CN113766727B - Flexible circuit board and manufacturing method thereof - Google Patents
Flexible circuit board and manufacturing method thereof Download PDFInfo
- Publication number
- CN113766727B CN113766727B CN202111032290.4A CN202111032290A CN113766727B CN 113766727 B CN113766727 B CN 113766727B CN 202111032290 A CN202111032290 A CN 202111032290A CN 113766727 B CN113766727 B CN 113766727B
- Authority
- CN
- China
- Prior art keywords
- layer
- film layer
- circuit
- circuit pattern
- carrier
- 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
- H05K1/02—Details
- H05K1/0277—Bendability or stretchability details
- H05K1/0283—Stretchable printed circuits
-
- 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
- H05K1/02—Details
- H05K1/0277—Bendability or stretchability details
- H05K1/0278—Rigid circuit boards or rigid supports of circuit boards locally made bendable, e.g. by removal or replacement of material
-
- 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
- H05K3/36—Assembling printed circuits with other printed circuits
- H05K3/361—Assembling flexible printed circuits with other printed circuits
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Manufacturing & Machinery (AREA)
- Manufacturing Of Printed Wiring (AREA)
Abstract
The invention provides a flexible circuit board and a manufacturing method thereof, wherein the method comprises the following steps: selecting a flexible base material as a supporting body of the circuit board; forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the bearing body in sequence, and forming a metal film layer on the lower surface of the bearing body; the thickness of the first seed layer is 10-200 nm, the thickness of the first copper film layer is 5-100 mu m, and the thickness of the first oxidation resistant layer is 0.5-30 mu m; the thickness of the metal film layer is 5.51-130.2 μm. The scheme can reduce the deformation amount of the bearing body with larger thermal expansion coefficient.
Description
Technical Field
The embodiment of the invention relates to the technical field of circuit boards, in particular to a flexible circuit board and a manufacturing method thereof.
Background
With the development of screen technology, LED (Light Emitting Diode) advertisement screens gradually become the mainstream display devices in modern times due to their advantages of bright color, wide dynamic range, high brightness, long service life, stable and reliable operation, etc. Flexible LED displays are receiving increasing attention because they can meet a variety of shapes (e.g., can be cylindrical, inner arc, ribbon, spiral, etc.).
Disclosure of Invention
The invention provides a flexible circuit board and a manufacturing method thereof, which can reduce the deformation of the flexible circuit board.
In a first aspect, the present invention provides a method for manufacturing a flexible circuit board, including:
selecting a flexible base material as a supporting body of the circuit board;
forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the bearing body in sequence, and forming a metal film layer on the lower surface of the bearing body;
the thickness of the first seed layer is 10-200 nm, the thickness of the first copper film layer is 5-100 mu m, and the thickness of the first oxidation resistant layer is 0.5-30 mu m; the thickness of the metal film layer is 5.51-130.2 μm.
Preferably, the metal film layer sequentially comprises on the lower surface of the carrier from top to bottom: the second seed layer, the second copper film layer and the second antioxidation layer;
the thickness of the second seed layer is 10-200 nm, the thickness of the second copper film layer is 5-100 mu m, and the thickness of the second antioxidation layer is 0.5-30 mu m.
Preferably, the sequentially forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the carrier, and forming a metal film layer on the lower surface of the carrier includes:
sputtering the first seed layer on the upper surface of the carrier by a magnetron sputtering method;
sputtering the second seed layer on the lower surface of the carrier by a magnetron sputtering method;
obtaining the first copper film layer and the second copper film layer by electroplating with an acid electroplating method or sputtering with a magnetron sputtering method;
and sputtering by using an acid electroplating method or a magnetron sputtering method to obtain the first oxidation resisting layer and the second oxidation resisting layer.
Preferably, after forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the carrier in sequence, and forming a metal film layer on the lower surface of the carrier, the method further includes: and manufacturing a first circuit pattern on the upper surface of the bearing body, and manufacturing a second circuit pattern on the lower surface of the bearing body.
Preferably, the first circuit pattern is identical to the second circuit pattern.
Preferably, a first seed layer, a first copper film layer and a first oxidation resistant layer are sequentially formed on the upper surface of the carrier, and the method includes:
sputtering the first seed layer on the upper surface of the carrier by a magnetron sputtering method;
electroplating the first copper film layer on the first seed layer by a magnetron sputtering method or an acid electroplating method;
manufacturing a first circuit pattern on the upper surface of the carrier;
filling blue gel in the non-circuit area of the first circuit pattern;
and forming a first oxidation resisting layer on the surface of the circuit area of the first circuit pattern, and removing the filled blue gel.
Preferably, the filling of the blue paste in the non-line region of the first circuit pattern includes:
hollowing out the silk-screen printing plate according to the first circuit pattern, so that the hollow-out area of the silk-screen printing plate is the same as the non-circuit area of the first circuit pattern;
aligning the silk-screen plate with the circuit board, so that the hollow area of the silk-screen plate is aligned with the non-circuit area of the first circuit pattern, and the non-hollow area of the silk-screen plate covers the circuit area of the first circuit pattern;
and filling blue gel into the non-circuit area of the first circuit pattern through the hollow area of the silk-screen printing plate.
Preferably, the thickness of the silk-screen printing plate is 0.01-100 μm.
Preferably, the method further comprises the following steps: and mounting the LED lamp beads on the upper surface of the circuit board in a reflow soldering or wave soldering mode according to the first circuit pattern.
In a second aspect, the invention provides a flexible circuit board, which is manufactured by any one of the above manufacturing methods.
The embodiment of the invention provides a flexible circuit board and a manufacturing method thereof, wherein a metal film layer is formed on the lower surface of a bearing body, in the high-temperature deformation recovery process, a first seed layer, a first copper film layer and a first oxidation resisting layer on the upper surface of the bearing body simultaneously generate tension on the upper surface of the bearing body, at the moment, the metal film layer generates tension on the lower surface of the bearing body, and the tension of the metal film layer on the lower surface of the bearing body can counteract part of the tension on the upper surface, so that the tension on the upper surface is reduced, and the deformation quantity of the bearing body with a larger thermal expansion coefficient is reduced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a circuit board according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of another circuit board according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a structure of another circuit board according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a structure of another circuit board according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of a structure of another circuit board according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a structure of another circuit board according to an embodiment of the present invention;
in the figure: 1: a carrier; 2: a first seed layer; 3: a first copper film layer; 4: a first oxidation resistant layer; 5: a metal film layer; 6: blue glue.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer and more complete, the technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention, and based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the scope of the present invention.
For the convenience of understanding the embodiments of the present invention, the inventive concept of the embodiments of the present invention will be described first.
