CN114025515A - Manufacturing process of multilayer circuit board with ultra-high copper thickness inner layer and circuit board - Google Patents
Manufacturing process of multilayer circuit board with ultra-high copper thickness inner layer and circuit board Download PDFInfo
- Publication number
- CN114025515A CN114025515A CN202111333108.9A CN202111333108A CN114025515A CN 114025515 A CN114025515 A CN 114025515A CN 202111333108 A CN202111333108 A CN 202111333108A CN 114025515 A CN114025515 A CN 114025515A
- Authority
- CN
- China
- Prior art keywords
- layer
- copper
- substrate
- circuit
- inner layer
- 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.)
- Pending
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
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/46—Manufacturing multilayer circuits
- H05K3/4644—Manufacturing multilayer circuits by building the multilayer layer by layer, i.e. build-up multilayer circuits
- H05K3/4664—Adding a circuit layer by thick film methods, e.g. printing techniques or by other techniques for making conductive patterns by using pastes, inks or powders
-
- 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
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/46—Manufacturing multilayer circuits
- H05K3/4644—Manufacturing multilayer circuits by building the multilayer layer by layer, i.e. build-up multilayer circuits
- H05K3/4652—Adding a circuit layer by laminating a metal foil or a preformed metal foil pattern
Abstract
The application discloses a multilayer circuit board manufacturing process with an ultra-high copper thickness inner layer, which comprises the following steps: manufacturing an inner layer substrate; manufacturing an inner layer circuit on the copper layer; printing a first layer of resin ink on a non-circuit area on the inner layer substrate; carrying out copper deposition treatment on the inner-layer substrate to enable the surface of the inner-layer substrate to be covered with a copper sheet; printing a photosensitive wet film on the surface of the copper sheet; exposing and developing the photosensitive wet film to expose the outer layer circuit pattern; copper plating is carried out on the outer layer circuit pattern for thickening; removing the photosensitive wet film and the copper sheet on the non-outer-layer circuit part on the surface of the inner-layer substrate; printing a second layer of resin ink on the first layer of resin ink to obtain a composite substrate; and pressing a copper plate containing the circuit on the surface of the composite substrate to finally obtain the multilayer circuit board with the ultrahigh copper thickness at the inner layer. The application breaks through the limit of the thickness of the copper in the inner layer of the multilayer thick copper circuit board, and can meet the market demand; the phenomenon of poor pressing due to the fact that the inner layer structure is not flat can be completely avoided, and the yield of machining is improved.
Description
Technical Field
The invention belongs to the field of circuit board production, and particularly relates to a manufacturing process of a multilayer circuit board with an ultra-high copper thickness inner layer and a circuit board.
Background
At present, in the multilayer circuit board manufacturing industry, along with the continuous development of 5G and new energy technology, more and more functional elements are integrated on the circuit board, the requirements on the current conduction capability and the bearing capacity of a circuit board circuit are higher and higher, the requirement on the copper thickness of a thick copper circuit board is higher and higher, and the printed circuit board which can provide large current and integrates a power supply and has an inner-layer ultrahigh copper thickness can inevitably become one of the novel trends of circuit board development.
The inner layer of the traditional multilayer circuit board thick copper plate process adopts a base copper and copper plating mode to meet the copper thickness requirement, and the 3OZ copper thickness of the inner layer of the multilayer circuit board thick copper plate is limited by the copper thickness of a substrate, copper plating and PP glue filling, is the limit processing capacity of the existing circuit board processing, and obviously cannot meet the requirement of the current market on the multilayer thick copper circuit board. On the other hand, in the existing thick copper circuit board manufacturing process, in the laminating stage of the inner layer and the outer layer, PP filling glue is needed to be used for laminating the inner layer and the outer layer together; due to the fact that the inner layer structure is uneven, PP glue filling is prone to being uneven, and therefore a hole is formed in the inner layer of the thick copper circuit board, and when the hole is pressed, creases appear on the outer circuit, and defective products are caused.
