JP3309747B2 - Alignment method of ceramic multilayer wiring board and thin film pattern - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment method for forming a thin film pattern on a ceramic multilayer wiring substrate, and more particularly, to a method for forming a large number of L layers on a ceramic multilayer wiring substrate.
The present invention relates to an alignment method suitable for forming a desired thin film wiring in an SI mounting area by a direct drawing exposure method.

[0002]

2. Description of the Related Art In recent years, as one of the notable LSI mounting techniques, there is a method of using a thick-film / thin-film hybrid substrate in which thin-film wiring and terminal pads are formed on a ceramic multilayer wiring substrate. In this method, a thin film pattern is formed by a technique such as photolithography, etching, and plating on a ceramic substrate having multilayer wiring formed inside the ceramic by using a sheet laminating method or a thick film printing method, and then a large number of layers are formed on the substrate. LSI chips are arranged side by side and mounted at high density, and these chips are interconnected using multilayer wiring inside the substrate and thin film wiring on the substrate.

In general, a thin film wiring is formed by applying a photoresist on a multilayer wiring substrate and transferring a predetermined photomask pattern onto the substrate by an exposing machine. In the case of this exposure method, a photomask corresponding to the formation of a thin film pattern is necessarily required. This is required for each thin film layer, product type, and size.

[0004] Recently, there is also a division exposure method in which exposure is divided to increase the size of the substrate and absorb distortion, deformation, and shrinkage of the ceramic substrate. In this case, a larger amount of photomask is required.

As described above, an increase in the required number of photomasks leads to an increase in the cost of thin-film wiring.

A maskless thin film pattern forming technique has been studied for a long time, and there is a direct drawing technique using an electron beam or a laser beam. These are put into practical use mainly as a method of manufacturing a photomask. When this technology is applied to the formation of thin-film wiring on a ceramic multilayer wiring board, it is necessary to form a thin-film wiring in consideration of the distortion, deformation, and shrinkage that occur during the firing process of ceramics. As in the case of the exposure method, it is necessary to perform alignment with high accuracy.

In a known example, a mark on a substrate is recognized and the substrate is aligned with the apparatus. A ceramic substrate having the above-described distortion, deformation, and contraction cannot be aligned.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to use a multi-layered ceramic wiring board including a strained or deformed ceramic multilayer wiring board over the entire area of the board. LSI mounting area
An object of the present invention is to provide an improved alignment method capable of forming a thin film wiring with high accuracy by a maskless exposure method.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is to provide a multi-layer LS provided on a ceramic multilayer wiring board.
The problem can be effectively solved by using both the I mounting area and the target marks arranged around the substrate as alignment reference marks.

A large number of LSI mounting areas are formed substantially over the front surface of the multilayer wiring board. For example, image data obtained by using a television camera can be converted into individual position coordinates by performing predetermined arithmetic processing. It is possible. In the present invention, the position coordinates of the LSI mounting area and the target mark converted in this way and the individual LSI
By performing predetermined arithmetic processing (for example, arithmetic processing by the least square method) on the design coordinates corresponding to the mounting area and the target mark, the correction amount (rotation angle and translation amount) of the multilayer wiring board required for alignment is calculated. By converting the exposure data based on the calculated correction amount, the substrate and the thin film pattern are aligned.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle of an alignment method according to the present invention will be described with reference to FIGS.

FIG. 1 is a conceptual diagram showing a configuration example of a typical ceramic multilayer wiring board. In the figure, 1 is a multilayer wiring board, 2 is a target mark required for aligning a thin film pattern, and 3 is a large number of LSI mounting areas provided on the side of the substrate 1 on which a thin film is formed. FIG.
FIG. 3 is a conceptual diagram showing a configuration example of a representative designed thin film pattern. In the figure, 4 is a design thin film pattern, 5 is a design pattern of a target mark, and 6 is a thin film pattern of a large number of LSI mounting areas. The target mark design pattern 5 is formed so as to match the target mark 2 if the substrate 1 does not include distortion, deformation, or contraction.