The flexible LED display screen selects a flexible substrate as a supporting body, and a metal film layer is formed on the supporting body to obtain the flexible circuit board. In the circuit board manufacture process, there is often the high temperature baking process, because the supporting body chooses for use flexible substrate, coefficient of thermal expansion is great, and the coefficient of thermal expansion of metal film layer is less, both the deformation volume that toast under high temperature is different, wherein, metal film layer deformation volume is little, flexible substrate's deformation volume is big, after the cooling, because the supporting body is held by metal film layer, lead to the great supporting body of deformation original shape of unable recovery, thereby lead to when welding lamp pearl, lamp pearl and welding point location are inaccurate, the yields of the circuit board of preparation is lower. Considering that the metal film layer is located the same side of the bearing body, in the high-temperature deformation recovery process, the metal film layer has a tensile force on one side of the bearing body, if the metal film layer can be additionally arranged on the other side of the bearing body, the tensile force is arranged on both sides of the bearing body in the high-temperature deformation recovery process, so that partial offset can be carried out, and the deformation quantity of the bearing body with a large thermal expansion coefficient is reduced.
The following are embodiments of the above inventive concept.
In a first aspect, the present invention provides a method for manufacturing a flexible circuit board, which may include:
s1: selecting a flexible base material as a supporting body of the circuit board;
s2: forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the bearing body in sequence, and forming a metal film layer on the lower surface of the bearing body;
the thickness of the first seed layer is 10-200 nm, the thickness of the first copper film layer is 5-100 mu m, and the thickness of the first oxidation resistant layer is 0.5-30 mu m; the thickness of the metal film layer is 5.51-130.2 μm.
In the embodiment of the invention, the metal film layer is formed on the lower surface of the bearing body, in the high-temperature deformation recovery process, the first seed layer, the first copper film layer and the first oxidation resisting layer on the upper surface of the bearing body simultaneously generate tension on the upper surface of the bearing body, at the moment, the metal film layer generates tension on the lower surface of the bearing body, and the tension of the metal film layer on the lower surface of the bearing body can counteract part of the tension on the upper surface, so that the tension on the upper surface is reduced, and the deformation amount of the bearing body with a large thermal expansion coefficient is reduced.
The manner in which the above-described steps are performed is described below.
First, in step S1, a flexible substrate is selected as a carrier of the circuit board.
In one embodiment of the present invention, flexible substrates such as flexible glass (thickness less than or equal to 0.2mm), PET (polyester resin), PA (polyamide), CPI (colorless transparent polyimide), or PI (polyimide) may be used as the supporting body of the circuit board.
In some preferred embodiments of the present invention, the thickness of the carrier body may be 0.02-8 mm (e.g., 0.02, 0.2, 1, 2, 3, 4, 5, 6, 7, or 8 mm).
In a preferred embodiment of the present invention, the carrier may be pretreated in order to improve the adhesion between the carrier and the circuit, and the pretreatment may include the following steps: spraying and cleaning with a weakly alkaline cleaning solution (pH of 7.1-7.9) or a weakly acidic cleaning solution (pH of 6.1-6.9), rolling and brushing, washing with high-purity water, air drying and drying.
Then, in step S2, a first seed layer, a first copper film layer and a first oxidation resistant layer are sequentially formed on the upper surface of the carrier, and a metal film layer is formed on the lower surface of the carrier.
In some preferred embodiments of the present invention, the material used for the first seed layer may be one or more of copper, copper-nickel alloy, copper-titanium alloy, copper-molybdenum alloy, and copper-chromium alloy; the copper film layer is made of copper; the material adopted by the first oxidation resisting layer can be one or more of nickel, tin, gold and silver.
The first function of the first seed layer is to serve as a seed layer of the first copper film layer, provide a conductive film layer for the electroplating process of the first copper film layer and ensure that the first copper film layer can be electroplated in the subsequent process; the second function of the first seed layer is to improve the adhesion between the first seed layer and the carrier and the first copper film layer. The first copper film layer is used as a conductive layer of the circuit board. The first oxidation resistant layer not only has the function of oxidation resistant protection for the first copper film layer, but also has the function of welding assistance.
In the embodiment of the present invention, in order to ensure that the first seed layer can achieve the second function, the thickness of the first seed layer may be 10 to 200nm (e.g., 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, or 200 nm); the thickness of the first copper film layer can be 5-100 μm (for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100um), and the thickness of the first copper film layer can effectively meet the requirement of a circuit board on low resistance or low impedance, so that the current loss of the circuit board is reduced. Through a large number of creative tests, the thickness of the first seed layer is 10-200 nm, if the seed layer is too thin, the resistance of the seed layer is larger, so that the electroplating current is smaller when a copper film layer is electroplated subsequently, and the electroplating effect is poor; also, too thin a seed layer may affect adhesion. If the seed layer is too thick, when the supporting body adopts flexible substrates such as PET, PA, CPI or PI, the deformation quantity that the supporting body was drawn is great with the thicker seed layer for the subsequent copper rete of electroplating is inhomogeneous when electroplating, and influences the welding position of follow-up lamp pearl. Therefore, when the thickness of the first seed layer is 10-200 nm, the requirement of the adhesive force between the bearing body and the first copper film layer can be well met, the adhesive force between the bearing body and the conductive copper film layer is improved, the copper film layer can be electroplated on the bearing body, and the drawing force of the bonding pad can reach more than 1N; and the thickness can ensure that when the copper film layer is electroplated, enough current is loaded to realize the electroplating process of the copper film layer. Considering that if the thickness of the first oxidation resistant layer is too thin, the copper circuit can not be covered by the oxidation resistant layer formed, the surface is uneven, the anti-oxidation effect is affected, and when the lamp bead is welded subsequently, the oxidation resistant layer is burnt through during welding due to the fact that the oxidation resistant layer is too thin, and the welding effect is affected; if the thickness of the anti-oxidation layer is too thick, although the anti-oxidation effect is obviously improved, the cost is higher, the whole thickness of the circuit board is larger, and the occupied space is higher. Therefore, in view of the above problems, it is found through a great deal of inventive experiments that the thickness of the antioxidation layer may be 0.5 to 30 μm (e.g., 0.5, 1, 2, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, or 30 μm). It should be noted that, when the thickness of the first copper film layer is larger in the range of 5-100 μm, the thickness of the seed layer also needs to be increased properly in the range of 10-200 nm, so as to achieve better adhesion.
Because the metal film layer has the function of generating tension on the lower surface of the bearing body, in order to ensure that the tension on the lower surface and the tension on the upper surface of the bearing body are similar or identical, the total thickness of the first seed layer, the first copper film layer and the first oxidation resisting layer on the upper surface of the bearing body is similar or identical to the thickness of the metal film layer. The total thickness of the first seed layer, the first copper film layer and the first oxidation resisting layer is 5.51-130.2 μm, so the thickness of the metal film layer is 5.51-130.2 μm. The thickness of the metal film layer and the total thickness of the first seed layer, the first copper film layer and the first oxidation resisting layer may be the same or different, and preferably, the thicknesses of the two layers are the same.
Preferably, since the first seed layer, the first copper film layer, the first oxidation-resistant layer and the metal film layer are all made of metal, in order to ensure that the deformation amount of the carrier is within an acceptable range, through a large number of creative tests, the absolute value of the difference between the total thickness of the first seed layer, the first copper film layer and the first oxidation-resistant layer and the thickness of the metal film layer is 0-30 μm (for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, 20, 22, 25, 28 or 30 μm).