Disclosure of Invention
In order to solve the problems in the prior art, the application provides a manufacturing process of a multilayer circuit board with an ultra-high copper thickness inner layer, and specifically provides the following technical scheme:
a manufacturing process of a multilayer circuit board with an ultra-high copper thickness inner layer comprises the following steps:
s1: manufacturing an inner layer substrate, wherein a copper layer is preset on the surface of the inner layer substrate;
s2: manufacturing an inner layer circuit on the copper layer;
s3: printing a first layer of resin ink on a non-circuit area on the inner layer substrate, and controlling the thickness of the first layer of resin ink to be the same as that of the inner layer circuit;
s4: carrying out copper deposition treatment on the inner layer substrate to enable the surface of the first layer of resin printing ink and the surface of the inner layer circuit to be covered with copper sheets;
s5: printing a photosensitive wet film with electroplating resistance and etching resistance on the surface of the copper sheet;
s6: exposing and developing the photosensitive wet film to expose the outer layer circuit pattern on the surface of the copper sheet;
s7: pattern electroplating, namely plating copper on the outer layer circuit pattern for thickening;
s8: removing the film and microetching, and removing the photosensitive wet film and the copper sheet on the non-outer-layer circuit part on the surface of the inner-layer substrate;
s9: printing a second layer of resin ink on the first layer of resin ink to obtain a composite substrate, and controlling the thickness of the second layer of resin ink to be the same as that of the outer layer circuit;
s10: and pressing, namely pressing a copper plate containing a circuit on the surface of the composite substrate.
Further, in step S1, the fabricating the inner layer substrate includes:
s11: cutting, namely cutting a circuit board substrate to a preset size, wherein the upper surface and the lower surface of the circuit board substrate are respectively provided with a base material with the thickness of 2 ounces of copper;
s12: drilling a hole on a circuit board substrate, and processing an inner layer buried hole;
s13: depositing copper to form a conductive coating on the wall of the inner-layer buried hole;
s14: and copper plating, namely electroplating copper plating is carried out on the circuit board substrate, so that the thickness of copper layers on the upper surface and the lower surface of the circuit board substrate reaches 3 ounces, and the inner layer substrate is obtained.
Further, in step S2, the fabricating the inner layer wiring includes the steps of:
s21: laminating a layer of photosensitive dry film on the surface of the inner layer substrate;
s22: exposing, namely performing ultraviolet irradiation on the photosensitive dry film to enable the photosensitive dry film to generate polymerization reaction, and transferring the required pattern to the surface of the inner layer substrate through the negative film;
s23: developing, removing unexposed parts in the photosensitive dry film to expose partial copper surfaces;
s24: etching, dissolving the exposed copper surface to form a required circuit pattern on the surface of the inner layer substrate;
s25: and stripping the film, and removing the exposed photosensitive dry film on the inner layer substrate to obtain the inner layer substrate containing the inner layer circuit.
Further, in step S3, the printing the first layer of resin ink includes the steps of:
s31: printing resin ink on the surface of the inner-layer substrate, and filling the resin ink into the non-inner-layer circuit area on the surface of the inner-layer substrate;
s32: baking the inner-layer substrate to solidify the resin printing ink;
s33: and polishing the surface of the inner-layer substrate to obtain the inner-layer substrate with the first layer of resin printing ink and the same thickness as the inner-layer circuit.
Further, in step S5, the printing the photosensitive wet film includes the steps of:
s51: printing photosensitive ink on the surface of the copper sheet in a screen printing missing mode, wherein the printing thickness of the photosensitive ink is 22-32 microns;
s52: and baking and curing the photosensitive ink, wherein the baking temperature is 70-80 ℃, and the baking time is 15-20 minutes.
Further, in step S6, the step of exposing the outer layer circuit pattern on the copper sheet surface includes the following steps:
exposure: carrying out ultraviolet irradiation on the photosensitive wet film to enable the photosensitive wet film to generate polymerization reaction, and transferring the required pattern to the surface of the copper sheet through the negative film;
developing, namely dissolving an unexposed part in the photosensitive wet film by using a developing solution to expose the copper surface of the outer layer circuit area, wherein the developing solution is a sodium carbonate solution with the concentration of 1%, and the temperature of the developing solution is 28-32 ℃;
washing with clear water at a pressure of 1.8-2.2kg/cm2The washing time is 20-30 seconds.
Further, in step S8, the following steps are included:
removing the film, namely placing the inner-layer substrate into a 5% sodium hydroxide aqueous solution to be soaked for 2-5 minutes, and removing the photosensitive wet film on the non-outer-layer circuit part on the surface of the inner-layer substrate;
and micro-etching, namely placing the inner-layer substrate on micro-etching horizontal line equipment for micro-etching, and removing the copper sheet of the non-outer-layer circuit part on the surface of the inner-layer substrate.
Further, in step S10, the pressing includes the following steps:
kissing, namely pasting PP filling glue on the surface of the composite substrate, melting resin in the PP filling glue into low-viscosity resin, infiltrating the low-viscosity resin into the surfaces of the composite substrate and the copper plate, and filling gaps of the outer-layer circuit;
full pressure, discharging air bubbles between the copper plate and the composite substrate, and enabling the curing crosslinking reaction of the resin to be complete;
and (5) cold pressing, cooling and placing the solidified resin to ensure that the composite substrate and the copper plate are stably connected.
