JPH02158706A - Lens constituted of 4 groups - Google Patents

Abstract

PURPOSE:To improve the transmittance of light in the photosensitive wavelength region of a photoresist and to improve various aberrations by consisting positive lenses and negative lenses of glass materials satisfying specific conditions and averting the intervention of adhesive agents between the positive and negative lenses and between the respective lens groups. CONSTITUTION:The positive lens consists of the material satisfying nd<1.63, nud>56 and the negative lens consists of the glass material satisfying nd>1.56, nud>49 when the refractive index and dispersion value of the glass materials with respect to (d) rays are respectively designated as nd and nud. These lenses are so formed that the adhesive agents are not intervened between the positive and negative lenses and between the respective lens groups. The transmittance, chromatic aberrations, etc., to the (g) rays, (h) rays, and (i) rays which are the main rays within the photosensitive wavelength region of the photoresist are improved in this way and the deterioration in the transmittance of the projecting lens by the secular change is prevented.

Description

[Detailed description of the invention] <Industrial application field> This invention applies to ICs such as tape carriers.

This invention relates to a projection lens used in the LSI manufacturing process to print a required lead pattern on a sensitive material coated with a photoresist, and in particular relates to a four-group lens suitable for printing with light containing near ultraviolet or ultraviolet light. be.

<Conventional technology> In recent years, electronic devices such as watches and electronic desktop calculators have become smaller and more multifunctional, and the lead patterns of IC and LSI packages used in these electronic devices have also become smaller and smaller. There is a trend toward

The tape carrier method forms this type of reticle pattern on a tape-like film to automatically process high-density packaging of TC and LSI packages. Figure 11 shows the pattern printing equipment used in the tape carrier manufacturing process. FIG.

This pattern printing device includes a printing light source 1 and a projection lens 2.
It is equipped with an original tape reel 3, a printing tape reel 4, a control device 5 for controlling automatic feeding and automatic exposure of both tapes, and positions the original tape and the printing tape 4a with high precision. The reticle pattern is continuously printed on the printing tape 4a of the photoresist coating stream at a magnification of 172 times to the same size.

As the projection lens 2, a plate-making lens whose various aberrations have been corrected with high precision has conventionally been used.
Lenses having a four-group structure are known as disclosed in Japanese Patent Application Laid-open No. 117030 and Japanese Patent Application Laid-Open No. 55-90930.

These projection lenses have a first lens group, a second lens group, a third lens group, and a fourth lens group arranged in order from the object side,
Each lens group is constructed by combining a positive lens and a negative lens.

<Problems to be Solved by the Invention> The conventional projection lens described above has various aberrations corrected with high precision, but since it is a plate-making lens that takes the visible light region into consideration, it has the following drawbacks.

B. The wavelength range that photoresists are sensitive to extends from the near-ultraviolet region to the ultraviolet region, but these wavelength regions are not taken into consideration in the conventional example described above, so the photoresist is sensitive to ultraviolet light, such as i! ! The transmittance of it was low, and the printing efficiency was inevitably lowered.

Since an adhesive such as Canadian balsam is interposed between the mouth, each positive and negative lens, or the joint surface between each lens group, the adhesive changes over time due to ultraviolet rays, reducing the transmittance of the entire projection lens.

The technical problem of the present invention is to solve the following three difficulties.

<Means for Solving the Problems> The present invention is configured as follows to solve the above problems.

That is, in the above 41'l configuration lens, when the refractive index and dispersion value for the d-line of the glass material are nd and white, respectively, the positive lens is nd < 1.63, the negative lens is nd < 1.56. , between the positive and negative lenses and each lens. It is characterized in that no adhesive is interposed between the iTs.

In the present invention, the iE lens and the negative lens constituting each lens group are made of a glass material that considers the ultraviolet and near-ultraviolet regions, and the g-ray (435, 83 nm), h line (404, 66 nm), i
Transmittance for lines (365,01 ns), chromatic aberration, etc. are significantly improved.

Furthermore, since no adhesive is used, the transmittance of the projection lens does not deteriorate due to aging.

<Example> Examples of the 4-group lens according to the present invention are shown below with lens data tables (Tables 1 to 5), lens arrangement diagrams, and diagrams showing various aberrations (Figs. 1 to 1O). Illustrated by.

In each lens data table, f is the focal length, 20 is the total angle of view, F
is the open aperture value, m is the standard magnification, Ti is the lens transmittance for the i-line, r, d, n, ν correspond to each symbol in Figure 1, n is the refractive index, and ν is the dispersion. Show the value.

In addition, the refractive index nd and the fractional value ν for the d-line (587, 56 nm) in the visible light region are determined for the glass material, taking into account the significant improvement in the transmittance of ultraviolet light or near-ultraviolet light, according to a conventional method. Each of the above G-line, H-line, IVA
The refractive indexes n1, nh, and n are also described.