In some preferred embodiments of the present invention, the metal film layer may be one layer, or may be two or more layers. When the metal film layer is a single layer, the metal film layer may be made of one or more of copper, copper-nickel alloy, copper-titanium alloy, copper-molybdenum alloy, and copper-chromium alloy in consideration of the manufacturing cost and the manufacturing process of the circuit board. When the metal film layers are two layers, the metal film layers sequentially comprise a second seed layer and a second copper film layer from top to bottom on the lower surface of the bearing body. When the metal film layer is three layers, the metal film layer sequentially includes a second seed layer, a second copper film layer and a second oxidation resistant layer from top to bottom on the lower surface of the carrier, and the thickness of the second seed layer is 10-200 nm (for example, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200nm), the thickness of the second copper film layer is 5-100 μm (for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100um), and the thickness of the second oxidation resistant layer is 0.5-30 μm (for example, 0.5, 1, 2, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28 or 30 μm). It is preferable that the number of the metal film layers is equal to the number of the film layers on the upper surface of the carrier, the sequence of the film layers is the same, and the thicknesses of the corresponding film layers are the same or similar. The thicknesses of the second seed layer and the first seed layer can be the same or different, the thicknesses of the second copper film layer and the first copper film layer can be the same or different, and the thickness of the second antioxidation layer and the thickness of the first antioxidation layer can be the same or different.
When the metal film layer sequentially includes the second seed layer, the second copper film layer and the second anti-oxidation layer from top to bottom on the lower surface of the carrier, in an embodiment of the present invention, the manufacturing process of each film layer in step S2 may include:
s21 a: and sputtering the first seed layer on the upper surface of the carrier by a magnetron sputtering method.
S22 a: and sputtering the second seed layer on the lower surface of the carrier by a magnetron sputtering method.
In the embodiment of the present invention, the process conditions of the magnetron sputtering seed layer in steps S21a and S22a are as follows: the total power of the sputtering power source is 1 to 20kW (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20kW), the argon pressure is 0.2 to 1.0Pa (e.g., 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0Pa), the temperature of the circuit board carrier is 50 to 200 ℃ (e.g., 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃, or 200 ℃).
S23 a: and sputtering by using an acid electroplating method or a magnetron sputtering method to obtain the first copper film layer and the second copper film layer.
When the magnetron sputtering method is employed, the process conditions are the same as in steps S21a, S22 a.
When the acid plating method is adopted, the process conditions may be: a pH of 3-6 (e.g., 3, 4, 5 or 6) and CuSO4The concentration is 20-200 g/L (for example, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200g/L), H2SO4The concentration is 100-300 g/L (such as 100, 120, 140, 160, 180, 200, 220, 240, 260, 280 or 300g/L), the concentration of the chloride ion is 10-200 ppm (such as 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180. 190 or 200ppm) at a temperature of 20 to 80 ℃ (e.g., 20 ℃, 30 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃ or 80 ℃).
Considering that seed layers are formed on the upper surface and the lower surface of the supporting body, and the materials adopted by the first copper film layer and the second copper film layer are both elemental copper, the acid electroplating method can be preferably adopted for electroplating in the step S23a, so that the first copper film layer and the second copper film layer can be obtained simultaneously in one electroplating process, the manufacturing cost is saved, the manufacturing complexity is reduced, and the manufacturing efficiency is improved.
S24 a: and sputtering by an acid electroplating method or a magnetron sputtering method to obtain a first oxidation resistant layer and a second oxidation resistant layer.
When the magnetron sputtering method is employed, the process conditions are the same as in steps S21a, S22 a.
When the acid plating method is adopted, the process conditions may be: a pH of 3-6 (e.g. 3, 4, 5 or 6), AgSO4Or NiSO4Or AuSO4The concentration is 20-200 g/L (for example, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200g/L), H2SO4The concentration is 100-300 g/L (such as 100, 120, 140, 160, 180, 200, 220, 240, 260, 280 or 300g/L), the concentration of chloride ions is 10-200 ppm (such as 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200ppm), and the temperature is 20-80 ℃ (such as 20 ℃, 30 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃ or 80 ℃).
Preferably, the first antioxidation layer and the second antioxidation layer are made of the same material, and the step S24a is obtained by electroplating by using an acid electroplating method.
After the circuit board is obtained after the step of completing S2, in an embodiment of the present invention, the method may further include:
s3: and manufacturing a first circuit pattern on the upper surface of the bearing body, and manufacturing a second circuit pattern on the lower surface of the bearing body.
In the test process, the tensile force applied to the upper and lower surfaces of the carrier during the recovery process of the circuit board after high temperature is related to the film thickness of the upper and lower surfaces and the contact area of the carrier. And the process of making the circuit pattern includes the etching process, therefore, after making and obtaining the first circuit pattern at the upper surface of supporting body, the contact area of the metal membranous layer of the upper surface and supporting body can diminish, the pulling force to one side of upper surface of supporting body can change so, in order to guarantee that the pulling force that both sides of supporting body receive is the same or close, make and obtain the second circuit pattern at the lower surface of supporting body too, so make the contact area of the metal membranous layer of the lower surface and supporting body diminish, make the metal membranous layer closer to the pulling force of one side of downward surface of supporting body to the pulling force of one side of upward surface, in order to further reduce the deformation of the supporting body, raise the non-defective rate of the circuit board. In addition, because the flexible substrate that the supporting body chose for use is transparent material, also makes the lower surface and obtains a second circuit pattern, can be so that the permeability of circuit board is bigger, and the luminousness is higher, and the LED display screen made by this circuit board when installing the outer window of building, reduces the influence to daylighting in the building.
The manufacturing process of the first circuit pattern and the second circuit pattern comprises the following steps:
s31, coating photoresist; for example, a photoresist layer is coated on the anti-oxidation layer, and the thickness of the photoresist layer can be 10-20 micrometers;
s32, designing a film circuit meeting the requirements; for example, a film circuit meeting the requirement is designed on the photoresist layer;
s33, exposure; exposing the photoresist layer with the designed film circuit: the exposure energy is preferably 30 to 70mj/cm2；
S34, developing; and developing the exposed photoresist layer, wherein the developing can adopt the following process conditions: the developing time can be 30-50 s, the temperature is 25-40 ℃, and the developing solution is NaCO with the concentration of 0.8-1.2 wt%3·H2O；
S35, etching; for example, the circuit can be etched in an acidic etching solution, and the following process conditions can be adopted for etching: the concentration of copper ions in the etching solution is 100-150 g/L, the concentration of chloride ions is 150-200 g/L, the temperature is 40-70 ℃, the thickness of an etching line can reach more than 50um, and the width can reach less than 20 um;
and S36, degumming. The etched circuit board is subjected to a degumming treatment, for example, NaOH may be used to degum the photoresist on the circuit area.
