LDI optical system

Abstract

The invention relates to the technical field of laser direct writing imaging, in particular to an LD I optical system which comprises a first lens group G1 and a second lens group G2 which are sequentially arranged from a DMD side to an exposure side. A diaphragm is arranged between the first lens group G1 and the second lens group G2; the focal power of the first lens group G1 and the focal power of the second lens group G2 are positive focal power; the first lens group G1 forms a telecentric light path; the second lens group G2 forms a telecentric light path; the focal length of the first lens group G1 is F1; the focal length of the second lens group G2 is F2; wherein, 0.34 lt, 0.34 lt; f1 / F2lt; and 0.42, the utilization rate of laser energy and the stability of direct writing multiplying power are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of laser direct writing imaging, and in particular to an LD I optical system. Background Art

[0002] LDI technology uses laser as a light source, and uses a laser beam to directly expose a pattern on a photosensitive material. Generally, a digital micromirror device (DMD) is used to allow the image to be finally presented on the PCB. The DMD here is equivalent to an optical element that plays a key imaging role. It can process the laser so that the image can be accurately imaged on the PCB through the optical system. It has high image resolution and simpler process. In practical applications, LDI technology also has limitations: since some applications require the use of short-wave high-power laser bands, only specific i-line glass materials can be used, resulting in less material selection when designing the optical system and increased design difficulty. Summary of the invention

[0003] The object of the present invention is to overcome the above-mentioned disadvantages and provide an LD I optical system.

[0004] To achieve the above object, the specific scheme of the present invention is as follows: an LDI optical system, comprising a first lens group G1 and a second lens group G2 arranged in sequence from the DMD side to the exposure side; an aperture is arranged between the first lens group G1 and the second lens group G2; the focal power of the first lens group G1 and the focal power of the second lens group G2 are both positive focal powers; the first lens group G1 forms a telecentric optical path; the second lens group G2 forms a telecentric optical path; the focal length of the first lens group G1 is F1; the focal length of the second lens group G2 is F2; ​​wherein, 0.34 <F1 / F2<0.42。

[0005] Furthermore, the first lens group G1 includes a first lens G11, a second lens G12, a third lens G13, a fourth lens G14, a fifth lens G15 and a sixth lens G16 which are arranged in sequence; the first lens G11 is a plano-convex lens; the second lens G12 is a meniscus lens; the third lens G13 is a symmetrical biconcave lens; the fourth lens G14 is a symmetrical biconvex lens; the fifth lens G15 is a plano-convex lens; and the sixth lens G16 is a plano-concave lens.

[0006] Further, the radius of curvature of the object side surface of the first lens is R1, and the radius of curvature of the image side surface of the first lens is R2; the radius of curvature of the object side surface of the second lens is R3, and the radius of curvature of the image side surface of the second lens is R4; the radius of curvature of the object side surface of the third lens is R5, and the radius of curvature of the image side surface of the third lens is R6; the radius of curvature of the object side surface of the fourth lens is R7, and the radius of curvature of the image side surface of the fourth lens is R8; the radius of curvature of the object side surface of the fifth lens is R9, and the radius of curvature of the image side surface of the fifth lens is R10; the radius of curvature of the object side surface of the sixth lens is R11, and the radius of curvature of the image side surface of the sixth lens is R12; the following relationship is satisfied:

[0007] R1≤-2000mm or R1≥2000mm; -60.45mm≤R2≤-73.90mm;

[0008] 46.53mm≤R3≤56.88mm; 203.04mm≤R4≤248.19mm;

[0009] -38.92mm≤R5≤-47.57m; 38.91mm≤R6≤47.57mm;

[0010] 39.32mm≤R7≤48.07mm; -39.327mm≤R8≤-48.07mm;

[0011] 18.73mm≤R9≤22.90mm; R10≤-2000mm or R10≥2000mm;

[0012] R11≤-2000mm or R11≥2000mm; 16.82mm≤R12≤20.56mm.

