CN101489353B - Design method for board dimension - Google Patents

Abstract

The invention relates to a method for designing the size of a board, which comprises the following steps: setting a first design size of the board; providing a board with the first design size, dividing the surface of the board to be processed into multiple partitions, and recording each partition The size of the board; and put the board in the thermal processing process to make it expand and shrink, calculate the expansion and contraction ratio of the board in each partition, and carry out compensation design on the size of the board in each partition according to the expansion and shrinkage ratio, so as to obtain the board the second design size of the second design size, making the board with the second design size, so that the size of the board with the second design size after the thermal processing process is consistent with the first design size. Using the method for designing the plate size of the present invention can significantly improve the consistency between the expanded and contracted size of the plate and the designed size, thereby improving the production yield of subsequent products, saving production raw materials and reducing production costs.

Description

Design method of plate size

technical field

The invention relates to the technical field of circuit board design, in particular to a method for designing board size.

Background technique

With the rapid development of the electronics industry, the circuits of circuit boards, which are the basic components of electronic products, are made more and more finely, and the holes are made smaller and smaller. Circuit boards are divided into single-sided boards, double-sided boards and multi-layer boards, which are made of copper-clad substrates through a series of processes such as drilling, pressing, etching, exposure and development.

The copper foil in the copper-clad substrate, especially the rolled copper foil, has good ductility, and it will expand due to heat during the circuit board manufacturing process such as lamination, laser drilling and other thermal processing processes. After processing, it will shrink due to heat volatilization and the internal temperature dropping to room temperature. See literature: A.Luft, U.Franz, L.Emsermann, J.Kaspar; Astudy of thermal and mechanical effects on materials induced by pulsed laserdrilling; Applied physics A: Materials Science &Processing; Volume 63, No.2, 1996, Pages 93~101. The expansion and contraction effect of copper foil seriously affects the fine production of circuit substrates, which will cause large errors, resulting in low product yields, waste of production materials and increase production costs. For example, in order to improve production efficiency and reduce costs, in actual production, when making circuit boards, it is usually necessary to design and cut a large-size copper-clad substrate first, use the copper-clad substrate to make a large-size circuit substrate, and then according to actual needs Cut a large-sized circuit board into multiple small-sized circuit boards. Since the expansion and shrinkage ratios of the points far apart in the surface to be processed of the large-size copper foil are relatively different, it is easy to cause inconsistent line widths of the two places far apart on the circuit substrate. As another example, in the process of laser drilling through-holes, the expansion and contraction of copper foil may easily cause the position of the drilled holes to deviate from the pre-designed position, and the shape of the through-holes will be distorted. For another example, in the process of developing solder mask, especially when the accuracy of solder mask exposure is required to be within 100 microns, or even 50 microns or 25 microns, the expansion and contraction of copper foil will lead to deviation of solder mask exposure.

Therefore, it is necessary to provide a design method for the size of the board to reduce or eliminate the obstruction of the expansion and contraction of the copper foil to the development of the circuit board in the direction of refinement.

Contents of the invention

A method for designing a high-precision plate size will be described below with an example, so as to save production raw materials and reduce production costs.

The design method of the plate size includes the following steps: setting the first design size of the plate; providing the plate with the first design size, dividing the surface to be processed of the plate into multiple partitions, and recording the size of the plate in each partition; And put the plate in the thermal processing process to make it expand and shrink, calculate the expansion and contraction ratio of the plate in each partition, and carry out compensation design for the size of the plate in each partition according to the expansion and shrinkage ratio, so as to obtain the second design size of the plate , making the board with the second design size, so that the size of the board with the second design size after the thermal processing process is consistent with the first design size.

The design method of the plate size of this technical solution divides the surface to be processed of the plate into multiple partitions, calculates the expansion and contraction ratio of the sheet in each partition, and designs and compensates the size of the sheet in each partition according to the expansion and contraction ratio of each partition , and use the compensated size to make the plate, which significantly improves the consistency between the expanded and contracted size of the plate and the design size, thereby improving the production yield of subsequent products, saving raw materials and reducing production costs.

