CN112739041B

CN112739041B - Chemical etching device and method based on vector turbulence method

Info

Publication number: CN112739041B
Application number: CN202110354180.3A
Authority: CN
Inventors: 凤培国
Original assignee: Wuhan Hongqiao Technology Co ltd
Current assignee: Wuhan Hongqiao Technology Co ltd
Priority date: 2021-04-01
Filing date: 2021-04-01
Publication date: 2021-07-02
Anticipated expiration: 2041-04-01
Also published as: CN112739041A

Abstract

The invention relates to a chemical etching device and a method based on a vector turbulence method, which controls etching liquid to generate directional vector turbulence in an etching area by adding a guide plate, wherein the directional vector turbulence comprises vortex, cavitation bubbles, kinetic laminar flow and kinetic microfluid; the biggest characteristic of the turbulent flow is that the turbulent flow has fluid diffusivity and energy conduction, can go deep into micropores and fine lines under vector pressure, solves the problem that metal in the micropores and the fine lines can not be etched due to the deep groove etching effect in the prior art, and greatly improves the etching precision; the invention solves the problems of pool effect and uneven etching of large-area circuit board, thereby increasing the yield and reducing the production cost.

Description

Chemical etching device and method based on vector turbulence method

Technical Field

Based on fluid mechanics, Reynolds number and Bernoulli principle, the invention provides a vector turbulence chemical etching method capable of etching micropores and fine circuit boards, which is called a flow method for short, in the field of chemical etching.

Background

The key point of the flow method is vector and random flow, and the vector and the random flow are absent; the vector refers to that the etching solution is under directional pressure in the whole etching process, and the flow direction of the etching solution forms an angle with the target circuit board in the process of moving instead of being parallel to the target circuit board; the vector can be analyzed into horizontal and downward component vectors or partial pressure, the pressure in the horizontal direction enables the flowing liquid to advance, and the downward pressure enables the turbulent flow to be mainly eddy current and enter the micropores and the thin line; the vortex is a multi-directional, unshaped kinetic fluid, has diffusivity, can deform under pressure and can enter the micropores and replace effusion in the micropores.

The turbulent flow is generated due to two reasons, namely, the flow velocity is increased and the flow direction is changed; when the flow velocity is increased, laminar flows with different directions and flow velocities can be generated in the fluid, relative velocity and dynamic pressure exist among the laminar flows, but the diffusibility is low, and the effect of the laminar flows on deep micropores is weak; the second reason is that: when the fluid is blocked and the direction must be changed, the kinetic energy fluid with different directions and pressures can be generated inside the fluid, pressure difference is generated between the fluid and the surrounding fluid due to different pressure directions, vortex flow is formed at the same time, cavitation can be generated when the pressure difference is larger, the inside of the cavitation is vacuum, high-speed shock waves can be generated when the cavitation breaks under the external pressure, the diffusivity is larger than the vortex flow, the cavitation can penetrate into micropores and fine lines, but the whole etching area can not be generated in design, and the flow and the vector can not be influenced; the design of the guide plate by the flow direction method has four parts, and the importance of vector, turbulent flow, vortex and cavitation is considered.

There are two reasons why conventional chemical etchers cannot etch micro-holes and fine lines, the first reason being: when the sprayed liquid impacts the target circuit board, the sprayed liquid is changed into a horizontal flow, the particle size of the sprayed liquid is 200-400 microns and is 50-100 microns larger than that of the micropores, so that the sprayed liquid cannot enter the micropores, the fluid in the liquid particles is the same as that of the advection laminar flow, only has one direction and flow speed, and has no relative speed, so that the accumulated liquid in the micropores can only generate static pressure, the accumulated liquid can generate the same large counter-static pressure for the etching liquid particles, and the final result is that the pressures are mutually offset, and the etching liquid particles cannot enter; the line width is 25-75 micrometers, although it is smaller than the particle size of the sprayed liquid, the line length is larger than the particle size of the sprayed liquid, so that the etching liquid can enter into the line in a limited way, but can not enter into the line.

