Circuit board expansion and shrinkage control method

Abstract

The invention discloses a circuit board expansion and shrinkage control method, which comprises the following steps of: A, preparing a board, and cutting the board; b, baking the plate, and measuring the plate for the first time to obtain a first measurement result; step C, presetting a stretching coefficient of the film, performing circuit pattern manufacturing on the plate to obtain a circuit pattern on the plate, and performing secondary measurement on the plate to obtain a second measurement result; d, performing post-treatment on the plate, and performing third measurement on the plate to obtain a third measurement result; e, compensating the stretching coefficient of the film according to the first measurement result, the second measurement result and the third measurement result; f, according to the compensated stretching coefficient of the film, circuit pattern manufacturing and post-processing are carried out on the plate again, fourth measurement is carried out on the plate, and a fourth measurement result is obtained; and step G, confirming to carry out batch production according to the fourth measurement result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit board production, in particular to a circuit board expansion and contraction control method. BACKGROUND

[0002] With the rapid development of the information industry, as an indispensable important pillar in the information industry, the circuit board is also developing towards small aperture, high density, multi-layer, and fine line. High-precision fine lines have become mainstream products.

[0003] However, in the production process of the circuit board, the problem of board expansion and contraction often occurs, which affects the production of subsequent processes and causes quality problems and scrap. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a circuit board expansion and contraction control method, which can ensure that the quality of the circuit board meets the production requirements, effectively improves the quality, and reduces rework and scrap.

[0005] The circuit board expansion and contraction control method according to the embodiments of the present application comprises: Step A: preparing a board material and cutting the board material; Step B: baking the board material and measuring the board material for the first time to obtain a first measurement result; Step C: presetting a stretching coefficient of a film, making a circuit pattern on the board material to obtain a circuit pattern on the board material, and measuring the board material for the second time to obtain a second measurement result; Step D: post-processing the board material and measuring the board material for the third time to obtain a third measurement result; Step E: compensating the stretching coefficient of the film according to the first measurement result, the second measurement result, and the third measurement result; Step F: making a circuit pattern and post-processing the board material again according to the compensated stretching coefficient of the film, and measuring the board material for the fourth time to obtain a fourth measurement result; Step G: confirming batch production according to the fourth measurement result.

[0006] According to the circuit board expansion and contraction management method provided in the embodiments of the present application, the following beneficial effects are achieved: the circuit board expansion and contraction management method provided in the embodiments of the present application compares and analyzes three measurement results to confirm the compensation value of the stretching coefficient of the film, and according to the compensation value of the stretching coefficient of the film, the circuit pattern is made again and post-processing is performed on the board, and the fourth measurement is performed on the board to obtain a fourth measurement result, and then according to the fourth measurement result, batch production is confirmed, so that the quality of the circuit board meets the production requirements, and the quality is effectively improved, and the rework and scrapping are reduced; meanwhile, baking the board after cutting can remove the moisture in the board, reduce the size change caused by evaporation of moisture in the subsequent processing process, reduce the expansion and contraction risk of the board, improve the stability of the board, and improve the product quality of the circuit board.

[0007] According to the circuit board expansion and contraction management method provided in the embodiments of the present application, in step B, the temperature of the baking is 130 DEG C, and the time of the baking is 2 hours.

[0008] According to the circuit board expansion and contraction management method provided in the embodiments of the present application, in steps B, C and D, the first measurement, the second measurement and the third measurement each include: performing measurement on the board to obtain a large plate measurement result and a unit plate measurement result.

[0009] According to the circuit board expansion and contraction management method provided in the embodiments of the present application, in step C, the following steps are included: Step C1: performing pre-processing on the board, and pasting a dry film on the board; Step C2: presetting a stretching coefficient of the film, and transferring the circuit pattern to the board by using the film; Step C3: performing etching on the non-pattern area of the board to obtain the circuit pattern on the board, and performing the second measurement on the board to obtain a second measurement result.

[0010] According to the circuit board expansion and contraction management method provided in the embodiments of the present application, in step D, the following steps are included: Step D1: performing tin spraying on the board, and performing the third measurement on the board to obtain a third measurement result.

