Automobile communication module circuit board preparation method based on black shadow line device and intelligent network connection automobile communication circuit board

Abstract

The invention provides an automobile communication module circuit board preparation method based on a black shadow line device and an intelligent network connection automobile communication circuit board. The method comprises the following steps: obtaining a circuit board after first drying and curing; the circuit board is placed on a roller platform to be subjected to first-time micro-etching operation, so that loose carbon powder on a surface copper layer and an inner copper layer of the circuit board is preliminarily removed, and the first-time micro-etching operation is jointly operated through a spray header and a water jet head; sequentially and circularly carrying out hole finishing, black shadow, fixing, drying curing and micro-etching operation on the circuit board; and the last micro-etching operation is carried out on the circuit board after the last drying and curing step is completed, and the last micro-etching operation adopts water cutter head operation so as to remove loose carbon powder on the surface copper layer and the inner copper layer of the circuit board. The water jet cutter can overcome the defect that the edge of the nozzle is crossed and counteracts the impact force, so that loose carbon powder in the through hole of the circuit board can be fully removed, and normal electric conduction of inner-layer copper and surface electroplating copper can be ensured.

Description

Technical Field

[0001] The present disclosure relates to the technical field of circuit board production, and in particular to a method for preparing an automobile communication module circuit board based on a black shadow line device and an intelligent networked automobile communication circuit board. Background Art

[0002] There are many types of circuit boards on the market. With the rapid development of intelligent connected vehicles, automobile companies have put forward higher requirements on the performance and reliability of automobile communication modules. As a key component of the communication module, the quality and performance of the circuit board have an important impact on the stability and reliability of the entire system.

[0003] In the current PCB process, during micro-etching, the nozzle is fan-shaped, the pressure in the middle and at the edge cannot be exactly the same, and there is a cross-offset impact force at the edge of each nozzle, resulting in the inability of the liquid to completely remove the loose carbon powder in the through-hole of the PCB. This causes defects in the through-hole of the PCB, resulting in insufficient bonding between the inner copper and the electroplated copper, and thus in subsequent tests, ICD (internal layer poor interconnection) occurs during multiple tinning, such as Figure 1 As shown, the above situation will cause the circuit of the intelligent connected vehicle communication circuit board to be open during subsequent use, and the subsequent intelligent connected vehicle communication function cannot be guaranteed.

[0004] As an advanced PCB manufacturing technology, the black shadow process has the advantages of improving signal transmission performance and reducing manufacturing defects. However, the circuit board of the communication module of the intelligent networked car usually requires strong transmission performance and good communication function. Therefore, it is necessary to use the micro-etching step to improve the circuit board process to ensure the reliability of the black shadow process and the electroplating layer. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing an automobile communication module circuit board based on a black shadow line device and an intelligent networked automobile communication circuit board, which can fully remove loose carbon powder in a through hole to ensure electrical conductivity between the inner copper layer and the electroplated copper and can pass multiple tin immersion tests.

[0006] The purpose of this disclosure is achieved through the following technical solutions:

[0007] A method for preparing a circuit board of an automobile communication module based on a black shadow line device, wherein the circuit board is subjected to black shadow processing by using a black shadow line device, wherein the black shadow line device comprises a roller platform, a plurality of spray heads and a plurality of water knife heads, wherein the roller platform is used to place the circuit board, and the plurality of spray heads and the plurality of water knife heads are distributed above and below the roller platform. The method for preparing a circuit board of an automobile communication module based on a black shadow line device comprises the following steps:

[0008] Obtain the circuit board after the first drying and curing;

[0009] Placing the circuit board on a roller platform for a first micro-etching operation to preliminarily remove the surface copper layer of the circuit board and loose carbon powder on the inner copper layer, wherein the first micro-etching operation is performed by the spray head and the water jet head together;

[0010] The circuit board is subjected to hole filling, black shadow, fixing, drying and curing, and micro-etching operations in sequence;

[0011] The circuit board is subjected to a final micro-etching operation after the last drying and curing step, wherein the final micro-etching operation is performed using the water jet head to remove the surface copper layer of the circuit board and loose carbon powder on the inner copper layer.

[0012] In one embodiment, placing the circuit board on a roller platform for a first micro-etching operation includes:

[0013] The circuit board is subjected to a first double-sided micro-etching operation.

[0014] In one embodiment, the first double-sided micro-etching operation on the circuit board includes:

[0015] The first double-sided micro-etching operation is performed by using X upper and lower sprays, Y upper water knives and Z lower water knives; wherein X≥7, Y≥4, and Z≥3.

[0016] In one embodiment, the first double-sided micro-etching operation is performed on the circuit board, and then further includes:

[0017] The circuit board is subjected to a first double-sided water washing operation.

[0018] In one embodiment, the first double-sided water washing operation on the circuit board includes:

[0019] The first double-sided water washing operation is performed by using P groups of sprays and Q groups of water knives; wherein P≥1, Q≥3.

