Rapid compensation method in the production of curved rigid-flexible substrates

Abstract

The present invention discloses a rapid compensation method in the production of a bent hard-soft combined substrate, which belongs to the technical field of printed circuit board production. First, the window in the bent hard-soft combined substrate is filled to turn the soft board into a regular rectangle. Then, according to the base soft board length 2L, the bending curvature radius R, the total number of layers N of the stacked structure and the interlayer spacing required by the customer, the length of each layer of the soft board is compensated, so that each layer of the compensated soft board is bent and installed to just meet the customer's installation requirements. The innermost layer of the bent hard-soft combined substrate is the base soft board, and the first layer of the soft board, the second layer of the soft board, ..., the Nth layer of the soft board are sequentially called the first layer of the soft board, the second layer of the soft board, ..., the Nth layer of the soft board, and the unilateral compensation value Δ corresponding to each layer of the soft board is iteratively calculated based on the base soft board starting from the first layer of the soft board. n , the unilateral compensation value Δ n The total compensation value of the soft board layer is multiplied by 2. The present invention does not introduce any parameters other than those required by the customer, and all parameters are replaced by equal values ​​in the calculation process, thus ensuring the robustness and accuracy of the calculation process.

Description

Technical Field

[0001] The present invention belongs to the technical field of printed circuit board production, and in particular relates to a rapid compensation method in the production of a bent rigid-flexible substrate. Background Art

[0002] Rigid-flex substrates are composed of a selectively laminated combination of rigid and flexible boards. They combine the regularity and toughness of conventional rigid boards with the flexibility and flexibility of flexible boards. They feature a compact structure and utilize metalized vias to form conductive connections. Rigid-flex boards can be moved, bent, folded, twisted, and allow for three-dimensional wiring, significantly reducing installation space for electronic components and aligning with the trend toward lighter, thinner, shorter, and smaller electronic products. Of all PCB types, rigid-flex PCBs offer the strongest resistance to harsh operating environments, making them a popular choice across many industries. High-end feature smartphones are currently the primary driver of the rigid-flex substrate market.

[0003] Figure 1 The figure is a schematic diagram of a curved rigid-flex substrate. In the production of a curved rigid-flex substrate, customers may require the flexible board to be bent and installed at a certain curvature. Taking a three-layer stack as an example, Figure 1 As can be seen from the figure, each layer of the flexible board is of different lengths, with the innermost layer being the shortest, the middle layer being slightly longer, and the outermost layer being the longest. The customer only provides the length of the innermost layer (i.e., the length of the base flexible board), the bending radius of curvature, and the specific stacking structure. The lengths of the middle and outermost layers of the flexible board are calculated by the manufacturer. This means that the length of each layer of the flexible board needs to be compensated according to the length of the base flexible board, so that each layer of the flexible board can meet the installation requirements. For installation purposes, the flexible board of the curved rigid-flex substrate is usually provided with windows, such as Figure 2 As shown in Figure 2, the interface between the soft and hard parts is irregular, which makes the compensation calculation more complicated. Summary of the Invention

[0004] The purpose of the present invention is to provide a rapid compensation method for the production of bent rigid-flexible substrates. After obtaining the parameters provided by the customer, including the length of the base flexible board, the bending curvature radius, and the specific stacking structure, the length compensation value of each layer of flexible board is obtained through rapid calculation of equivalent substitution, so that each layer of compensated flexible board, after being bent and installed, just meets the customer's installation requirements.

[0005] The present invention provides a rapid compensation method for the production of a bent rigid-flexible substrate. First, the window in the bent rigid-flexible substrate is filled to transform the flexible substrate into a regular rectangle. Then, based on the customer's required base flexible substrate length 2L, bending curvature radius R, total number of stacked layers N, and interlayer spacing, length compensation is performed on each layer of the flexible substrate. This ensures that each compensated layer of the flexible substrate, after being bent and installed, just meets the customer's installation requirements. The innermost layer of the bent rigid-flexible substrate is the base flexible substrate, and the layers are sequentially referred to as the first layer, second layer, ..., and Nth layer. The unilateral compensation value Δ corresponding to each layer of the flexible substrate is iteratively calculated based on the base flexible substrate, starting from the first layer. n , n=1, 2, ..., N, the unilateral compensation value Δ n Multiplying by 2 is the total compensation value of the flexible board layer. The specific steps are as follows:

[0006] Step 1. Draw a base circle with the bending radius R and the center O, and place the hard board close to the base circle and tangent to the base circle; with O as the center, draw a circle O0 with the sum of the radius R of the base circle and the thickness h0 of the base soft board as the radius, and draw a tangent to the circle O0 at the edge of the base soft board where the hard board is clamped. Let the intersection of the tangent and the circle O0 be the tangent point T0, and then measure the distance from the edge of the base soft board to the tangent point T0. This distance is the length of the tangent segment and is recorded as d0; connect the center O and the tangent point T0 to obtain the line segment OT0, and use L minus d0 to obtain the length of the arc segment s0, and then use the formula To calculate the central angle θ0 corresponding to the arc length s0, rotate the line segment OT0 by θ0 degrees with the center of the base circle O as the center. If s0+d0=L-d0+d0=L, the length of the base flexible board meets the customer's requirements;

[0007] Step 2. Iterate and calculate the unilateral compensation value Δ of the nth layer of soft board respectively n , n=1, 2, ..., N:

[0008] With O as the center, n-1 The radius and the thickness h of the nth soft plate n The sum of the radius is the circle O n , the radius is R+h0+h1+…+h n ; The edge of the nth layer of soft board sandwiched between the hard board is directed to the circle O n Draw a tangent line and set the tangent line to circle O n The intersection point is the tangent point T n , measure the distance from the edge of the nth layer of soft board to the tangent point T n The distance is the length of the tangent segment and is recorded as d n ; Connect the center O and the tangent point T n Get line segment OT n ;Measure OT0 and OT n The angle θ between n , then calculate the arc length sn , Finally, the unilateral compensation Δ of the nth layer of soft board is obtained n , Δ n =d n +s n -L.

[0009] Using the above technical solution, the present invention first fills the window in the bent rigid-flex substrate, transforming the flexible board into a regular rectangle. Since the filled rectangle does not affect the overall length of the flexible board, the length of the tangent segment and arc segment of each layer of the flexible board can be calculated using the tangent arc calculation method. The length compensation value of each layer of the flexible board is obtained by adding them together and then subtracting the customer's required base flexible board length. After the compensation, the flexible board is bent and installed, it just meets the customer's requirements. This invention has the following advantages:

[0010] 1) No parameters other than those required by the customer are introduced, ensuring calculation accuracy;

[0011] 2) Equivalent substitutions are performed during the calculation process, ensuring the robustness of the calculation process and achieving the accuracy desired by the customer; it also enables iterative algorithms and is easy to implement through programming. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of a curved rigid-flex substrate;

[0013] Figure 2 Schematic diagram of a curved rigid-flex substrate with windows;

[0014] Figure 3 In the present invention, Figure 2 Schematic diagram showing that the flexible board becomes a regular rectangle after the window is filled. DETAILED DESCRIPTION

[0015] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0016] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this disclosure more thorough and complete and to fully convey the concepts of the example embodiments to those skilled in the art.

[0017] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details will be provided, so as to fully understand the embodiments disclosed in the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps etc. can be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects disclosed in the present application.

[0018] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0019] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or solution described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or solutions. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0020] The principle of the present invention is described as follows:

[0021] First, fill the window in the bent rigid-flex substrate and turn the flexible board into a regular rectangle, such as Figure 1 and 3 As shown, each layer of flexible board is composed of two tangent segments and one arc segment. You only need to calculate the length of the tangent segment and arc segment of each layer of flexible board, add them together and then subtract the base flexible board length required by the customer to get the length compensation value of each layer of flexible board.

[0022] The present invention provides a rapid compensation method for the production of a bent rigid-flexible substrate. First, the window in the bent rigid-flexible substrate is filled to transform the flexible board into a regular rectangle. Then, based on the customer's required base flexible board length 2L, bending curvature radius R, total number of stacked layers N, and interlayer spacing (the interlayer spacing refers to the spacing between each two layers of flexible boards), length compensation is performed on each layer of flexible board. This ensures that each compensated layer of flexible board, after being bent and installed, just meets the customer's installation requirements. The innermost layer of the bent rigid-flexible substrate is the base flexible board, and the layers are sequentially referred to as the first layer, the second layer, ..., and the Nth layer. Based on the base flexible board, the unilateral compensation value Δ corresponding to each layer of flexible board is iteratively calculated starting from the first layer. n , n=1, 2, ..., N, the unilateral compensation value Δ n Multiplying by 2 is the total compensation value of the soft board layer, such as Figure 1 As shown, at the edge of the M0 base soft board, S0 is the arc length, θ0 is the central angle, R is the bending curvature radius, O0 is the center of the circle, and T0 is the tangent point.

[0023] The specific steps are as follows:

[0024] Step 1. Figure 1 As shown, the hard board is placed closely against the base circle and tangent to the base circle, M0 is the edge of the base soft board, S0 is the arc length on the soft board, θ0 is the central angle corresponding to the arc length S0, R is the bending curvature radius required by the customer, O0 is the center of the circle, T0 is the tangent point, and half of the base soft board length required by the customer is set as L. The base circle is drawn with the bending curvature radius R and the center of O; with O as the center of the circle, the sum of the radius R of the base circle O and the thickness h0 of the base soft board (R+h0) is used as the radius to draw circle O0, and a tangent is made to the edge of the base soft board M0 where the hard board is clamped, and the intersection of the tangent and the circle O0 is set as the tangent point T0, and then the distance from the edge of the base soft board M0 to the tangent point T0 is measured. This distance is the length of the tangent segment and is recorded as d0; the line segment OT0 is obtained by connecting the center of the circle O and the tangent point T0, and d0 is subtracted from L as the length of the arc segment s0, s0=L-d0, and then the formula is used To calculate the central angle θ0 corresponding to the arc length s0, rotate the line segment OT0 by θ0 degrees with the center O as the center, it can be proved that: s0+d0=L-d0+d0=L, that is, the length of the base flexible board meets the customer's requirements;

[0025] Step 2. Calculate the unilateral compensation value Δ1 of the first layer of flexible board:

[0026] With O as the center, draw a circle O1 with the sum of the radius of circle O0 and the thickness h1 of the first layer of soft board as the radius (R+h0+h1), and make a tangent to the circle O1 with the edge M1 of the first layer of soft board sandwiched between the hard board. Let the intersection of the tangent and the circle O1 be the tangent point T1, then measure the distance from the edge M1 of the first layer of soft board to the tangent point T1, and record it as the length of the tangent segment and record it as d1. Connect the center of the circle O and the tangent point T1 to get the line segment OT1, measure the angle θ1 between OT0 and OT1, and then use the formula To calculate the arc length s1, the unilateral compensation value Δ1 of the first layer of soft board is calculated, Δ1 = d1 + s1 - L;

[0027] Step 3. Calculate the unilateral compensation value Δ2 of the second layer of flexible board:

[0028] With O as the center, draw a circle O2 with the sum of the radius of circle O1 and the thickness h2 of the second layer of soft board as the radius (R+h0+h1+h2); draw a tangent to the circle O2 with the edge M2 of the second layer of soft board sandwiched between the hard board, and let the intersection of the tangent and the circle O2 be the tangent point T2. Then measure the distance from the edge M2 of the second layer of soft board to the tangent point T2. This distance is the length of the tangent segment and is recorded as d2. Connect the center of the circle O and the tangent point T2 to obtain the line segment OT2. Measure the angle θ2 between OT0 and OT2, and then use the formula To calculate the arc length s2; calculate the unilateral compensation value Δ2 of the second layer of soft board, Δ2=d2+s2-L;

[0029] Step 4. Similarly, iteratively calculate the unilateral compensation value Δ of the nth layer of flexible board n :

[0030] With O as the center, n-1 The radius and the thickness h of the nth soft plate n The sum is the radius (R+h0+h1+…+h n )Draw a circle O n ; The edge M of the nth layer of soft board sandwiched between the hard board n Towards the circle O n Draw a tangent line and set the tangent line to circle O n The intersection point is the tangent point T n , then measure the edge M of the nth layer of soft board n To the tangent point T n The distance is the length of the tangent segment and is recorded as d n ; Connect the center O and the tangent point T n Get line segment OT n ;Measure OT0 and OT n The angle θ between n Then use the formula To calculate the arc length s n ; Calculate the unilateral compensation value Δ of the nth layer of soft board n , Δn =d n +s n -L.

[0031] The present invention provides an iterative calculation method to achieve a rapid compensation method in the production of a bent rigid-flexible substrate. First, the window in the bent rigid-flexible substrate is filled to transform the flexible board into a regular rectangle. Then, according to the customer's required base flexible board length 2L, bending curvature radius R, total number of stacked layers N, and interlayer spacing, length compensation is performed on each layer of flexible board. This ensures that each compensated layer of flexible board, after being bent and installed, just meets the customer's installation requirements. The innermost layer of the bent rigid-flexible substrate is the base flexible board, and the layers are sequentially referred to as the first layer, the second layer, ..., and the Nth layer. Based on the base flexible board, the unilateral compensation value Δ corresponding to each layer of flexible board is iteratively calculated starting from the first layer. n , n=1, 2, ..., N, the unilateral compensation value Δ n Multiplying by 2 is the total compensation value of the flexible board layer, including the following steps:

[0032] Step 1. Draw a base circle O with the coordinate origin as the center, and the bending curvature radius R as the radius of the base circle:

[0033] x 2 +y 2 =R 2 ;

[0034] Draw a circle O0 with the sum of the base circle radius R and the thickness of the first soft board h0 R+h0 as the radius:

[0035] x 2 +y 2 =(R+h0) 2 ;

[0036] Let x 2 +y 2 =(R+h0) 2 The straight line of an external point (x0, y0) is:

[0037] y=k0x+b0;

[0038] From this we can conclude that:

[0039]

[0040] Since the line is tangent to the circle, we have:

[0041]

[0042] In this way, the coordinates of the tangent point T0 can be obtained as:

[0043]

[0044] The angle and equation connecting the center of the circle (0,0) to the tangent point T0 are:

[0045]

[0046] The distance d0 from a point outside the circle (x0, y0) to the tangent point T0 is:

[0047]

[0048] Using s0=L-d0 as the arc length s0, the central angle θ0 of the arc length s0 is calculated as:

[0049]

[0050] Taking the center of the base circle O as the center of rotation, rotate the line segment OT0 connecting the center of the circle to the tangent point T0 in the forward direction by θ0 degrees, and the equation is:

[0051]

[0052] Right now:

[0053]

[0054] It can be proved that s0+d0=L-d0+d0=L, that is, the length of the base layer meets the customer's requirements;

[0055] Step 2. Iterate outwards and calculate the compensation value 2Δ corresponding to the first layer of soft board, the second layer of soft board, ..., the Nth layer of soft board n , n=1, 2, ..., N:

[0056] Take the center of the base circle as the center of the circle and circle O as the center of the circle. n-1 The radius and the thickness h of the nth soft plate n The sum is the radius (R+h0+h1+…+h n )Draw a circle O n :

[0057] x 2 +y 2 =(R+h0+h1+…+h n ) 2 ;

[0058] Over the circle x 2 +y 2 =(R+h0+h1+…+h n ) 2 An external point (x0, y0+y1+…+y n ) is:

[0059] y=k n x+b n

[0060] From this we can conclude that:

[0061] (1+k n 2 )x 2 +2k n b n x+b n 2 -(R+h0+h1+…+h n ) 2 =0;

[0062] Since the line is tangent to the circle, we have:

[0063]

[0064] In this way, we can find the tangent point T n The coordinates are:

[0065]

[0066] Connect the center of the circle (0,0) to the tangent point T n The angles and equations are:

[0067]

[0068] Get circle x 2 +y 2 =(R+h0+h1+…+h n ) 2 An external point (x0, y0+y1+…+y n ) to the tangent point T n The distance is:

[0069]

[0070] So we have:

[0071]

[0072] That is, the unilateral compensation of the nth layer of flexible board is:

[0073]

[0074] Where:

[0075]

[0076] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A rapid compensation method in the production of a bent rigid-flexible substrate, characterized in that: First, fill the window in the bent rigid-flex substrate to turn the soft board into a regular rectangle. Then, according to the base soft board length 2L, bending radius R, total number of layers N and interlayer spacing required by the customer, compensate the length of each layer of soft board, so that each layer of compensated soft board can meet the customer's installation requirements after being bent and installed. The innermost soft board of the bent rigid-flex substrate is the base soft board, and the first soft board, the second soft board, ..., the Nth soft board are called the first soft board, the second soft board, ..., the Nth soft board in turn. The unilateral compensation value Δ corresponding to each layer of soft board is iteratively calculated based on the base soft board starting from the first soft board. n , n=1, 2, ..., N, the unilateral compensation value Δ n Multiplying by 2 is the total compensation value of the soft board. The specific steps are as follows: Step 1. Draw a base circle with the bending radius R and the center O, and place the hard board close to the base circle and tangent to the base circle; draw a circle O0 with O as the center and the sum of the radius R of the base circle and the thickness h0 of the base soft board as the radius, and draw a tangent to the circle O0 from the edge of the base soft board where the hard board is clamped, and set the intersection of the tangent and the circle O0 as the tangent point T0, and then measure the distance from the edge of the base soft board to the tangent point T0, which is the length of the tangent segment and is recorded as d0; connect the center O and the tangent point T0 to get the line segment OT0, and use L minus d0 as the length of the arc segment s0, and then use the formula To calculate the central angle θ0 corresponding to the arc length s0, take the center O of the base circle as the center, rotate the line segment OT0 by θ0 degrees. If s0+d0=L-d0+d0=L, the length of the base soft board meets the customer's requirements; Step 2. Iterate and calculate to obtain the unilateral compensation value Δ of the nth layer of soft board n , n = 1, 2, ..., N: With O as the center, n-1 The radius and the thickness h of the nth soft plate n The sum of the two is the radius of the circle O n , the radius is R+h0+h1+…+h n ; The edge of the nth layer of soft board sandwiched between the hard board is directed toward the above circle O n Draw a tangent line and set the tangent line to circle O n The intersection point is the tangent point T n , measure the distance from the edge of the nth layer of soft board to the tangent point T n The distance is the length of the tangent segment and is recorded as d n ; Connect the center O and the tangent point T n Get line segment OT n ;Measure OT0 and OT n The angle θ between n , then calculate the arc length s n , Finally, the unilateral compensation Δ of the nth layer of soft board is obtained n , Δ n =d n +s n -L.

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