[0011] According to the circuit board expansion and contraction management method provided in the embodiments of the present application, after step C is completed and before step D1 is performed, the following steps are further included: Step D2: performing solder mask on the board; Step D3: performing character making on the board, and performing the fifth measurement on the board to obtain a fifth measurement result; Step D4: performing baking on the board, and performing the sixth measurement on the board to obtain a sixth measurement result.

[0012] According to the circuit board expansion and contraction management method of some embodiments of the present application, in step D4, the baking temperature is 150°C, and the baking time is 30 minutes.

[0013] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0014] The present application will be further described below in conjunction with the accompanying drawings and embodiments, in which: Figure 1 Flow chart of the circuit board expansion and contraction management method of some embodiments of the present application; Figure 2 Flow chart of the circuit board expansion and contraction management method of some embodiments of the present application; Figure 3 Flow chart of the circuit board expansion and contraction management method of some embodiments of the present application; Figure 4 Flow chart of the circuit board expansion and contraction management method of some embodiments of the present application; Figure 5 Large plate measurement scheme of the plate material of some embodiments of the present application; Figure 6 Large plate measurement scheme of the plate material of some embodiments of the present application. DETAILED DESCRIPTION

[0015] The embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, in which the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary only, and are used only for explanation of the present application, and cannot be understood as a limitation of the present application.

[0016] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as a limitation of the present application, which does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0017] In the description of the present application, the meaning of several is one or more, the meaning of multiple is more than two, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If it is described as first, second, etc. is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of indicated technical features.

[0018] In the description of this application, unless otherwise expressly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly. Those skilled in the art can reasonably determine the specific meaning of these terms in this application based on the specific content of the technical solution. In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. In the description of this specification, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0019] Reference Figures 1 to 3 This application provides a circuit board expansion and contraction control method, including but not limited to steps A, B, C, D, E, F and G.

[0020] Step A: Prepare the board material and cut it into pieces.

[0021] Specifically, the process involves preparing the board material and then cutting it into the correct size, which reduces waste and lowers production costs. Next, the board material is drilled to achieve electrical connections between different circuit layers in the circuit board. The process is simple and easy to operate.

[0022] Step B: Bake the board and take the first measurement to obtain the first measurement result.

[0023] By baking the board material after cutting, moisture can be removed, reducing dimensional changes caused by moisture evaporation during subsequent processing, lowering the risk of expansion and contraction, improving board stability, and enhancing circuit board product quality. In this embodiment, CEM-1 board material is used, and the baking temperature is 130℃ for 2 hours. It should be noted that other board materials can also be used, and the baking temperature and baking time will differ for different materials. Those skilled in the art can make reasonable choices based on actual conditions, and this application does not impose any restrictions.

[0024] Then, after baking, the board is measured for the first time to obtain the initial measurement results, which are used for subsequent compensation of the film's tensile coefficient. This initial measurement includes both large-scale board measurements and unit board measurements to obtain the large-scale board measurement results and unit board measurement results, respectively.

[0025] Step C: Set the stretching factor of the film, create the circuit pattern on the board, and perform a second measurement on the board to obtain the second measurement result.

[0026] Among them, reference Figure 2 , Figure 2 yes Figure 1 A schematic diagram of an embodiment of the detailed process of step C, which includes, but is not limited to: Step C1: Pre-treat the board and apply dry film to the board; Step C2: Preset the stretch factor of the film and use the film to transfer the circuit pattern onto the board. Step C3: Etch the non-graphic areas of the board to obtain the circuit pattern on the board, and perform a second measurement on the board to obtain the second measurement result.

[0027] Specifically, the board material undergoes pretreatment by cleaning and roughening the surface before applying a dry film to improve adhesion between the film and the board surface. Based on production requirements, the film's stretch factor is preset, and the circuit pattern on the film is transferred to the board through exposure and development. Subsequently, non-patterned areas on the board are etched to create the circuit pattern. Finally, after etching, a second measurement is performed to obtain the second measurement result, which is used for subsequent compensation of the film's stretch factor. This second measurement includes both large-scale board measurements and unit board measurements to obtain the large-scale board measurement results and unit board measurement results, respectively.