[0013] Furthermore, the spacing range from the object plane of the DMD to the object side surface of the first lens is: 82.27mm~100.57mm; the spacing range from the image side surface of the first lens to the object side surface of the second lens is: 0.62mm~0.76mm; the spacing range from the image side surface of the second lens to the object side surface of the third lens is: 28.43mm~34.75mm; the spacing range from the image side surface of the third lens to the object side surface of the fourth lens is: 9.92mm~12.14mm; the spacing range from the image side surface of the fourth lens to the object side surface of the fifth lens is: 2.35mm~2.89mm; the spacing range from the image side surface of the fifth lens to the object side surface of the sixth lens is: 0.36mm~0.46mm; the spacing range from the image side surface of the sixth lens to the aperture is: 2.64mm~3.24mm.

[0014] Further, the thickness of the first lens G11 is in the range of 5.70 mm to 6.98 mm; the thickness of the second lens G12 is in the range of 7.33 mm to 8.97 mm; the thickness of the third lens G13 is in the range of 1.28 mm to 1.58 mm; the thickness of the fourth lens G14 is in the range of 8.53 mm to 10.43 mm; the thickness of the fifth lens G15 is in the range of 4.56 mm to 5.58 mm; the thickness of the sixth lens G16 is in the range of 0.9 mm to 1.1 mm;

[0015] The refractive index of the first lens G11 ranges from 1.467 to 1.527, and the Abbe number thereof ranges from 78.345 to 84.875; the refractive index of the second lens G12 ranges from 1.588 to 1.653, and the Abbe number thereof ranges from 34.972 to 37.888; the refractive index of the third lens G13 ranges from 1.549 to 1.613, and the Abbe number thereof ranges from 39.254 to 42.526; The refractive index of the fourth lens G14 is in the range of 1.467 to 1.527, and the Abbe number thereof is in the range of 78.345 to 84.875; the refractive index of the fifth lens G15 is in the range of 1.467 to 1.527, and the Abbe number thereof is in the range of 78.345 to 84.875; the refractive index of the sixth lens G16 is in the range of 1.549 to 1.613, and the Abbe number thereof is in the range of 39.254 to 42.526.

[0016] Furthermore, the second lens group G2 includes a seventh lens G21, an eighth lens G22 and a ninth lens G23 which are arranged in sequence; the seventh lens G21 is a convex-concave lens; the eighth lens G22 is a symmetrical biconvex lens; and the ninth lens G23 is a convex-concave lens.

[0017] Further, the radius of curvature of the object side surface of the seventh lens is R13, and the radius of curvature of the image side surface of the seventh lens is R14; the radius of curvature of the object side surface of the eighth lens is R15, and the radius of curvature of the image side surface of the eighth lens is R16; the radius of curvature of the object side surface of the ninth lens is R17, and the radius of curvature of the image side surface of the ninth lens is R18; the following relationship is satisfied:

[0018] -15.18mm≤R13≤-18.57mm, -21.96mm≤R14≤-26.85mm;

[0019] 264.57mm≤R15≤323.37mm, -264.57mm≤R16≤-323.37mm;

[0020] 112.15mm≤R17≤137.09mm, 136.44mm≤R18≤166.76mm.

[0021] Furthermore, the spacing range from the aperture to the object side surface of the seventh lens is: 12.28mm~15.02mm; the spacing range from the image side surface of the seventh lens to the object side surface of the eighth lens is: 137.88mm~168.54mm; the spacing range from the image side surface of the eighth lens to the object side surface of the ninth lens is: 81.14mm~99.18mm; the spacing range from the image side surface of the ninth lens to the exposure surface is: 81mm~99mm.

[0022] Further, the thickness of the seventh lens G21 is in the range of 10.59 mm to 12.95 mm; the thickness of the eighth lens G22 is in the range of 6.38 mm to 7.80 mm; the thickness of the ninth lens G23 is in the range of 5.76 mm to 7.04 mm;

[0023] The refractive index of the seventh lens G21 ranges from 1.587 to 1.653, and the Abbe number thereof ranges from 34.972 to 37.888; the refractive index of the eighth lens G22 ranges from 1.549 to 1.613, and the Abbe number thereof ranges from 39.254 to 42.526; the refractive index of the ninth lens G23 ranges from 1.587 to 1.653, and the Abbe number thereof ranges from 34.972 to 37.888.

