JP2006082280A - Screen printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen printing method which enables printing with a good positional accuracy. <P>SOLUTION: Reference pattern holes 124 to be references of positional alignment of a screen mask 120 with a substrate 10 are provided in the screen mask 120, and positional alignment patterns 60b having almost the same shape and size as reference patterns 60a printed through the reference pattern holes 124 are provided on the substrate 10 in accordance with the positional relationship of pattern holes 121 and the reference pattern holes 124. Printing is conducted with the screen mask 120 brought into contact with a dummy substrate 200, and positions of the reference patterns 60a printed on the dummy substrate 200 are detected. Then, the substrate 10 is so positioned that the detected positions of the reference patterns 60a be almost the same as those of the positional alignment patterns 60b, and the screen mask 120 is brought into contact with the substrate in this positioning state, so as to execute printing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a screen printing method in which a screen mask provided with a desired pattern hole is brought into contact with a substrate and a paste is printed on the substrate through the pattern hole, and in particular, between a pair of electrodes formed on the substrate. The present invention relates to a screen printing method for forming a moisture sensitive film in a capacitive humidity sensor having a moisture sensitive film interposed therebetween.

  Conventionally, the present applicant has previously disclosed Patent Document 1 as an example of a capacitive humidity sensor in which a moisture-sensitive film whose relative dielectric constant changes according to humidity is interposed between a pair of electrodes.

  In the capacitive humidity sensor shown in Patent Document 1, a pair of electrodes are formed on the same plane on the substrate so as to face each other with a distance therebetween, and the humidity is applied to the substrate so as to cover the pair of electrodes and the pair of electrodes. Accordingly, a moisture sensitive film whose relative dielectric constant changes is formed.

Here, in the manufacture of the capacitive humidity sensor, when a moisture-sensitive film is formed by screen-printing and curing a paste containing a polymer material that is a constituent material, a photo process required when the spin coat method is applied The patterning by can be made unnecessary. That is, the process can be simplified. There is also an advantage that the device is easy to handle.
JP 2002-243690 A

  By the way, in the screen printing, since the paste is printed on the substrate through the pattern holes provided in the screen mask, it is necessary to accurately align the screen mask and the substrate. In the capacitive humidity sensor as well, the positional accuracy of the moisture sensitive film is required particularly with the downsizing of the sensor body, and it is necessary to accurately align the screen mask and the substrate.

  Therefore, conventionally, when aligning the screen mask and the substrate, for example, the screen mask is brought into contact with a dummy substrate (test substrate) and screen printing is performed, and the position of the printed region printed through the pattern hole is determined by a CCD camera or the like. It detects using the imaging device. Then, the substrate is positioned and arranged on the stage so that the detected print area and the area to be printed on the substrate are substantially at the same position, and printing is performed in this positioned state.

  However, in the case of screen printing, it is difficult to make the film thickness of the moisture sensitive film uniform (for example, due to a saddle phenomenon in the end region). Therefore, the pattern hole is set larger than the area to be printed in order to arrange the central area (enclosed by the edge) where the film thickness is almost uniform in the area to be printed on the substrate. In the case of screen printing, since the paste is printed by sliding the squeegee, the shape and / or size of the actually printed region (moisture sensitive film) is somewhat different from the pattern hole. That is, there is a large difference in shape and / or size between the area to be printed on the board and the area actually printed on the dummy board, and the position is not limited even if the board is positioned with reference to the printed area. There is a problem that a moisture sensitive film cannot be formed with high accuracy.

  In view of the above problems, an object of the present invention is to provide a screen printing method capable of printing with high positional accuracy.

  In order to achieve the above object, the invention according to any one of claims 1 to 8 is a screen printing in which a screen mask provided with a desired pattern hole is brought into contact with the substrate and a paste is printed on the substrate through the pattern hole. It is about the method.

  First, as described in claim 1, the screen mask is provided with a reference pattern hole serving as a reference for alignment between the screen mask and the substrate, and on the substrate according to the positional relationship between the pattern hole and the reference pattern hole. In addition, in the plane direction of the substrate, a step of forming an alignment pattern having substantially the same shape and size as the reference pattern printed through the reference pattern hole, and printing is performed by bringing the screen mask into contact with the dummy substrate. The step of detecting the position of the reference pattern printed on the dummy substrate and the substrate are positioned so that the alignment pattern is substantially at the same position with respect to the detected position of the reference pattern. And a step of printing by contacting the mask.