Further, in the cold pressing step, the cold pressing temperature is 60 ℃ and the cold pressing time is 3-4 hours.
On the other hand, the application also provides a multilayer circuit board with an inner layer with ultrahigh copper thickness, which is manufactured by the manufacturing process.
Compared with the existing thick copper plate process of the multilayer circuit board, the resin printing ink is filled between the thick copper circuits of each layer, so that the surface of each layer of circuit is smooth, the limit that the inner layer of the traditional multilayer thick copper circuit board can only process 3OZ copper thickness is broken through, the use scene of the multilayer thick copper circuit board is enlarged, and the requirement of the market on the multilayer thick copper circuit board can be met; on the other hand, before the pressfitting, resin printing ink and outer layer circuit are smooth, consequently when the outer copper board of pressfitting, can avoid completely because of the inner layer structure unevenness, the crease appears in outer layer circuit when leading to the pressfitting, causes the phenomenon of defective products, has improved the yields of circuit board processing.
Drawings
In order to illustrate the present application or prior art more clearly, a brief description of the drawings needed for the description of the embodiments or prior art will be given below, it being clear that the drawings in the following description are some embodiments of the present application and that other drawings can be derived from them by a person skilled in the art without inventive effort.
FIG. 1 is a flow chart of an embodiment of the present application;
FIG. 2 is a schematic structural diagram of the product obtained after step S1 in the embodiment of the present application;
FIG. 3 is a schematic structural diagram of the product obtained after step S2 in the embodiment of the present application;
FIG. 4 is a schematic structural diagram of the product obtained after step S3 in the embodiment of the present application;
FIG. 5 is a schematic structural diagram of the product obtained after step S4 in the embodiment of the present application;
FIG. 6 is a schematic structural diagram of the product obtained after step S5 in the embodiment of the present application;
FIG. 7 is a schematic structural diagram of the product obtained after step S6 in the embodiment of the present application;
FIG. 8 is a schematic structural diagram of the product obtained after step S7 in the embodiment of the present application;
FIG. 9 is a schematic structural diagram of the product obtained after step S8 in the embodiment of the present application;
FIG. 10 is a schematic structural diagram of the product obtained after step S9 in the embodiment of the present application;
fig. 11 is a schematic structural diagram of a product obtained after step S10 in this embodiment.
Reference numerals: 1. a circuit board substrate; 2. plating a copper layer; 3. an inner layer circuit; 4. a first resin ink; 5. copper sheet; 6. a photosensitive wet film; 7. an outer layer circuit; 8. a second layer of resin ink; 9. filling PP glue; 10. a copper plate.
Detailed Description
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the description and claims of this application or in the above-described drawings are used for distinguishing between different objects and not for describing a particular order.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.
In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.
As shown in fig. 1, a process for manufacturing a multilayer circuit board with an ultra-high copper thickness inner layer, in this example, a circuit structure with an inner layer substrate as two sides, includes the following steps:
s1: manufacturing an inner layer substrate, wherein copper layers with the thickness of 3 ounces are arranged on the upper surface and the lower surface of the inner layer substrate;
s2: manufacturing an inner layer circuit on a copper layer of the inner layer substrate;
s3: printing a first layer of resin ink on a non-circuit area on the inner layer substrate, and controlling the thickness of the first layer of resin ink to be the same as that of the inner layer circuit; the surface of the first layer of resin printing ink is flush with the surface of the inner layer circuit, so that the upper surface and the lower surface of the inner layer substrate are flat.
S4: carrying out copper deposition treatment on the inner-layer substrate to enable the surface of the first layer of resin printing ink and the surface of the inner-layer circuit to be covered with a layer of copper sheet; the copper deposition is to prepare for the subsequent outer layer circuit, and ensure that the upper and lower surfaces of the inner layer substrate are covered by the copper sheet.
S5: printing a photosensitive wet film with electroplating resistance and etching resistance on the surface of the copper sheet;
s6: exposing and developing the photosensitive wet film to expose an outer layer circuit pattern on the surface of the copper sheet;
s7: pattern electroplating, namely plating copper on the outer layer circuit pattern to thicken the outer layer circuit pattern so as to enable the copper thickness of the outer layer circuit pattern to reach 3 ounces;
s8: removing the film and microetching, and removing the photosensitive wet film and the copper sheet on the non-outer-layer circuit part on the surface of the inner-layer substrate;
s9: printing a second layer of resin ink on the first layer of resin ink to obtain a composite substrate, and controlling the thickness of the second layer of resin ink to be the same as that of the outer layer circuit; and the surface of the second layer of resin printing ink is flush with the surface of the outer layer circuit, so that the upper surface and the lower surface of the composite substrate are smooth.