[0028] In some other embodiments of this application, the circuit pattern can also be obtained by screen printing on the board material. The fabrication of screen-printed circuit patterns is prior art and will not be described in detail here.

[0029] Step D: Perform post-processing on the board and take a third measurement to obtain the third measurement result.

[0030] Among them, reference Figure 3 , Figure 3 yes Figure 1 A schematic diagram of an embodiment of the detailed process of step D, which includes, but is not limited to: Step D1: Apply tin plating to the board and perform a third measurement on the board to obtain the third measurement result.

[0031] The board material is tin-sprayed using high-pressure tin-spraying equipment to uniformly adhere high-temperature molten tin to its surface. This protects the surface from oxidation and contamination while facilitating subsequent soldering. A third measurement is then performed to obtain the results, which are used to compensate for the film's tensile coefficient. This third measurement includes both large-scale board measurements and unit board measurements to obtain the large-scale board measurement results and unit board measurement results, respectively. Reference Figure 4 In some embodiments, after completing step C and before proceeding to step D1, the method further includes: Step D2: Apply solder resist to the board material; Step D3: Create characters on the board and take a fifth measurement to obtain the fifth measurement result; Step D4: Bake the board and perform a sixth measurement on the board to obtain the sixth measurement result; Specifically, a solder resist layer is formed on the board surface by applying solder resist. Then, characters are created on the board surface, forming character symbols. After character creation, a fifth measurement is performed on the board to obtain the fifth measurement result, which is used for subsequent compensation of the film's tensile coefficient. Next, the board is baked at 150℃ for 30 minutes to cure the ink, improving curing efficiency and ensuring the quality of the circuit board. Subsequently, a sixth measurement is performed on the board to obtain the sixth measurement result, which is used for subsequent compensation of the film's tensile coefficient.

[0032] The fifth and sixth measurements both included large-scale panel measurements and unit panel measurements to obtain the large-scale panel measurement results and unit panel measurement results.

[0033] Step E: Compensate for the stretching coefficient of the film based on the first, second, and third measurement results.

[0034] Specifically, the first, second, and third measurement results are analyzed and compared to obtain the expansion and contraction of the board after baking, after circuit pattern making, and after post-processing, respectively, so as to confirm the compensation value of the film's stretch coefficient and compensate for the film's stretch coefficient.

[0035] Step F: Based on the stretching coefficient of the compensated film, the circuit pattern of the board is made and post-processed again, and the board is measured for the fourth time to obtain the fourth measurement result.

[0036] Specifically, based on the compensated film stretching coefficient, the board material is re-processed and its circuit pattern is created, and a fourth measurement is performed to obtain the fourth measurement result. This fourth measurement includes both large-scale board measurement and unit board measurement to obtain the large-scale board measurement result and the unit board measurement result, respectively.

[0037] Step G: Based on the fourth measurement result, confirm the commencement of mass production.

[0038] Specifically, if the fourth measurement result meets the production requirements, mass production is confirmed; if the fourth measurement result does not meet the production requirements, mass production cannot proceed. In this case, the compensation value of the film stretching coefficient needs to be readjusted, and the circuit pattern production and post-processing of the board continue until the final measurement result meets the production requirements. Only then can the batch review be confirmed, thereby ensuring that the quality of the circuit board meets the production requirements, effectively improving quality, reducing rework and scrap.

[0039] In this embodiment, CEM-1 board material was selected for production. The preset tensile coefficient of the film was 100.02%. After comparative analysis of measurement results, the tensile coefficient of the compensated film was 100.05%. Then, 300 PNLs were produced in batches, and the first and last pieces were collected. A board was sampled every 30 PNLs produced, and the measurement results of the large board and unit boards of each PNL were collected. The large board measurement scheme diagram is shown below. Figure 5 As shown, the measurement data for the large board is shown in Table 1; the measurement scheme diagram for the unit board is shown in... Figure 6 As shown in the figure, the measurement data of the unit board is shown in Table 2.