The second reason is that: the etching liquid spray is changed to flow in the horizontal direction, and turbulence and vortex are generated due to the change of the direction, but no downward pressing vector exists because no upper pressing exists; the turbulent flow is a diffusive kinetic energy which is easy to disappear, the liquid quickly becomes flat flow, the fluid in the inner pool has only static pressure, and no downward pressure; the conventional chemical etching machine generally adopts a wheel-type shaft for a transmission shaft, and even if a solid shaft is used, the generated turbulent flow is useless because of no pressing; different from the conventional chemical etching method, the guide plate of the counter-flow method suppresses the upward diffusion of the turbulent flow and increases the downward pressure vector.

The etching capability of the conventional chemical etching machine is generally 75 microns of line width, 75 microns of line distance, 12 microns of copper thickness and 25 microns of photosensitive film thickness, and the upper limit of the pursuit is 50 multiplied by 50 microns; the line width and line distance of the etching line by the counter current method is 25 multiplied by 25 microns, and if a finer line below 25 microns is to be etched, other processes must be matched, for example, photosensitive technology and equipment must be upgraded; the upper limit of the 365nm wavelength, i-line parallel optical bench energy to manufacture is 50 x 50 microns line width to line spacing.

In the manufacture of fine circuit boards, chemical etchers are the most important devices, and an ideal etcher has two key problems to solve: the former causes uneven etching, and the latter cannot etch micro-holes and fine lines.

Pool effect: etch large tracts of land fine line board 400mm 500mm, the etch rate of central part is than both sides part slow, by industry accepted saying that, the liquid medicine that etches is arranged to the distance on the limit from board central authorities and is far away, the time of staying is longer on the board, form central part ponding, and the liquid medicine that etches near the board edge can be got rid of very fast, therefore the etch rate is faster, cause whole face etching uneven, if use toper nozzle and wheel piece formula transmission shaft, then the pond effect is more serious.

Etching deep groove effect: the etching liquid is ejected from the nozzle to impact the target circuit board at high speed, the etching liquid consists of dense particles, the particle size is usually 300-400 microns, and when the particle size is larger than the diameter of the micropores, the liquid medicine cannot penetrate deeply; because the liquid medicine exerts static pressure on the micropores and the fine lines, the static pressure can be counteracted by the reaction static pressure, the pressure is increased, and the reaction force is larger; the line distance has two directions of length and width, which determine and influence the etching width, and the particle size of the etching spray liquid is 300-400 microns, which is larger than the line width but smaller than the line length, so that the liquid medicine can enter the thin line but cannot go deep.

Disclosure of Invention

The invention provides a chemical etching device and a chemical etching method based on a vector turbulence method, which are called a flow direction method for short; the guide plate controls the etching liquid to generate turbulent flow comprising vortex, cavitation bubble and kinetic energy microfluid, and the fluid is accelerated in a certain area under the action of the guide plate to change the direction, so that the flow liquid in the horizontal direction is changed into vector flow liquid; the downward pressure is helpful for etching micropores and fine lines, local pressure difference must be generated in fluid due to generation of cavitation, cavitation is generated due to the design of a C/D region of a hollow gate region under a titanium wall of the guide plate, and etching liquid penetrates into the micropores and the fine lines for etching by utilizing shock waves generated by cavitation destruction; the counter-current method has simple structure, does not need expensive materials and complex processes, has low manufacturing cost, can solve the technical problem that the etching process of the micropores and the fine lines is too complex in the prior art, and achieves the technical effect of etching the metal in the micropores and the fine lines without complex processes.

The etching apparatus according to the counter flow method is characterized by comprising: the etching solution nozzle, the spray pipe, the guide plate and the target circuit board; the etching solution nozzle is arranged below the spray pipe, the guide plate is arranged above the etching machine, the forward speed of the target circuit board is controlled by the upper and lower transmission shafts when the target circuit board passes through the vector etching area, and the etching solution nozzle is used for fixedly releasing etching solution with preset flow and preset particle size.