In a preferred embodiment of the present invention, the first circuit pattern is the same as the second circuit pattern.
The first circuit pattern is the same as the second circuit pattern, which indicates that the metal film layers (the metal film layers are the circuit regions of the circuit patterns) on the two sides of the bearing body are the same as the bearing body in contact area and are corresponding in contact position, and in the recovery process of the circuit board after high temperature, because the circuit patterns on the two sides of the bearing body are the same, the tension points on the two sides of the bearing body are the same, so that the tension on the two sides of each tension point can be mutually offset, if the tension on the two sides of the tension points is the same, the tension points can not be affected by tension inequality, and the deformation of the tension points can be gradually recovered to the original shape after cooling. Therefore, when the first circuit pattern and the second circuit pattern are the same, it can be ensured that the amount of deformation of the carrier is very low. In addition, because the circuit regions on the two sides of the supporting body are corresponding in position, the non-circuit regions are corresponding in position, and the supporting body is made of a flexible base material made of a transparent material, light can penetrate through the non-circuit regions, so that the light transmittance of the circuit board is higher than that of the circuit patterns on the two sides of the supporting body at different times, the permeability is higher, and the deformation amount is lower.
Fig. 1 is a schematic structural diagram of a flexible circuit board with the first circuit pattern on the upper surface of the carrier being identical to the second circuit pattern on the lower surface. The flexible circuit board includes: the structure comprises a carrier 1, a first seed layer 2, a first copper film layer 3, a first oxidation resistant layer 4 and a metal film layer 5.
Considering that the first seed layer and the first copper film layer are made of copper similar to each other, and the oxidation resistant layer is made of a material that does not include copper, if the oxidation resistant layer is etched together with the seed layer and the copper film layer, the etching process is complicated, the requirement for the etching solution is too high, and the manufacturing efficiency of the circuit board is relatively low, therefore, it can be considered that the following processes are adopted when the first seed layer, the first copper film layer, and the first oxidation resistant layer are formed in step S2:
s21 b: and sputtering the first seed layer on the upper surface of the carrier by a magnetron sputtering method.
The magnetron sputtering method in step S21b is the same as the magnetron sputtering method in steps S21a and S22a, and is not described herein again.
S22 b: and electroplating the first copper film layer on the first seed layer by a magnetron sputtering method or an acid electroplating method.
The magnetron sputtering method or the acid plating method in step S22b is the same as the process conditions in step S23a, and will not be described herein.
Referring to fig. 2, a schematic structural diagram of the flexible circuit board (the metal film layer is not shown in the figure) after S22b is completed, the flexible circuit board includes a carrier 1, a first seed layer 2, and a first copper film layer 3.
S23 b: a first circuit pattern is formed on the upper surface of the carrier.
S24 b: and filling blue gel in the non-circuit area of the first circuit pattern.
The execution process for steps S23b and S24b may include the following two execution manners:
in the first mode, the step of filling the blue photoresist is performed after the photoresist is removed.
And in the second mode, after the etching is finished, a blue glue filling step is executed, and then a photoresist removing step is executed.
The following describes the above two modes, respectively.
In the first embodiment, the process of fabricating the first circuit pattern in step S23b is the same as that in steps S31 to S36, except that a photoresist layer is coated on the first copper film layer in step S31.
In the first mode, since the first seed layer is made of copper or copper alloy, that is, copper is used as a material similar to that of the first copper film layer, during the etching process for forming the first circuit pattern, an etching solution capable of etching copper may be used to perform etching on the first seed layer and the first copper film layer. When the first seed layer is made of copper alloy and the first seed layer is etched by using the etching solution, copper in the first seed layer can be decomposed, and nickel, titanium, molybdenum or chromium atoms in the copper alloy are not decomposed but are in dispersed granular shapes, so that the first seed layer is etched. Therefore, the first seed layer in the scheme adopts one or more of copper, copper-nickel alloy, copper-titanium alloy, copper-molybdenum alloy and copper-chromium alloy, and the copper film layer adopts copper, so that the etching difficulty can be reduced, the cost can be reduced, the etching efficiency can be improved, and the yield of finished products can be improved.
Referring to fig. 3, a schematic structural diagram of the flexible circuit board (the metal film layer is not shown in the figure) after S23b is completed, the flexible circuit board includes a carrier 1, a first seed layer 2, and a first copper film layer 3.
In this way, in an embodiment of the present invention, step 24b can be implemented in at least one of the following ways:
a1: hollowing out the silk-screen printing plate according to the first circuit pattern, so that the hollow-out area of the silk-screen printing plate is the same as the non-circuit area of the first circuit pattern;
a2: aligning the silk-screen plate with the circuit board, so that the hollow area of the silk-screen plate is aligned with the non-circuit area of the first circuit pattern, and the non-hollow area of the silk-screen plate covers the circuit area of the first circuit pattern;
a3: and filling blue gel into the non-circuit area of the first circuit pattern through the hollow area of the silk-screen printing plate.
In step a1, the stencil is hollowed out to make the pattern formed on the stencil after the hollowing out process consistent with the first circuit pattern, that is, the hollowed-out area is the same as the non-circuit area of the first circuit pattern (both shape and size are the same), and the non-hollowed-out area is the same as the circuit area of the first circuit pattern (both shape and size are the same).
In step a2, the screen printing plate is aligned with the circuit board, such that the hollow area of the screen printing plate is aligned with the non-circuit area of the first circuit pattern, and the non-hollow area of the screen printing plate covers the circuit area of the first circuit pattern. After alignment, the silk screen printing plate and the circuit board can be pressed tightly, and the phenomenon that when blue glue is filled into a non-circuit area, the blue glue is squeezed into a gap between the silk screen printing plate and the circuit board to cause the surface of the circuit area to be stuck with the blue glue to influence the formation of an oxidation resistant layer and reduce the contact surface of the oxidation resistant layer and the circuit area, even the oxidation resistant layer cannot be formed or is not contacted with the circuit area, the yield of the circuit board is influenced, and the service life of the circuit board is shortened is avoided. Therefore, the silk screen printing plate is tightly pressed with the circuit board, so that the blue gel can only be filled into the non-circuit area, and after the silk screen printing plate is taken down to be molded, the blue gel is not adhered to the circuit area, so that the formation of an anti-oxidation layer is facilitated, and the service life of the circuit board is prolonged.
In step a3, the blue gel may be filled into the non-circuit area of the first circuit pattern through the hollow area of the screen printing plate by coating, spraying or printing.
It should be noted that the blue glue needs to fill the non-circuit region, that is, the blue glue contacts the carrier, so that it can be ensured that the anti-oxidation layer only exists on the surface of the circuit region without affecting other regions when the anti-oxidation layer is formed subsequently.