  As described above, according to the present invention, since the alignment pattern formed on the substrate and the reference pattern printed on the dummy substrate have substantially the same shape and size, the substrate and the screen mask are accurately positioned. can do. Therefore, according to the screen printing method of the present invention, it is possible to perform printing with pattern holes with high positional accuracy on the region to be printed on the substrate.

  The alignment pattern is a portion serving as a reference for alignment between the screen mask and the substrate, instead of the region where the paste is to be printed on the substrate via the pattern hole. Since the shape and / or size of the alignment pattern is not fixed in terms of characteristics like the area to be printed, it is substantially the same as the shape and size of the reference pattern printed through the reference pattern hole. It can be formed to have a shape and size.

  Further, the method of detecting the formation position of the reference pattern printed on the dummy substrate and the method of aligning the alignment pattern with respect to the detection position (substrate positioning) are not particularly limited, and a known technique is applied. can do. For example, the position of the reference pattern printed on the dummy substrate (with respect to the stage) is detected by an imaging device (for example, a CCD camera) disposed above the stage where the substrate and the dummy substrate are disposed at the time of printing. Then, this detection position is defined as coordinates (as an example, defined by a scaler displayed on the monitor overlaid on the reference pattern image), and the substrate is positioned on the stage so that the coordinates of the alignment pattern match. Just do it.

  Only one alignment pattern may be formed. However, if the number is one, even if the position where the alignment pattern is formed is positioned, there is a possibility that the positions of other parts are shifted. Therefore, it is preferable that a plurality of alignment patterns are provided apart from each other as described in claim 2.

  Further, as described in claim 3, the plurality of alignment patterns are preferably provided at opposing positions across a region where the paste is printed on the substrate via the pattern holes. In this case, even if the difference in shape and size between the reference pattern hole and the reference pattern differs depending on the position where the alignment pattern is formed, printing with the pattern hole can be performed with higher positional accuracy.

  The screen printing method according to any one of claims 1 to 3 described above is provided, for example, as described in claim 4, such that a pair of electrodes are spaced apart from each other on the same plane on the substrate. A polymer material in which a pattern hole is provided corresponding to a formation region of a moisture sensitive film formed on the substrate so as to cover between the pair of electrodes and the pair of electrodes, and the paste is a constituent material of the moisture sensitive film It is applicable to the formation of a moisture sensitive film in the manufacture of a capacitive humidity sensor that contains

  In addition, as described in claim 5, a portion of the substrate that is not covered with the moisture sensitive film can also be used as an alignment pattern. In this case, since it is not necessary to separately form an alignment pattern, the sensor size can be reduced and the manufacturing cost can be reduced.

  In addition, as described in claim 6, the shape of the reference pattern hole is preferably L-shaped or circular. In the case of the L-shaped shape, even if there is one, it is easy to determine the position in the plane direction (two directions) from the reference pattern printed on the dummy substrate. In the case of a circle, since the difference in shape between the reference pattern hole and the printed reference pattern is small and there are no corners, clogging and the like are unlikely to occur. Easy to define (detect).

  As described in claim 7, it is preferable that the dimension of the reference pattern hole in the plane direction of the substrate is set in a range of 50 μm or more and 1000 μm or less. If it is less than 50 μm, it is difficult to make the reference pattern printed from the mesh size constituting the screen mask a fine pattern. Further, since the chip size on which the capacitive humidity sensor is formed is usually about 1000 μm to 2000 μm, the maximum dimension is set to 1000 μm or less. The minimum dimension is a setting for a diameter in the case of a circle, and a setting for one side in the case of an L-shape or a polygon.

  In particular, when the moisture sensitive film is polyimide, chemical resistance is required for the emulsion composing the screen mask (coating portions other than the pattern hole and the reference pattern hole), and thus it is necessary to increase the resist thickness of the emulsion. In this case, when the dimension of the reference pattern hole in the plane direction of the substrate is less than 100 μm, the printed reference pattern cannot be a fine pattern. Therefore, when the moisture sensitive film is polyimide, the dimension of the reference pattern hole in the plane direction of the substrate is preferably set in the range of 100 μm or more and 1000 μm or less.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the screen printing method of the present invention is used to form a moisture sensitive film of a capacitive humidity sensor in which a moisture sensitive film whose relative dielectric constant changes according to humidity is interposed between a pair of electrodes. An example that applies to.
(First embodiment)
First, a schematic configuration of a capacitive humidity sensor will be described with reference to FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along the line AA of FIG. In FIG. 1A, for the sake of convenience, a pair of electrodes under the moisture-sensitive film and the second insulating film are shown in a transparent manner. Further, in FIGS. 1A and 1B, for convenience, only the periphery of the detection unit whose capacity changes according to the surrounding humidity change is illustrated.