Furthermore, in the following embodiments, no adhesive is inserted between each lens group and between the positive and first lenses constituting each lens group.

On the other hand, diagrams showing lens characteristics (Fig. 2, Fig. 4, Fig. 6,
8 and 10) correspond to Examples 1 to 5, and include three types of graphs A, B, and C showing spherical aberration, astigmatism, and distortion aberration.

In the graph of spherical aberration A, the horizontal axis shows the aberration rl
j(s+n) is taken as a standard value with open aperture values of 5 and 6 as 1 on the vertical axis, and spherical aberration curves g, h, and i due to the g-line, h-line, and i-line are shown, respectively. In graph B showing astigmatism, S indicates a sagittal image plane, and M indicates a meridional image plane, both of which indicate astigmatism for the h-line.

'Tomo-Kitai 11 The lens data of this example is shown in Table 1, the arrangement diagram of the lens is shown in FIG. 1, and the aberration diagram is shown in FIG. 2.

In this embodiment, each lens ffTG, ~G4 is composed of a combination of g-line, h-line, and i-line achromatic double rays), and the front groups G, , G, form convex-concave-concave patterns in order from the object side. The rear groups G3 and G4 are arranged symmetrically with respect to the aperture. With this configuration, various aberrations at the reference magnification m=l can be well corrected,
It is possible to secure the required aperture value. Note that the transmittance for i-line is high, reaching 81.4%.

Below, the lens data of this example is shown in Table 2, the lens arrangement diagram is shown in FIG. 3, and the aberration diagram is shown in FIG. 4.

In this embodiment, each lens group 61 to G4 is connected to the g-line and h-line, respectively.
It consists of a combination of achromatic doublets of line and i line, and the front group G
, , G are arranged in order from the object side so as to form a concave-convex pattern, and the rear groups G, , G are arranged symmetrically with respect to the aperture surface. The other points are the same as in Example 1, and the transmittance for i-line reaches 79.2%.

Margin below f=100■ " 59, 8+53 23.6363 24, 2307 146, 5781 47.6258 35,650+ 47, 6927 75, 1682 75.1682 47, 6927 35, 6501 47, 6258 146, 5781 24, 230? 23, 6363 59.8153 n　Iln　Is n:l+n12 5lnII n? ＋　n　＠ 20・20゜ 1,733 0,908 5.775 7.174 +, 733 3, 57? 3,224 5,0g4 3,224 3,577 1,733 7, +74 5.775 0,908 1.733 nlI 1,54222 1,63312 1,54222 1,63312 Table 1 5.6 1,52944 1,62041 1,52944 1.62041 1,62041 1,52944 1,62041 1,52944 Refractive index of glass material h 1,54695 1,63774 +, 54695 1,63774 T+=81.4% νd 51.7 60.3 51.7 60°3 60.3 51.7 60.3 51.7 1.555+5 1,64599 1.55515 1,64559 f = lOO 閤 63, 8534 36,0534 40.7760 21,7684 17.4180 17, 4180 21,7684 215.1308 -40.771i0 36,0534 63, 8534 lInl5 3InI3 1s, nlI n,,n・ 20=20° 3. Go.

2,062 3,000 11.385 4,000 0,429 2,000 26,380 2,000 0.429 4,000 11°385 3,0GO 2,062 3,000 ngi1,56508 1,63316 1,63316 1,56508 Table 2 F-5,6m=1 d 1,55115 1.62041 1,62041 1,55115 1,55115 1.62041 1.62041 1.55115 Refractive index of glass material h 1,57028 1, 63778 1, 63778 1, 57028 T +=79.2% νd 49.7 60.3 60.3 49.7 49.7 60.3 60.3 49.7 1, 57936 1, 64568 ! , 64568 1, 57936 χ1 Prefecture The lens data of this example is shown in Table 3, the arrangement diagram of the lens is shown in FIG. 5, and the aberration diagram is shown in FIG.

In this embodiment, each lens nG, ~G4 has a g-line and a h-line, respectively.
It consists of a combination of achromatic doublets of line and i line, and the front group G
, , G are arranged in a convex-concave manner in order from the object side, and the rear group G3. G is arranged so as to be symmetrical with respect to the aperture. In other respects, Example 1
The transmittance for i-rays reaches 81.5%.

The following is a large margin. Lens data of this example is shown in Table 4, a lens arrangement diagram is shown in FIG. 7, and an aberration diagram is shown in FIG.

In this embodiment, each lens group G, ~G4 is connected to the g-line and h-line, respectively.
It consists of a combination of achromatic doublets of line and i line, and the front group G
, , G are arranged in order from the object side so as to form a convex-concave-concave pattern, and the rear groups G, , G are arranged symmetrically with respect to the aperture surface. In other respects, Example 1
The transmittance for i-rays reaches 80.1%.

Margin below 00m " 43.5202 86.8289 g5.6022 79, 9692 184.8635 307, 3162 20.0080 20.0080 307, 3162 184.8635 26, 3549 79, 9692 85.6022 43, 5202 nI+n1S n 3 + n 13 nSln■ n? +n11 20=20° 4. Go.

O,286 0,100 4,000 2,021 2,021 0,928 4,000 0,100 2,0g4 0,286 4,000 n" 1,6+539 1,54222 1,63316 1,56508 Table 3 5 .6 m d 1.60311 1, 52944 1.62041 1, 55115 1.55115 1.62041 1, 52944 1.60311 Glass material refractive index h 1, 61984 1, 54695 1, 63778 1, 57028 T, ・81. 5% νd 60.7 51.7 60.3 49.7 49.7 60.3 51.7 60.7 nm 1, 62743 1, 55516 1, 64568 1, 57936 27, 5621 161, 4335 77, 8672 20.1100 34, 8476 20, 1500 19, 9367 93.3780 93, 3780 19, 9367 20, 1500 34, 8476 20.1100 77, 8612 161.4335 27, 5621 nl+rlls n 3+ n l 3 nSln■ n ?+ n @ 20=20゜5, 332 3,066 3,999 1,800 2,066 0.733 3,866 6,666 3,866 0,733 2,066 1,800 3,999 3,066 5, 332 0 rin 1, 63316 1.54222 1.52621 1, 50450 Table 4 F=5.6 m d 1, 62041 1, 52944 1, 51633 1.49700 1.49700 1.51633 1, 52944 1.62041 Glass material Refractive index h 1, 63778 1, 54695 1, 52976 1, 50720 T , = 80.1% ν1 51.7 64.1 81.6 81.6 64.1 51.7 60.3 n+ 1, 64568 1. 55516 1, 53577 1.51173 Example 5 Lens data of this example is shown in Table 5, a lens arrangement diagram is shown in FIG. 9, and an aberration diagram is shown in FIG. 10.

In this embodiment, the reference magnification is set to 1/2, and accordingly, the lens intervals are arranged so as to be asymmetrical with respect to the diaphragm. In other respects, each lens J! TG, -G are each composed of a combination of achromatic doublets of g-line, h-line, and i-line, the front groups G, , G are arranged in a convex-concave-concave manner in order from the object side, and the rear group G3 ．． The radius of curvature r1 of each lens forming G and the thickness of each lens are the same as each lens of the front group G1, G, but the distance between the surfaces of each lens is different depending on the required magnification. There is. In this way, by changing the distance between the surfaces of each lens, changes in magnification can be easily accommodated in other embodiments. In addition, the transmittance for i-line is 80
．． It has reached 1%.

Margin below 00I 27, 5621 161, 4335 77, 8672 20. 61, 4335 n l+ n Is n 31n lpn Sln single n7.n self 2e=20°5, 332 2, 870, 999 0, 709 2, 066 3, 866 6.671 3, 866 0, 824 2, 066 2.515 3,999 3,253 5,332 n' 1,63316 1,54222 1,52621 1,50450 Table 5 5.6 m=0.5 1,62041 1,51633 1.49700 1.4970G 1, 51633 1, 52944 1, 62041 Glass material refractive index h 1, 63778 1, 54695 1, 52976 1, 50720 T, ・80.1% νd 60.3 51.7 64, ■ 81.6 81.6 64.1 51.7 60.3 t 1, 64568 1, 55516 1, 53577 1.51173 <Effects of the Invention> As is clear from the above description, the four-group lens according to the present invention is configured as described above. Therefore, the following effects are achieved.

B. The positive lens and negative lens constituting each lens li'\ are made of a glass material that takes ultraviolet and near-ultraviolet regions into consideration, and the light transmittance in the photoresist sensitive wavelength range is greatly improved, Aberrations are largely eliminated. This makes it possible to shorten the printing time and improve image quality.

Since no adhesive is used to join the mouth and lens, there is no risk of the transmittance decreasing due to aging of the adhesive as in conventional examples.

[Brief explanation of the drawing]

FIG. 1, FIG. 3, FIG. 5, FIG. 7, and FIG. Figure, Figure 6, Figure 8, Figure 1
0 is an aberration diagram of lenses corresponding to Examples 1 to 5, respectively, and FIG. 11 is a perspective view of a pattern printing apparatus. G1...first lens group, G,...second lens group,
G,...Third lens group, G,...Fourth lens group,
n, 1... refractive index for d-line, white... dispersion value for d-line.

Claims (1)

[Claims] 1. In order from the object side, the first lens group, the second lens group, and the third lens group.
In a 4-group lens in which a lens group and a fourth lens group are arranged, and each lens group is configured by combining a positive lens and a negative lens, the refractive index and dispersion value for the d-line of the glass material are respectively n_d.
and ν_d, the positive lens is made of a glass material that satisfies n_d<1.63, ν_d>56 and the negative lens is n_d<1.56, ν_d>49, and adhesive is used between the positive and negative lenses and between each lens group. A four-group lens with no intervening