In an embodiment of the present invention, the thickness of the silk screen may be 0.01 to 100 μm (e.g., 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 8, 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100 μm). Considering that if the blue gel is filled in the non-line area and the height of the blue gel is lower than that of the first copper film layer, the first oxidation resistant layers of the adjacent line areas may be connected when the first oxidation resistant layers are formed subsequently, a short circuit may be caused when the circuit board is electrified for use, and the service life of the circuit board is reduced; therefore, the height of the blue gel is higher than that of the first copper film layer, and the height of the blue gel can be realized by the thickness of the screen printing plate, for example, the height of the blue gel is 0.01-100 μm higher than that of the copper film layer, and after the non-circuit area is filled with the blue gel, the thickness of the blue gel is 5.52-230.2 μm. If the thickness of the screen printing plate is too thick, the alignment with the circuit board may be affected, and therefore, the thickness of the screen printing plate is 0.01 to 100 μm, which is obtained through a great deal of creative experiments.
In an embodiment of the invention, after the step a3, in order to rapidly form the blue gel, the circuit board may be baked at a temperature of 120 to 180 ℃ (e.g., 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃ or 180 ℃) for 3 to 7 minutes (e.g., 3, 4, 5, 6 or 7), so that the blue gel is baked to rapidly form the blue gel, thereby improving the manufacturing efficiency of the circuit board.
It should be noted that, besides the above manner, the blue gel may be directly coated or sprayed in the non-circuit area without using a screen printing plate, and after the non-circuit area is filled up, the blue gel adhered to the circuit area of the copper film layer is scraped by a scraper, so as to prevent the subsequent oxidation resistant layer formation process from being affected.
Referring to fig. 4, a schematic structural diagram of the flexible circuit board (the metal film layer is not shown in the figure) after S24b is completed, the flexible circuit board includes a carrier 1, a first seed layer 2, a first copper film layer 3 and a blue gel 6.
The above is a description of the first embodiment, and the following is a description of the second embodiment.
In the second embodiment, the process of fabricating the first circuit pattern in step S23b includes the above steps S31 to S35, but in step S31, a photoresist layer is coated on the first copper film layer.
In the second embodiment, after the first circuit pattern is manufactured by performing the step S23b, the step S24b is performed to fill the blue gel in the non-circuit region of the first circuit pattern, and in the second embodiment, the step S24b is performed in the same manner as the step a1-A3, which is specifically referred to as the step a1-A3 and is not repeated herein.
It can be seen that, in the process of fabricating the first circuit pattern, the photoresist on the line region is not degummed after etching, so that when S24b is executed, on one hand, since the photoresist is in a molding state and the blue photoresist is in an unmolding state, and the two are different organic matters, adhesion of the blue photoresist to the photoresist can be avoided, on the other hand, if the blue photoresist is adhered to the edge of the line region, since the photoresist is also present on the line region, after filling the blue photoresist, the photoresist coated in the process of fabricating the first circuit pattern is degummed, at this time, the photoresist can be preferably mechanically degummed, so that after the photoresist is degummed, the unmolded blue photoresist adhered to the photoresist can be mechanically stripped along with the photoresist, so that the line region without adhesion of the blue photoresist after stripping, and formation of an anti-oxidation layer is facilitated, thereby improving the yield of the circuit board.
In an embodiment of the invention, after the photoresist is degummed, in order to rapidly form the blue gel, the circuit board may be baked at 120-180 ℃ (e.g., 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃ or 180 ℃) for 3-7 minutes (e.g., 3, 4, 5, 6 or 7 minutes), so that the blue gel is baked to rapidly form the blue gel, thereby improving the manufacturing efficiency of the circuit board.
The description of equation two is completed above.
S25 b: and forming a first oxidation resisting layer on the surface of the circuit area of the first circuit pattern, and removing the filled blue gel.
In an embodiment of the present invention, the forming of the first anti-oxidation layer can be implemented by at least an acid electroplating method, and the process conditions of the acid electroplating method in steps S25b and S24a are the same, and are not described herein again.
Because the blue gel fills up the non-circuit area, the first seed layer can not expose outside, the side surface of the first copper film layer can not expose outside, the first seed layer can only expose on the surface of the metal area (namely the etched first copper film layer) outside, and because the blue gel is organic matter, the blue gel can not conduct electricity, therefore, in the acid electroplating process, one or more of nickel, tin, gold and silver can only be electroplated on the surface of the circuit area, and thus, the first oxidation resistant layer is formed on the surface of the circuit area.
It should be noted that, in addition to the formation of the first oxidation resistant layer by the acid electroplating method in step S25b, other methods may be used, such as spraying the oxidation resistant paint, and after spraying the oxidation resistant paint and before the oxidation resistant paint is completely dried, the blue gel may be removed to prevent the removal of the blue gel from being affected after the sprayed oxidation resistant paint is completely dried.
Referring to fig. 5, a schematic structural diagram of a flexible circuit board after forming a first oxidation resistant layer (a metal film layer is not shown in the figure) includes a carrier 1, a first seed layer 2, a first copper film layer 3, a blue glue 6, and a first oxidation resistant layer 4.
In an embodiment of the present invention, the blue gel may be removed by dissolving in an organic solvent or by mechanical demolding.
Preferably, 1.5 to 2.5kg/cm can be used2(e.g., 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, or 2.5kg/cm2) The tensile force of (2) to perform mechanical stripping. After the blue gel is formed, a mechanical demoulding mode is adopted, and the formed blue gel can be pulled out in a large area under the action of external force, so that the blue gel removing speed can be increased, an organic solvent is not required, and the manufacturing cost of the circuit board is reduced.
In addition, regardless of the number of the metal film layers on the lower surface of the carrier, the respective film layers on the upper surface of the carrier can be realized in steps S21b to S25b, and if the metal film layers are the same as the respective film layers on the upper surface of the carrier, the same can be realized in steps S21b to S25 b. The lower surface of the bearing body is not required to be welded with the lamp beads, so that the metal film layer on the lower surface is not required to be subjected to anti-oxidation treatment, the metal film layer on the lower surface of the bearing body only comprises a copper or copper alloy film layer or only comprises a second seed layer and a second copper film layer, the complexity of the manufacturing process can be reduced, the cost can be reduced, and the manufacturing efficiency is improved.
In an embodiment of the present invention, after obtaining the flexible circuit board after performing S2, the method may further include: and mounting the LED lamp beads on the upper surface of the flexible circuit board in a reflow soldering or wave soldering mode according to the first circuit pattern.
In this scheme, because the lower surface of supporting body forms the metal coating, consequently after the in-process of this step paster LED lamp pearl toasts through high temperature, at the cooling recovery stage, because the both sides of supporting body all have the pulling force, consequently both sides pulling force can offset to can make the deformation of supporting body resume gradually, the deformation volume is lower.
In a second aspect, the invention provides a flexible circuit board, which is manufactured by the above manufacturing method. As shown in fig. 6, the circuit board includes a carrier 1, a first seed layer 2, a first copper film layer 3, a first oxidation resistant layer 4, and a metal film layer 5.