[0020] In one embodiment, the last micro-etching operation on the circuit board after the last fixing step is performed includes:

[0021] The circuit board is subjected to a final double-sided micro-etching operation.

[0022] In one embodiment, the last double-sided micro-etching operation on the circuit board includes:

[0023] The last double-sided micro-etching operation is performed by using M upper water jets and N lower water jets; wherein M≥8 and N≥7.

[0024] In one embodiment, the circuit board is subjected to a final double-sided micro-etching operation, and then further comprises:

[0025] The circuit board is subjected to a final double-sided water washing operation.

[0026] In one embodiment, the last double-sided water washing operation on the circuit board includes:

[0027] The last double-sided water washing operation is performed by using U group spraying and V group water jets together; wherein U≥1, V≥2.

[0028] A smart networked automobile communication circuit board is obtained by using the automobile communication module circuit board preparation method based on a black shadow line device described in any of the above embodiments.

[0029] Compared with the prior art, the present invention has at least the following advantages:

[0030] 1. The above-mentioned method for preparing a circuit board for an automobile communication module based on a black shadow line device adopts a black shadow process to perform black shadow treatment on the circuit board, wherein the black shadow line device partially adopts a high-efficiency water jet, so that in the micro-etching step of the circuit board, the water jet can overcome the cross-offsetting impact force at the edge of the nozzle, resulting in insufficient exchange capacity of the liquid medicine in the hole, so that the loose carbon powder in the through hole of the circuit board can be fully removed, ensuring that the inner copper and the surface electroplated copper can be electrically conductive normally, thereby improving the reliability of the black shadow process and the electroplating layer.

[0031] 2. When the loose carbon powder in the through-holes of the circuit board can be fully removed, after the circuit board is completed, during the subsequent tinning test, it is less likely to have poor inner layer interconnection compared to the ordinary circuit board process, thus ensuring the communication function of the intelligent connected vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 This is a diagram showing the effect of using a nozzle to remove loose carbon powder in a through hole of a circuit board multiple times in a conventional circuit board process in the prior art;

[0034] Figure 2 Flow chart of a method for preparing a circuit board of an automobile communication module based on a black shadow line device in one embodiment;

[0035] Figure 3 This is a diagram showing the effect of using a water jet to remove loose carbon powder in the through hole of the automobile communication module circuit board in this embodiment. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.

[0037] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] In order to better understand the technical solutions and beneficial effects of the present invention, the present invention is further described in detail below in conjunction with specific embodiments:

[0040] like Figure 2 As shown, it is a method for preparing a circuit board of an automobile communication module based on a black shadow line device according to an embodiment of the present invention, wherein a black shadow line device is used to perform black shadow processing on the circuit board, and the black shadow line device includes a roller platform, a plurality of spray heads and a plurality of water knife heads, and the roller platform is used to place the circuit board, and the plurality of spray heads and the plurality of water knife heads are distributed above and below the roller platform. In this embodiment, the roller platform includes a plurality of roller rows, wherein the plurality of roller rows rotate when placing the circuit board so that the circuit board moves in a single direction, and the adjacent roller rows are arranged at intervals so that the water outlets of the spray heads and the water knife heads are arranged toward the interval area formed between the adjacent roller rows. Furthermore, the plurality of spray heads and the plurality of water knife heads are arranged toward the upper and lower surfaces of the plurality of roller rows, and the spray heads include a medicine spray head and a water washing spray head, and the water knife heads include a medicine water knife head and a water washing water knife head.

[0041] The method for preparing a circuit board of an automobile communication module based on a black shadow line device includes some or all of the following steps:

[0042] S101, obtain the circuit board after the first drying and curing. It can be understood that this solution adopts a black shadow line device to perform black shadow operation, specifically adopts a black shadow process, which includes hole filling → black shadow → fixing → drying and curing → micro-etching, wherein, after the circuit board passes through the hole filling, black shadow and fixing operations in sequence, a certain amount of moisture remains on its surface, and the existing moisture will affect the subsequent process and performance of the circuit board during use, so it is necessary to dry the circuit board and preliminarily solidify the carbon layer adsorbed in the through hole. It should be noted that the black shadow process belongs to the known technology, and the present invention only adopts the micro-etching step in the black shadow process as an improvement point for the preparation method of the circuit board.

[0043] S103, placing the circuit board on the roller platform for the first micro-etching operation to preliminarily remove the surface copper layer and the loose carbon powder on the inner copper layer of the circuit board, wherein the first micro-etching operation is performed by a spray head and a water jet head. It can be understood that when the spray and the water jet are used together, the spray is used to corrode the loose carbon powder on the surface of the circuit board, and the water jet is used to preliminarily erode the loose carbon powder on the through hole of the circuit board, so as to achieve the effect of preliminarily cleaning the circuit board.