The etching device based on the counter-flow method is characterized in that the guide plate comprises a first guide plate part, a second guide plate part, a third guide plate part and a fourth guide plate part; wherein:

the first part of the guide plate is used for wrapping the upper half part of the spray pipe;

the second part A area of the guide plate is connected with the first part of the guide plate and the third part of the guide plate at 45 degrees, etching liquid is controlled to generate directional turbulent flow, and a moving target circuit board forms a 45-degree vector, the 45-degree vector can be analyzed into a horizontal component vector and a downward component vector, the horizontal component vector enables the etching liquid to flow forwards, and the downward component vector applies downward pressure to the turbulent flow, so that the turbulent flow is favorably led into micropores and fine lines;

the area B of the third part of the guide plate is parallel to the target circuit board for a distance of 1.5-2 cm, and the flow rate of the etching solution is increased and turbulent flow is generated due to the reduction of the volume;

the fourth part of the guide plate, namely the titanium wall, is vertically connected with the third part of the guide plate in the C/D/E area, the upper half part of the etching solution is blocked to generate cavitation bubbles and turbulent flow and is discharged to one side at a preset angle, and the angle is determined by the angle formed by the nozzle and the spray pipe, and is 25 degrees in the example; the lower half part of the etching solution enters the E area through the empty grid D area below the titanium wall, and is subjected to strong pressure when rotating the bottom of the middle transmission shaft, so that turbulent flow is promoted to enter the micropores and the fine lines for etching.

The etching device based on the counter-current method is characterized in that a transmission shaft is arranged on the left side and the right side of the surface of a target circuit board, 2-4 transmission shafts are arranged below the target circuit board to bear the weight of the target circuit board in the process of advancing and the pressure of etching liquid, and three shafts are used in the example; the two shafts have the important functions of generating turbulence and increasing a pressing vector besides assisting the transmission and stabilizing a target circuit board in advancing.

The etching device based on the counter flow method is characterized in that the etching liquid nozzle is used for spraying fan-shaped etching liquid and controlling the etching liquid to impact a target circuit board at a preset angle; the sector coverage of each nozzle is determined by the distance between the nozzle and the target circuit board, the width of the sprayed liquid is 1-5 cm, and the sector angle is 90-110 degrees, and each 1.25 m × 1.25 m etching machine can be provided with 2-3 vector etching units.

The etching device based on the counter-flow method is characterized in that the spray pipe is used as a center line, the guide plate is divided into a left etching area and a right etching area which are symmetrical, and the guide plate of each area is divided into a first part, a second part and a third part.

The etching device based on the counter-current method is characterized in that the nozzle is a fan-shaped nozzle, the center of the fan-shaped nozzle is taken as a base point, the fan-shaped spray liquid is divided into a left half fan shape and a right half fan shape, the full range of the example fan-shaped spray liquid is 110 degrees, and the example fan-shaped spray liquid consists of a left half fan shape and a right half fan shape of 55 degrees; the left half fan-shaped spray liquid flows to the left etching area guide plate and advances at a preset angle of the nozzle, and the right half fan-shaped spray liquid flows to the right etching area guide plate in the opposite direction and advances at a preset angle of the nozzle.

The etching device based on the counter-current method is characterized in that etching liquid which is not carried to the bottom of the shaft generates turbulent flow due to the fact that the flow is blocked by the transmission shaft and flows to one side at a preset angle, and the preset angle is 10-45 degrees, namely 25 degrees in an example, of the angle set by the fan-shaped nozzle on the spray pipe.

The etching device based on the counter-current method is characterized in that the nozzle is a fan-shaped nozzle, and the fan-shaped nozzle has two preset angles: the first is a 90-110 vertical angle, with the nozzle moving from top to bottom, and an example is 110 degrees; the second is a 10-45 horizontal angle, i.e., the angle of intersection between the nozzle and the nozzle, an example being 25 degrees, which becomes horizontal and progresses at an angle of 25 degrees to the drive shaft after the spray impacts the traveling target circuit board.