The circuit board has one or more of the following properties:
the circuit thickness of the circuit board is not less than 50 mu m;
the line width of a circuit board of the circuit board is 0.05-10000 mu m;
the permeability is more than 90%, the number of LED lamp beads in each square meter is more than 1 ten thousand, the brightness is more than 7000 lumens, the anti-oxidation service life is more than 3 years, and the deformation amount is about 0.3%.
The following are several examples of the present invention.
Example 1
And S1, taking the polyester resin as a circuit supporting body, and sequentially carrying out spray cleaning, rolling brush cleaning, high-purity water washing, air drying and drying treatment on the polyester resin by using a weak base cleaning solution (with the pH value of 7.1) for later use.
S2, obtaining a first seed layer (elemental copper) and a second seed layer (elemental copper) on the upper surface and the lower surface of the polyester resin through magnetron sputtering technology, wherein the thicknesses of the first seed layer and the second seed layer are 10nm, and the technological conditions are as follows: the power density of a sputtering power supply is 2kw/cm2Argon pressure is 0.6Pa, and the temperature of a circuit board carrier is 150 ℃;
electroplating on the surface of the first seed layer and the surface of the second seed layer by an acid electroplating process to obtain a first copper film layer and a second copper film layer, wherein the thicknesses of the first copper film layer and the second copper film layer are both 5 micrometers, and the process conditions are as follows: pH 3, CuSO4Concentration of 20g/L, H2SO4The concentration was 160g/L, the chloride ion concentration was 100ppm, and the temperature was 30 ℃.
Electroplating the surface of the first copper film layer and the surface of the second copper film layer by an acid electroplating process to obtain a first oxidation resistant layer and a second oxidation resistant layerThe thickness of the layer is 10 μm, the process condition is that the pH value is 4, NiSO4Concentration of 40g/L, H2SO4The concentration was 160g/L, the chloride ion concentration was 100ppm, and the temperature was 30 ℃.
S3, coating photoresist on the first anti-oxidation layer and the second anti-oxidation layer, wherein the thickness is 10 μm, designing a film circuit meeting the customer requirement, and installing the film circuit in an exposure machine for exposure, wherein the exposure energy is 30mj/cm2(ii) a After the exposure, the developing process is carried out, the developing time is 30s, the temperature is 25 ℃, and the developing solution is NaCO with the concentration of 0.8wt percent3.H2O; after the development is finished, an etching process is carried out, wherein the concentration of copper ions in the etching solution is 100g/L, the concentration of chloride ions is 150g/L, the temperature is 40 ℃, the etching line width is 20 micrometers, and the thickness is 50 micrometers; and after etching, carrying out a photoresist removing process, degumming by adopting NaOH to obtain a first circuit pattern on the upper surface of the polyester resin, and obtain a second circuit pattern on the lower surface of the polyester resin, wherein the first circuit pattern is the same as the second circuit pattern.
And S4, attaching the LED lamp beads to the upper surface of the obtained circuit board by adopting an SMT technology to manufacture the LED display screen. The transparency of the circuit board can reach more than 90%, the drawing resistance of the film layer is 1N, the number of LED lamp beads in each square meter is more than 1 ten thousand, the brightness is more than 7000 lumens, and the resolution of the whole display screen can be improved to the level of P10; the anti-oxidation service life can reach more than 3 years; the yield can reach 97%; the deformation amount is within 0.28%.
In the embodiment of the invention, the anti-oxidation life test result is obtained by the following method: the test result is equivalent to a test effect of more than three years by continuously testing for more than 15 days in a high-temperature and high-humidity environment (temperature 80 ℃ and humidity 80%).
Example 2
S1, using polyamide as a circuit supporting body, and sequentially carrying out spraying cleaning, rolling brush cleaning, high-purity water washing, air drying and drying treatment on the polyamide by using weak acid cleaning solution (the pH value is 6.2) for later use.
S2, sputtering a copper-nickel alloy film layer on the upper surface of the polyamide by a magnetron sputtering process, wherein the thickness is 20nm, and the process conditions are as follows: power density of sputtering power supply 3kw/cm2Argon pressure of 0.7Pa, circuitThe temperature of the board carrier is 150 ℃;
electroplating a copper film layer on the surface of the copper-nickel alloy film layer by an acid electroplating process, wherein the thickness is 10 mu m, and the process conditions are as follows: pH 4, CuSO4Concentration of 30g/L, H2SO4The concentration is 140g/L, the concentration of chloride ions is 80ppm, and the temperature is 30 ℃;
electroplating an antioxidation layer on the surface of the copper film layer by an acid electroplating process, wherein the thickness of the antioxidation layer is 5 mu m, the process conditions are that the pH value is 3, and AgSO4Concentration of 40g/L, H2SO4The concentration is 160g/L, the chloride ion concentration is 100ppm, and the temperature is 30 ℃;
sputtering a copper film layer on the lower surface of the polyamide by a magnetron sputtering process, wherein the thickness of the copper film layer is 15 mu m, and the process conditions are as follows: power density of sputtering power supply 3kw/cm2Argon pressure of 0.7Pa and circuit board carrier temperature of 150 ℃.
S3, coating photoresist on the antioxidation layer on the upper surface of the polyamide and the copper film layer on the lower surface of the polyamide with the thickness of 10 μm, designing a film circuit meeting the customer requirement, and installing the film circuit in an exposure machine for exposure with the exposure energy of 70mj/cm2(ii) a After the exposure, the developing process is carried out, the developing time is 50s, the temperature is 40 ℃, and the developing solution is NaCO with the concentration of 1.2wt percent3.H2O; after the development is finished, an etching process is carried out, wherein the concentration of copper ions in an etching solution is 150g/L, the concentration of chloride ions is 200g/L, the temperature is 70 ℃, the etching line width is 20 micrometers, and the thickness is 50 micrometers; and after etching, carrying out a photoresist removing process, degumming by adopting NaOH to obtain a first circuit pattern on the upper surface of the polyamide and a second circuit pattern on the lower surface of the polyester resin, wherein the first circuit pattern is the same as the second circuit pattern.
And S4, attaching the LED lamp beads to the obtained circuit board by adopting an SMT technology to manufacture the LED display screen. The transparency of the circuit board can reach more than 90%, the drawing resistance of the film layer is 1N, the number of LED lamp beads in each square meter is more than 1 ten thousand, the brightness is more than 7000 lumens, and the resolution of the whole display screen can be improved to the level of P10; the anti-oxidation service life can reach more than 3 years; the yield can reach 97 percent, and the deformation amount is within 0.3 percent.
Example 3
And S1, taking the colorless transparent polyimide as a circuit supporting body, and sequentially carrying out spray cleaning, rolling brush cleaning, high-purity water washing, air drying and drying on the colorless transparent polyimide by using a weak acid cleaning solution (the pH value is 6.7) for later use.