[0044] S105, the circuit board is subjected to the operations of hole filling, black shading, fixing, drying and curing, and micro-etching in a cycle. It can be understood that after the first micro-etching operation is completed, it only plays a role in preliminary removal of carbon powder, and the solidified carbon layer is not completely adsorbed on the circuit board. In order to better remove the loose carbon powder in the through hole, it is necessary to perform the hole filling, black shading, fixing, drying and curing, and micro-etching operations (hereinafter referred to as the intermediate steps) in a cycle. At this time, the solidified carbon layer is gradually and firmly adsorbed on the circuit board, which is conducive to the micro-etching solution in the subsequent micro-etching step to effectively remove the carbon powder, and the solidified carbon layer is less likely to be bitten by the micro-etching solution than the carbon layer in the first micro-etching operation state and the micro-etching operation state corresponding to the previous intermediate step. In this embodiment, the micro-etching operation in the intermediate step is the same as the first micro-etching operation, and will not be repeated here.

[0045] S107. Perform a final micro-etching operation on the circuit board after the last drying and curing step, wherein the final micro-etching operation is performed using a water jet to remove the loose carbon powder on the surface copper layer and the inner copper layer of the circuit board. It can be understood that when a water jet is used, the water jet is used to erode the loose carbon powder in the through-holes of the circuit board after multiple shadows and fixation, and increase the number of chemical solution exchanges to achieve the effect of deep removal of carbon powder. Specifically, after multiple cycles of whole-hole, shadow, fixation, drying and curing, and micro-etching operations, the solidified carbon layer is gradually and completely adsorbed on the surface and through-holes of the circuit board. At this time, in order to allow the carbon powder in the through-holes of the circuit board to be fully eroded by the chemical solution for removal, a full water jet operation is required to ensure that the loose carbon powder in each through-hole can be removed. The effect of using a water jet to remove the loose carbon powder is shown in the figure below. Figure 3 shown.

[0046] In this embodiment, the method for preparing a circuit board of a car communication module based on a black shadow line device uses a black shadow process to perform black shadow treatment on the circuit board, wherein the black shadow line device partially uses a high-efficiency water jet, so that in the micro-etching step of the circuit board, the water jet can overcome the cross-offset impact force at the edge of the nozzle, resulting in insufficient exchange capacity of the liquid medicine in the hole, so that the loose carbon powder in the through hole of the circuit board can be fully removed, ensuring that the inner copper and the surface electroplated copper can be normally electrically conductive, thereby improving the reliability of the black shadow process and the electroplating layer; when the loose carbon powder in the through hole of the circuit board can be fully removed, after the circuit board is completed, in the subsequent tinning test, it is less likely to have poor inner layer interconnection compared to the ordinary circuit board process flow, ensuring the function of intelligent networked car communication. It can be understood that the nozzle is fan-shaped, and the pressure in the middle and the edge cannot be exactly the same, while the water outlet surface of the water jet is flat, so that the pressure in the middle and the edge is the same, thereby overcoming the problem that the loose carbon powder in the through hole of the circuit board cannot be completely removed in the last micro-etching step.

[0047] In another embodiment, the nozzles of the medicine water spray head and the water washing spray head are arranged toward the upper and lower surfaces of the roller row, forming an upper medicine water spray head and a lower medicine water spray head, as well as an upper water washing spray head and a lower water washing spray head; the water outlets of the medicine water knife head and the water washing water knife head are also arranged toward the upper and lower surfaces of the roller row, forming an upper medicine water knife head and a lower medicine water knife head, as well as an upper water washing water knife head and a lower water washing water knife head, wherein the upper water washing spray head and the lower water washing spray head constitute a water washing spray head group, and the upper water washing water knife head and the lower water washing water knife head constitute a water washing water knife head group.

[0048] In one embodiment, placing the circuit board on a roller platform for a first micro-etching operation includes:

[0049] Perform the first double-sided micro-etching operation on the circuit board.