Drawings

FIG. 1 is a schematic cross-sectional view of a design structure of a counter-current chemical etching machine;

FIG. 2 is an enlarged partial cross-sectional view of the etched area of FIG. C, D, E;

FIG. 3 is a schematic top view of the fan nozzle mounted on the nozzle;

FIG. 4 is a schematic side view of a 110 degree nozzle angle of the fan nozzle.

Detailed Description

The principles and features of this invention are described below in conjunction with specific embodiments, the examples given are intended to illustrate the invention and are not intended to limit the scope of the invention.

The invention provides a chemical etching device based on a counter-current method.

Referring to fig. 1: in order to illustrate the structure of the etching apparatus based on the counter flow method of the present invention, the etching apparatus based on the counter flow method in the embodiment of the present invention includes: etching solution nozzles and guide plates; the central part of the guide plate is arranged above the spray pipe, the etching solution nozzle is arranged below the spray pipe and forms an angle of 10-45 degrees with the spray pipe, wherein:

specifically, the etching solution nozzle is used for spraying 110-degree fan-shaped etching solution, and becomes flowing solution in the horizontal direction after impacting a target circuit board; the advancing direction of the flowing liquid forms a preset angle of 10-45 degrees with the spray pipe and the transmission shaft, and in the example, the angle is 25 degrees.

It should be noted that, because most of the existing etching solution nozzles are designed by using a conical spraying solution, after impacting a target circuit board, the existing etching solution nozzles are not discharged directionally, accumulated water is only diffused to the periphery, particularly, the distance between the central part of the target circuit board and the side edge is far, a water pool effect is easily caused, and meanwhile, the flow rate of the etching solution received by the left side edge and the right side edge of the target circuit board is more than that of the etching solution received by the center, so that the problem of uneven etching can be caused when a large-area target circuit board is etched because the etching rate.

The fan-shaped spray head is used, and fan-shaped spray liquid becomes horizontal flow liquid after impacting a target circuit board and moves forwards towards the direction of the transmission shaft at a preset angle, namely 25 degrees in the example, instead of diffusing around; if 5-9 fan-shaped spray heads are arranged on one spray pipe, and a 25-degree intersection angle is set between the spray pipes, in the example, the spray amplitude of 110 degrees becomes horizontal flow liquid on the target circuit board, and then the horizontal flow liquid is divided into two flow liquids in opposite directions; the fan-shaped spray liquid has directionality and can be divided into a left half fan-shaped spray liquid and a right half fan-shaped spray liquid with 55 degrees by taking the center of the fan-shaped spray liquid as a reference; the left half is sprayed to the left deflector etch zone and proceeds upward at 25 degrees on the target board, and the right half is sprayed downward at 25 degrees; the flow directions of the two half-sector spray liquids are opposite and symmetrical to form a left-right and upper-lower mode, so that each point on the target circuit board receives equal amount of etching solution, and the problem of uneven etching is solved without pool effect; the application of the fan-shaped nozzle can generate better vector control and generate a large amount of turbulent flow in a flow-direction method, and the problem that the conventional chemical etching machine needs to use the nozzle and the spray pipe to swing or vacuum to suck the accumulated liquid to solve the pool effect and the uneven etching is solved.

The invention is used for etching precise patterns and fine circuit rigid printed circuit boards; when the flexible circuit board is etched, the board is firstly arranged on a hard light and thin guide plate, and then the guide plate is sent into a counter-current etching machine, wherein the material of the guide plate can be selected from various plastic materials; the metal capable of being etched by the invention comprises copper, nickel, aluminum, stainless steel and the like, and products comprise optical components, evaporation degree covers, precision circuit boards, lead frames, connectors, flexible chip boards COFs and the like.