S10: and pressing, namely pressing a layer of copper plate containing the circuit on the surface of the composite substrate.
In the above manner, in this example, the upper and lower surfaces of the inner substrate are stacked with one layer of 3-ounce circuit, so that the copper thickness of the circuit on one side of the entire composite substrate reaches 6 ounces, and the limit that the inner layer of the conventional multilayer thick copper circuit board can only be processed with 3OZ copper thickness is broken through. It is understood that in other embodiments, other numbers of copper wiring layers may be stacked on the upper and lower surfaces of the inner substrate by repeating the operations of steps S4-S9 after step S9. On the other hand, before the copper plate is pressed, the resin ink and the outer layer circuit are smooth, so that when the outer layer copper plate is pressed, the phenomenon that the outer layer circuit is folded due to the fact that the inner layer structure is not flat and pressed to cause defective products can be completely avoided, and the yield of circuit board processing can be improved.
The specific manufacturing process of the manufacturing process is explained in detail by the following steps:
as shown in fig. 2, the fabricating of the inner layer substrate in step S1 includes the steps of:
s11: cutting, namely cutting the circuit board substrate to a preset size by using a cutting machine. In this example, the wiring board substrate used was a substrate having a thickness of 2 ounce copper on both the upper and lower surfaces of the base material.
S12: and the holes are formed in the circuit board substrate and comprise inner-layer buried holes and tool holes. In this example, a mechanical drilling mode is adopted, and the drilling parameters are as follows: pressure foot 0.25-0.35MPa, main air pressure 0.68 +/-0.1 MPa, rotating speed: 25-120 kr/min; feeding speed: 0.5-2.5 m/min; the speed of the cutter is 6-25 m/min. It should be apparent that in other embodiments, laser or any other known process may be used to open the holes.
S13: copper deposition, wherein the circuit board substrate is subjected to copper deposition treatment; the function of the copper deposition is to form a copper conductive coating on the wall of the inner buried hole and to serve as a conductive medium in the subsequent electroplated copper hole.
The copper deposition specifically comprises the following steps: the process comprises the steps of removing glue residues, neutralizing, washing, alkaline degreasing, washing, coarsening (also called micro-etching), washing, presoaking, activating, dispergating (also called accelerating), washing, copper deposition and washing, and the lower plate is manufactured.
The copper deposition steps are as follows:
removing glue residues: the method is used for removing residual drilling slag in the hole after the drilling of the circuit board, and dissolving part of resin on the hole wall to expose glass fiber;
neutralizing: neutralizing the matter to eliminate glue residue;
alkaline degreasing: removing grease on the board surface and adjusting electric charges in the holes;
coarsening: part of copper is dissolved by a chemical method, so that the surface area of the copper is increased;
pre-dipping: is protective of the activating lotion below;
and (3) activation: adhering catalyst to the surface of copper;
accelerating: substances of the activating agent are exposed, so that the activating agent is better combined with copper ions during copper deposition;
copper deposition: the copper ions are combined with an activating agent, so that the copper ions are reduced and attached to the board surface.
And (4) copper plating, namely electroplating copper on the circuit board substrate to ensure that the thickness of copper layers on the upper surface and the lower surface of the circuit board substrate reaches 3 ounces, thus obtaining the inner layer substrate.
In step S1, the copper layer of the circuit board substrate, which originally has a thickness of only 2 ounces, is made into a thickness of 3 ounces, so as to provide a substrate meeting the requirement of copper thickness for the subsequent inner layer circuit.
As shown in fig. 3, the step S2 of fabricating the inner layer wire includes the steps of:
s21: and (3) pressing the film, namely laminating a layer of photosensitive material dry film on the surface of the inner layer substrate by using a film pressing machine to prepare for the subsequent formation of the inner layer circuit. Parameters of the film pressing machine: the temperature is 90-120 deg.C, the speed is 0.8-2.5m/min, and the air pressure is 0.5-0.8mpa/cm2。
S22: exposing, namely exciting UV ultraviolet irradiation by using the photosensitivity of the dry film through an exposure machine to enable the dry film to generate polymerization reaction, and transferring a required pattern to the surface of the inner layer substrate through a negative film; exposure parameters: the exposure ruler has 3-9 lattices, and the air inlet pressure is more than or equal to 0.5 Mpa.
S23: and developing, namely dissolving the unexposed part of the photosensitive dry film by using weak alkali to expose part of the copper surface.
S24: and etching, namely dissolving the exposed copper surface by using an etching solution to form a required circuit pattern on the surface of the inner layer substrate.
S25: and removing the exposed photosensitive dry film on the inner layer substrate to obtain the inner layer substrate containing the inner layer circuit.
As shown in fig. 4, printing the first layer of resin ink in step S3 includes the steps of:
s31: the non-inner layer circuit area on the inner layer substrate surface was filled with resin ink by printing 3 ounces thick on the inner layer substrate surface with a printer. In this example, the signal of the selected resin ink was BTH-8000 PHP-LV. The printing operation parameters are as follows: the hardness of the scraper is 75 degrees, the angle of the scraper is 5-15 degrees, the speed is 1-3inch/sec, and the pressure is 0.4-0.6Mpa/cm2。
S32: and baking the inner-layer substrate until the resin ink is cured. Baking is divided into two sections: the baking temperature of the first section is controlled to be 75-85 ℃, and the baking time is 30 minutes; the second stage baking temperature is controlled at 150-160 ℃ and the baking time is 70 minutes.
S33: and removing redundant resin on the surface of the inner-layer circuit by using a ceramic brush to obtain the inner-layer substrate with the first layer of resin printing ink having the same thickness as the inner-layer circuit.
After the first layer of resin ink is printed and cured, the surface of the inner layer circuit is possibly covered by resin, and the purpose of the ceramic brush is to grind off the resin on the surface of the inner layer circuit to obtain a smooth surface of the inner layer substrate with exposed circuits; the ceramic grinding brush is implemented by adopting a special grinding plate line and using a roller with 500-mesh and 800-mesh.
As shown in fig. 5, in step S4, the inner substrate is subjected to a copper deposition process to cover the surface of the first resin ink layer and the surface of the inner wiring with a copper sheet; wherein, the thickness of the copper sheet needs to be controlled within 3-5 microns. The copper deposition method is the same as the above step S13, and will not be described herein.
As shown in fig. 6, in step S5, the printing photosensitive wet film is used to protect the outer non-circuit area with the wet film, and ensure that the non-circuit area will not be plated with copper when the pattern plating is performed later. In this example, the method selects the ER1006 anti-electroplating and anti-etching ink, and specifically comprises the following steps:
s51: printing photosensitive ink on the surface of the copper sheet of the inner-layer substrate in a screen printing missing mode, wherein the printing thickness of the photosensitive ink is 22-32 microns, and is preferably 27 microns;
s52: and baking and curing the photosensitive ink, wherein the baking temperature is 70-80 ℃, and the baking time is 15-20 minutes.
It should be noted that the method for printing the photosensitive ink may be not only screen printing, but also roll coating or dip coating. Before printing photosensitive ink, wet film pretreatment is required: the adhesion of the wet film to the circuit board is accomplished by chemical bonding, the wet film is a polymer with acrylate as the basic component, and the wet film is combined with copper by free-moving unpolymerized acrylate groups; in this example, the chemical cleaning method was used to ensure bonding, so that the surface was free of oxidation, oil contamination, and water.
As shown in fig. 7, in step S6, the following steps are required to expose the outer layer circuit pattern on the copper sheet surface:
exposure: and (3) carrying out ultraviolet irradiation on the photosensitive wet film to enable the photosensitive wet film to generate polymerization reaction, and transferring the required pattern to the surface of the copper sheet through the negative film.
Developing, namely dissolving an unexposed part in the photosensitive wet film by using a developing solution to expose the copper surface of the outer layer area (in the embodiment, the unexposed part is the outer layer circuit area, the outer layer circuit area is exposed, and the non-circuit area is protected by the wet film); wherein the developing solution is 1% sodium carbonate solution, the temperature of the developing solution is 28-32 deg.C, and the developing time is 40-60 s.
Washing with clear water at a pressure of 1.8-2.2kg/cm2The washing time is 20-30 seconds.
As shown in fig. 8, in step S7, a pattern plating process is used to plate copper over the exposed outer circuit areas to a thickness of 3 ounces.
The process flow of pattern electroplating is that the upper plate → oil removal → double water washing → micro etching → double water washing → acid dipping → copper plating → water washing → lower plate → acid washing → overflow water washing → drying → plate collection.
The functions of the steps are as follows:
oil removal: the grease on the surface of the plate is removed, and the electric charge in the hole is adjusted.
Micro-etching: and removing copper surface oxides and impurity ions, coarsening the copper surface and improving the binding force.
Acid leaching: and removing copper surface oxides and impurity ions, and avoiding the pollution of the copper cylinder.
Copper plating: and carrying out whole-plate electrolytic copper on the product after the black hole is formed, thickening surface copper and plating the required copper thickness on the carbon surface of the hole.
Acid washing: and removing the copper surface oxide and impurity ions.
Stripping and hanging: and removing the copper powder and the coating on the femto clamp.
Washing with water: cleaning the residual liquid medicine in the holes and on the surface.
Drying: avoid the oxidation of the board surface.
After pattern plating, an outer layer circuit pattern of 3 ounce copper was formed on both the upper and lower surfaces of the inner layer substrate.
In other embodiments, the above steps S4-S8 may be replaced by plating copper on the entire board, i.e., plating a copper layer with a thickness of 3 ounces on the surface of the inner substrate, and then performing the step S2 to form the outer layer circuit on the surface of the inner substrate. However, in the same-layer circuit, thick copper is etched twice by the second alignment, so that the thickened circuit and the original substrate circuit have one offset, which causes the local conductor of the circuit to be narrowed. Therefore, in this way, the fraction defective is increased and strict requirements are imposed on the processing environment, the technical requirements of the operators, and the like.
As shown in fig. 9, in step S8, the following steps are included:
removing the film, namely placing the inner-layer substrate into a 5% sodium hydroxide aqueous solution to be soaked for 2-5 minutes, and removing the photosensitive wet film on the non-outer-layer circuit part on the surface of the inner-layer substrate; wherein the temperature of the sodium hydroxide solution is controlled to be 45-55 ℃.
And microetching, namely, a copper deposition layer of 3-5 micrometers is also arranged in a non-circuit area between the circuits on the current board surface, a microetching horizontal line device is adopted to set the microetching amount to be 1.5 micrometers, and the microetching is carried out for 5 times, so that the thin copper in the outer non-circuit area is removed, and the complete outer circuit is exposed on the surface of the inner substrate.
As shown in fig. 10, in step S9, a second layer of resin ink is printed on the first layer of resin ink to obtain a composite substrate, and the thickness of the second layer of resin ink is controlled to be the same as the thickness of the outer layer of wiring. The manner of printing the second layer of resin ink is the same as the manner of printing the first layer of resin ink in step S3, and therefore, description thereof will not be repeated. After step S9 is completed, the surface of the outer layer circuit in the resulting composite substrate is flush with the surface of the second layer resin ink.
As shown in fig. 11, in step S10, the purpose of the pressing process is mainly due to the fact that more and more functional devices are integrated on the circuit board, the traditional single-double panel and the unsatisfied requirement are met, and the multi-layer circuit board design with multiple conductive layers becomes the first choice.
And in the lamination, all layers of the multilayer circuit board are combined together by completely curing PP resin under high temperature and high pressure, so that the electrical property and the mechanical property of the multilayer circuit board are ensured.
The pressing machine is adopted in the pressing work and comprises the following steps:
kissing, namely pasting PP filling glue on the surface of the composite substrate, melting resin in the PP filling glue into low-viscosity resin, infiltrating the low-viscosity resin into the composite substrate and the inner surface of the copper plate, and filling gaps of the outer-layer circuit;
full pressure, discharging air bubbles between the copper plate and the composite substrate, and enabling the curing crosslinking reaction of the resin to be complete;
and (5) cold pressing, cooling and placing the solidified resin to ensure that the composite substrate and the copper plate are stably connected. The cold pressing temperature is 60 ℃, and the cold pressing time is 3-4 hours.
The manufacturing process comprises the steps of filling resin in a rear seat of an inner layer 3 ounce copper thick circuit of a circuit board, and exposing the inner layer circuit through a ceramic baking and grinding process; then, an outer layer circuit part is exposed in a photosensitive wet film mode (pain points of a traditional dry film plating-intolerant process are avoided), and then the circuit is plated to be 6 ounces thick in copper through a pattern electroplating process, so that the problems of difficult copper plating process of a thick copper plate, inaccurate circuit etching and insufficient glue filling and layered board explosion risk during pressing of the thick copper plate are solved.
It is to be understood that the above-described embodiments are merely illustrative of some, but not restrictive, of the broad invention, and that the appended drawings illustrate preferred embodiments of the invention and do not limit the scope of the invention. This application is capable of embodiments in many different forms and is provided for the purpose of enabling a thorough understanding of the disclosure of the application. Although the present application has been described in detail with reference to the foregoing embodiments, it will be apparent to one skilled in the art that the present application may be practiced without modification or with equivalents of some of the features described in the foregoing embodiments. All equivalent structures made by using the contents of the specification and the drawings of the present application are directly or indirectly applied to other related technical fields and are within the protection scope of the present application.