[0050] It can be understood that after the circuit board has been processed by black shadow and fixing, there is residual carbon powder in its through-holes, and the loose carbon powder is distributed in the through-holes, one side of the circuit board adjacent to the circuit board, and the other side of the circuit board adjacent to the circuit board. In order to ensure that the loose carbon powder can be removed, it is necessary to perform the first micro-etching operation on both sides of the circuit board. Both sides of the circuit board are micro-etched by spraying and water jets to preliminarily remove the loose carbon powder on the through-holes and the surface, and then, the loose carbon powder content is preliminarily reduced to preliminarily ensure the reliability of the connection of the inner copper hole wall. Further, the circuit board is subjected to the first double-sided micro-etching operation, including: the first double-sided micro-etching operation is performed by upper and lower X sprays, Y upper water jets, and Z lower water jets; wherein X≥7, Y≥4, and Z≥3. In this embodiment, X=7, Y=4, Z=3, that is, the first double-sided micro-etching operation uses 7 upper and lower sprays, 4 upper water knives, and 3 lower water knives. Further, the first double-sided micro-etching operation uses 7 upper and lower water spray heads, 4 upper water knife heads, and 3 lower water knife heads. It can be understood that in the first double-sided micro-etching operation, since the circuit board has passed the initial black shadow and fixation, the solidified carbon layer is not completely and firmly attached to the through hole. At this time, there is a lot of carbon powder on the surface of the circuit board and the through hole, and the carbon powder needs to be initially removed by the liquid medicine, and the preliminary solidified carbon layer is prevented from being removed, so as to ensure that the loose carbon powder is removed in the next micro-etching and the solidified carbon layer can be further adsorbed in the through hole, wherein the upper and lower 7 liquid medicine sprays are used to remove the loose carbon powder on the surface of the circuit board, and the 4 upper water knives and 3 lower water knives are used to remove the loose carbon powder in the through hole of the circuit board.

[0051] Furthermore, after completing the first micro-etching operation, the circuit board is subjected to the first water washing operation to remove the chemicals and impurities on the surface of the circuit board and in the through-holes, thereby reducing the corrosion of the circuit board surface and through-holes by the chemicals, resulting in poor conductivity of the circuit board. In this embodiment, after the circuit board is simply cleaned of carbon powder, the black shadow line device will use a water washing spray head and a water washing water knife head to jointly clean the surface and through-holes of the circuit board.

[0052] In one embodiment, a first double-sided micro-etching operation is performed on the circuit board, and then the following steps are further included:

[0053] Perform the first double-sided water washing operation on the circuit board.

[0054] It can be understood that after the loose carbon powder in the through hole is removed by spraying and water jet, the residual liquid medicine on the surface and in the through hole is distributed on both sides of the circuit board. Therefore, it is necessary to clean by spraying and water jet together so that the liquid medicine can be fully removed and the residual liquid medicine on the circuit board is reduced. Further, the circuit board is subjected to the first double-sided water washing operation, including: the first double-sided water washing operation is carried out by using P groups of spraying and Q groups of water jets; wherein P≥1, Q≥3. In this embodiment, P=1, Q=3, that is, the first double-sided water washing operation uses 1 group of spraying and 3 groups of water jets. Further, the first double-sided water washing operation uses 1 group of water washing spray head groups and 3 groups of water washing water jet head groups. It can be understood that 1 group of spraying can remove the residual liquid medicine on the surface of the circuit board. In order to ensure that the residual liquid medicine in the through hole of the circuit board can be completely removed, the number of water jets needs to be increased, that is, at least 3 groups of water jets are used to clean the through hole of the circuit board. On the one hand, a double-sided water washing can prevent the residual solution from corroding both sides and through-holes of the circuit board. On the other hand, the production of circuit boards requires multiple micro-etchings, and each micro-etching step uses a different type of solution. This double-sided water washing operation needs to completely remove the residual solution to prevent the residual solution after the previous micro-etching operation from interacting with the solution used in the next micro-etching, resulting in the solution used in the next micro-etching having a poor effect on the carbon powder on the surface of the circuit board and in the through-holes.

[0055] In one embodiment, performing a final micro-etching operation on the circuit board includes:

[0056] Perform the final double-sided micro-etching operation on the circuit board.

[0057] It can be understood that after multiple intermediate steps, there is a certain amount of residual carbon powder on the surface and through-holes of the circuit board, and the loose carbon powder is distributed in the through-holes, one side adjacent to the circuit board, and the other side adjacent to the circuit board. In order to ensure that the loose carbon powder can be completely removed, it is necessary to perform a final micro-etching operation on both sides of the circuit board. Both sides of the circuit board are micro-etched by water jets to further remove the loose carbon powder and ensure that the circuit board has good communication performance in subsequent use. Further, the circuit board is subjected to a final double-sided micro-etching operation, including: the final double-sided micro-etching operation is performed by using M upper water jets and N lower water jets; wherein M≥8, N≥7. In this embodiment, M=8, N=7, that is, the last double-sided micro-etching operation uses 8 upper water knives and 7 lower water knives. Further, the last double-sided micro-etching operation uses 8 upper and lower water knife heads and 7 lower water knife heads. In other words, the number of upper and lower water knives used in the last double-sided micro-etching operation is approximately doubled compared to the number of upper and lower water knives used in the first double-sided micro-etching operation. It can be understood that after the last micro-etching of the circuit board, the solidified carbon layer is adsorbed in the through hole again and again through hole filling, black shadow and fixation, and the number of upper and lower water knives is increased to remove loose carbon powder while ensuring the integrity of the adsorbed carbon layer. Under the condition of ensuring the integrity of the carbon layer, the qualified rate of the manufactured circuit board is improved.

[0058] Furthermore, before the first double-sided micro-etching operation is performed on the circuit board, it is cured by the first drying after black shadow fixing. At this time, the carbon layer is cured initially and has not yet reached a high degree of adsorption and adhesion to the surface and through-holes of the circuit board. In order to avoid excessive etching of the micro-etching solution used in the first double-sided micro-etching operation, which may cause the initially cured carbon layer to be corroded, the time of this micro-etching is shortened to simply remove the loose carbon powder. In the subsequent intermediate steps, the time of each micro-etching operation is the same as the micro-etching time of the first double-sided micro-etching operation, thereby facilitating the cured carbon layer to be more and more firmly adsorbed on the surface and through-holes of the circuit board. When the carbon layer after multiple drying and curing has a certain charge to be firmly adsorbed on the surface and in the through-holes, the circuit board enters the last double-sided micro-etching operation. At this time, it is necessary to extend the time for the liquid to bite the carbon powder to increase the exchange of the liquid. At this time, the loose carbon powder can be fully eroded. In addition, in order to overcome the defect of different pressures in the middle and edge of the nozzle of the liquid spray head, the liquid spray head is no longer used this time, but a liquid water cutter head is used to improve the liquid exchange capacity. The firmly adsorbed carbon layer is less likely to be washed away by the liquid than the previously cured carbon layer, thereby ensuring that the circuit board will not have an open circuit problem when in use.

[0059] Furthermore, after the last micro-etching operation is completed, the circuit board is subjected to a final water washing operation to remove the solution after deep removal of residual carbon powder on the surface of the circuit board and in the through-holes, thereby reducing the situation where the solution corrodes the surface of the circuit board and the through-holes, resulting in poor conductivity of the circuit board, thereby facilitating subsequent steps to better manufacture the automotive communication module circuit board.

[0060] In one embodiment, the circuit board is subjected to a final double-sided micro-etching operation, followed by:

[0061] Perform a final double-sided water washing operation on the circuit board.

[0062] It can be understood that after the loose carbon powder in the through hole is removed by the water jet, there is residual liquid medicine on the surface and in the through hole, and the liquid medicine is distributed on both sides of the circuit board and in the through hole. Therefore, it is necessary to use the water jet cleaning to fully remove the liquid medicine, reduce the liquid medicine remaining on the circuit board, and then reduce the liquid medicine corroding the surface of the circuit board and affecting the performance of the subsequent communication of the circuit board. At the same time, spraying is also used to clean the surface of the circuit board to wash away the residual liquid medicine on the surface. Further, the circuit board is subjected to the last double-sided water washing operation, including: the last double-sided water washing operation is carried out by using U group spraying and V group water jets; wherein U≥1, V≥2. In this embodiment, U=1, V=2, that is, the last double-sided water washing operation uses 1 group of spraying and 2 groups of water jets. Further, the last double-sided water washing operation uses 1 group of water washing spray heads and 2 groups of water washing water jet heads. It can be understood that after passing the intermediate steps, the carbon layer has been further adsorbed on the through-hole and the surface through the electric charge, and the adsorption is firm. After the last double-sided micro-etching operation which takes a relatively long time, the loose carbon powder has been fully eroded by the solution used this time, retaining the solidified carbon layer, and there is no need to perform the next hole filling, black shadow, fixing, drying and curing and micro-etching operations. Therefore, compared with the first double-sided water washing operation, in the last double-sided water washing operation, the number of water washing spray head groups remains unchanged, and the number of water washing water knife head groups is reduced, so that the solution can be fully washed away while saving water resources, maintaining the cleanliness of the circuit board, and also avoiding the situation where unnecessary water knife groups wash away the solidified carbon layer.

[0063] In the micro-etching step (including the first double-sided micro-etching operation, the micro-etching operation in the intermediate step, and the last double-sided micro-etching operation), a water jet is used to erode the carbon powder in the through-holes of the circuit board. To ensure that the loose carbon powder is sufficiently eroded by the liquid medicine and the solidified carbon layer is not washed away, the water pressure of the water jet needs to be controlled. However, the water jet head used in the black shadow line device may have water pressure fluctuations. When the water pressure is too high, the water jet will wash away the solidified carbon layer, causing the circuit to be open during subsequent use after the circuit board is copper-plated.

[0064] Therefore, in order to adjust the water pressure value of the water jet so that it is within a reasonable range, the black shadow line device also includes a water jet pressure regulator and a water pressure monitor. The control end of the water jet pressure regulator is electrically connected to the water pressure controlled end of the water jet head to adjust the water pressure value of the water jet. The water pressure monitor is electrically connected to the water pressure monitoring end of the water jet head to monitor the water pressure value of the water jet in real time. In this embodiment, the control end of the water jet pressure regulator is electrically connected to the water pressure controlled ends of the water washing water jet head group, the upper medicine water jet head and the lower medicine water jet head at the same time, and the water pressure monitor is electrically connected to the water pressure monitoring ends of the water washing water jet head group, the upper medicine water jet head and the lower medicine water jet head. It can be understood that when the circuit board is placed on the roller platform, the water pressure monitor starts to monitor the water pressure status of the water jet head. If the water pressure of the water jet head exceeds the water pressure threshold, there is a possibility that the circuit board will be subjected to excessive water force, causing the solidified carbon layer on its surface and in the through hole to be washed away. At this time, the water pressure detector alarms to inform the operator to operate the water jet pressure regulator to reduce the water pressure value of the water jet head to keep it within the normal water pressure range. Furthermore, the water pressure threshold is 3.0MPa. Under normal conditions, the water pressure value range of the upper and lower water jets is 0.3MPa to 1.5MPa, to ensure that the water jet using the liquid medicine can bite the loose carbon powder while ensuring that the solidified carbon layer is not washed away. In a preferred embodiment, the water pressure value of the upper and lower water jet heads is 0.3 MPa, which is the water pressure value under normal pressure. In this way, while ensuring that the liquid medicine can bite into the loose carbon powder, there is no need to increase the water pressure, thereby avoiding unnecessary pressure adjustment operations that may cause the solidified carbon layer to be washed away due to excessively high water pressure.

[0065] Similarly, after completing the micro-etching step, the water washing operation of the circuit board (including the first double-sided water washing operation, the water washing operation in the intermediate step and the last double-sided water washing operation) also needs to control the water pressure value of the water jet group to ensure that the liquid medicine can be removed while ensuring that the solidified carbon layer is not washed away. Therefore, it is also necessary to operate the water jet pressure regulator to adjust the water pressure value of the water jet group to keep it within the normal range. Further, the normal range is 0.3MPa to 1.5MPa. In a preferred embodiment, the water pressure value of the water jet group is 0.3MPa, which belongs to the water pressure value under normal pressure. In this way, after the circuit board is micro-etched, there is no need to adjust the water pressure value of the water jet, so that the water jet can fully remove the residual liquid medicine and will not wash away the solidified carbon layer.

[0066] In order to ensure that the loose carbon powder of the circuit board is removed more effectively, the carbon powder removal in the hole and on the surface is more complete, and no more steps are required for subsequent processing, after the circuit board undergoes the first micro-etching operation, some or all of the following steps are also included:

[0067] Get the micro-etching sequence time of the automobile communication module circuit board;

[0068] Detect whether the micro-etching time is greater than or equal to the preset micro-etching time;

[0069] When the micro-etching time is greater than or equal to the preset micro-etching time, the micro-etching quantity of the water jet head is increased.

[0070] In this embodiment, when the micro-etching time is greater than the preset micro-etching time, the micro-etching number of the upper and lower water jet heads is increased. It can be understood that the initial multiple micro-etching operations will use a general number of water jets. In the first and subsequent micro-etching operations, the carbon powder on the surface of the circuit board and in the through-hole is simply bitten, so that the carbon powder is initially removed and the solidified carbon layer is initially adsorbed on the surface and in the through-hole. At this time, when the micro-etching operation is performed for the first time, the micro-etching time is recorded. After a series of operations such as multiple micro-etching, hole filling, black shadow, fixing, pre-micro-etching and micro-etching, the solidified carbon layer will be more firmly adsorbed on the surface and in the through-hole of the circuit board, and will not be easily washed away by the impact of the water jet. When each series of operations starts to execute the corresponding micro-etching steps, the micro-etching time is recorded, and the micro-etching time of different times is accumulated. When a series of operations such as micro-etching, hole-filling, black shadow, fixing, pre-micro-etching and micro-etching are cyclically executed and the micro-etching segment time is continuously recorded, the last micro-etching operation is performed when the accumulated micro-etching segment time exceeds the preset micro-etching time. Since the solidified carbon layer gradually and firmly adsorbs on the through-hole and surface of the circuit board with a series of operations such as multiple micro-etching, hole-filling, black shadow, fixing, pre-micro-etching and micro-etching, the spraying is cancelled at this time, and the number of micro-etching of the upper and lower water knives is increased. The increased number of upper and lower water knives can overcome the shortcomings of the nozzles of the spray head and better remove the carbon powder in the through-hole, so as to achieve a higher degree of completion of the removal of carbon powder in the hole and on the surface, thereby ensuring the neatness of the circuit board surface and through-hole, avoiding the interference of loose carbon powder in the subsequent use of the circuit board, resulting in poor communication performance, thereby improving the qualified rate of intelligent networked vehicle communication circuit board products. It can be understood that the preset micro-etching time corresponds to the start time of the last pre-micro-etching, and the micro-etching segment time is the time of the current micro-etching process in the black shadow process.

[0071] In this embodiment, the first several micro-etching operations use a normal number of water jet heads, and the last micro-etching operation uses double the number of water jet heads. For example, the first several micro-etching operations use 4 upper micro-etching water jet heads and 3 lower micro-etching water jet heads, and the last micro-etching operation uses 8 upper micro-etching water jet heads and 7 lower micro-etching water jet heads.

[0072] In another embodiment, when the micro-etching segment time is less than the preset micro-etching time, the number of water jets is kept unchanged and S105 is continued.

[0073] In addition, in order to prevent the circuit board from being washed away by excessive water washing, the solidified carbon layer in the through hole may be washed away, and the following steps may be performed after the circuit board has been washed for the first time:

[0074] Get the washing sequence time of the circuit board of the automobile communication module;

[0075] Check whether the washing section time is greater than or equal to the preset washing time;

[0076] When the water washing section time is greater than or equal to the preset water washing time, the water washing quantity of the spray head remains unchanged, and the water washing quantity of the water jet head decreases.

[0077] In this embodiment, when the water washing segment time is greater than the preset water washing time, the number of water washing spray head groups remains unchanged, and the number of water washing water knife head groups decreases. It can be understood that the previous multiple water washings use a general number of water knives. Specifically, the production of the circuit board needs to go through multiple black shadow process steps, wherein each time the micro-etching operation is performed, the type of micro-etching solution used is different. Therefore, when completing each micro-etching operation, a certain number of water washing spray head groups and water washing water knife head groups are required to fully remove the residual solution on the circuit board, and avoid the interaction between the solution used in this micro-etching and the solution used in the next micro-etching, resulting in cross-contamination of the black shadow line device, thereby avoiding the situation where the solution used in the next micro-etching has a poor effect on the carbon powder biting. At this time, when the water washing operation is performed for the first time, the water washing segment time is recorded. After a series of operations such as multiple micro-etching, hole filling, black shadow, fixing, pre-micro-etching and micro-etching, the solidified carbon layer will be more firmly adsorbed on the surface and through-holes of the circuit board, and will not be easily washed away by the impact of the water jet. When each series of operations completes the corresponding micro-etching step and starts the water washing step, the water washing segment time is recorded, and the water washing segment time of different times is accumulated. When the water washing segment time accumulates to exceed the preset water washing time, this series of operations is interrupted, and the overall steps of the last black shadow process are performed, in which the last micro-etching operation is performed. After the micro-etching operation is completed, the loose carbon powder has been fully bitten by the medicine. At this time, the last water washing operation is performed to reduce the water washing water knife head group. In addition to saving water resources, this also reduces the situation where the solidified carbon layer is washed away by the water jet, and can also remove residual medicine, which is convenient for the subsequent process flow and ensures the normal communication of the intelligent networked vehicle communication circuit board product. It can be understood that the preset water washing time corresponds to the time when the last pre-micro-etching ends, and the water washing segment time is the time of the current water washing process in the black shadow process.

[0078] In this embodiment, the first several water washing operations use a normal number of water washing water knife head groups, and the last water washing operation uses a number of water washing water knife head groups reduced by 1. For example, the first several micro-etching operations use 3 water washing water knife head groups, and the last water washing operation uses 2 water washing water knife head groups.

[0079] In another embodiment, when the water washing sequence time is less than the preset water washing time, the water washing quantity of the spray head and the water washing quantity of the water jet head remain unchanged, and S105 is continuously executed.

[0080] After completing the last micro-etching and water washing steps, the circuit board is immersed in order to detect the connectivity between the inner copper and the plated copper in the through-holes of the micro-etched circuit board. Further, the circuit board is immersed in tin. It can be understood that the circuit board after micro-etching and water washing is immersed in molten tin to form a layer of tin on the surface of the PCB. This layer of tin can improve the solderability of the PCB and enhance the stability of the circuit connection. When the circuit board is immersed in tin after the spraying and water jet operation, multiple tinning is less likely to cause poor interconnection of the inner layer, ensuring the communication function of the intelligent networked vehicle.

[0081] Furthermore, the tinning temperature of the tinning operation is 270-290°C. In the present embodiment, the tinning temperature is 288°C to simulate the performance test of the use of circuit board solder. It can be understood that since the circuit board used for intelligent networked vehicle communication requires higher communication performance requirements than ordinary circuit boards, the circuit board of this scheme needs to pass multiple tinning tests, and there will be no poor memory interconnection after multiple tinning, so as to meet the safety and reliability requirements of customers using circuit boards. In the case of making circuit boards by black shadow lines, the circuit boards used for intelligent networked vehicle communications have better communication performance and service life.

[0082] The present disclosure also provides an intelligent network-connected automobile communication circuit board, which is obtained by using the method for preparing an automobile communication module circuit board based on a black shadow line device according to any one of the above embodiments. It can be understood that after the automobile communication module circuit board is micro-etched multiple times by using a black shadow line device, the last micro-etching is performed by a full water jet operation, so that the loose carbon powder in the through hole of the circuit board is fully removed by the liquid water jet, so that the inner copper and the electroplated copper can be electrically conductive normally, and when the subsequent tinning is used as a test, the circuit board can pass multiple tinning steps without the inner layer interconnection being poor, thereby ensuring the communication function of the intelligent network-connected automobile.

[0083] Compared with the prior art, the present invention has at least the following advantages:

[0084] 1. The above-mentioned method for preparing a circuit board for an automobile communication module based on a black shadow line device adopts a black shadow process to perform black shadow treatment on the circuit board, wherein the black shadow line device partially adopts a high-efficiency water jet, so that in the micro-etching step of the circuit board, the water jet can overcome the cross-offsetting impact force at the edge of the nozzle, resulting in insufficient exchange capacity of the liquid medicine in the hole, so that the loose carbon powder in the through hole of the circuit board can be fully removed, ensuring that the inner copper and the surface electroplated copper can be electrically conductive normally, thereby improving the reliability of the black shadow process and the electroplating layer.

[0085] 2. When the loose carbon powder in the through-holes of the circuit board can be fully removed, after the circuit board is completed, during the subsequent tinning test, it is less likely to have poor inner layer interconnection compared to the ordinary circuit board process, thus ensuring the communication function of the intelligent connected vehicle.

[0086] The above-mentioned embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the disclosed patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the disclosed patent shall be subject to the attached claims.

Claims

1. A method for preparing a circuit board of an automobile communication module based on a black shadow line device, wherein the circuit board is subjected to black shadow processing by using a black shadow line device, wherein the black shadow line device comprises a roller platform, a plurality of spray heads and a plurality of water knife heads, wherein the roller platform is used to place the circuit board, and the plurality of spray heads and the plurality of water knife heads are distributed above and below the roller platform, wherein: The method for preparing a circuit board of an automobile communication module based on a black shadow line device comprises the following steps: Obtain the circuit board after the first drying and curing; Placing the circuit board on a roller platform for a first micro-etching operation to preliminarily remove the surface copper layer of the circuit board and loose carbon powder on the inner copper layer, wherein the first micro-etching operation is performed by the spray head and the water jet head together; The circuit board is subjected to hole filling, black shadow, fixing, drying and curing, and micro-etching operations in sequence; The circuit board is subjected to a final micro-etching operation after the last drying and curing step, wherein the final micro-etching operation is performed using the water jet head to remove the surface copper layer of the circuit board and loose carbon powder on the inner copper layer.

2. The method for preparing a circuit board of an automobile communication module based on a black shadow line device according to claim 1, characterized in that: Placing the circuit board on the roller platform for the first micro-etching operation includes: The circuit board is subjected to a first double-sided micro-etching operation.

3. The method for preparing a circuit board of an automobile communication module based on a black shadow line device according to claim 2, characterized in that: The first double-sided micro-etching operation on the circuit board includes: The first double-sided micro-etching operation is performed by using X upper and lower sprays, Y upper water knives and Z lower water knives; wherein X≥7, Y≥4, and Z≥3.

4. The method for preparing a circuit board of an automobile communication module based on a black shadow line device according to claim 2, characterized in that: The circuit board is subjected to a first double-sided micro-etching operation, and then further comprises: The circuit board is subjected to a first double-sided water washing operation.

5. The method for preparing a circuit board of an automobile communication module based on a black shadow line device according to claim 4, characterized in that: The first double-sided water washing operation on the circuit board comprises: The first double-sided water washing operation is performed by using P groups of sprays and Q groups of water knives; wherein P≥1, Q≥3.

6. The method for preparing a circuit board of an automobile communication module based on a black shadow line device according to claim 1, characterized in that: The last micro-etching operation is performed on the circuit board after the last fixing step is completed, comprising: The circuit board is subjected to a final double-sided micro-etching operation.

7. The method for preparing a circuit board of an automobile communication module based on a black shadow line device according to claim 6, characterized in that: The last double-sided micro-etching operation on the circuit board comprises: The last double-sided micro-etching operation is performed by using M upper water jets and N lower water jets; wherein M≥8 and N≥7.

8. The method for preparing a circuit board of an automobile communication module based on a black shadow line device according to claim 6, characterized in that: The circuit board is subjected to a final double-sided micro-etching operation, and then further comprises: The circuit board is subjected to a final double-sided water washing operation.

9. The method for preparing a circuit board of an automobile communication module based on a black shadow line device according to claim 8, characterized in that: The last double-sided water washing operation on the circuit board includes: The last double-sided water washing operation is performed by using U group spraying and V group water jets together; wherein U≥1, V≥2.

10. A communication circuit board for an intelligent networked vehicle, characterized in that: The method for preparing an automobile communication module circuit board based on a black shadow line device as described in any one of claims 1 to 9 is adopted.

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