S2, obtaining a first seed layer (simple substance copper) and a second seed layer (simple substance copper) on the upper surface and the lower surface of the colorless transparent polyimide through magnetron sputtering technology, wherein the thicknesses of the first seed layer and the second seed layer are both 20nm, and the technological conditions are as follows: the power density of a sputtering power supply is 2kw/cm2Argon pressure is 0.6Pa, and the temperature of a circuit board carrier is 150 ℃;
electroplating on the surface of the first seed layer and the surface of the second seed layer by an acid electroplating process to obtain a first copper film layer and a second copper film layer, wherein the thicknesses of the first copper film layer and the second copper film layer are both 20 micrometers, and the process conditions are as follows: pH 5, CuSO4Concentration of 20g/L, H2SO4The concentration was 160g/L, the chloride ion concentration was 100ppm, and the temperature was 30 ℃.
Coating photoresist on the first copper film layer and the second copper film layer, designing a film circuit with a thickness of 10 μm and meeting the requirements of customers, and installing the film circuit in an exposure machine for exposure, wherein the exposure energy is 30mj/cm2(ii) a After the exposure, the developing process is carried out, the developing time is 30s, the temperature is 25 ℃, and the developing solution is NaCO with the concentration of 0.8wt percent3.H2O; after the development is finished, an etching process is carried out, wherein the concentration of copper ions in the etching solution is 100g/L, the concentration of chloride ions is 150g/L, the temperature is 40 ℃, the etching line width is 20 micrometers, and the thickness is 50 micrometers; and after etching, carrying out a photoresist removing process, degumming by adopting NaOH to obtain a first circuit pattern on the upper surface of the polyester resin, and obtain a second circuit pattern on the lower surface of the polyester resin, wherein the first circuit pattern is the same as the second circuit pattern.
Preparing a silk-screen printing plate with the thickness of 0.2 mu m, and hollowing out the silk-screen printing plate according to the circuit pattern to ensure that the hollow-out area of the silk-screen printing plate is the same as the non-circuit area of the circuit pattern; aligning a silk-screen plate with the upper surface of the circuit board, filling blue gel into a non-circuit area of the first circuit pattern through a hollow-out area of the silk-screen plate, so that the non-circuit area is filled with the blue gel, the blue gel is 0.2 mu m higher than a copper film layer, aligning the silk-screen plate with the lower surface of the circuit board, filling the blue gel into a non-circuit area of the second circuit pattern through the hollow-out area of the silk-screen plate, so that the non-circuit area is filled with the blue gel, the blue gel is 0.2 mu m higher than the copper film layer, and baking the circuit board at the temperature of 150 ℃ for 5 minutes.
Electroplating a nickel film layer on the surface of the circuit area by an acid electroplating process, wherein the thickness of the nickel film layer is 1 mu m, and the process conditions are as follows: pH 3, NiSO4Concentration of 20g/L, H2SO4The concentration was 160g/L, the chloride ion concentration was 100ppm, and the temperature was 30 ℃.
The blue film was pulled out with a pulling force of 2.5kg/cm2 to obtain a circuit board.
And S3, attaching the LED lamp beads to the upper surface of the obtained circuit board by adopting an SMT technology to manufacture the LED display screen. The transparency of the circuit board can reach more than 90%, the drawing resistance of the film layer is 1N, the number of LED lamp beads in each square meter is more than 1 ten thousand, the brightness is more than 7000 lumens, and the resolution of the whole display screen can be improved to the level of P10; the anti-oxidation service life can reach more than 3 years; the yield can reach 99%; the deformation amount is within 0.28%.
Example 4
Basically the same as example 1, except that:
the supporting body in S1 is polyimide;
in S2, the thickness of the first seed layer is 100nm, the thickness of the first copper film layer is 50 μm, and the thickness of the first oxidation resistant layer is 20 μm.
And S4, attaching the LED lamp beads to the upper surface of the obtained circuit board by adopting an SMT technology to manufacture the LED display screen. The transparency of the circuit board can reach more than 90%, the drawing resistance of the film layer is 1N, the number of LED lamp beads in each square meter is more than 1 ten thousand, the brightness is more than 7000 lumens, and the resolution of the whole display screen can be improved to the level of P10; the anti-oxidation service life can reach more than 3 years; the yield can reach 97%; the deformation amount is within 0.38%.
Example 4
Basically the same as example 2, except that:
and S2, sputtering a copper film layer on the lower surface of the polyamide by a magnetron sputtering process, wherein the thickness of the copper film layer is 1 μm.
And S4, attaching the LED lamp beads to the obtained circuit board by adopting an SMT technology to manufacture the LED display screen. The transparency of the circuit board can reach more than 90%, the drawing resistance of the film layer is 1N, the number of LED lamp beads in each square meter is more than 1 ten thousand, the brightness is more than 7000 lumens, and the resolution of the whole display screen can be improved to the level of P10; the anti-oxidation service life can reach more than 3 years; the yield can reach 97 percent, and the deformation amount is within 0.4 percent.
In addition to the above examples, comparative samples were prepared in the inventive examples, as shown in comparative examples 1 and 2.
Comparative example 1
S1, a carrier is prepared, similar to example 1.
S2, forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the carrier in sequence, and carrying out a circuit pattern manufacturing process on the first seed layer, the first copper film layer and the first oxidation resistant layer to obtain the circuit board. The formation process and thickness parameters were the same as in example 1.
And S3, attaching the LED lamp beads to the upper surface of the obtained circuit board by adopting an SMT technology to manufacture the LED display screen. Because the circuit board only has each film layer on the upper surface, the deformation of the circuit board after the LED display screen is manufactured is more than 1%, and the yield is 95%, which is greatly reduced compared with the yield and the deformation of the embodiment 1.
Comparative example 2
S1, a carrier is prepared, similar to example 1.
S2, forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the carrier in sequence, and carrying out a circuit pattern manufacturing process on the first seed layer, the first copper film layer and the first oxidation resistant layer to obtain the circuit board. The thickness of the first seed layer is 50nm, the thickness of the first copper film layer is 50 μm, and the thickness of the first oxidation resistant layer is 10 μm.
And S3, attaching the LED lamp beads to the upper surface of the obtained circuit board by adopting an SMT technology to manufacture the LED display screen. As the thickness of each film layer on the upper surface of the bearing body is increased relative to the thickness of each film layer in the comparative example 1, the deformation amount is 1.3 percent, the deformation amount of the comparative example 2 is increased by 0.3 percent relative to the comparative example 1, and the yield is reduced to 90 percent.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an …" does not exclude the presence of other similar elements in a process, method, article, or apparatus that comprises the element.