Description of drawings

Fig. 1 is a schematic diagram of copper foil designed by the design method of plate size according to the technical solution.

FIG. 2 is a schematic diagram of design size compensation of the zone _M1 of the copper foil shown in FIG. 1 .

Detailed ways

The design method of the plate size of this technical solution is suitable for compensating the design size of the plate when designing plates with thermal expansion and contraction effects, such as copper-clad substrates and circuit substrates in production, so that the plate is thermally processed and formed. The size is consistent with the design size. Since when the copper-clad substrate is used to make a circuit board, the processed surface of the copper-clad substrate is actually the surface of the copper foil, so the design size of the copper-clad substrate is the size of the surface to be processed of the copper foil. Taking the design of copper foil as a copper-clad substrate as an example, the design method of the plate size of the technical solution will be described in conjunction with embodiments and accompanying drawings.

The design method of the plate size provided by the embodiment of the technical solution includes the following steps when used to design the copper foil of the copper-clad substrate:

The first step is to preset the first design size of the copper foil;

In the second step, the copper foil having the first design size is provided, the surface to be processed of the copper foil is divided into a plurality of partitions, and the size of the surface to be processed of the copper foil of each partition is recorded.

Please refer to FIG. 1 , the copper foil 10 can be rolled copper foil or electrolytic copper foil, and has a surface 11 to be processed. The first design dimension of the surface to be processed 11 is length A and width B.

The partitioning refers to virtual partitioning of the surface to be processed 11 in design through relevant software in the computer, so as to compensate the first design size of the surface to be processed 11 according to the principle of partition compensation. The number of partitions depends on actual needs. Of course, due to the need for high precision, the more partitions the better. Preferably, each subregion is in the shape of a rectangle, so as to facilitate subsequent monitoring of the expansion and contraction ratio of the copper foil in each subregion.

In this embodiment, the surface to be processed 11 has a first subregion M ₁ , a second subregion M ₂ , a third subregion M ₃ and a fourth subregion M ₄ . Two adjacent sides of the first subregion M ₁ share the same side with the second subregion M ₂ and the third subregion M ₃ respectively, and a vertex formed by the adjacent two sides forms an opposite vertex angle with a vertex angle of the fourth subregion M ₄ . That is, if the first partition M ₁ has a length of L ₁ and a width of L ₁₁ , the second partition M ₂ has a length of L ₂ and a width of L ₂₂ , the third partition M ₃ has a length of L ₃ and a width of L ₃₃ , and the fourth partition M 2 has a length of L 2 and a width of L 22 . The length of partition M ₄ is L ₄ and the width is L ₄₄ , then L ₁ =L ₂ , L ₃ =L ₄ , L ₁₁ =L ₃₃ , L ₂₂ =L ₄₄ , L ₁ +L ₃ =A, L ₁₁ +L ₂₂ = B.

In the third step, the copper foil 10 is placed in a thermal processing process to cause expansion and contraction, and the expansion and contraction ratios of the copper foils in each partition are calculated, and the size of the copper foils in each partition is compensated according to the expansion and contraction ratios, so that The second design size of the copper foil is obtained, and the copper foil with the second design size is manufactured, so that the size of the copper foil with the second design size after thermal processing is consistent with the first design size.

The calculation of the expansion and contraction value of the copper foil in each subregion includes making at least one reference area in the surface to be processed in each subregion, and selecting at least one reference point in each reference area, so as to facilitate the subsequent measurement of the reference points in each subregion The expansion and contraction ratio of the copper foil at each area can be obtained from the expansion and contraction ratio of the copper foil in each partition.

Each reference area can be set anywhere in each partition, preferably, each reference area is equally spaced in the surface to be processed 11 . Taking the partition _M1 as an example, the reference area may be located at each edge of the partition _M1 . Specifically, the reference area may be a groove 12 disposed in the partition _M1 . The groove 12 can be formed by chemically etching the copper foil 10 , and is opened from the surface to be processed 11 to the inside of the copper foil 10 . The reference point may be any point on the copper foil corresponding to the groove 12 . Preferably, the reference point is the center point of the bottom surface of the groove 12 . When the plate is a copper-clad base material including copper foil and an insulating base material, part of the copper foil can also be etched away by chemical etching, so that the copper foil layer and the insulating base material layer are enclosed to form a groove. Of course, when the plate is a copper-clad substrate with multiple layers of copper foil, it is necessary to etch part of the outermost copper foil of the copper-clad substrate. When the plate is a circuit substrate in production, a reference area can be obtained by etching a certain circuit, as long as it is convenient to set an identifiable reference area in the surface 11 to be processed and then measure the expansion and contraction rate of the copper foil at the reference point to obtain the reference area. The expansion and contraction rate of the copper foil in the partition where the reference point is located can be obtained. In this embodiment, the copper foil 10 has a plurality of grooves 12 opened from the surface 11 to be processed to the inside thereof, and each groove 12 is disposed at four corner regions of each partition. The cross section of the groove 12 is circular with a diameter of 1 mm, and the reference point is the center point of the bottom surface of each groove 12 . Taking the first partition _M1 as an example, there are four reference points E, F, G, and H in it. The four reference points are respectively located in the four corner areas of the partition _M1 .

It is worth mentioning that since the surface 11 of the copper foil 10 to be processed and each partition can be regarded as composed of infinitely many points, although the expansion and contraction ratios of the copper foil corresponding to each point are different, but the adjacent two The expansion and contraction ratio of the two points is relatively small, that is, the expansion and contraction ratio of the copper foil corresponding to the two points is close to a constant. Therefore, in order to further improve the accuracy, more reference areas can be made in each partition, so that more reference points can be selected, and the reference points can be evenly distributed in the surface to be processed in each partition as far as possible.

For the copper foil used for making circuit boards, the thermal processing process includes processes such as thermocompression bonding, drilling, and solder masking.

The calculation of the expansion and contraction ratios of the copper foils in each partition can be obtained by calculating the position coordinate difference of the copper foil at each reference point relative to the surface to be processed 11 before and after expansion and contraction.

Taking the first subregion _M1 and the reference point E set in the first subregion _M1 as examples, the calculation of the coordinate position difference of the copper foil at each reference point after the expansion and contraction of the surface 11 to be processed and the expansion and contraction of the subregion _M1 will be described. Rate.

Referring to FIG. 1 , a rectangular coordinate axis XOY is established first, and the first coordinate position E(X ₁ , Y ₁ ) of the reference point E is recorded. The coordinate axis can be established in the surface to be processed 11, that is to say, the position coordinates of each reference point in each partition can be identified through the coordinate axis, and the coordinate axis can also be established in each partition respectively, but as long as it can be marked The location coordinates of the reference point are sufficient. In this embodiment, the coordinate axis XOY is set in the surface to be processed 11 , and the position coordinates of all reference points in the surface to be processed 11 are marked by the coordinate axis XOY. The X axis of the coordinate axis XOY is parallel to the length direction of the partition _M1 , and the Y axis is parallel to the width direction of the partition _M1 . Secondly, the copper foil 10 is placed in the same environment as the subsequent processing parameters, such as a thermocompression bonding process, so that it undergoes the same process as the subsequent processing to simulate the dimensional change of the copper foil 10 in the subsequent processing process. After completion, the second coordinate position E′(X ₂ , Y ₂ ) of the reference point E on the coordinate axis XOY is obtained immediately to obtain the expansion and contraction state of the copper foil at the reference point E during the thermocompression bonding process. Finally, according to the first coordinate position E(X ₁ , Y ₁ ) and the second coordinate position E′(X ₂ , Y ₂ ) of the reference point E, the front and rear coordinate position difference of the reference point E is calculated. Then the expansion and contraction rate _E 1 of the partition M ₁ along the X axis at the reference point E is (X ₂ -X ₁ )/X ₁ , and the expansion and contraction rate E ₂ along the Y axis is (Y ₂ -Y ₁ )/Y ₂ .