Claims (10)
1. A manufacturing process of a multilayer circuit board with an ultra-high copper thickness inner layer is characterized by comprising the following steps:
s1: manufacturing an inner layer substrate, wherein a copper layer is preset on the surface of the inner layer substrate;
s2: manufacturing an inner layer circuit on the copper layer;
s3: printing a first layer of resin ink on a non-circuit area on the inner layer substrate, and controlling the thickness of the first layer of resin ink to be the same as that of the inner layer circuit;
s4: carrying out copper deposition treatment on the inner layer substrate to enable the surface of the first layer of resin printing ink and the surface of the inner layer circuit to be covered with copper sheets;
s5: printing a photosensitive wet film with electroplating resistance and etching resistance on the surface of the copper sheet;
s6: exposing and developing the photosensitive wet film to expose the outer layer circuit pattern on the surface of the copper sheet;
s7: pattern electroplating, namely plating copper on the outer layer circuit pattern for thickening;
s8: removing the film and microetching, and removing the photosensitive wet film and the copper sheet on the non-outer-layer circuit part on the surface of the inner-layer substrate;
s9: printing a second layer of resin ink on the first layer of resin ink to obtain a composite substrate, and controlling the thickness of the second layer of resin ink to be the same as that of the outer layer circuit;
s10: and pressing, namely pressing a copper plate containing a circuit on the surface of the composite substrate.
2. The process for manufacturing a multilayer wiring board having an ultra-high copper thickness as claimed in claim 1, wherein the step of manufacturing the inner substrate in step S1 comprises the steps of:
s11: cutting, namely cutting a circuit board substrate to a preset size, wherein the upper surface and the lower surface of the circuit board substrate are respectively provided with a base material with the thickness of 2 ounces of copper;
s12: drilling a hole on a circuit board substrate, and processing an inner layer buried hole;
s13: depositing copper to form a conductive coating on the wall of the inner-layer buried hole;
s14: and copper plating, namely electroplating copper plating is carried out on the circuit board substrate, so that the thickness of copper layers on the upper surface and the lower surface of the circuit board substrate reaches 3 ounces, and the inner layer substrate is obtained.
3. The process for fabricating an ultra-high copper thickness multilayer wiring board for internal layer as claimed in claim 1, wherein in step S2, fabricating the internal layer circuit comprises the steps of:
s21: laminating a layer of photosensitive dry film on the surface of the inner layer substrate;
s22: exposing, namely performing ultraviolet irradiation on the photosensitive dry film to enable the photosensitive dry film to generate polymerization reaction, and transferring the required pattern to the surface of the inner layer substrate through the negative film;
s23: developing, removing unexposed parts in the photosensitive dry film to expose partial copper surfaces;
s24: etching, dissolving the exposed copper surface to form a required circuit pattern on the surface of the inner layer substrate;
s25: and stripping the film, and removing the exposed photosensitive dry film on the inner layer substrate to obtain the inner layer substrate containing the inner layer circuit.
4. The process for manufacturing a multilayer wiring board having an ultra-high copper inner layer thickness according to claim 1, wherein the step of printing the first resin ink in step S3 comprises the steps of:
s31: printing resin ink on the surface of the inner-layer substrate, and filling the resin ink into the non-inner-layer circuit area on the surface of the inner-layer substrate;
s32: baking the inner-layer substrate to solidify the resin printing ink;
s33: and polishing the surface of the inner-layer substrate to obtain the inner-layer substrate with the first layer of resin printing ink and the same thickness as the inner-layer circuit.
5. The process for manufacturing a multilayer wiring board having an ultra-high copper inner layer thickness according to claim 1, wherein the step of printing the photosensitive wet film in step S5 comprises the steps of:
s51: printing photosensitive ink on the surface of the copper sheet in a screen printing missing mode, wherein the printing thickness of the photosensitive ink is 22-32 microns;
s52: and baking and curing the photosensitive ink, wherein the baking temperature is 70-80 ℃, and the baking time is 15-20 minutes.
6. The process for manufacturing a multilayer wiring board having an ultra-high copper inner layer thickness as claimed in claim 1, wherein the step of exposing the outer layer wiring pattern on the copper sheet surface in step S6 comprises the steps of:
exposure: carrying out ultraviolet irradiation on the photosensitive wet film to enable the photosensitive wet film to generate polymerization reaction, and transferring the required pattern to the surface of the copper sheet through the negative film;
developing, namely dissolving an unexposed part in the photosensitive wet film by using a developing solution to expose the copper surface of the outer layer circuit area, wherein the developing solution is a sodium carbonate solution with the concentration of 1%, and the temperature of the developing solution is 28-32 ℃;
washing with clear water at a pressure of 1.8-2.2kg/cm2The washing time is 20-30 seconds.
7. The process for manufacturing a multilayer wiring board having an ultra-high copper inner layer thickness according to claim 1, wherein in step S8, the process comprises the steps of:
removing the film, namely placing the inner-layer substrate into a 5% sodium hydroxide aqueous solution to be soaked for 2-5 minutes, and removing the photosensitive wet film on the non-outer-layer circuit part on the surface of the inner-layer substrate;
and micro-etching, namely placing the inner-layer substrate on micro-etching horizontal line equipment for micro-etching, and removing the copper sheet of the non-outer-layer circuit part on the surface of the inner-layer substrate.
8. The process for manufacturing a multilayer circuit board with an ultra-high copper inner layer thickness according to claim 1, wherein in step S10, the pressing comprises the following steps:
kissing, namely pasting PP filling glue on the surface of the composite substrate, melting resin in the PP filling glue into low-viscosity resin, infiltrating the low-viscosity resin into the surfaces of the composite substrate and the copper plate, and filling gaps of the outer-layer circuit;
full pressure, discharging air bubbles between the copper plate and the composite substrate, and enabling the curing crosslinking reaction of the resin to be complete;
and (5) cold pressing, cooling and placing the solidified resin to ensure that the composite substrate and the copper plate are stably connected.
9. The process for making a multilayer circuit board having an ultra-high copper content as claimed in claim 8, wherein in the step of cold pressing, the cold pressing temperature is 60 ℃ and the cold pressing time is 3-4 hours.
10. A wiring board, characterized in that it is produced by the process for producing a multilayer wiring board having an inner layer of ultra-high copper thickness according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111333108.9A CN114025515A (en) | 2021-11-11 | 2021-11-11 | Manufacturing process of multilayer circuit board with ultra-high copper thickness inner layer and circuit board |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111333108.9A CN114025515A (en) | 2021-11-11 | 2021-11-11 | Manufacturing process of multilayer circuit board with ultra-high copper thickness inner layer and circuit board |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114025515A true CN114025515A (en) | 2022-02-08 |
Family
ID=80063526
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111333108.9A Pending CN114025515A (en) | 2021-11-11 | 2021-11-11 | Manufacturing process of multilayer circuit board with ultra-high copper thickness inner layer and circuit board |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114025515A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115955791A (en) * | 2023-03-15 | 2023-04-11 | 深圳明阳电路科技股份有限公司 | Preparation method for mini-LED PCB |
-
2021
- 2021-11-11 CN CN202111333108.9A patent/CN114025515A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115955791A (en) * | 2023-03-15 | 2023-04-11 | 深圳明阳电路科技股份有限公司 | Preparation method for mini-LED PCB |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104244616B (en) | A kind of preparation method of centreless thin base sheet | |
| JPS62276893A (en) | Manufacture of conductor circuit board | |
| CN104080275B (en) | A kind of preparation method of ladder wiring board | |
| CN103491732A (en) | Method for manufacturing circuit board layer-adding structure | |
| CN104918414A (en) | Template electroplating peeling technology for conductive circuit | |
| CN105072816B (en) | A kind of modified template plating stripping technology of conducting wire | |
| CN114302561B (en) | Manufacturing method of multilayer board with ultralow copper residue and semi-through holes | |
| CN101312619A (en) | Manufacturing method for multi-layer high-density interconnected printed circuit board | |
| CN105870026A (en) | Carrier and manufacturing method therefor, and method for manufacturing core-less packaging substrate from carrier | |
| CN111615268A (en) | Novel local copper plating method for flexible circuit board | |
| CN105704948A (en) | Manufacturing method of ultra-thin printed circuit board and ultra-thin printed circuit board | |
| CN114025515A (en) | Manufacturing process of multilayer circuit board with ultra-high copper thickness inner layer and circuit board | |
| CN114190011B (en) | High-heat-dissipation PCB and manufacturing process thereof | |
| CN101437367B (en) | Method for preparing printed circuit board | |
| JP3392066B2 (en) | Composite copper foil, method for producing the same, copper-clad laminate and printed wiring board using the composite copper foil | |
| CN114096080A (en) | Manufacturing process of thick-hole copper in printed circuit board | |
| CN108901137A (en) | A kind of method that temperature control dissociation film auxiliary makes ultra-thin printed circuit board | |
| CN111405772B (en) | Surface treatment method for semiconductor device | |
| CN115066110B (en) | Micro-LED PCB ultra-Micro huge blind hole manufacturing method | |
| CN114206001B (en) | High-voltage-resistant MEMS (micro-electromechanical systems) packaging loading plate and manufacturing process thereof | |
| CN114340223B (en) | Manufacturing method of high aspect ratio-based selective semi-conductive hole multilayer board | |
| CN105430925A (en) | Fabrication method of thick copper circuit board | |
| JPH02113591A (en) | Manufacture of printed-wiring board | |
| CN113923878A (en) | Thick copper circuit board solder mask process manufacturing method and circuit board | |
| JPS6388895A (en) | Manufacture of conductor circuit plate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication |