Method for manufacturing circuit board with pad-free design

Abstract

The invention discloses a method for manufacturing a circuit board with a pad-free design, and the method comprises the following steps: S1, a circuit board processing selection step: integrating and putting the circuit board into processing equipment, and selecting a processing route according to a required processing mode; and S2, targeted circuit board processing is conducted, specifically, two sets of circuit board processing technologies are arranged, one set of circuit board processing technologies is a vacuum hole plugging technology, the other set of circuit board processing technologies is a graph electrotinning technology, and the circuit board is transferred and conveyed out after the processing technologies are selected according to needs to process the circuit board. Two groups of different systems are set to complete processing of the circuit board, specific processing requirements are met according to the required processing process, and compared with a traditional manufacturing method of reserving a bonding pad, the circuit board without the bonding pad design manufactured by the process saves a large amount of wiring and hole arrangement space and can support closer hole-to-wire or hole-to-hole distance; the non-pad design can reduce the reflection of the non-functional pad to the signal in the signal transmission process, reduce the loss of the signal, and improve the integrity of the signal.

Description

Technical Field

[0001] The invention relates to the technical field of PCB board preparation, in particular to a method for manufacturing a circuit board with a pad-free design. Background Art

[0002] As electronic products develop towards miniaturization and multifunctionality, circuit boards also develop towards high integration and miniaturization. How to save space in the circuit board and make the circuits denser has become a key point in the development of circuit boards.

[0003] According to the authorization announcement number CN 102869205 A, a method for forming metallized holes in a PCB board is disclosed, including: an electroplating step, electroplating a substrate with a through hole drilled therein to obtain a metallized hole; a plugging step, filling the metallized hole where no pad is required to be retained with an anti-corrosion material; a pattern processing step, processing a circuit pattern on the bottom copper, so that the non-circuit bottom copper and the pad that does not need to be retained of the metallized hole are exposed; an etching step, etching with an acidic etching solution, etching the non-circuit bottom copper, and the exposed pad bottom copper at at least one end of the metallized hole filled with the anti-corrosion material is also etched away, so as to obtain a metallized hole without a pad at at least one end of the metallized hole. The present invention breaks the limitations of traditional design and process, and the hole opening of the formed metallized hole at one end or even at both ends has no pad, and can also be used to achieve no pad for the hole in the step, which is suitable for batch processing and stable. The resulting PCB board product can effectively improve the signal quality of radio frequency products and can be widely used in fields such as communications and military that require high-frequency microwave signals.

[0004] Most circuit boards are designed with through holes or buried holes, and these holes usually have corresponding pads when they are designed. The pads are used to cover the dry film or tin plating during the pattern making to prevent the copper in the hole from being etched away. In addition, some of the outer pads are used to connect with the electronic components that are subsequently mounted on the surface of the circuit board; some of the outer pads are sealed under the ink after the solder mask is printed and have no subsequent function. In order to optimize these pads that have no additional function and occupy more space in the board, a padless design is proposed. By deleting the surface pads of the through and blind holes to further compress the distance from the hole to the surrounding graphics, the design problem of insufficient spacing can be solved, so a circuit board manufacturing method with a padless design is now needed. Summary of the invention

[0005] The purpose of the present invention is to provide a method for manufacturing a circuit board with a padless design, which selects two different systems to perform different processing operations on circuit boards with different processing requirements to meet the efficient processing of different circuit boards and solve the technical problems mentioned in the background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for manufacturing a circuit board with a padless design, comprising the following steps:

[0007] S1. Circuit board processing selection step: by integrating the circuit board into the processing equipment, the processing route is selected according to the required processing method;

[0008] S2. Targeted circuit board processing: There are two groups of circuit board processing processes, one of which is the vacuum plugging process and the other is the electroplating tinning process. After the circuit board is processed according to the required processing process, the circuit board will be transported out;

[0009] S2.1, vacuum plugging process: including the following steps: drilling - electroplating - vacuum plugging - film pasting - exposure - development - etching - film removal;

[0010] S2.2, pattern electroplating tinning process: including the following steps: drilling - electroplating - film lamination - exposure - development - pattern electroplating - etching - tin stripping;

[0011] S3. Detect the circuit board before it is sent out: After the circuit board is processed through different processing techniques, the staff will perform current and voltage detection on the processed circuit board, and at the same time observe whether the circuit board has been film-removed and tin-removed, so as to avoid the problem of poor signal output during the use of the circuit board.

[0012] Preferably, in S1, the circuit boards need to be classified, and the classification requires classification according to whether the circuit board body includes vacuum plug holes or not;

[0013] Specifically, it can be distinguished according to the buried holes or through holes opened or required to be opened on the surface of the circuit board. When transporting the circuit boards, it is necessary to ensure the distance between the circuit boards to avoid contact between the circuit boards and reduce damage during the processing of the circuit boards;

[0014] If the S1 mid-board process includes vacuum plugging, you can choose the vacuum plugging process. If the S1 mid-board process does not include vacuum plugging, you can choose the electroplating tinning process. No additional process is required.

[0015] Preferably, the specific operation flow of the vacuum plugging process mentioned in S2 is to prepare drilling for the position of the circuit board and perform electroplating operation on the circuit board, and the vacuum plugging operation is to fill the target through hole with a filler, and the selected filler is specifically a plugging resin, which protects the copper on the hole wall inside the hole.

[0016] Preferably, the film-lamination-exposure-development mentioned in S2 is an operation for protecting the circuit board. At the same time, the drilling and electroplating positions of the circuit board can be specifically marked to facilitate subsequent etching operations, so that all copper in the drilled holes of the circuit board will not be etched away during etching, thereby improving the processing quality of the circuit board.

[0017] Preferably, the electrotin plating process mentioned in S2 is different from the vacuum plugging process in that the vacuum plugging operation is not set. The circuit board protection operation of film pasting-exposure-development is advanced to achieve direct protection of the circuit board after drilling and electroplating, and then tin is plated in the through holes opened in the circuit board through the set electrotin plating operation.

[0018] Preferably, the electroplating tinning process mentioned in S2 protects the copper in the hole wall through the tin layer, so that all the copper in the drilled hole of the circuit board will not be etched away during the etching of the circuit board, thereby improving the processing quality of the circuit board.

[0019] Preferably, the vacuum plugging process in S2 can be produced by either DES or SES etching methods. Since the pattern electroplating tinning process is produced by pattern electroplating tinning, it is limited to SES etching.

[0020] Preferably, the two processing systems in S2 can work independently or synchronously, and a specific working system can be selected according to different processing requirements to complete the processing operation of the circuit board;

[0021] The difference between the film stripping step after the etching step in the vacuum plugging process and the tin stripping step after the etching step in the electroplating tinning process in the two processing systems in S2 can protect the circuit board according to different processing methods and improve the processing quality of the circuit board.

[0022] Preferably, the vacuum plugging process mentioned in S2 and the electroplating tinning process in Figure 2 produce a padless design circuit board using this process, while retaining the traditional pad manufacturing method, and saving a lot of wiring hole layout space through different protection methods, and can support closer hole-to-line or hole-to-hole distances; the padless design can reduce the reflection of signals by non-functional pads during signal transmission, reduce signal loss, and improve signal integrity.

[0023] Preferably, after the circuit board is processed in S2 and then transported out, the circuits need to be classified and stored according to different processing methods. At the same time, multiple groups of tests need to be performed after the circuit board processing is completed, and the tests include current and voltage tests, signal reflection tests, and signal integrity tests to ensure the processing quality of the circuit board.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] By setting up two different systems to complete the processing of the circuit board, and at the same time targeting the processing process to meet the specific processing needs, the padless design circuit board produced by this process saves a lot of wiring and hole layout space compared to the traditional method of retaining pads, and can support closer hole-to-line or hole-to-hole distances; the padless design can reduce the reflection of signals by non-functional pads during signal transmission, reduce signal loss, and improve signal integrity. The process flow involved in this patent is not significantly different from the conventional process. If the board process includes vacuum plugging, the vacuum plugging process flow can be selected. If the board process does not include vacuum plugging, the electroplating tinning process flow can be selected. No additional process is required, ensuring that the production cost is not increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the processing flow of the present invention;

[0027] Figure 2 This is a schematic diagram of the vacuum plugging process of the present invention;

[0028] Figure 3 The figure is a schematic diagram of the production process of the electrotin plating process of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention provides: a method for manufacturing a circuit board with a pad-free design, such as Figure 1-Figure 3 As shown, the following steps are included: S1, circuit board processing selection step: by integrating the circuit board into the processing equipment, the processing route is selected according to the required processing method; S2, targeted circuit board processing: there are two groups of circuit board processing processes, one of which is a vacuum plugging process, and the other is a graphic electroplating tinning process. After the circuit board is processed according to the required processing technology, the circuit board is transferred and shipped out; S2.1, vacuum plugging process: including the following steps: drilling-electroplating-vacuum plugging-filming-exposure-development-etching-film removal; S2.2, graphic electroplating tinning process: including the following steps: drilling-electroplating-filming-exposure-development-graphic electroplating-etching-tin stripping; S3, detection of circuit board delivery: after the processing of the circuit board is completed through different processing technology selections, the staff will perform current and voltage detection on the processed circuit board, and observe whether the film removal and tin stripping of the circuit board are completed, so as to avoid the problem of poor signal output during the use of the circuit board.

[0031] Preferably, circuit boards need to be classified in S1, and the classification requires classification based on whether the circuit board body includes vacuum plugging holes or the circuit board body does not include vacuum plugging holes; specifically, it can be distinguished based on the buried holes or through holes opened or required to be opened on the surface of the circuit board. When transporting the circuit boards, it is necessary to ensure the distance between the circuit boards to avoid contact between the circuit boards and reduce damage to the circuit boards during processing; if the board process in S1 includes vacuum plugging holes, the vacuum plugging process can be selected for production; if the board process does not include vacuum plugging holes, the electroplating tinning process can be selected for production without the need to add additional processes.

[0032] Furthermore, the specific operation flow of the vacuum plugging process mentioned in S2 is to prepare for drilling at the position of the circuit board and to perform electroplating operations on the circuit board. The vacuum plugging operation is to fill the target through-hole with a filler. The selected filler is specifically a plugging resin, which protects the copper on the hole wall in the hole; the film-sticking-exposure-development mentioned in S2 is an operation to protect the circuit board. At the same time, it can specifically mark the drilling and electroplating positions of the circuit board, which is convenient for subsequent etching operations, so that all the copper in the drilled holes of the circuit board will not be etched away during etching, thereby improving the processing quality of the circuit board.

[0033] Furthermore, the electrotinning process mentioned in S2 is different from the vacuum plugging process in that the vacuum plugging operation is not set. The circuit board protection operation of film pasting, exposure and development is advanced to achieve direct protection of the circuit board after drilling and electroplating. Then, tin is plated in the through holes opened in the circuit board through the set electrotinning operation. The electrotinning process mentioned in S2 protects the copper on the hole wall through the tin layer, so that all the copper in the drilled hole of the circuit board will not be etched away during etching, thereby improving the processing quality of the circuit board.

[0034] Specifically, the vacuum plugging process in S2 can be produced by either DES or SES etching methods. The electroplating tinning process uses graphic electroplating tinning, so it is limited to SES etching. The two processing systems in S2 can work independently or synchronously. The specific working system is selected according to different processing requirements to complete the processing operation of the circuit board. The film stripping step after the etching step in the vacuum plugging process in the two processing systems in S2 is different from the tin stripping step after the etching step in the electroplating tinning process. The circuit board is protected according to different processing methods to improve the processing quality of the circuit board.

[0035] It is worth noting that the padless design circuit boards produced by the vacuum plugging process and the electroplating tinning process mentioned in S2 retain the traditional pad manufacturing method, and at the same time save a lot of wiring hole layout space through different protection methods, and can support closer hole-to-line or hole-to-hole distances; the padless design can reduce the reflection of signals by non-functional pads during signal transmission, reduce signal loss, and improve signal integrity.

[0036] In addition, after the circuit board is processed in S2 and then transported out, the circuits need to be classified and stored according to different processing methods. At the same time, multiple sets of tests need to be performed after the circuit board processing is completed, including current and voltage tests, signal reflection tests, and signal integrity tests, to ensure the quality of circuit board processing.

[0037] The above is a rough process of selecting processing methods for different circuit boards and processing circuit boards in this embodiment. The specific implementation method also includes the following contents:

[0038] Select specific processing routes according to production needs to plan circuit board screening, loading, processing, and testing work, and set up independent staff to complete specific operations at different operating positions;

[0039] For the speed control after the circuit board is put on the machine, the spacing control of the circuit board during the circuit board processing, the control of the single-group processing system or the double-group processing system, etc.

[0040] When any group of systems is selected to process the circuit board, the route should be selected to ensure that the film removal or tin stripping work after etching is stable and continuous, to ensure the protection of the circuit board during the circuit board processing, and to save a lot of wiring and hole layout space through different protection methods, and to support closer hole-to-line or hole-to-hole distance; the padless design can reduce the reflection of the signal by the non-functional pad during the signal transmission process, reduce the signal loss, and improve the signal integrity.

[0041] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a circuit board with a pad-free design, characterized in that: The following steps are involved: S1. Circuit board processing selection step: by integrating the circuit board into the processing equipment, the processing route is selected according to the required processing method; S2. Targeted circuit board processing: There are two groups of circuit board processing processes, one of which is the vacuum plugging process and the other is the electroplating tinning process. After the circuit board is processed according to the required processing process, the circuit board will be transported out; S2.1, vacuum plugging process: including the following steps: drilling - electroplating - vacuum plugging - film pasting - exposure - development - etching - film removal; S2.2, pattern electroplating tinning process: including the following steps: drilling - electroplating - film lamination - exposure - development - pattern electroplating - etching - tin stripping; S3. Detect the circuit board before it is sent out: After the circuit board is processed through different processing techniques, the staff will perform current and voltage detection on the processed circuit board, and at the same time observe whether the circuit board has been film-removed and tin-removed, so as to avoid the problem of poor signal output during the use of the circuit board.

2. A method for manufacturing a circuit board with a padless design according to claim 1, characterized in that: In S1, the circuit boards need to be classified, and the classification requires classification according to whether the circuit board body includes vacuum plug holes or the circuit board body does not include vacuum plug holes; Specifically, it can be distinguished according to the buried holes or through holes opened or required to be opened on the surface of the circuit board. When transporting the circuit boards, it is necessary to ensure the distance between the circuit boards to avoid contact between the circuit boards and reduce damage during the processing of the circuit boards; If the S1 mid-board process includes vacuum plugging, you can choose the vacuum plugging process. If the S1 mid-board process does not include vacuum plugging, you can choose the electroplating tinning process. No additional process is required.

3. A method for manufacturing a circuit board with a padless design according to claim 2, characterized in that: The specific operation process of the vacuum plugging process mentioned in S2 is to prepare drilling for the position of the circuit board and perform electroplating operations on the circuit board. The vacuum plugging operation is to fill the target through-hole with a filler. The selected filler is specifically a plugging resin, which protects the copper on the hole wall inside the hole.

4. A method for manufacturing a circuit board with a padless design according to claim 3, characterized in that: The film-lamination-exposure-development mentioned in S2 is an operation to protect the circuit board. At the same time, it can specifically mark the drilling and electroplating positions of the circuit board to facilitate subsequent etching operations, so that all copper in the holes of the circuit board will not be etched away during etching, thereby improving the processing quality of the circuit board.

5. The method for manufacturing a circuit board with a padless design according to claim 4, characterized in that: The electrotin plating process mentioned in S2 is different from the vacuum plugging process in that the vacuum plugging operation is not set. The circuit board protection operation of film pasting, exposure and development is advanced to achieve direct protection of the circuit board after drilling and electroplating, and then tin is plated in the through holes opened in the circuit board through the set electrotin plating operation.

6. The method for manufacturing a circuit board with a pad-free design according to claim 5, characterized in that: The electroplating tinning process mentioned in Figure S2 protects the copper in the hole wall through the tin layer, so that all the copper in the hole of the circuit board will not be etched away during the etching of the circuit board, thereby improving the processing quality of the circuit board.

7. A method for manufacturing a circuit board with a pad-free design according to claim 6, characterized in that: The vacuum plugging process in S2 can be produced by either DES or SES etching methods. The pattern electroplating tinning process is produced by pattern electroplating tinning, so it is limited to SES etching.

8. The method for manufacturing a circuit board with a pad-free design according to claim 7, characterized in that: The two processing systems in S2 can work independently or synchronously. The specific working system can be selected according to different processing requirements to complete the processing operation of the circuit board; The difference between the film stripping step after the etching step in the vacuum plugging process and the tin stripping step after the etching step in the electroplating tinning process in the two processing systems in S2 can protect the circuit board according to different processing methods and improve the processing quality of the circuit board.

9. A method for manufacturing a circuit board with a pad-free design according to claim 8, characterized in that: The vacuum plugging process mentioned in S2 and the electroplating tinning process in Figure 2 retain the traditional pad manufacturing method. At the same time, different protection methods are used to save a lot of wiring hole layout space, and can support closer hole-to-line or hole-to-hole distances. The padless design can reduce the reflection of non-functional pads on the signal during signal transmission, reduce signal loss, and improve signal integrity.

10. The method for manufacturing a circuit board with a pad-free design according to claim 9, characterized in that: After the circuit board is processed in S2 and then transported out, the circuits need to be classified and stored according to different processing methods. At the same time, multiple sets of tests need to be performed after the circuit board processing is completed, including current and voltage tests, signal reflection tests, and signal integrity tests, to ensure the processing quality of the circuit board.

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