WO2019119770A1 - Method for estimating expansion and contraction compensation coefficient of new pcb material - Google Patents

Abstract

A method for estimating an expansion and contraction compensation coefficient of a new PCB material. The method comprises: selecting a common PCB material as a contrast material; respectively testing the expansion and contraction change values of a first core plate and a first prepreg of a new PCB material, and respectively testing the expansion and contraction change values of a second core plate and a second prepreg of the contrast material; carrying out a contrastive analysis on the expansion and contraction change values and the differences of the first core plate and the second core plate in respective processing flows; carrying out a contrastive analysis on the expansion and contraction change values and the differences of the first prepreg and the second prepreg in respective processing flows; and carrying out analogical derivation in combination with an expansion and contraction compensation rule of the contrast material, and deriving an expansion and contraction compensation rule of the new PCB material. According to the present invention, the expansion and contraction variation of a new PCB material can be quickly and effectively derived, so as to obtain an expansion and contraction compensation coefficient of the new PCB material, without requiring bulk testing of the expansion and contraction variation of a copper thickness, a plate thickness, a copper residual rate, a prepreg type, a prepreg number, etc., when designing different laminations of the new PCB material, thereby saving a large amount of manpower, material resources and financial resources.

Description

Method for evaluating the compensation coefficient of PCB new material expansion and contraction Technical field

The invention relates to the field of printed circuit boards, and more particularly to a method for evaluating the compensation coefficient of new material of PCB.

Background technique

At present, PCBs are increasingly moving toward high speed, high frequency, high heat dissipation, and high reliability, prompting PCB substrate manufacturers to continuously optimize and upgrade the composition of the substrate to obtain low dielectric constant and low dielectric loss. With high heat dissipation characteristics and high reliability of substrate materials, there are more and more PCB substrate types and specifications. At the same time, another important development trend of PCB is high alignment accuracy and high dimensional accuracy. In the process of PCB manufacturing, the PCB is aligned due to the shrinkage and contraction effect of the substrate in complex environments such as force, heat and humidity. Accuracy and dimensional accuracy have an important impact. With the increasing variety of substrates, how to quickly and effectively evaluate the amount of change in PCB material during processing is a major problem in PCB fabrication.

For the evaluation of the shrinkage and shrinkage characteristics of new materials, the current practice of PCB manufacturers is to first do a batch or batch of test boards, test the dimensional change values of each core board, and determine the material's shrinkage compensation coefficient, and then increase or decrease the material. The compensation coefficient is used in the PCB of the subsequent batch to reduce the influence of the shrinkage change on the alignment accuracy and dimensional accuracy of the PCB. Although this method can solve the influence of the shrinkage effect on the PCB fabrication to some extent, due to the production process. The file design and stack design of each order product are inconsistent, so the file design and stack design of the shrink test board are different from the actual order, and a large number of tests are required to obtain a stable shrinkage coefficient. In addition, another method of shrinking and testing in the industry is based on the big data level, which greatly tests the shrinkage and change of copper thickness, plate thickness, residual copper ratio, prepreg type, and number of prepregs in different laminate designs to obtain the rise of new materials. Reducing the law and establishing the corresponding PCB shrinkage compensation rules, but when the types/models of materials continue to increase, more manpower, material resources, and financial resources are needed to study the shrinkage behavior of different materials, and this method cannot adapt to current electronic products. Faster, more competitive demands.

Summary of the invention

Based on this, the present invention overcomes the defects that the prior art cannot quickly and effectively evaluate the amount of change in the shrinkage and contraction of new PCB materials during processing, and provides an evaluation method for the compensation coefficient of the new material of the PCB.

Its technical solutions are as follows:

A method for evaluating the compensation coefficient of a new PCB material, including:

Select a common PCB material that has been determined to be a perfect inflation compensation rule as a comparison material;

Testing the first core plate of the new material of the PCB and the change value of the first prepreg, and the change values of the second core plate and the second half solid film of the comparative material respectively, the first core plate is selected The specifications are the same as the specifications of the second core sheet, and the first prepreg is selected to have the same specifications as the second prepreg;

Contrast and analyze the change and difference of the first core plate and the second core plate in the respective processing flow; compare and analyze the change and difference of the first prepreg and the second prepreg in the respective processing flow;

Combining the expansion and contraction compensation rules of the comparative materials, the analogy derivation is carried out, and the expansion and contraction compensation rules of the new PCB materials are derived.

The comparative material selected in the technical solution is a commonly used PCB material which has been determined by the big data method to have a perfect expansion and contraction compensation rule, and the different matching structure, core thickness, core copper thickness, prepreg type, and prepreg quantity of the comparative material. When there is a change, there is a corresponding expansion and contraction compensation rule. Test the difference between the shrinkage and change of the core plate and the prepreg of the specific specification of the new PCB material to be evaluated in the key processing flow affecting the shrinkage value, and the key of the core plate and the prepreg of the specific material of the comparison material influencing the shrinkage value The difference between the ups and downs in the processing flow, combined with the comparison of the ups and downs compensation rules of the comparative materials, can be used to quickly and effectively derive the ups and downs of the new PCB materials, thereby obtaining the expansion and contraction compensation coefficient of the new PCB materials. There is no need to extensively test the shrinkage and change of copper thickness, plate thickness, residual copper ratio, prepreg type, and number of prepregs in different laminate design, saving a lot of manpower, material and financial resources.