[0024] Furthermore, a protective glass is provided between the DMD and the first lens group G1.

[0025] The beneficial effects of the present invention are as follows: both the DMD side and the exposure side adopt a telecentric optical path design to ensure the utilization rate of laser energy and the stability of the direct writing rate; the system supports a wide spectral band of 365 to 450 nm and has a wider application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0027] Figure 1 is the optical path diagram of this embodiment;

[0028] Figure 2 is a light path diagram of the first lens group G1 in this embodiment;

[0029] Figure 3 is a light path diagram of the second lens group G2 in this embodiment;

[0030] Figure 4 This is a spherical aberration data diagram of the imaging optics simulation of this embodiment;

[0031] Figure 5 This is a distortion data diagram of imaging optics simulation of this embodiment;

[0032] Figure 6 It is the modulation transfer function MTF diagram of the full field of view of this embodiment.

[0033] Among them: 1. Protective glass; 2. Aperture. DETAILED DESCRIPTION

[0034] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively with reference to the relevant accompanying drawings. Preferred embodiments of the present invention are given in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. It should be noted that when an element is referred to as "fixed to" another element, it can be directly on another element or there can also be a centered element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there may be a centered element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for illustrative purposes.

[0035] like Figure 1-6 As shown, an LD I optical system of this embodiment, an LD I optical system, comprises a first lens group G1 and a second lens group G2 arranged in sequence from the DMD side to the exposure side; an aperture 1 is arranged between the first lens group G1 and the second lens group G2; the focal power of the first lens group G1 and the focal power of the second lens group G2 are both positive focal powers; the first lens group G1 forms a telecentric optical path; the second lens group G2 forms a telecentric optical path; the focal length of the first lens group G1 is F1; the focal length of the second lens group G2 is F2; ​​wherein, 0.34 <F1 / F2<0.42。

[0036] In this embodiment, the first lens group G1 includes a first lens G11, a second lens G12, a third lens G13, a fourth lens G14, a fifth lens G15 and a sixth lens G16 which are arranged in sequence; the first lens G11 is a plano-convex lens; the second lens G12 is a meniscus lens; the third lens G13 is a symmetrical biconcave lens; the fourth lens G14 is a symmetrical biconvex lens; the fifth lens G15 is a plano-convex lens; and the sixth lens G16 is a plano-concave lens.

[0037] In this embodiment, the radius of curvature of the object side surface of the first lens is R1, and the radius of curvature of the image side surface of the first lens is R2; the radius of curvature of the object side surface of the second lens is R3, and the radius of curvature of the image side surface of the second lens is R4; the radius of curvature of the object side surface of the third lens is R5, and the radius of curvature of the image side surface of the third lens is R6; the radius of curvature of the object side surface of the fourth lens is R7, and the radius of curvature of the image side surface of the fourth lens is R8; the radius of curvature of the object side surface of the fifth lens is R9, and the radius of curvature of the image side surface of the fifth lens is R10; the radius of curvature of the object side surface of the sixth lens is R11, and the radius of curvature of the image side surface of the sixth lens is R12; the following relationship is satisfied:

[0038] R1≤-2000mm or R1≥2000mm; -60.45mm≤R2≤-73.90mm;

[0039] 46.53mm≤R3≤56.88mm; 203.04mm≤R4≤248.19mm;

[0040] -38.92mm≤R5≤-47.57m; 38.91mm≤R6≤47.57mm;

[0041] 39.32mm≤R7≤48.07mm; -39.327mm≤R8≤-48.07mm;

[0042] 18.73mm≤R9≤22.90mm; R10≤-2000mm or R10≥2000mm;

[0043] R11≤-2000mm or R11≥2000mm; 16.82mm≤R12≤20.56mm.

[0044] Specifically, the object-side surface of the first lens, the image-side surface of the fifth lens, and the object-side surface of the sixth lens can all be set to be planes.