The etching rate of the counter current method is 2-3 times faster than that of the conventional chemical etching machine, the counter current method is simpler and more effective than the SAP and MSAP manufacturing processes of the semi-addition method, and the cost is one third of that of the SAP of the semi-addition method, because the semi-addition method needs to plant seed copper firstly, and then carry out the complicated steps of electroplating, removing the seed copper and the like; the most significant disadvantage of the semi-finished method is that micro-holes cannot be etched, so that double-layer and multi-layer flexible boards, etc. cannot be manufactured.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A chemical etching device based on a vector turbulence method is characterized by comprising the following components: the etching solution nozzle, the spray pipe, the guide plate and the target circuit board; the etching solution nozzle is arranged below the spray pipe, the guide plate is arranged above the etching machine, the forward speed of the target circuit board is controlled by an upper transmission shaft and a lower transmission shaft when the target circuit board passes through the vector etching area, and the etching solution nozzle is used for fixedly releasing etching solution with preset flow and preset particle size;

the guide plate comprises a first guide plate part, a second guide plate part, a third guide plate part and a fourth guide plate part; wherein:

the fourth part of the guide plate, namely the titanium wall, is vertically connected with the third part of the guide plate in the C/D/E area, the upper half part of the etching solution is blocked to generate cavitation bubbles and turbulent flow, and the cavitation bubbles and the turbulent flow are discharged to one side at a preset angle, and the angle is determined by the angle formed by the nozzle and the spray pipe; the lower half part of the etching solution enters an E area formed by the intersection of the transmission shaft and the target circuit board through an empty grid D area below the titanium wall, and is forced to flow disorderly to enter the micropores and the thin lines for etching by receiving strong pressure when the bottom of the transmission shaft rotates.

2. The chemical etching device based on the vector turbulence method as claimed in claim 1, wherein the target circuit board is provided with a transmission shaft on the left and the right, and the lower part of the target circuit board is provided with 2-4 transmission shafts for bearing the weight of the target circuit board and the etching liquid pressure during traveling; the two shafts have the important functions of generating turbulence and increasing a pressing vector besides assisting the transmission and stabilizing a target circuit board in advancing.

3. The vector turbulence method-based chemical etching apparatus of claim 2, wherein 3 transmission shafts are provided under the target circuit board.

4. The chemical etching device based on the vector turbulence method as recited in claim 1, wherein the etching solution nozzle is used for spraying fan-shaped etching solution and controlling the etching solution to impact the target circuit board at a preset angle; the sector range covered by each nozzle is determined by the distance between the nozzle and a target circuit board, the width of a sprayed liquid is 1-5 cm, and the sector angle is 90-110 degrees, and 2-3 vector etching units are arranged in each 1.25 m multiplied by 1.25 m etching area.

5. The vector turbulence method-based chemical etching device of claim 1, wherein the spray pipe is used as a center line, the guide plate is divided into two symmetrical etching areas from left to right, and the guide plate of each area is divided into a first part to a fourth part.

6. The chemical etching apparatus according to claim 1, wherein the nozzle is a fan-shaped nozzle, the fan-shaped spray is divided into two half fan-shaped parts, namely a left half fan-shaped part and a right half fan-shaped part, by taking the center of the fan-shaped nozzle as a base point, the full amplitude of the fan-shaped spray is 110 degrees, and the fan-shaped spray is composed of two half fan-shaped parts, namely a left half fan-shaped part and a right half fan-shaped part, namely; the left half fan-shaped spray liquid flows to the left etching area guide plate and advances at a preset angle of the nozzle, and the right half fan-shaped spray liquid flows to the right etching area guide plate in the opposite direction and advances at a preset angle of the nozzle.

7. The chemical etching apparatus according to claim 1, wherein the etching solution not carried to the bottom of the shaft is disturbed by the driving shaft and flows to one side at a predetermined angle, which is 10-45 degrees of the angle set by the fan nozzle on the nozzle.

8. The chemical etching apparatus according to claim 7, wherein the etching solution not carried to the bottom of the shaft is disturbed by the transmission shaft and flows to one side at a predetermined angle, which is 25 degrees of the angle set by the fan nozzle on the nozzle.

9. An etcher comprising the vector turbulence method-based chemical etching apparatus according to any one of claims 1 to 8.