In one embodiment, the test method for the change in the change in the first core plate and the second core plate is:

Forming at least four spaced apart first test holes on the first core board, at least four of the first test holes having a center line connection having a rectangular shape; and forming at least four interval settings on the second core board a first test hole, at least four of the first test holes have a center line connecting the rectangle;

Measuring the positions of the first test holes in the first core plate and the second core plate respectively, and calculating the distances F ₁ , F ₂ , W ₁ , W ₂ between the adjacent first test holes, and recording the initial distances;

Etching the first core plate into a graphic design having a first residual copper ratio; etching the second core plate into a graphic design having a second residual copper ratio, the first residual copper ratio and the second residual copper The same rate;

Laminating the first core plate under a pressing process corresponding to the material; laminating the second core plate under a pressing process corresponding to the material;

Measuring the positions of the first test holes after the lamination treatment in the first core plate and the second core plate, respectively, and calculating the distances F ₁ ', F ₂ ', W ₁ ' between the adjacent first test holes, W ₂ ', recorded as the final distance;

The dimensional change values ΔF ₁ , ΔF ₂ , ΔW ₁ , ΔW _{2 of the} first core plate and the second core plate after etching and pressing are respectively calculated; wherein ΔF ₁ = (F ₁ '-F ₁ )/F ₁ , ΔF ₂ = (F ₂ '-F ₂ ) / F ₂ , ΔW ₁ = (W ₁ '-W ₁ ) / W ₁ , ΔW ₂ = (W ₂ '-W ₂ ) / W ₂ .

In one embodiment, the first residual copper ratio and the second residual copper ratio are 0%, 50%, or 100%.

In one embodiment, at least four of the first test holes on the first core board are respectively disposed around the first core board; and at least four of the first tests on the second core board The holes are respectively disposed around the second core plate, and the two adjacent first test holes on the first core plate are respectively located in the warp or weft direction of the fiberglass cloth in the first core plate, and the second core The two adjacent first test holes on the plate are respectively located in the warp or weft direction of the fiberglass cloth in the second core plate.

In one embodiment, the graphic design of the first core plate and the graphic design of the second core plate are graphic designs that are evenly arranged in the warp and weft directions.

In one embodiment, the test method for the change in the change in the first prepreg and the second prepreg is:

Forming a layer of copper foil on the top bottom layer of the first prepreg to form a first pre-laminated sheet, and respectively forming a layer of copper foil on the top bottom layer of the second prepreg to form a second pre-stack;

Quickly pressing the first pre-stack into a first dummy board, and pressing the second pre-stack into a second dummy board;

Forming at least four spaced second test holes on the first dummy board, at least four of the second test holes having a center line connection having a rectangular shape; and forming at least four intervals on the second core board a second test hole is disposed, and a center line of at least four of the second test holes is rectangular;

Measure the positions of the second test holes in the first dummy plate and the second dummy plate, respectively, and calculate the distances F ₃ , F ₄ , W ₃ , and W ₄ between the adjacent second test holes, and record the initial distance. ;

Laminating the first dummy board under a pressing process corresponding to the material; and laminating the second dummy board under a pressing process corresponding to the material;

Measure the positions of the second test holes after the lamination process in the first dummy plate and the second dummy plate, respectively, and calculate the distances F ₃ ', F ₄ ', W ₃ between the adjacent second test holes. ', W ₄ ', recorded as the final distance;

Calculating the dimensional change values ΔF ₃ , ΔF ₄ , ΔW ₃ , ΔW ₄ after pressing the first dummy plate and the second dummy plate, respectively; wherein ΔF ₃ = (F ₃ '-F ₃ )/F ₃ , ΔF ₄ = (F ₄ '-F ₄ ) / F ₄ , ΔW ₁ = (W ₃ '-W ₃ ) / W ₃ , ΔW ₄ = (W ₄ '-W ₄ ) / W ₄ .

In one embodiment, at least four of the second test holes on the first dummy board are respectively disposed around the first dummy board; at least four of the second dummy board are The second test holes are respectively disposed around the second dummy board, and the adjacent second test holes on the first dummy board are respectively located in the warp or weft direction of the fiberglass cloth in the first dummy board, and The adjacent second test holes on the second dummy board are respectively located in the warp or weft direction of the fiberglass cloth in the second dummy board.

