electroplating solution for 60min, wherein the current density is 2A/dm 2Partially filling a metal seed layer without being covered by the corrosion inhibitor to form a metal conductor layer;
(4) etching metal seed and resist layers
Preparing an etching solution consisting of 100g/L of copper chloride, 100g/L of ammonia chloride, 600g/L of ammonia water and deionized water; removing the resist covering the surface of the printed circuit board, soaking the printed circuit board in the etching solution for 30s, and etching off the metal seed layer area outside the embedded inductance coil protected by the resist to form the embedded inductance coil;
(5) forming magnetic cobalt film on surface of embedded inductor
a. Preparing a solution consisting of 28g/L of cobalt sulfate heptahydrate, 30g/L of boric acid and deionized water, and adjusting the pH value to 4.0 by using dilute sulfuric acid and sodium hydroxide to obtain electroplating solution; electroplating the embedded inductor obtained in the step (2) as a cathode and the metal titanium mesh as an anode in 25 ℃ electroplating solution for 30min at the current density of 2A/dm2The flow rate of the air stirring is 1L/min;
b. and (b) quickly taking out the embedded inductor obtained after the treatment in the step (a) from the electroplating solution after the electroplating is finished, washing the embedded inductor with deionized water for 1-3 min, then washing the embedded inductor with absolute ethyl alcohol for 0.5-2 min, and finally drying the embedded inductor with cold air to obtain the printed circuit embedded inductor with the surface modified magnetic cobalt film.
The micro-topography of the plating layer of the embedded inductor obtained in this example is shown in fig. 7 a. Compared with the embedded inductor (1.373 muH @1MHz) which is not modified by the cobalt film, the inductance value is improved by 4.7 percent.
Comparative example 2:
a method for preparing a printed circuit embedded inductor comprises the following specific implementation steps:
(1) forming a metal seed layer
a. Cleaning: preparing an acidic deoiling liquid consisting of 5 volume percent of sulfuric acid, 5 volume percent of OP emulsion and deionized water; soaking a 4cm x 5cm epoxy resin substrate in 50 ℃ acid degreasing liquid for 3min, carrying out ultrasonic treatment for 1min to remove oil stains on the surface, and washing the epoxy resin substrate with deionized water to remove degreasing liquid attached to the surface after finishing the degreasing treatment;
b. micro-etching: preparing microetching solution consisting of 5 volume percent of sulfuric acid, 50g/L of sodium persulfate and deionized water; b, carrying out ultrasonic treatment on the epoxy resin substrate obtained after the treatment in the step a in a microetching solution at 25 ℃ for 2min to change the surface into a rough structure with unevenness and ensure that a coating is tightly combined with the surface, and washing the epoxy resin substrate with deionized water to remove the microetching solution attached to the surface after the microetching treatment is finished;
c. pre-dipping: preparing a pre-immersion liquid consisting of 5% sulfuric acid and deionized water by volume percentage; b, soaking the epoxy resin substrate obtained after the treatment in the step b in a pre-immersion liquid at 25 ℃ for 1min, adjusting the acid-base property of an adhesion solution on the surface of the epoxy resin substrate, and maintaining the acidity of the activation tank;
d. And (3) activation: preparing an activation solution consisting of 60mg/L palladium chloride, 5% sulfuric acid by volume percentage concentration and deionized water by using metal; c, soaking the epoxy resin substrate obtained after the treatment in the step c in a pre-immersion liquid at 25 ℃ for 5min, and depositing required catalytic seed crystals on the surface of the epoxy resin substrate;
e. manufacturing a metal seed layer: preparing copper plating solution consisting of 25g/L of copper chloride, 20g/L of copper sulfate, 4g/L of formaldehyde, 20g/L of ethylene diamine tetraacetic acid disodium salt, 10g/L of potassium sodium tartrate, 15g/L of sodium hydroxide and deionized water; d, soaking the epoxy resin substrate obtained after the treatment of the step d in a copper plating solution at 35 ℃ for 5min to complete the chemical copper plating process to form a metal seed layer;
(2) forming a patterned resist layer
Covering the surface of a metal seed layer obtained by chemical copper plating with a resist of a negative image inductance coil pattern;
(3) filling metal
Preparing copper plating solution consisting of 75g/L copper sulfate, 220g/L concentrated sulfuric acid, 60mg/L chloride ions and deionized water; electroplating the epoxy resin substrate treated in the step f in 25 ℃ electroplating solution for 60min, wherein the current density is 2A/dm2Partially filling a metal seed layer without being covered by the corrosion inhibitor to form a metal conductor layer;
(4) etching metal seed and resist layers
Preparing an etching solution consisting of 100g/L of copper chloride, 100g/L of ammonia chloride, 600g/L of ammonia water and deionized water; removing the resist covering the surface of the printed circuit board, soaking the printed circuit board in the etching solution for 30s, and etching off the metal seed layer area outside the embedded inductance coil protected by the resist to form the embedded inductance coil;
(5) forming magnetic cobalt film on surface of embedded inductor
a. Preparing a solution consisting of 28g/L of cobalt sulfate heptahydrate, 30g/L of boric acid, 30mg/L of glycine and deionized water, and adjusting the pH value to 4.0 by using dilute sulfuric acid and sodium hydroxide to obtain electroplating solution; electroplating the embedded inductor obtained in the step (2) as a cathode and the metal titanium mesh as an anode in 25 ℃ electroplating solution for 30min at the current density of 2A/dm2The flow rate of the air stirring is 1L/min;
b. and (b) quickly taking out the embedded inductor obtained after the treatment in the step (a) from the electroplating solution after the electroplating is finished, washing the embedded inductor with deionized water for 1-3 min, then washing the embedded inductor with absolute ethyl alcohol for 0.5-2 min, and finally drying the embedded inductor with cold air to obtain the printed circuit embedded inductor with the surface modified magnetic cobalt film.