Now, as a first calculation, a positional relationship between the LSI mounting area on the substrate 1 and the corresponding design thin film pattern 4 for minimizing the deviation is obtained.
It performs the following arithmetic processing.

The total number of photographing units in the LSI mounting area 3 provided on the multilayer wiring board 1 is n, and the position coordinates are (xi,
yi), position coordinates on the design thin film pattern 4 corresponding to the position coordinates are (Xi, Yi). In this case, the substrate 1
The positional relationship between the LSI mounting area above and the design thin film pattern 4 corresponding to the LSI mounting area is as follows:
It can be obtained by the following calculation method.

That is, assuming that the position coordinates of each LSI mounting area when the substrate 1 rotates by an angle θ and moves (a, b) in parallel is (x′i, y′i), the so-called least square method is used. Then, L = {(Xi−x′i) ² + (Yi−y′i) ² } (1) The value of θ, a, b at which L becomes minimum is obtained by setting L to θ, a, b. Partially differentiated to 0
Is the solution of the following equation:

∂L / ∂θ = 0 (2) ∂L / ∂a = 0 (3) ∂L / ∂b = 0 (4) tanθ = ｛(ΣXiΣyi−ΣxiΣYi) / n + Σ ( xiYi-Xiyi)｝ ÷ ｛(ΣxiΣXi + ΣyiΣYi) / n-Σ (xiXi-yiYi)｝ ... (5) a = (cosθΣxi-sinθΣyi-ΣXi) / n ... (6) (7) Accordingly, (x′i, y′i) representing the position coordinates of each LSI mounting area after rotating and translating the substrate 1 can be obtained by the following formula.

X′i = xicosθ + yisinθ + a (8) y′i = −xisinθ + yicosθ + b (9) Next, the position coordinates (x′i, y′i) of each LSI mounting area after the movement and the individual The maximum value and the minimum value of the deviation in the x direction and the y direction from the position coordinates (Xi, Yi) of the designed thin film pattern corresponding to the area are max (x), min, respectively.
(x), max (y), min (y), (x "i, y" i) can be defined by the following equation.

Α = x ″ i−x′i = (| max (x) | − | min (x) |) / 2 (10) β = y ″ i−y′i = (| max (y ) | − | Min (y) |) / 2 (11) Next, as a second operation, this time, between the target mark 2 on the substrate 1 and the corresponding target mark design pattern 5 The positional relationship between the two to reduce the deviation is determined. The total number of target marks 2 necessary for aligning the thin film pattern is n, and the position coordinates are (xi, y
i), the position coordinates of the design pattern 5 of the target mark corresponding to the position coordinates are set to (Xi, Yi), and the calculation is performed using the above equations 1 to 11 as in the first calculation.

Finally, θ, a, b, α, β obtained by the first and second calculations are respectively θ1, a1, b1, α1, β1, θ
Assuming that 2, a2, b2, α2, β2, the correction amount required for forming a thin film pattern on the substrate 1 can be expressed as follows.

1) Primary conversion movement Rotation angle: θ1-θ2 Parallel movement (x direction): a1-a2 Parallel movement (y direction): b1-b2 2) Parallel movement for minimizing the maximum displacement x direction: α1-α2 y direction: β1-β2 Then, by converting the exposure data for forming the thin film pattern according to the correction amount obtained above, the substrate and the thin film pattern can be aligned.

As a method of exposing the thin film pattern, a direct drawing method without using a photomask may be used.

As a light source for direct drawing exposure, it is possible to use a laser beam suitable for the photosensitive material to be used.

The position coordinates of the LSI mounting area can be represented by the position coordinates of specific components (for example, connection pads formed at four corners) in the area where images can be recognized. Also, the position coordinates of the LSI mounting area need not necessarily be calculated for all the LSI mounting areas, and alignment can be performed by calculating the position coordinates of every other LSI mounting area, for example.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for aligning a ceramic multilayer wiring board and a thin film pattern formed thereon according to the present invention will be described below in detail with reference to the drawings.