In one embodiment, the method for deriving the shrinkage compensation rule of the new PCB material is:

Calculate the dimensional change ΔF _A and the dimensional change ΔW _{A of the} first core in the warp direction during the machining process respectively; calculate the dimensional change ΔF _B and the dimensional change ΔW of the warp direction of the second core during the machining process, respectively. _B ;

Calculating a difference ΔF _c =ΔF _A -ΔF _B of the dimensional change of the first core plate and the second core plate in the radial direction, and calculating a difference ΔW _c of the dimensional change of the first core plate and the second core plate in the weft direction ΔW _{A -} ΔW _B ;

Calculating the dimensional change ΔF _A ' of the warp direction of the first dummy web during the lamination process and the dimensional change ΔW _A ' of the weft direction respectively; calculating the dimensional change of the warp direction of the second dummy web during the laminating process ΔF _B ' and zonal dimensional change ΔW _B ';

Calculating a difference ΔF _p =ΔF _A ′−ΔF _B ′ of the dimensional change of the first dummy plate and the second dummy plate in the radial direction, and calculating a dimensional change of the first dummy plate and the second dummy plate in the weft direction The difference ΔW _p = ΔW _A '- ΔW _B ';

Then, the change values of the new material of the PCB and the contrast material in the warp and latitude are ΔF=(ΔF _c +ΔF _p )/2; ΔW=(ΔW _c +ΔW _p )/2;

Combined with the comparison of the ups and downs compensation rules of comparative materials, the analogy derivation is derived, and the rules for the expansion and contraction of new PCB materials are derived.

In one embodiment, wherein ΔF _A = ∑ [(ΔF _1A + ΔF _2A )/2], ΔW _A = ∑ [(ΔW _1A + ΔW _2A )/2], the ΔF _1A , ΔF _2A are respectively a core plate of size variation value ΔF _1, ΔF _2, the ΔW _1A, ΔW _2A are dimensional changes in the value of the first core plate is ΔW _1, ΔW _2, Σ is the first size and number of each core plate The sum of the changes; where ΔF _B = ∑ [(ΔF _1B + ΔF _2B )/2], ΔW _B = ∑ [(ΔW _1B + ΔW _2B )/2], the ΔF _1B , ΔF _2B are the second core plates respectively the dimensional change value ΔF _1, ΔF _2, the ΔW _1B, ΔW _2B are dimensional changes in the value of the second core plate is ΔW _1, ΔW _2, Σ is a change in the size and number of second core plate of each of sum.

In one of the embodiments, wherein ΔF _A '= ∑ [(ΔF _1A ′ + ΔF _2A ′)/2], ΔW _A ′ = ∑ [(ΔW _1A ′ + ΔW _2A ′)/2], the ΔF _1A ', ΔF _2A ' is the distance F ₁ ', F ₂ ' between the two adjacent test holes in the first dummy plate, respectively, and the ΔW _1A , ΔW _2A are respectively in the first dummy plate The distance W ₁ ', W ₂ ' between the adjacent test holes of the two latitudinal directions, which is the sum of changes of the first dummy plates of various specifications and numbers; wherein ΔF _B '= ∑ [(ΔF _1B ′+ ΔF _2B ')/2], ΔW _B ' = ∑ [(ΔW _1B ′ + ΔW _2B ′) /2], the ΔF _1B ′, ΔF _2B ′ are respectively two meridional adjacent in the second dummy plate Distances F ₁ ', F ₂ ' between the test holes, the ΔW _1B ', ΔW _2B ' are the distances W ₁ ', W between the two latitudinal adjacent test holes in the second dummy plate, respectively ₂ ', the ∑ is the sum of changes of the second dummy splicing plates of various specifications and quantities.

DRAWINGS

1 is a schematic structural view of a first core board or a second core board of the present invention;

2 is a schematic view showing the structure of a first prepreg or a second prepreg according to the present invention.

Description of the reference signs:

10. The first test hole; 20, the second test hole.

Detailed ways

The present invention will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of the invention.

A method for evaluating the compensation coefficient of a new PCB material, including:

Select a commonly used PCB material that has been determined by a perfect inflation and contraction compensation rule as a comparison material;

Testing the first core plate of the new material of the PCB and the change value of the first prepreg, and the change values of the second core plate and the second half solid film of the comparative material respectively, the first core plate is selected The specifications are the same as those of the second core sheet, and the first prepreg is selected to have the same specifications as the second prepreg; the specifications are the same including at least the thickness and the glass fiber type.

Contrast and analyze the change and difference of the first core plate and the second core plate in the respective processing flow; compare and analyze the change and difference of the first prepreg and the second prepreg in the respective processing flow;

Combining the expansion and contraction compensation rules of the comparative materials, the analogy derivation is carried out, and the expansion and contraction compensation rules of the new PCB materials are derived.

The comparative material selected in the embodiment is a common PCB material which has been determined by the big data method to obtain a perfect shrinkage compensation rule, and the different matching structure, core thickness, core copper thickness, prepreg type, and prepreg number of the comparative material. When there is a change, there is a corresponding expansion and contraction compensation rule. Test the difference between the shrinkage and change of the core plate and the prepreg of the specific specification of the new PCB material to be evaluated in the key processing flow affecting the shrinkage value, and the key of the core plate and the prepreg of the specific material of the comparison material influencing the shrinkage value The difference between the ups and downs in the processing flow, combined with the comparison of the ups and downs compensation rules of the comparative materials, can be used to quickly and effectively derive the ups and downs of the new PCB materials, thereby obtaining the expansion and contraction compensation coefficient of the new PCB materials. There is no need to extensively test the shrinkage and change of copper thickness, plate thickness, residual copper ratio, prepreg type, and number of prepregs in different laminate design, saving a lot of manpower, material and financial resources.

As shown in FIG. 1, the test method for the change of the first core plate and the second core plate is:

The first core plate and the second core plate are selected, wherein the first core plate and the second core plate are thin thickness specifications such as 0.05 mm, 0.10 mm, 0.13 mm, 0.15 mm, 0.20 mm, etc., which are easy to change in size, and the first core The copper thickness of the plate and the second core plate is 0.5 oz, 1 oz, and the like. In addition, in the embodiment, the first core plate and the second core plate are both rectangular core plates. In order to test the accuracy of the expansion and contraction compensation rule of the embodiment, the number of the first core board and the second core board are multiple, and the specifications of the first core board and the second core board are one-to-one correspondence. , including the following specifications: 0.075mm thickness, with this: 1080 * 1; 0.10mm thickness, with this: 3313 * 1; 0.125mm thickness, with this: 2116 * 1; 0.15mm thickness, with this: 1080 * 2; 0.20mm , with this: 3313 * 2, 0.25mm, with this: 2116 * 2, size is 16 * 18inch, 16 * 21inch or 18 * 24inch and other common specifications.

At least four first test holes 10 are formed on the first core board. In this embodiment, four first test holes 10 are arranged at intervals, and the center points of the four first test holes 10 are connected. Forming a rectangle; forming at least four first test holes 10 at intervals in the second core plate. In this embodiment, four first test holes 10 are arranged at intervals, and the center points of the four first test holes 10 are The connection is rectangular. In this embodiment, the four first test holes 10 are located at four corners of the rectangular core plate, that is, the four first test holes on the first core plate are respectively disposed around the first core plate; The four first test holes on the second core board are respectively disposed around the second core board, and the two adjacent first test holes on the first core board are respectively located in the first core board. In the warp or weft direction of the fiberglass cloth, adjacent first test holes on the second core board are respectively located in the warp or weft direction of the fiberglass cloth in the second core board. This setting facilitates measurement of the change in the warp and weft of the first core in the warp and weft directions, as well as the change in the warp and weft of the second core in the warp and weft directions. The first test hole 10 may be a circular shape, a regular polygon or the like. The distance between the first test hole 10 and the edge of the core plate is 2.54 mm - 50.8 mm, and the diameter or side length of the first test hole is 0.5. Mm-4mm, the larger the diameter of the first test hole, the higher the dimensional test accuracy. In this embodiment, a circular shape is adopted as the shape of the first test hole 10. The distance from the first test hole 10 to the edge of the core plate is 25.4 mm, and the diameter of the first test hole 10 is 3.175 mm.

Measuring the positions of the first test holes 10 in the first core plate and the second core plate respectively, and calculating the distances F ₁ , F ₂ , W ₁ , and W ₂ between the adjacent first test holes 10, which are recorded as initial distances. The distance between the adjacent first test holes 10 is the center distance of each of the first test holes 10. The F ₁ includes F _1A , F _1B , wherein F _1A represents a center distance F _{1 of the} first core plate in which the two meridional adjacent first test holes 10, and F _1B represents a second core plate in which two meridional adjacent portions a central hole 10 from the test F _1; Similarly, the F ₂ comprising F _2A, F _2B; W ₁ comprises the W _1A, W _1B; the W ₂ comprising a W _2A, W _2B.

Etching the first core plate into a graphic design having a first residual copper ratio; etching the second core plate into a graphic design having a second residual copper ratio, the first residual copper ratio and the second residual copper The rate is the same. In this embodiment, the first core plate is subjected to a pretreatment line, that is, chemically microetched, cleaned, and then adhered to a dry film, and then transferred, developed, etched, and ejected by a pattern to obtain a graphic design having a 50% residual copper ratio. The graphic design is a pattern uniformly arranged in the warp and weft directions, and avoids the case where the warp and weft patterns interfere with each other when measuring the warp direction and the zonal up and down value; similarly, the second core board is made the same Processed to give it a graphic design with a 50% residual copper ratio. In other embodiments, the first residual copper ratio and the second residual copper ratio may be 0%, 100%, or other values.

Laminating the first core plate under a pressing process; laminating the second core plate under a pressing process; the pressing process is a new material of the PCB and a prepreg corresponding to the comparative material Pressing procedure.

The positions of the first test holes 10 after the lamination treatment in the first core plate and the second core plate are respectively measured, and the distances F ₁ ', F ₂ ', W ₁ between the adjacent first test holes 10 are calculated. ', W ₂ ', denoted as the final distance; the F ₁ 'includes F _1A ', F _1B ', where F _1A ' represents the center distance F _{1 of the} first core plate in which the two longitudinally adjacent first test holes 10 are adjacent ', F _1B ' represents the center distance F ₁ ' of the second core plate in which the two longitudinally adjacent first test holes 10; similarly, the F ₂ ' includes F _2A ', F _2B '; the W ₁ ' W _1A ', W _1B ' is included; and W ₂ ' includes W _2A ', W _2B '.

The dimensional change values ΔF ₁ , ΔF ₂ , ΔW ₁ , ΔW _{2 of the} first core plate and the second core plate after etching and pressing are respectively calculated; wherein ΔF ₁ = (F ₁ '-F ₁ )/F ₁ , ΔF ₂ = (F ₂ '-F ₂ ) / F ₂ , ΔW ₁ = (W ₁ '-W ₁ ) / W ₁ , ΔW ₂ = (W ₂ '-W ₂ ) / W ₂ . The ΔF ₁ includes ΔF _1A , ΔF _1B , wherein ΔF _1A represents the size change value ΔF _{1 of the} first core plate after etching and pressing, and ΔF _1B represents the dimensional change value ΔF of the second core plate after etching and pressing. _1; Similarly, the ΔF ₂ comprises ΔF _2A, F _2B; Delta] W ₁ comprises said ΔW _1A, ΔW _1B; ΔW ₂ comprises the ΔW _2A, ΔW _2B.

In the present embodiment, the test method for the change in the shrinkage and contraction of the first prepreg and the second prepreg is as follows:

A layer of copper foil is respectively disposed on the top layer of the first prepreg to form a first pre-laminated sheet, and a layer of copper foil is respectively disposed on the top layer of the second prepreg to form a second pre-stack; the first prepreg selected in the embodiment The specifications of the second prepreg are 106, 1080, 3313, and 2116. The prepreg of each specification is a high-adhesive prepreg. The higher the amount of glue, the larger the shrinkage, and the higher the dimensional accuracy. The copper foil has a thickness of 0.33 oz or 0.5 oz.

The first pre-stack is placed in a vacuum quick press, and is pressed into a first dummy plate at a certain temperature/pressure and time, wherein the pressing temperature is 105 ° C, the pressing time is 30 s, and the pressure is 50 psi; Similarly, the second pre-laminated sheet is pressed into the second dummy board; the degree of curing reaction in each of the dummy boards is extremely low during the rapid pressing process, and the degree of curing is similar to that of the semi-curing. In this embodiment, the first dummy board and the second dummy board are both rectangular dummy boards.

At least four second test holes 20 are formed on the first dummy board. In this embodiment, four second test holes 20 are used, and the center points of the four test holes 20 are rectangular. Forming at least four second test holes 20 at intervals in the second dummy board. In this embodiment, four second test holes 20 are used, and the center points of the four of the second test holes 20 are rectangular. In this embodiment, the four second test holes 20 are located at the four corners of the rectangular dummy board, that is, the four second test holes 20 on the first dummy board are respectively disposed on the first dummy. The four test holes 20 on the second dummy board are respectively disposed around the second dummy board, and the two adjacent ones on the first dummy board are second The test holes 20 are respectively located in the warp or weft direction of the fiberglass cloth in the first dummy board, and the adjacent second test holes 20 on the second dummy board are respectively located in the fiber cloth of the second dummy board. Toward or latitude. This setting facilitates the measurement of the change in the warp and weft of the first dummy web and the change in the warp and weft of the second dummy web in the warp and weft directions. The second test hole 20 may be a circular shape, a regular polygon, or the like. The distance between the second test hole 20 and the side of the dummy board is 2.54 mm - 50.8 mm, and the diameter or side length of the second test hole 20 is The diameter of the second test hole 20 is 0.5 mm to 4 mm, and the dimensional test accuracy is higher. In this embodiment, a circular shape is adopted as the shape of the second test hole 20. The distance from the first test hole 20 to the side of the dummy board is 25.4 mm, and the diameter of the second test hole 20 is 3.175 mm.

The positions of the second test holes 20 in the first dummy plate and the second dummy plate are respectively measured, and the distances F ₃ , F ₄ , W ₃ , and W ₄ between the adjacent second test holes 20 are calculated and recorded as initials. The distance between the adjacent second test holes 20 is the center distance of each of the second test holes 20; the F ₃ includes F _3A , F _3B , wherein F _3A represents the first dummy plate, wherein the two meridional phases vicinity of the center hole 20 from the second test F _3, F _3B representative of a second prosthesis from contact plate via two F ₃ wherein the centers of adjacent test wells 20 of the second; Similarly, comprising the F ₄ F _4A, F _4B The W ₃ includes W _3A , W _3B ; the W ₄ includes W _4A , W _4B .

Laminating the first dummy board under a pressing process; laminating the second dummy board under a pressing procedure; the pressing procedure is corresponding to a new PCB material and a comparative material Pressing procedure for prepregs.

The positions of the second test holes 20 after the lamination treatment in the first dummy board and the second dummy board are respectively measured, and the distances F ₃ ', F ₄ ', W between the adjacent second test holes 20 are calculated. ₃ ', W ₄ ', denoted as the final distance; F ₃ 'includes F _3A ', F _3B ', where F _3A ' represents the center distance of the first dummy board from the two adjacent test holes 20 F ₃ ', F _3B ' represents the center distance F ₃ ' of the second dummy board in which two of the two adjacent test holes 20 are adjacent; similarly, the F ₄ ' includes F _4A ', F _4B '; W ₃ ' includes W _3A ', W _3B '; and W ₄ ' includes W _4A ', W _4B '.

Calculating the dimensional change values ΔF ₃ , ΔF ₄ , ΔW ₃ , ΔW ₄ after pressing the first dummy plate and the second dummy plate, respectively; wherein ΔF ₃ = (F ₃ '-F ₃ )/F ₃ , ΔF ₄ = (F ₄ '-F ₄ ) / F ₄ , ΔW ₁ = (W ₃ '-W ₃ ) / W ₃ , ΔW ₄ = (W ₄ '-W ₄ ) / W ₄ . The ΔF ₃ includes ΔF _3A , ΔF _3B , wherein ΔF _3A represents the size change value ΔF ₃ after etching and pressing of the first dummy board, and ΔF _3B represents the dimensional change of the second dummy board after etching and pressing. The value ΔF ₃ ; for the same reason, the ΔF ₄ includes ΔF _4A , F _4B ; the ΔW ₃ includes ΔW _3A , ΔW _3B ; the ΔW ₄ includes ΔW _4A , ΔW _4B .

In one embodiment, the method for deriving the shrinkage compensation rule of the new PCB material is:

Calculate the dimensional change ΔF _A and the dimensional change ΔW _{A of the} first core in the warp direction during the machining process respectively; calculate the dimensional change ΔF _B and the dimensional change ΔW of the warp direction of the second core during the machining process, respectively. _B ;

Calculating a difference ΔF _c =ΔF _A -ΔF _B of the dimensional change of the first core plate and the second core plate in the warp direction, and calculating a difference ΔW _c of the dimensional change of the first core plate and the second core plate in the weft direction ΔW _{A -} ΔW _B ;

Calculating the dimensional change ΔF _A ' of the warp direction of the first dummy web during processing and the dimensional change ΔW _A ' of the weft direction respectively; calculating the dimensional change ΔF _B ' of the warp direction of the second dummy web during processing, respectively Dimension change in latitude ΔW _B ';

Calculating the difference in size of the first dummy plate and the second dummy plate in the warp direction by ΔF _p = ΔF _A '- ΔF _B ', and calculating the dimensional change of the first dummy plate and the second dummy plate in the weft direction The difference ΔW _p = ΔW _A '- ΔW _B ';

Then, the change values of the new material of the PCB and the contrast material in the warp and latitude are ΔF=(ΔF _c +ΔF _p )/2; ΔW=(ΔW _c +ΔW _p )/2;

Combined with the comparison of the ups and downs compensation rules of comparative materials, the analogy derivation is derived, and the rules for the expansion and contraction of new PCB materials are derived.

Where ΔF _A = ∑ [(ΔF _1A + ΔF _2A )/2], ΔW _A = ∑ [(ΔW _1A + ΔW _2A )/2], the ΔF _1A , ΔF _2A are the dimensional change values of the first core plate, respectively ΔF ₁ , ΔF ₂ , wherein ΔW _1A and ΔW _2A are dimensional change values ΔW ₁ , ΔW ₂ in the first core plate, respectively; wherein ΔF _B = ∑ [(ΔF _1B + ΔF _2B )/2], ΔW _B = ∑[(ΔW _1B +ΔW _2B )/2], the ΔF _1B , ΔF _2B are the dimensional change values ΔF ₁ , ΔF ₂ in the second core plate, respectively, and the ΔW _1B and ΔW _2B are the second core plates respectively The dimensional change values ΔW ₁ , ΔW ₂ in the middle.

Where ΔF _A ′=∑[(ΔF _1A ′+ΔF _2A ′′/2], ΔW _A ′=∑[(ΔW _1A ′+ΔW _2A ′′/2], the ΔF _1A ′, ΔF _2A ′ are respectively The distance F ₁ ', F ₂ ' between two adjacent test holes in the first dummy plate, the ΔW _1A , ΔW _2A are respectively two latitudinal adjacent tests in the first dummy plate The distance between the holes W ₁ ', W ₂ '; where ΔF _B ' = ∑ [(ΔF _1B ′ + ΔF _2B ′)/2], ΔW _B ′ = ∑ [(ΔW _1B ′ + ΔW _2B ′) /2 ΔF _1B ′, ΔF _2B ′ are respectively distances F ₁ ′, F ₂ ′ between two adjacent test holes in the second dummy plate, respectively, ΔW _1B ′, ΔW _2B ′ respectively It is the distance W ₁ ', W ₂ ' between adjacent test holes in the two latitudinals of the second dummy board. Since the specifications and the number of the first core board, the second core board, the first dummy board, and the second dummy board are two or more, ∑ represents the core board or the dummy of each specification and quantity of the test. The sum of the calculated results of the board.

The above embodiment is specifically described by the following procedure of the specific embodiment:

Table 1

Among them, Table 1 is the compensation rules for some specifications of the existing materials.