[0045] In this embodiment, the spacing range from the object plane of the DMD to the object side surface of the first lens is: 82.27mm~100.57mm; the spacing range from the image side surface of the first lens to the object side surface of the second lens is: 0.62mm~0.76mm; the spacing range from the image side surface of the second lens to the object side surface of the third lens is: 28.43mm~34.75mm; the spacing range from the image side surface of the third lens to the object side surface of the fourth lens is: 9.92mm~12.14mm; the spacing range from the image side surface of the fourth lens to the object side surface of the fifth lens is: 2.35mm~2.89mm; the spacing range from the image side surface of the fifth lens to the object side surface of the sixth lens is: 0.36mm~0.46mm; the spacing range from the image side surface of the sixth lens to the aperture 2 is: 2.64mm~3.24mm.

[0046] In this embodiment, the thickness of the first lens G11 is in the range of 5.70 mm to 6.98 mm; the thickness of the second lens G12 is in the range of 7.33 mm to 8.97 mm; the thickness of the third lens G13 is in the range of 1.28 mm to 1.58 mm; the thickness of the fourth lens G14 is in the range of 8.53 mm to 10.43 mm; the thickness of the fifth lens G15 is in the range of 4.56 mm to 5.58 mm; the thickness of the sixth lens G16 is in the range of 0.9 mm to 1.1 mm;

[0047] The refractive index of the first lens G11 ranges from 1.467 to 1.527, and the Abbe number thereof ranges from 78.345 to 84.875; the refractive index of the second lens G12 ranges from 1.588 to 1.653, and the Abbe number thereof ranges from 34.972 to 37.888; the refractive index of the third lens G13 ranges from 1.549 to 1.613, and the Abbe number thereof ranges from 39.254 to 42.526; The refractive index of the fourth lens G14 is in the range of 1.467 to 1.527, and the Abbe number thereof is in the range of 78.345 to 84.875; the refractive index of the fifth lens G15 is in the range of 1.467 to 1.527, and the Abbe number thereof is in the range of 78.345 to 84.875; the refractive index of the sixth lens G16 is in the range of 1.549 to 1.613, and the Abbe number thereof is in the range of 39.254 to 42.526.

[0048] In this embodiment, the second lens group G2 includes a seventh lens G21, an eighth lens G22 and a ninth lens G23 arranged in sequence; the seventh lens G21 is a convex-concave lens; the eighth lens G22 is a symmetrical biconvex lens; and the ninth lens G23 is a convex-concave lens.

[0049] In this embodiment, the curvature radius of the object side surface of the seventh lens is R13, and the curvature radius of the image side surface of the seventh lens is R14; the curvature radius of the object side surface of the eighth lens is R15, and the curvature radius of the image side surface of the eighth lens is R16; the curvature radius of the object side surface of the ninth lens is R17, and the curvature radius of the image side surface of the ninth lens is R18; the following relationship is satisfied:

[0050] -15.18mm≤R13≤-18.57mm, -21.96mm≤R14≤-26.85mm;

[0051] 264.57mm≤R15≤323.37mm, -264.57mm≤R16≤-323.37mm;

[0052] 112.15mm≤R17≤137.09mm, 136.44mm≤R18≤166.76mm.

[0053] In this embodiment, the spacing range from the aperture 2 to the object side surface of the seventh lens is: 12.28mm~15.02mm; the spacing range from the image side surface of the seventh lens to the object side surface of the eighth lens is: 137.88mm~168.54mm; the spacing range from the image side surface of the eighth lens to the object side surface of the ninth lens is: 81.14mm~99.18mm; the spacing range from the image side surface of the ninth lens to the exposure surface is: 81mm~99mm.

[0054] In this embodiment, the thickness of the seventh lens G21 is in the range of 10.59 mm to 12.95 mm; the thickness of the eighth lens G22 is in the range of 6.38 mm to 7.80 mm; the thickness of the ninth lens G23 is in the range of 5.76 mm to 7.04 mm;

[0055] The refractive index of the seventh lens G21 ranges from 1.587 to 1.653, and the Abbe number thereof ranges from 34.972 to 37.888; the refractive index of the eighth lens G22 ranges from 1.549 to 1.613, and the Abbe number thereof ranges from 39.254 to 42.526; the refractive index of the ninth lens G23 ranges from 1.587 to 1.653, and the Abbe number thereof ranges from 34.972 to 37.888.

[0056] In this embodiment, a protective glass 1 is further provided between the DMD and the first lens group G1 .

[0057] Specifically, the side of the system close to the DMD device is the DMD side, and the side close to the photosensitive material is the exposure side; the laser beam starting from the DMD device passes through the first lens group G1, the aperture 2, and the second lens group G2 in sequence to reach the exposure side; the first lens group G1 and the second lens group G2 both have positive refractive index optical power, the first lens group G1 constitutes a telecentric optical path, and the second lens group G2 constitutes a telecentric optical path, that is, a double telecentric optical path. Figure 4-6 It can be concluded from the data that the distortion of the present invention is less than 0.02% under the wide spectral band of 365-450nm, and the quality is excellent. In practical application, the imaging magnification of the present invention can be stably maintained at 2.5X magnification, and the exposure accuracy of the lens is high.

[0058] In addition, the protective glass 1 can be located at any position between the DMD device and the first lens G11.

[0059] The above is only a preferred embodiment of the present invention. Therefore, any equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the patent application of the present invention are included in the protection scope of the patent application of the present invention.

Claims

1. An LDI optical system, characterized in that: It comprises a first lens group G1 and a second lens group G2 which are arranged in sequence from the DMD side to the exposure side; a stop (2) is arranged between the first lens group G1 and the second lens group G2; The focal power of the first lens group G1 and the focal power of the second lens group G2 are both positive focal powers; The first lens group G1 forms a telecentric optical path; The second lens group G2 forms a telecentric optical path; The focal length of the first lens group G1 is F1; The focal length of the second lens group G2 is F2; ​​wherein, 0.34 <F1 / F2<0.42。 2. An LDI optical system according to claim 1, characterized in that: The first lens group G1 includes a first lens G11, a second lens G12, a third lens G13, a fourth lens G14, a fifth lens G15 and a sixth lens G16 which are arranged in sequence; The first lens G11 is a plano-convex lens; the second lens G12 is a concave-convex lens; the third lens G13 is a symmetrical biconcave lens; the fourth lens G14 is a symmetrical biconvex lens; the fifth lens G15 is a plano-convex lens; and the sixth lens G16 is a plano-concave lens.

3. An LDI optical system according to claim 2, characterized in that: The radius of curvature of the object side surface of the first lens is R1, and the radius of curvature of the image side surface of the first lens is R2; the radius of curvature of the object side surface of the second lens is R3, and the radius of curvature of the image side surface of the second lens is R4; the radius of curvature of the object side surface of the third lens is R5, and the radius of curvature of the image side surface of the third lens is R6; the radius of curvature of the object side surface of the fourth lens is R7, and the radius of curvature of the image side surface of the fourth lens is R8; the radius of curvature of the object side surface of the fifth lens is R9, and the radius of curvature of the image side surface of the fifth lens is R10; the radius of curvature of the object side surface of the sixth lens is R11, and the radius of curvature of the image side surface of the sixth lens is R12; the following relationship is satisfied: R1≤-2000mm or R1≥2000mm; -60.45mm≤R2≤-73.90mm; 46.53mm≤R3≤56.88mm; 203.04mm≤R4≤248.19mm; -38.92mm≤R5≤-47.57m; 38.91mm≤R6≤47.57mm; 39.32mm≤R7≤48.07mm; -39.327mm≤R8≤-48.07mm; 18.73mm≤R9≤22.90mm; R10≤-2000mm or R10≥2000mm; R11≤-2000mm or R11≥2000mm; 16.82mm≤R12≤20.56mm.

4. The LDI optical system according to claim 2, characterized in that: The distance between the object plane of the DMD and the object side surface of the first lens is in the range of 82.27 mm to 100.57 mm. The distance between the image side surface of the first lens and the object side surface of the second lens is in the range of 0.62 mm to 0.76 mm; The distance between the image side surface of the second lens and the object side surface of the third lens is in the range of 28.43 mm to 34.75 mm. The distance between the image side surface of the third lens and the object side surface of the fourth lens is in the range of 9.92 mm to 12.14 mm; The interval range between the image side surface of the fourth lens and the object side surface of the fifth lens is: 2.35mm~2.89mm; The interval range between the image side surface of the fifth lens and the object side surface of the sixth lens is: 0.36mm~0.46mm; The interval between the image side surface of the sixth lens and the aperture (2) is in the range of 2.64 mm to 3.24 mm.

5. The LDI optical system according to claim 2, characterized in that: The thickness of the first lens G11 is in the range of 5.70 mm to 6.98 mm; The thickness of the second lens G12 is in the range of 7.33 mm to 8.97 mm; The thickness of the third lens G13 is in the range of 1.28 mm to 1.58 mm; The thickness of the fourth lens G14 is in the range of 8.53 mm to 10.43 mm; The thickness of the fifth lens G15 is in the range of 4.56 mm to 5.58 mm; The thickness of the sixth lens G16 is in the range of 0.9 mm to 1.1 mm; The refractive index of the first lens G11 ranges from 1.467 to 1.527, and the Abbe number ranges from 78.345 to 84.875; The refractive index of the second lens G12 is in the range of 1.588 to 1.653, and the Abbe number thereof is in the range of 34.972 to 37.888; The refractive index of the third lens G13 is in the range of 1.549 to 1.613, and the Abbe number thereof is in the range of 39.254 to 42.526; The refractive index of the fourth lens G14 is in the range of 1.467 to 1.527, and the Abbe number thereof is in the range of 78.345 to 84.875; The refractive index of the fifth lens G15 is in the range of 1.467 to 1.527, and the Abbe number thereof is in the range of 78.345 to 84.875; The refractive index of the sixth lens G16 ranges from 1.549 to 1.613, and the Abbe number thereof ranges from 39.254 to 42.

526.

6. The LDI optical system according to claim 1, characterized in that: The second lens group G2 includes a seventh lens G21, an eighth lens G22 and a ninth lens G23 arranged in sequence; The seventh lens G21 is a convex-concave lens; the eighth lens G22 is a symmetrical biconvex lens; and the ninth lens G23 is a convex-concave lens.

7. The LDI optical system according to claim 6, characterized in that: The curvature radius of the object side surface of the seventh lens is R13, and the curvature radius of the image side surface of the seventh lens is R14; the curvature radius of the object side surface of the eighth lens is R15, and the curvature radius of the image side surface of the eighth lens is R16; the curvature radius of the object side surface of the ninth lens is R17, and the curvature radius of the image side surface of the ninth lens is R18; the following relationship is satisfied: -15.18mm≤R13≤-18.57mm, -21.96mm≤R14≤-26.85mm; 264.57mm≤R15≤323.37mm, -264.57mm≤R16≤-323.37mm; 112.15mm≤R17≤137.09mm, 136.44mm≤R18≤166.76mm.

8. The LDI optical system according to claim 6, characterized in that: The interval range between the aperture (2) and the object side surface of the seventh lens is: 12.28 mm to 15.02 mm; The distance between the image side surface of the seventh lens and the object side surface of the eighth lens is in the range of 137.88 mm to 168.54 mm. The distance between the image side surface of the eighth lens and the object side surface of the ninth lens is in the range of 81.14 mm to 99.18 mm. The interval range between the image side surface of the ninth lens and the exposure surface is: 81mm~99mm.

9. The LDI optical system according to claim 6, characterized in that: The thickness of the seventh lens G21 is in the range of 10.59 mm to 12.95 mm; The thickness of the eighth lens G22 is in the range of 6.38 mm to 7.80 mm; The thickness of the ninth lens G23 is in the range of 5.76 mm to 7.04 mm. The refractive index of the seventh lens G21 is in the range of 1.587 to 1.653, and the Abbe number thereof is in the range of 34.972 to 37.888; The refractive index of the eighth lens G22 is in the range of 1.549 to 1.613, and the Abbe number thereof is in the range of 39.254 to 42.526; The refractive index of the ninth lens G23 ranges from 1.587 to 1.653, and the Abbe number thereof ranges from 34.972 to 37.

888.

10. The LDI optical system according to claim 1, characterized in that: A protective glass (1) is also provided between the DMD and the first lens group G1.

Images