Those of ordinary skill in the art will understand that: all or part of the steps for realizing the method embodiments can be completed by hardware related to program instructions, the program can be stored in a computer readable storage medium, and the program executes the steps comprising the method embodiments when executed; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. A method for manufacturing a flexible circuit board is characterized by comprising the following steps:
selecting a flexible base material as a supporting body of the circuit board;
forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the bearing body in sequence, and forming a metal film layer on the lower surface of the bearing body;
the thickness of the first seed layer is 10-200 nm, the thickness of the first copper film layer is 5-100 mu m, and the thickness of the first oxidation resistant layer is 0.5-30 mu m; the thickness of the metal film layer is 5.51-130.2 mu m;
forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the carrier in sequence, and forming a metal film layer on the lower surface of the carrier, and then: manufacturing a first circuit pattern on the upper surface of the bearing body, and manufacturing a second circuit pattern on the lower surface of the bearing body;
the first circuit pattern is the same as the second circuit pattern;
the contact area between the metal film layer consisting of the first seed layer, the first copper film layer and the first oxidation resisting layer and the bearing body on the upper surface of the bearing body is the contact area between the circuit area of the first circuit pattern and the bearing body;
the contact area between the metal film layer on the lower surface of the carrier and the carrier is the contact area between the circuit region of the second circuit pattern and the carrier;
the contact area of the circuit area of the first circuit pattern and the carrier is the same as the contact area of the circuit area of the second circuit pattern and the carrier, and the contact positions of the circuit area of the first circuit pattern and the circuit area of the second circuit pattern correspond to each other.
2. The method of claim 1, wherein the metal film layer comprises, from top to bottom, on the lower surface of the carrier body: the second seed layer, the second copper film layer and the second antioxidation layer;
the thickness of the second seed layer is 10-200 nm, the thickness of the second copper film layer is 5-100 mu m, and the thickness of the second antioxidation layer is 0.5-30 mu m.
3. The method of claim 2, wherein the sequentially forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the carrier and a metal film layer on the lower surface of the carrier comprises:
sputtering the first seed layer on the upper surface of the carrier by a magnetron sputtering method;
sputtering the second seed layer on the lower surface of the carrier by a magnetron sputtering method;
obtaining the first copper film layer and the second copper film layer by electroplating with an acid electroplating method or sputtering with a magnetron sputtering method;
and sputtering by using an acid electroplating method or a magnetron sputtering method to obtain the first oxidation resisting layer and the second oxidation resisting layer.
4. The method of claim 1, wherein sequentially forming a first seed layer, a first copper film layer and a first oxidation resistant layer on the upper surface of the carrier comprises:
sputtering the first seed layer on the upper surface of the carrier by a magnetron sputtering method;
electroplating the first copper film layer on the first seed layer by a magnetron sputtering method or an acid electroplating method;
manufacturing a first circuit pattern on the upper surface of the carrier;
filling blue gel in the non-circuit area of the first circuit pattern;
and forming a first oxidation resisting layer on the surface of the circuit area of the first circuit pattern, and removing the filled blue gel.
5. The method of claim 4, wherein filling a blue gel in the non-circuit region of the first circuit pattern comprises:
hollowing out the silk-screen printing plate according to the first circuit pattern, so that the hollow-out area of the silk-screen printing plate is the same as the non-circuit area of the first circuit pattern;
aligning the silk-screen plate with the circuit board, so that the hollow area of the silk-screen plate is aligned with the non-circuit area of the first circuit pattern, and the non-hollow area of the silk-screen plate covers the circuit area of the first circuit pattern;
and filling blue gel into the non-circuit area of the first circuit pattern through the hollow area of the silk-screen printing plate.
6. The method as claimed in claim 5, wherein the thickness of the silk screen is 0.01-100 μm.
7. The method of claim 1 or 4, further comprising: and mounting the LED lamp beads on the upper surface of the circuit board in a reflow soldering or wave soldering mode according to the first circuit pattern.
8. A flexible circuit board produced by the method of any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111032290.4A CN113766727B (en) | 2021-09-03 | 2021-09-03 | Flexible circuit board and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111032290.4A CN113766727B (en) | 2021-09-03 | 2021-09-03 | Flexible circuit board and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113766727A CN113766727A (en) | 2021-12-07 |
| CN113766727B true CN113766727B (en) | 2022-04-29 |
Family
ID=78792911
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111032290.4A Active CN113766727B (en) | 2021-09-03 | 2021-09-03 | Flexible circuit board and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113766727B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115426869B (en) * | 2022-08-05 | 2023-12-08 | 东莞市翰普电子科技有限公司 | FPC component pasting technology for solving expansion and contraction effect positioning problem |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105578720B (en) * | 2015-12-29 | 2018-07-06 | 广东欧珀移动通信有限公司 | Flexible PCB and mobile terminal |
| CN108650776B (en) * | 2018-05-15 | 2020-04-03 | 武汉华星光电半导体显示技术有限公司 | Flexible circuit board and display screen |
| CN110856364A (en) * | 2019-11-21 | 2020-02-28 | 珠海市凯诺微电子有限公司 | Immersion gold plating method for manufacturing rigid-flex board |
| CN113068313A (en) * | 2021-03-05 | 2021-07-02 | 江西展耀微电子有限公司 | Manufacturing method of circuit board, circuit board manufactured by manufacturing method and electronic equipment |
-
2021
- 2021-09-03 CN CN202111032290.4A patent/CN113766727B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113766727A (en) | 2021-12-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4741616B2 (en) | Method for forming photoresist laminated substrate | |
| TWI415535B (en) | Printed circuit board and manufacturing method thereof | |
| JP2006347165A (en) | Metal mask for making pattern | |
| KR20010105366A (en) | Method of manufacturing multilayer wiring board | |
| CN113766727B (en) | Flexible circuit board and manufacturing method thereof | |
| CN116744585B (en) | Ultrathin medium-thickness substrate, manufacturing method thereof and voice coil motor | |
| CN113777880A (en) | Micro LED device and preparation method thereof | |
| KR20070106669A (en) | Circuit board and the method of its fabrication | |
| CN113825321B (en) | Circuit board and manufacturing method and application thereof | |
| US6981318B2 (en) | Printed circuit board manufacturing method | |
| JP7426560B2 (en) | Method for manufacturing plating pattern plate and wiring board | |
| TW202137597A (en) | Led display module and led display | |
| KR100747393B1 (en) | Film carrier tape for mounting electronic part, process for producing the same, and screen for solder resist coating | |
| WO2006098863A1 (en) | A 2-metal flex circuit and a method of manufacturing the same | |
| JP3935558B2 (en) | Pattern formation method | |
| JPS6050349B2 (en) | Lead frame manufacturing method | |
| JPH08288603A (en) | Printed wiring board, its manufacture, and original plate for transfer | |
| KR102490505B1 (en) | Transpaparent glass display substrate, transpaparent led display device and method for fabricating the same | |
| KR102497891B1 (en) | Transparent glass display substrate manufacturing method and transparent glass display substrate manufactured therefrom | |
| KR102539797B1 (en) | Transparent glass display substrate manufacturing method and transparent glass display substrate manufactured therefrom | |
| CN114613741B (en) | Conductive structure and manufacturing method thereof | |
| JP3836085B2 (en) | Film carrier tape for mounting electronic parts and manufacturing method thereof | |
| CN116723643A (en) | Novel metal circuit preparation method | |
| KR101878163B1 (en) | Circuit pattern making method for display electrode, and display electrode having circuit pattern made by the method | |
| CN117580248A (en) | Multilayer ceramic substrate structure and preparation method thereof |
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 |