The micro-topography of the plated layer of the embedded inductor obtained in this example is shown in fig. 7 b. Compared with the embedded inductor (1.373 muH @1MHz) which is not modified by the cobalt film, the inductance value is improved by 6.8 percent.
In example 2, the addition of glycine significantly reduces the grain size of the plating layer, the coercivity is reduced along with the reduction of the grain size (the coercivity of the plating layer is 150Oe when no glycine is added, and the coercivity of the plating layer is reduced to 71Oe after glycine is added), the magnetic properties of the plating layer are improved, and for an inductor, a material with high saturation magnetic induction and low coercivity is more suitable for being used as a magnetic medium, so that the inductance value is improved. It can be known from the comparison of examples 1 and 2 and example 3 that the addition of glycine obviously reduces the grain size of the plating layer, and the addition of glycine reduces the coercive force of the plating layer, and at the same time, the sodium 3-mercapto-1-propane sulfonate has the function of inhibiting crystal face growth in a characteristic crystal face in the crystal growth process, so that the two substances have influence on the grain growth of the plating layer. Further research shows that the optimal concentration of the first complexing agent is 30mg/L, and on the basis of keeping the optimal concentration of the first complexing agent, the balance action of the second complexing agent and the first complexing agent in a certain range is beneficial to improving the inductance value, as shown in FIG. 8. As the magnetic performance of the cobalt plating layer has important influence on the specific crystal face of the crystal, the magnetic saturation intensity of the plating layer is increased (the magnetic saturation intensity of the plating layer is 19emu/g when glycine and 3-mercapto-1-propane sodium sulfonate are not added, and the magnetic saturation intensity of the plating layer is increased to 31emu/g after glycine and 3-mercapto-1-propane sodium sulfonate are added), thus the inductance value of the plating layer obtained based on the cobalt electroplating system is improved when the cobalt electroplating system is applied to the embedded inductor compared with that of the traditional electroplating system.
While the present invention has been particularly shown and described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (6)
1. A method for preparing a printed circuit embedded inductor is characterized by comprising the following steps:
step 1: forming a metal seed layer on the surface of the dielectric layer by adopting a sputtering process or a chemical plating process;
step 2: covering the metal seed layer prepared in the step 1 with a patterned anti-corrosion layer by using a pattern transfer technology;
and step 3: growing a metal conductor layer on the metal seed layer without the coverage of the anti-corrosion layer;
and 4, step 4: removing the anti-corrosion layer and the metal seed layer covered by the anti-corrosion layer to prepare and obtain a conductor structure of the embedded inductor;
and 5: forming a metal organic thin film layer on the surface of the embedded inductor conductor structure prepared in the step 4 by a browning treatment technology;
step 6: and (5) forming a magnetic film on the surface of the metal organic film layer prepared in the step (5), wherein the method for forming the magnetic film is magnetron sputtering, electroplating or ink-jet printing.
2. The method for preparing the printed circuit embedded inductor according to claim 1, wherein the magnetic film in the step 6 is a pure cobalt film, and the pure cobalt film is prepared by an electroplating method, and the method comprises the following specific operations: placing the conductor structure with the metal organic thin film layer prepared in the step 5 into electroplating solution, and electroplating under the action of an electrode; the electroplating solution comprises cobalt salt, a first complexing agent, a second complexing agent, a buffering agent, a pH regulator and deionized water, wherein: the first complexing agent comprises any one or a mixture of more of glycine, alanine, valine, leucine, isoleucine, aspartic acid, glutamic acid, lysine and arginine, and the second complexing agent comprises any one or a mixture of two of sodium polydithio-dipropyl sulfonate and sodium 3-mercapto-1-propane sulfonate.
3. The method for preparing the printed circuit embedded inductor according to claim 2, wherein the concentration of the cobalt salt in the electroplating solution is 20-300 g/L, the concentration of the first complexing agent is 1-2000 mg/L, the concentration of the second complexing agent is 1-200 mg/L, and the concentration of the buffer agent is 10-50 g/L; the electroplating conditions were as follows: the pH value of the electroplating solution is 3-6, the electroplating temperature is 20-40 ℃, and the current density is 0.5-4A/dm 2The electroplating time is 5-90 min.
4. The method for preparing the printed circuit embedded inductor according to claim 1, wherein the magnetic film in the step 6 is a pure cobalt film, and the pure cobalt film is prepared by a magnetron sputtering method, and the method comprises the following specific operations: and (5) completely covering the cobalt film on the surface of the printed circuit board obtained by the step (5) through a magnetron sputtering device, then covering an etching resist on the surface of the metal organic thin film layer, etching to remove the cobalt film without the protection of the etching resist, and finally removing the etching resist to realize the manufacture of the magnetic thin film.
5. The method for preparing the printed circuit embedded inductor according to claim 1, wherein the magnetic thin film in the step 6 is a cobalt composite material, and the cobalt composite material is prepared by an ink-jet printing method, and the method comprises the following specific operations: and (3) directly printing the cobalt film composite material on the surface of the metal organic thin film layer obtained by the step (5) through an ink-jet printing method.
6. The method for preparing the printed circuit embedded inductor according to claim 5, wherein the raw materials for ink-jet printing comprise thermoplastic resin and cobalt particles, wherein the thermoplastic resin is any one of polylactic acid, polyethylene, polypropylene and polybutadiene, and the mass fraction of the cobalt particles is 60-90%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910337319.6A CN110035603B (en) | 2019-04-25 | 2019-04-25 | Method for preparing printed circuit embedded inductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910337319.6A CN110035603B (en) | 2019-04-25 | 2019-04-25 | Method for preparing printed circuit embedded inductor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110035603A CN110035603A (en) | 2019-07-19 |
| CN110035603B true CN110035603B (en) | 2021-08-03 |
Family
ID=67240170
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910337319.6A Active CN110035603B (en) | 2019-04-25 | 2019-04-25 | Method for preparing printed circuit embedded inductor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110035603B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113053849B (en) * | 2021-03-04 | 2022-02-15 | 珠海越亚半导体股份有限公司 | Embedded support frame and substrate of integrated inductor and manufacturing method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6493861B1 (en) * | 1999-12-28 | 2002-12-10 | Intel Corporation | Interconnected series of plated through hole vias and method of fabrication therefor |
| SG100666A1 (en) * | 2000-04-04 | 2003-12-26 | Nec Tokin Corp | Wiring board comprising granular magnetic film |
| JP2008103622A (en) * | 2006-10-20 | 2008-05-01 | Fujifilm Corp | Laminate for fabricating printed wiring board and method for fabricating printed wiring board using it |
| CN101286454B (en) * | 2007-04-10 | 2011-03-30 | 上海美维科技有限公司 | Printed circuit board producing method |
-
2019
- 2019-04-25 CN CN201910337319.6A patent/CN110035603B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110035603A (en) | 2019-07-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9788423B2 (en) | Copper foil with carrier | |
| TWI479958B (en) | Copper foil for printed wiring board and manufacturing method thereof | |
| KR101740092B1 (en) | Copper foil for printed wiring board, method for producing said copper foil, resin substrate for printed wiring board, and printed wiring board | |
| JP5871426B2 (en) | Surface treated copper foil for high frequency transmission, laminated plate for high frequency transmission and printed wiring board for high frequency transmission | |
| EP1276358A1 (en) | Copper foil excellent in laser beam drilling performance and production method therefor | |
| CN110035603B (en) | Method for preparing printed circuit embedded inductor | |
| JP2022120813A (en) | Ultrathin copper foil, and method of producing the same | |
| US8545992B2 (en) | Aluminum article | |
| JP5457594B2 (en) | Printed wiring board resin, printed wiring board, semiconductor package substrate, and printed wiring board manufacturing method | |
| CN204697393U (en) | Micro-induction structure on a kind of pcb board based on iron ni-based amorphous alloy magnetic core | |
| CN114016098B (en) | Copper-clad plate electroplated Ni-Co-Ce film plating solution for PCB and film preparation method | |
| CN113628875B (en) | Method for preparing inductor based on ultrathin modified insulation layer deposited magnetic core | |
| JP5399582B2 (en) | Copper foil with carrier, method for producing copper foil with carrier, copper foil with carrier for printed wiring board and printed wiring board | |
| CN108364765B (en) | A kind of potting core inductance and preparation method thereof | |
| TW202214051A (en) | Copper-clad laminate and manufacturing method thereof | |
| JP5285180B1 (en) | Copper foil with carrier, method for producing copper foil with carrier, copper foil with carrier for printed wiring board and printed wiring board |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |