Secondary double-sided exposure method for maintaining high-precision alignment of substrate patterns

Abstract

The invention relates to PCB (Printed Circuit Board) manufacturing, in particular to a secondary double-sided exposure method for keeping high-precision alignment of a substrate pattern, which comprises the following steps of: capturing the position of an A-side target, calculating an accurate camera position of a laser pattern in the pattern according to a target capturing result of the A side, and exposing the A side to realize alignment of an A-side exposure pattern and a first-time exposure pattern; a laser pattern is used for shooting on the B surface while the A surface is exposed, the laser pattern is recognized on the B surface to serve as a target hole, the B surface is exposed, and the B surface exposure pattern is aligned with the A surface exposure pattern; according to the technical scheme provided by the invention, the defect that the A-side exposure pattern, the B-side exposure pattern and the first-time exposure pattern are difficult to achieve relatively high alignment precision in the prior art can be effectively overcome.

Description

Technical Field

[0001] The invention relates to PCB manufacturing, and in particular to a secondary double-sided exposure method for maintaining high-precision alignment of substrate patterns. Background Art

[0002] In the actual manufacturing process of PCB, some substrates need to be exposed twice on both sides after one-side exposure and etching. For the second double-sided exposure, not only the exposure pattern on side A (front) needs to be aligned with the exposure pattern on side B (back), but also needs to be aligned with the first exposure pattern. In the prior art, the outer layer is generally used for processing, that is, the first exposure pattern (which becomes a through hole after etching) is used as the target hole exposure pattern on both sides A and B of the substrate (the specific process is as follows Figure 2 shown).

[0003] The above technical solution has the following main disadvantages: 1) The center deviation of the etched through hole between the A and B surfaces of the substrate is large, which cannot meet the requirements of the pattern alignment of the A and B surfaces of the substrate; 2) Under some processes, the through hole cannot be completely etched, resulting in the hole on the B surface being unusable. Summary of the invention

[0004] 1. Technical issues to be solved

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a secondary double-sided exposure method for maintaining high-precision alignment of substrate patterns, which can effectively overcome the defect of the prior art that it is difficult to achieve high alignment accuracy for the A-side exposure pattern, the B-side exposure pattern and the first exposure pattern.

[0006] (II) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] The secondary double-sided exposure method maintains high-precision alignment of the substrate pattern. The position of the target on the A side is captured, and the precise camera position of the laser pattern in the pattern is calculated based on the target capture result on the A side. The A side is then exposed to align the exposed pattern on the A side with the first exposure pattern.

[0009] While exposing the A side, a laser pattern is used to target the B side, the laser pattern is recognized as a target hole on the B side, and the B side is exposed to align the exposure pattern of the B side with the exposure pattern of the A side.

[0010] Preferably, the capturing of the position of the target on the surface A, calculating the precise camera position of the laser pattern in the pattern according to the target capturing result on the surface A, and exposing the surface A to align the exposure pattern of the surface A with the first exposure pattern, comprises:

[0011] S1. Expand and shrink the target of the layer;

[0012] S2, taking the lower left corner target as the reference point, calculate the position of the reference point on the substrate;

[0013] S3, calculating the positions of other targets on the substrate according to the relative positions between other targets and the reference points;

[0014] S4, calculating the position of the substrate in the camera image according to the reference point;

[0015] S5. Calculate the displacement of each piece relative to the origin of the swing piece according to the swing piece template;

[0016] S6. Calculate the theoretical position WCenter1 of the first target of each target on the A surface in the world coordinate system according to the swing sheet template and the table parameters;

[0017] S7, calculating the first position SCAMCenter1 of each target on the A surface in the camera image after expansion and contraction, and calculating the transformation matrix WCenterMartrix1 from the first position SCAMCenter1 of each target on the A surface in the camera image after expansion and contraction to the first target theoretical position WCenter1 of each target in the world coordinate system;

[0018] S8, grab the actual position RWCenter1 of the first target of all targets on surface A;

[0019] S9, calculating the transformation matrix M1 from the theoretical position WCenter1 of the first target of each target on the A surface in the world coordinate system to the actual position RWCenter1 of the first target of each target;

[0020] S10, determining whether it is a fixed expansion and contraction, if it is a fixed expansion and contraction, eliminating the expansion and contraction in the transformation matrix M1, and superimposing the transformation matrix M1 on the transformation matrix WCenterMartrix1 as the exposure matrix MA, otherwise directly superimposing the transformation matrix M1 on the transformation matrix WCenterMartrix1 as the exposure matrix MA;

[0021] S11. Expose surface A using exposure matrix MA.

[0022] Preferably, while exposing the A surface, a laser pattern is used to target the B surface, the laser pattern is identified as a target hole on the B surface, and the B surface is exposed to align the exposure pattern of the B surface with the exposure pattern of the A surface, including:

[0023] S12, determining a target SPM pattern within the substrate range;

[0024] S13, calculating the second position SCAMCenter2 of each target SPM figure in the camera image after expansion and contraction;

[0025] S14, calculating the second target theoretical position WCenter2 of each target on the B surface in the world coordinate system, and the transformation matrix WCenterMartrix2 from the second position SCAMCenter2 of each target SPM figure in the camera image after expansion and contraction to the second target theoretical position WCenter2 of each target in the world coordinate system;

[0026] S15, grab the actual position RWCenter2 of the second target of all targets on surface B;

[0027] S16, calculating the transformation matrix M2 from the second target theoretical position WCenter2 of each target on the B surface in the world coordinate system to the second target actual position RWCenter2 of each target;

[0028] S17, determine whether it is fixed expansion and contraction, if it is fixed expansion and contraction, eliminate the expansion and contraction in the transformation matrix M2, and superimpose the transformation matrix M2 on the transformation matrix WCenterMartrix2 as the exposure matrix MB, otherwise directly superimpose the transformation matrix M2 on the transformation matrix WCenterMartrix2 as the exposure matrix MB;

[0029] S18. Expose surface B using exposure matrix MB.

[0030] (III) Beneficial effects

[0031] Compared with the prior art, the secondary double-sided exposure method provided by the present invention maintains high-precision alignment of substrate patterns, by grasping the position of the target on the A side, calculating the precise camera position of the laser pattern in the pattern according to the target grasping result on the A side, and exposing the A side, so as to align the exposure pattern on the A side with the first exposure pattern; while exposing the A side, the laser pattern is used to target the B side, the laser pattern is identified as the target hole on the B side, and the B side is exposed, so as to align the exposure pattern on the B side with the exposure pattern on the A side, thereby achieving precise alignment of the exposure pattern on the A side, the exposure pattern on the B side and the first exposure pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 It is a schematic diagram of the process of the present invention;

[0034] Figure 2 The figure is a schematic diagram of the process of performing secondary double-sided exposure on a substrate according to the prior art. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The secondary double-sided exposure method maintains high-precision alignment of the substrate pattern. The position of the target on the A side is captured, and the precise camera position of the laser pattern in the pattern is calculated based on the target capture result on the A side. The A side is then exposed to align the exposed pattern on the A side with the first exposure pattern.

[0037] While exposing the A side, a laser pattern is used to target the B side, the laser pattern is recognized as a target hole on the B side, and the B side is exposed to align the exposure pattern of the B side with the exposure pattern of the A side.

[0038] like Figure 1 As shown, the position of the target on the A surface is captured, the precise camera position of the laser pattern in the pattern is calculated according to the target capture result on the A surface, and the A surface is exposed to align the exposure pattern on the A surface with the first exposure pattern, including:

[0039] S1. Expand and shrink the target of the layer;

[0040] S2, taking the lower left corner target as the reference point, calculate the position of the reference point on the substrate;

[0041] S3, calculating the positions of other targets on the substrate according to the relative positions between other targets and the reference points;

[0042] S4, calculating the position of the substrate in the camera image according to the reference point;

[0043] S5. Calculate the displacement of each piece relative to the origin of the swing piece according to the swing piece template;

[0044] S6. Calculate the theoretical position WCenter1 of the first target of each target on the A surface in the world coordinate system according to the swing sheet template and the table parameters;

[0045] S7, calculating the first position SCAMCenter1 of each target on the A surface in the camera image after expansion and contraction, and calculating the transformation matrix WCenterMartrix1 from the first position SCAMCenter1 of each target on the A surface in the camera image after expansion and contraction to the first target theoretical position WCenter1 of each target in the world coordinate system;

[0046] S8, grab the actual position RWCenter1 of the first target of all targets on surface A;

[0047] S9, calculating the transformation matrix M1 from the theoretical position WCenter1 of the first target of each target on the A surface in the world coordinate system to the actual position RWCenter1 of the first target of each target;

[0048] S10, determining whether it is a fixed expansion and contraction, if it is a fixed expansion and contraction, eliminating the expansion and contraction in the transformation matrix M1, and superimposing the transformation matrix M1 on the transformation matrix WCenterMartrix1 as the exposure matrix MA, otherwise directly superimposing the transformation matrix M1 on the transformation matrix WCenterMartrix1 as the exposure matrix MA;

[0049] S11. Expose surface A using exposure matrix MA.

[0050] like Figure 1 As shown, while exposing the A side, a laser pattern is used to target the B side, the laser pattern is identified as a target hole on the B side, and the B side is exposed to achieve alignment of the exposure pattern of the B side with the exposure pattern of the A side, including:

[0051] S12, determining a target SPM pattern within the substrate range;

[0052] S13, calculating the second position SCAMCenter2 of each target SPM figure in the camera image after expansion and contraction;

[0053] S14, calculating the second target theoretical position WCenter2 of each target on the B surface in the world coordinate system, and the transformation matrix WCenterMartrix2 from the second position SCAMCenter2 of each target SPM figure in the camera image after expansion and contraction to the second target theoretical position WCenter2 of each target in the world coordinate system;

[0054] S15, grab the actual position RWCenter2 of the second target of all targets on surface B;

[0055] S16, calculating the transformation matrix M2 from the second target theoretical position WCenter2 of each target on the B surface in the world coordinate system to the second target actual position RWCenter2 of each target;

[0056] S17, determine whether it is fixed expansion and contraction, if it is fixed expansion and contraction, eliminate the expansion and contraction in the transformation matrix M2, and superimpose the transformation matrix M2 on the transformation matrix WCenterMartrix2 as the exposure matrix MB, otherwise directly superimpose the transformation matrix M2 on the transformation matrix WCenterMartrix2 as the exposure matrix MB;

[0057] S18. Expose surface B using exposure matrix MB.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A secondary double-sided exposure method for maintaining high-precision alignment of substrate patterns, characterized in that: Grab the position of the target on surface A, calculate the precise camera position of the laser pattern in the pattern based on the target grabbing result on surface A, and expose surface A to align the exposed pattern on surface A with the first exposed pattern; While exposing the A side, a laser pattern is used to target the B side, the laser pattern is recognized as a target hole on the B side, and the B side is exposed to align the exposure pattern of the B side with the exposure pattern of the A side.

2. The method for secondary double-sided exposure with high-precision alignment of substrate patterns according to claim 1, characterized in that: The method of capturing the position of the target on the A surface, calculating the precise camera position of the laser pattern in the pattern according to the target capture result on the A surface, and exposing the A surface to align the exposed pattern on the A surface with the first exposure pattern includes: S1. Expand and shrink the target of the layer; S2, taking the lower left corner target as the reference point, calculate the position of the reference point on the substrate; S3, calculating the positions of other targets on the substrate according to the relative positions between other targets and the reference points; S4, calculating the position of the substrate in the camera image according to the reference point; S5. Calculate the displacement of each piece relative to the origin of the swing piece according to the swing piece template; S6. Calculate the theoretical position WCenter1 of the first target of each target on the A surface in the world coordinate system according to the swing sheet template and the table parameters; S7, calculating the first position SCAMCenter1 of each target on the A surface in the camera image after expansion and contraction, and calculating the transformation matrix WCenterMartrix1 from the first position SCAMCenter1 of each target on the A surface in the camera image after expansion and contraction to the first target theoretical position WCenter1 of each target in the world coordinate system; S8, grab the actual position RWCenter1 of the first target of all targets on surface A; S9, calculating the transformation matrix M1 from the theoretical position WCenter1 of the first target of each target on the A surface in the world coordinate system to the actual position RWCenter1 of the first target of each target; S10, determining whether it is a fixed expansion and contraction, if it is a fixed expansion and contraction, eliminating the expansion and contraction in the transformation matrix M1, and superimposing the transformation matrix M1 on the transformation matrix WCenterMartrix1 as the exposure matrix MA, otherwise directly superimposing the transformation matrix M1 on the transformation matrix WCenterMartrix1 as the exposure matrix MA; S11. Expose surface A using exposure matrix MA.

3. The secondary double-sided exposure method for maintaining high-precision alignment of substrate patterns according to claim 2, characterized in that: The method of using a laser pattern to target on the B surface while exposing the A surface, identifying the laser pattern on the B surface as a target hole, and exposing the B surface to achieve alignment of the exposure pattern on the B surface with the exposure pattern on the A surface includes: S12, determining a target SPM pattern within the substrate range; S13, calculating the second position SCAMCenter2 of each target SPM figure in the camera image after expansion and contraction; S14, calculating the second target theoretical position WCenter2 of each target on the B surface in the world coordinate system, and the transformation matrix WCenterMartrix2 from the second position SCAMCenter2 of each target SPM figure in the camera image after expansion and contraction to the second target theoretical position WCenter2 of each target in the world coordinate system; S15, grab the actual position RWCenter2 of the second target of all targets on surface B; S16, calculating the transformation matrix M2 from the second target theoretical position WCenter2 of each target on the B surface in the world coordinate system to the second target actual position RWCenter2 of each target; S17, determine whether it is fixed expansion and contraction, if it is fixed expansion and contraction, eliminate the expansion and contraction in the transformation matrix M2, and superimpose the transformation matrix M2 on the transformation matrix WCenterMartrix2 as the exposure matrix MB, otherwise directly superimpose the transformation matrix M2 on the transformation matrix WCenterMartrix2 as the exposure matrix MB; S18. Expose surface B using exposure matrix MB.

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