The configuration of an apparatus for obtaining the position coordinates of a target mark for aligning an LSI mounting area and a thin film pattern provided on the substrate 1 will be described with reference to FIG. In FIG. 3, a camera 7 sends image data of the substrate 1 to a computer 8 for arithmetic processing. The arithmetic processing computer 8 calculates the position coordinates of each measurement point from the transmitted image data, and calculates the correction amount by the above-described method. Then, the arithmetic processing computer 8 gives an instruction of the correction amount to the exposure machine control computer 9. Next, the configuration of an exposure apparatus that exposes a substrate to form a thin film pattern will be described with reference to FIG. FIG.
, The camera 10 is mounted on the substrate 1 set on the exposure machine.
It is used to measure the position coordinates of the target mark for aligning the thin film pattern. Then, the above-described arithmetic processing is performed by using the exposure machine control computer 9 from the obtained position coordinates. In consideration of the result and the correction amount sent from the arithmetic processing computer 8, the exposure machine control computer 9 converts the exposure data and aligns the substrate 1 with the thin film pattern.

[0026]

As is apparent from the above detailed description, according to the method for aligning a ceramic multilayer wiring board and a thin film pattern formed thereon according to the present invention, distortion,
The entire ceramic multilayer wiring board including deformation and shrinkage can be aligned with the thin film pattern with high precision, and the pattern can be formed without using a photomask.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration example of a ceramic multilayer wiring board.

FIG. 2 is a conceptual diagram showing a configuration example of a designed thin film pattern.

FIG. 3 is a configuration diagram of an apparatus for calculating position coordinates and a correction amount of a pattern on a substrate according to the present invention;

FIG. 4 is a configuration diagram of an apparatus for exposing a thin film pattern according to the present invention.

[Explanation of symbols]

 1: Ceramic multilayer wiring board 2: Target mark 3: LSI mounting area 4: Design thin film pattern 5: Design target mark pattern 6: LSI mounting area thin film pattern 7: Camera 8: Computer for arithmetic processing 9: Computer for exposure machine control 10: Camera 11: Substrate support 12: Substrate controller 13: Exposure unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-20909 (JP, A) JP-A-60-179745 (JP, A) JP-A-4-37023 (JP, A) JP-A-10- 106931 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G03F ^7/ 20-7/24 G03F 9/00-9/02

Claims (4)

(57) [Claims] A plurality of LSI mounting areas provided on a ceramic multi-layered wiring board and a target mark for aligning a thin film pattern with the LSI mounting area and the target mark based on image data obtained by photographing the target mark; By calculating predetermined position coordinates and performing predetermined arithmetic processing on the calculated position coordinates and the design position coordinates corresponding to the target mark for aligning the individual LSI mounting area and the thin film pattern, the correction amount required for the alignment is obtained. (Rotation angle and translation amount) and converting exposure data necessary for exposing the thin film pattern based on the calculated correction amount. . 2. The method according to claim 1, wherein the correction amount is calculated by subjecting the position coordinates of the LSI mounting area and the design coordinates corresponding to each LSI mounting area to an arithmetic processing by the least square method, and further calculating the corrected individual LSI area. 2. The method according to claim 1, further comprising calculating a parallel movement amount for minimizing a maximum value of a shift amount between the position coordinates of the mounting area and the corresponding design coordinates in the X-axis direction and the Y-axis direction. Alignment method of ceramic multilayer wiring board and thin film pattern. 3. The method according to claim 1, wherein a direct writing exposure method without using a photomask is used in the exposure of the thin film pattern. 4. The method according to claim 1, wherein in converting the exposure data necessary for exposing the thin film pattern, the designed thin film pattern is moved on the basis of the correction amount, not on the ceramic multilayer wiring substrate side. 4. The method for aligning a ceramic multilayer wiring board and a thin film pattern according to any one of items 1 to 3.