[0040] Table 1. Large-plate measurement data for each PNL

[0041] Table 2 Measurement data of unit boards for each PNL

[0042] Tables 1 and 2 show that the maximum longitudinal deviation of the large KB board is -0.1756 mm (expansion / shrinkage rate 100.05%), and the minimum deviation is -0.0008 mm (expansion / shrinkage rate 100.002%). The maximum weft deviation of the KB board is -0.1113 mm (expansion / shrinkage rate 100.03%), and the minimum deviation is -0.0186 mm (expansion / shrinkage rate 100.003%). For the unit KB board, the maximum longitudinal deviation is -0.1359 mm (expansion / shrinkage rate 100.038%), and the minimum deviation is -0.0013 mm (expansion / shrinkage rate 100.004%). The maximum weft deviation of the unit KB board is -0.108 mm (expansion / shrinkage rate 100.03%), and the minimum deviation is -0.0131 mm (expansion / shrinkage rate 100.003%).

[0043] Therefore, after the CEM-1 board is cut, baked, and the film stretching coefficient is compensated to 100.05%, the board, after tin plating, has the following maximum deviations: Large board KB longitudinal maximum deviation -0.1756mm, KB weft maximum deviation -0.1113mm; Unit board KB longitudinal maximum deviation -0.1359mm, KB weft maximum deviation -0.108mm, meeting quality requirements. CEM-1 board can be mass-produced in this manner to improve board expansion and contraction issues and ensure production quality.

[0044] The circuit board expansion and contraction control method described in this application involves analyzing and comparing the results of three measurements to determine the compensation value of the film's stretch coefficient. Based on the compensated film stretch coefficient, the circuit pattern is fabricated and post-processed on the board again. A fourth measurement is then performed on the board to obtain the fourth measurement result. Based on this fourth measurement result, mass production is confirmed, thereby ensuring that the circuit board quality meets production requirements, effectively improving quality, reducing rework and scrap. Simultaneously, baking the board after cutting removes moisture from the board, reducing dimensional changes caused by moisture evaporation during subsequent processing, lowering the risk of expansion and contraction, improving board stability, and enhancing the product quality of the circuit board.

[0045] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A method for controlling the expansion and contraction of a circuit board, characterized in that, include: Step A: Prepare the board material and cut it into pieces; Step B: Bake the board material and perform a first measurement on the board material to obtain a first measurement result; Step C: Set the stretching coefficient of the film, create a circuit pattern on the board, and perform a second measurement on the board to obtain the second measurement result; Step D: Perform post-processing on the board material and conduct a third measurement on the board material to obtain the third measurement result; Step E: Based on the first measurement result, the second measurement result, and the third measurement result, compensate for the stretching coefficient of the film; Step F: Based on the stretching coefficient of the compensated film, perform circuit pattern fabrication and post-processing on the board again, and perform a fourth measurement on the board to obtain the fourth measurement result; Step G: Based on the fourth measurement result, confirm the commencement of mass production.

2. The circuit board expansion and contraction control method according to claim 1, characterized in that, In step B, the temperature of the baking plate is 130°C, and the baking time is 2 hours.

3. The circuit board expansion and contraction control method according to claim 1, characterized in that, In steps B, C, and D, the first measurement, the second measurement, and the third measurement all include: measuring the large board and the unit board of the board respectively, so as to obtain the measurement results of the large board and the measurement results of the unit board respectively.

4. The circuit board expansion and contraction control method according to claim 1, characterized in that, Step C includes: Step C1: Pre-treat the board and apply dry film to the board; Step C2: Preset the stretching factor of the film, and use the film to transfer the circuit pattern onto the board; Step C3: Etch the non-graphic areas of the board to obtain a circuit pattern on the board, and perform a second measurement on the board to obtain a second measurement result.

5. The circuit board expansion and contraction control method according to claim 1, characterized in that, Step D includes: Step D1: The board material is tin-plated and a third measurement is performed to obtain the third measurement result.

6. The circuit board expansion and contraction control method according to claim 5, characterized in that, After completing step C and before proceeding to step D1, the following steps are also included: Step D2: Apply solder resist to the plate material; Step D3: Create characters on the board and perform a fifth measurement on the board to obtain the fifth measurement result; Step D4: Bake the board and perform a sixth measurement on the board to obtain the sixth measurement result.

7. The circuit board expansion and contraction control method according to claim 6, characterized in that, In step D4, the baking temperature is 150°C and the baking time is 30 minutes.

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