In the same way, the front and rear coordinate position differences of the three points F, G, and H can be calculated according to the aforementioned method. If the expansion and contraction ratios of partition M ₁ at the reference points F, G, and H along the X axis are F ₁ , G ₁ , and H ₁ respectively, and the expansion and contraction rates along the Y axis are F ₂ , G ₂ , and H ₂ , respectively, Then the expansion and contraction rate N ₁ of the partition M ₁ along the X axis is (E ₁ +F ₁ +G ₁ +H ₁ )/4, and the expansion and contraction rate N ₂ along the Y axis is (E ₂ +F ₂ +G ₂ + H ₂ )/4. The expansion and contraction ratios of the second subregion M ₂ , the third subregion M ₃ and the fourth subregion M ₄ along the X-axis and Y-axis directions can be calculated according to the aforementioned method.

The dimension compensation design of the copper foil of each partition according to the expansion and contraction ratio refers to compensating the first design dimension of the surface to be processed 11 of the copper foil 10 through related software in the computer.

Taking the first partition M ₁ as an example, if its expansion and contraction ratio N ₁ along the X axis (E ₁ +F ₁ +G ₁ +H ₁ )/4 is greater than zero, then the first partition M ₁ obtained after compensation The length of the second design dimension L ₁ /(1+N ₁ ), if N ₁ is less than zero, the length of the second design dimension of the first partition M ₁ obtained after compensation is L ₁ /(1-N ₁ ), If its expansion and contraction ratio N ₂ along the Y axis (E ₂ +F ₂ +G ₂ +H ₂ )/4 is greater than zero, the width of the second design dimension of the first partition M ₁ obtained after compensation should be L ₁₁ /(1+N ₂ ), if N ₂ is less than zero, the width of the second design dimension of the partition M ₁ should be L ₁₁ /(1-N ₂ ). Please refer to FIG. 2. In this embodiment, since N ₁ is greater than zero and N ₂ is less than zero, the expansion value of the first partition M ₁ along the X axis is L ₆ , and the shrinkage value along the Y axis is L ₅ . Therefore, the partition M ₁ The second design dimension obtained after compensation should be length L ₁ -L ₆ and width L ₁₁ +L ₅ . The length and width of the first design dimension of the second subregion M ₂ , the third subregion M ₃ and the fourth subregion M ₄ can be designed and compensated according to the aforementioned method.

The design method of the plate size in this embodiment divides the copper foil into multiple partitions virtually, calculates the copper foil expansion and contraction ratio of each partition, and performs size compensation on the copper foil of each partition according to the expansion and contraction ratio of each partition to obtain the sheet material The second design size, so that before making the circuit board, it is only necessary to cut the copper foil of the corresponding size according to the compensated size of each partition, that is, the second design size, and use the copper clad substrate including the copper foil of the second size for Just make the circuit board. Due to the predictable design compensation of the copper foil 10 before making the circuit board, the size of the copper foil with the second size after the compensation can be highly consistent with the first design size after the thermal processing process, so the expansion and contraction can be greatly reduced The impact on the precision of products that require thermal processing such as subsequent drilling, solder mask development, etc., so as to improve the production yield of subsequent products, save production raw materials and reduce production costs.

The design method of the plate size of the technical solution has been described in detail above, but it should not be understood as a limitation to the concept of the technical solution. It can be understood that, for those skilled in the art, various other corresponding changes and modifications can be made according to the technical concept of the technical solution, and all these changes and modifications should belong to the protection scope of the claims of the present application .

Claims (9)

1. the method for designing of a board dimension may further comprise the steps:

Set first designing dimension of board;

Sheet material with this first design size is provided, the face to be processed of sheet material is divided into a plurality of subregions, write down the size of the sheet material of each subregion; And

Sheet material is placed hot processing manufacture process, make it that breathing take place, calculate the breathing rate of the sheet material of each subregion, and the size of the sheet material of each subregion is compensated design according to this breathing rate, thereby obtain second design size of sheet material, making has the sheet material of second design size, so that it is consistent with described first design size to have the size of sheet material after hot processing manufacture process of second design size.

2. the method for designing of board dimension as claimed in claim 1, it is characterized in that, the breathing rate of the sheet material of described each subregion of calculating is included in to be processed of sheet material of each subregion and makes at least one reference region, in this reference region, choose at least one datum mark, calculate the mean value of the breathing rate of the sheet material of whole datum in each subregion.

3. the method for designing of board dimension as claimed in claim 2, it is characterized in that, in each subregion of described calculating all the mean value of the breathing rate of the sheet material of datum be included in to be processed of sheet material with described first design size and set up reference axis, write down second coordinate position of each datum mark of first coordinate position of each datum mark and this sheet material after breathing, the difference of calculating first coordinate position of each datum mark and second coordinate position draws the breathing rate of the sheet material of each datum, and calculates the step of mean value of breathing rate of the sheet material of the whole datum of each subregion according to the breathing rate of the sheet material of each datum.

4. the method for designing of board dimension as claimed in claim 3 is characterized in that, be set forth in and set up reference axis in to be processed of sheet material with this first design size and be included in and respectively set up a reference axis in each subregion.

5. as claim

The method for designing of described board dimension is characterized in that, DescribedEach reference region is equidistantly arranged in to be processed.

6. as claim The method for designing of described board dimension is characterized in that, described each reference region lays respectively to be processed edge of described sheet material.

7. the method for designing of board dimension as claimed in claim 5 is characterized in that, described each reference region lays respectively at the edge of described each subregion.

8. as the method for designing of each described board dimension of claim 5～7, it is characterized in that described reference region is a groove, described groove is offered towards sheet material inside from the to be processed of sheet material.

9. the method for designing of board dimension as claimed in claim 8 is characterized in that, described groove cross section is circular, and described datum mark is the central point of groove floor.

1. the method for designing of a board dimension may further comprise the steps:

Set first designing dimension of board;

Sheet material with this first design size is provided, the face to be processed of sheet material is divided into a plurality of subregions, write down the size of the sheet material of each subregion; And

Sheet material is placed hot processing manufacture process, make it that breathing take place, calculate the breathing rate of the sheet material of each subregion, and the size of the sheet material of each subregion is compensated design according to this breathing rate, thereby obtain second design size of sheet material, making has the sheet material of second design size, so that it is consistent with described first design size to have the size of sheet material after hot processing manufacture process of second design size.

2. the method for designing of board dimension as claimed in claim 1, it is characterized in that, the breathing rate of the sheet material of described each subregion of calculating is included in to be processed of sheet material of each subregion and makes at least one reference region, in this reference region, choose at least one datum mark, calculate the mean value of the breathing rate of the sheet material of whole datum in each subregion.

3. the method for designing of board dimension as claimed in claim 2, it is characterized in that, in each subregion of described calculating all the mean value of the breathing rate of the sheet material of datum be included in to be processed of sheet material with described first design size and set up reference axis, write down second coordinate position of each datum mark of first coordinate position of each datum mark and this sheet material after breathing, the difference of calculating first coordinate position of each datum mark and second coordinate position draws the breathing rate of the sheet material of each datum, and calculates the step of mean value of breathing rate of the sheet material of the whole datum of each subregion according to the breathing rate of the sheet material of each datum.

4. the method for designing of board dimension as claimed in claim 3 is characterized in that, be set forth in and set up reference axis in to be processed of sheet material with this first design size and be included in and respectively set up a reference axis in each subregion.

5. the method for designing of board dimension as claimed in claim 2 is characterized in that, described each reference region is equidistantly arranged in to be processed.

6. the method for designing of board dimension as claimed in claim 2 is characterized in that, described each reference region lays respectively to be processed edge of described sheet material.

7. the method for designing of board dimension as claimed in claim 5 is characterized in that, described each reference region lays respectively at the edge of described each subregion.

8. as the method for designing of each described board dimension of claim 5～7, it is characterized in that described reference region is a groove, described groove is offered towards sheet material inside from the to be processed of sheet material.

9. the method for designing of board dimension as claimed in claim 8 is characterized in that, described groove cross section is circular, and described datum mark is the central point of groove floor.

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