After passing the test, the dimensional changes of the new and comparative materials of the PCB in the warp and weft directions are as follows:

First core plate: ΔF _A = -3, ΔW _A = -2; second core plate: ΔF _B = -2.5, ΔW _B = -1.6;

First half-cured sheet: ΔF _A '=-5, ΔW _A '=-4.2; second prepreg: ΔF _B '=-3.8, ΔW _B '=-2.5

Then: ΔF _c = ΔF _{A -} ΔF _B = -3 + 2.5 = -0.5; ΔW _c = ΔW _{A -} ΔW _B = -2 + 1.6 = -0.4;

ΔF _p =ΔF _A '-ΔF _B '=-5+3.8=-1.2; ΔW _p =ΔW _A '-ΔW _B '=-4.2+2.5=-1.7;

Therefore, the change values of the new material and the comparative material in the warp and weft directions are respectively

ΔF=(ΔF _c +ΔF _p )/2=(-0.5-1.2)/2=-0.85; ΔW=(ΔW _c +ΔW _p )/2=(-0.4-1.7)/2=-1.05;

Combined with the ups and downs compensation rules of the comparative materials, the compensation coefficients for the new PCB materials can be introduced as shown in Table 2:

Table 2

The technical features of the above-described embodiments may be arbitrarily combined. For the sake of brevity of description, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be considered as the scope of this manual.

The above-described embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims (10)

1. A method for evaluating a compensation coefficient for a new material of a PCB, characterized in that it comprises:

   Select a common PCB material that has been determined to be a perfect inflation compensation rule as a comparison material;

   Testing the first core plate of the new material of the PCB and the change value of the first prepreg, and the change values of the second core plate and the second half solid film of the comparative material respectively, the first core plate is selected The specifications are the same as the specifications of the second core sheet, and the first prepreg is selected to have the same specifications as the second prepreg;

   Contrast and analyze the change and difference of the first core plate and the second core plate in the respective processing flow; compare and analyze the change and difference of the first prepreg and the second prepreg in the respective processing flow;

   Combining the expansion and contraction compensation rules of the comparative materials, the analogy derivation is carried out, and the expansion and contraction compensation rules of the new PCB materials are derived.
2. The method for evaluating a shrinkage compensation coefficient of a new material of a PCB according to claim 1, wherein the test method for the change of the expansion and contraction of the first core plate and the second core plate is:

   Forming at least four spaced apart first test holes on the first core board, at least four of the first test holes having a center line connection having a rectangular shape; and forming at least four interval settings on the second core board a first test hole, at least four of the first test holes have a center line connecting the rectangle;

   Measuring the positions of the first test holes in the first core plate and the second core plate respectively, and calculating the distances F ₁ , F ₂ , W ₁ , W ₂ between the adjacent first test holes, and recording the initial distances;

   Etching the first core plate into a graphic design having a first residual copper ratio; etching the second core plate into a graphic design having a second residual copper ratio, the first residual copper ratio and the second residual copper The same rate;

   Laminating the first core sheet under a pressing process; laminating the second core sheet under a pressing process;

   Measuring the positions of the first test holes after lamination in the first core plate and the second core plate, respectively, and calculating distances F ₁ ', F ₂ ', W ₁ ', W between adjacent first test holes ₂ ', recorded as the final distance;

   The dimensional change values ΔF ₁ , ΔF ₂ , ΔW ₁ , ΔW _{2 of the} first core plate and the second core plate after etching and pressing are respectively calculated; wherein ΔF ₁ = (F ₁ '-F ₁ )/F ₁ , ΔF ₂ = (F ₂ '-F ₂ ) / F ₂ , ΔW ₁ = (W ₁ '-W ₁ ) / W ₁ , ΔW ₂ = (W ₂ '-W ₂ ) / W ₂ .
3. The method for evaluating a new material shrinkage compensation coefficient of a PCB according to claim 2, wherein the first residual copper ratio and the second residual copper ratio are 0%, 50% or 100%.
4. The method for evaluating a new material shrinkage compensation coefficient of a PCB according to claim 2, wherein at least four of the first test holes on the first core board are respectively disposed around the first core board; At least four of the first test holes on the second core board are respectively disposed around the second core board, and two adjacent first test holes on the first core board are respectively located in the first core board In the warp or weft direction of the fiberglass cloth, adjacent first test holes on the second core board are respectively located in the warp or weft direction of the fiberglass cloth in the second core board.
5. The method for evaluating a new material expansion and contraction compensation coefficient of a PCB according to claim 2, wherein the graphic design of the first core plate and the graphic design of the second core plate are graphic designs uniformly arranged in the warp and weft directions.
6. The method for evaluating a shrinkage compensation coefficient of a new material of a PCB according to any one of claims 2 to 5, characterized in that the test method for the change of the expansion and contraction of the first prepreg and the second prepreg is:

   Forming a layer of copper foil on the top bottom layer of the first prepreg to form a first pre-laminated sheet, and respectively forming a layer of copper foil on the top bottom layer of the second prepreg to form a second pre-stack;

   Quickly pressing the first pre-stack into a first dummy board, and pressing the second pre-stack into a second dummy board;

   Forming at least four spaced second test holes on the first dummy board, at least four of the second test holes having a center line connection having a rectangular shape; and forming at least four intervals on the second core board a second test hole is disposed, and a center line of at least four of the second test holes is rectangular;

   Measure the positions of the second test holes in the first dummy plate and the second dummy plate, respectively, and calculate the distances F ₃ , F ₄ , W ₃ , and W ₄ between the adjacent second test holes, and record the initial distance. ;

   Laminating the first dummy board under a pressing process; laminating the second dummy board under a pressing procedure;

   Measure the positions of the second test holes after the lamination process in the first dummy plate and the second dummy plate, respectively, and calculate the distances F ₃ ', F ₄ ', W ₃ between the adjacent second test holes. ', W ₄ ', recorded as the final distance;

   Calculating the dimensional change values ΔF ₃ , ΔF ₄ , ΔW ₃ , ΔW ₄ after pressing the first dummy plate and the second dummy plate, respectively; wherein ΔF ₃ = (F ₃ '-F ₃ )/F ₃ , ΔF ₄ = (F ₄ '-F ₄ ) / F ₄ , ΔW ₁ = (W ₃ '-W ₃ ) / W ₃ , ΔW ₄ = (W ₄ '-W ₄ ) / W ₄ .
7. The method for evaluating a new material expansion and contraction compensation coefficient of a PCB according to claim 6, wherein at least four of the second test holes on the first dummy board are respectively disposed around the first dummy board. The at least four second test holes on the second dummy board are respectively disposed around the second dummy board, and the adjacent second test holes on the first dummy board are respectively located at the first The warp or weft direction of the fiberglass cloth in the dummy board, and the adjacent second test holes on the second dummy board are respectively located in the warp or weft direction of the fiberglass cloth in the second dummy board.
8. The method for evaluating a new material shrinkage compensation coefficient of a PCB according to claim 6, wherein the method for deriving the expansion and contraction compensation rule of the new PCB material is:

   Calculate the dimensional change ΔF _A and the dimensional change ΔW _{A of the} first core in the warp direction during the machining process respectively; calculate the dimensional change ΔF _B and the dimensional change ΔW of the warp direction of the second core during the machining process, respectively. _B ;

   Calculating a difference ΔF _c =ΔF _A -ΔF _B of the dimensional change of the first core plate and the second core plate in the warp direction, and calculating a difference ΔW _c of the dimensional change of the first core plate and the second core plate in the weft direction ΔW _{A -} ΔW _B ;

   Calculating the dimensional change ΔF _A ' of the warp direction of the first dummy web during processing and the dimensional change ΔW _A ' of the weft direction respectively; calculating the dimensional change ΔF _B ' of the warp direction of the second dummy web during processing, respectively Dimension change in latitude ΔW _B ';

   Calculating the difference in size of the first dummy plate and the second dummy plate in the warp direction by ΔF _p = ΔF _A '- ΔF _B ', and calculating the dimensional change of the first dummy plate and the second dummy plate in the weft direction The difference ΔW _p = ΔW _A '- ΔW _B ';

   Then, the change values of the new material of the PCB and the contrast material in the warp and latitude are ΔF=(ΔF _c +ΔF _p )/2; ΔW=(ΔW _c +ΔW _p )/2;

   Combined with the comparison of the ups and downs compensation rules of comparative materials, the analogy derivation is derived, and the rules for the expansion and contraction of new PCB materials are derived.
9. The method for evaluating a new material shrinkage compensation coefficient of a PCB according to claim 8, wherein ΔF _A = ∑ [(ΔF _1A + ΔF _2A )/2], ΔW _A = ∑ [(ΔW _1A + ΔW _2A) /2], the ΔF _1A and ΔF _2A are the dimensional change values ΔF ₁ and ΔF ₂ of the first core plate, respectively, and the ΔW _1A and ΔW _2A are the dimensional change values ΔW ₁ and ΔW in the first core plate, respectively. ₂ , the ∑ is the sum of the changes of the first core plates of various specifications and quantities; wherein ΔF _B = ∑ [(ΔF _{`</sub> + ΔF <sub>2B</sub> )/2], ΔW <sub>B</sub> = ∑ [(ΔW <sub>`} + ΔW _2B )/2 The ΔF _1B and ΔF _2B are the dimensional change values ΔF ₁ and ΔF ₂ in the second core plate, respectively, and the ΔW _1B and ΔW _2B are the dimensional change values ΔW ₁ and ΔW ₂ in the second core plate, respectively. The crucible is the sum of the variations of the second core sheets of various specifications and quantities.
10. The method for evaluating a PCB new material expansion and contraction compensation coefficient according to claim 8, wherein ΔF _A ' = ∑ [(ΔF _1A ′ + ΔF _2A ′)/2], ΔW _A ′ = ∑ [(ΔW) _1A '+ΔW _2A ')/2], the ΔF _1A ', ΔF _2A ' are the distances F ₁ ', F ₂ ' between the two adjacent test holes in the first dummy board, respectively ΔW _1A and ΔW _2A are the distances W ₁ ', W ₂ ' between the two latitudinal adjacent test holes in the first dummy board, respectively, which are the first dummy boards of various specifications and numbers. The sum of changes; where ΔF _B '= ∑ [(ΔF _1B ′ + ΔF _2B ′)/2], ΔW _B ∑ [(ΔW _1B ′ + ΔW _2B ′) /2], the ΔF _1B ′, ΔF _2B ′ The distances F ₁ ', F ₂ ' between the two adjacent test holes in the second dummy plate, respectively, the ΔW _1B ′, ΔW _2B ′ are the two latitudinals in the second dummy plate The distance W ₁ ', W ₂ ' between adjacent test holes, which is the sum of changes of the second dummy plates of various specifications and numbers.

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