  In FIG. 1B, reference numeral 10 denotes a semiconductor substrate as a substrate, which is made of silicon in this embodiment. A silicon oxide film 20 is formed as a first insulating film on the upper surface of the semiconductor substrate 10. In addition, the pair of electrodes 31 and 32 are disposed opposite to each other on the same plane on the silicon oxide film 20.

  Although the shape of the electrodes 31 and 32 is not particularly limited, in the present embodiment, as shown in FIG. 1A, each of the electrodes 31 and 32 includes the common electrode portions 31a and 32a. A plurality of comb electrode portions 31b and 32b extending in one direction from the common electrode portions 31a and 32a. And a pair of electrodes 31 and 32 are arrange | positioned so that each comb-tooth electrode part 31b and 32b of a pair of electrodes 31 and 32 may be arranged alternately. In this way, by adopting the comb-teeth shape as the pair of electrodes 31 and 32, the area where the electrodes 31 and 32 are opposed to each other is increased while the arrangement area of the electrodes 31 and 32 is reduced. Can do. As a result, the amount of change in capacitance between the electrodes 31 and 32 that changes with changes in the surrounding humidity increases, and the sensitivity of the capacitive humidity sensor is improved.

  As the electrodes 31 and 32, for example, a low-resistance metal material such as Al, Ag, Au, Cu, Ti, or Poly-Si can be applied. In this embodiment, the electrodes 31 and 32 are formed using Al. The comb electrode portions 31b and 32b correspond to the electrodes shown in the claims, and the common electrode portions 31a and 32a correspond to the wiring portions shown in the claims.

  In the present embodiment, a silicon nitride film 40 is formed as a second insulating film on the semiconductor substrate 10 so as to cover the pair of electrodes 31 and 32. Thereby, the corrosion by the water | moisture content of the electrodes 31 and 32 is suppressed. For example, when the electrodes 31 and 32 have corrosion resistance against moisture, the silicon nitride film 40 may be omitted.

  As shown in FIG. 1A, the electrodes 31 and 32 are provided with pads 31c and 32c as external connection terminals at their ends, and the output is corrected via the pads 31c and 32c. And a signal processing circuit for detecting the amount of change in capacitance and the like. The pads 31c and 32c need to be exposed for connection to a correction circuit or the like, and are not covered with the silicon nitride film 40. In the present embodiment, since the semiconductor substrate 10 is adopted as a substrate constituting the capacitive humidity sensor, the above-described correction circuit and the like can be formed on the same substrate.

  A moisture sensitive film 50 made of a hygroscopic polymer material is formed on the silicon nitride film 40 so as to cover the pair of electrodes 31 and 32 and the electrodes 31 and 32. As the polymer material, polyimide, cellulose acetate butyrate, or the like can be applied. In the present embodiment, polyimide is used. As a forming method thereof, a screen printing method that can eliminate the need for patterning by a photo process is applied. The manufacturing method will be described later.

  In the capacitive humidity sensor 100 configured as described above, when moisture permeates into the moisture sensitive film 50, the moisture has a large relative dielectric constant, so that the relative dielectric constant of the moisture sensitive film 50 depends on the amount of the penetrated moisture. Changes. As a result, the capacitance of the capacitor constituted by the pair of electrodes 31 and 32 with the moisture sensitive film 50 as a part of the dielectric changes. Since the amount of moisture contained in the moisture sensitive film 50 corresponds to the humidity around the capacitive humidity sensor 100, the humidity can be detected from the capacitance between the pair of electrodes 31 and 32.

  Next, a method for manufacturing the capacitive humidity sensor 100 will be described with reference to FIGS. 2A and 2B are cross-sectional views by process for explaining the outline of the manufacturing method of the capacitive humidity sensor 100 in the present embodiment, wherein FIG. 2A is an electrode forming process, FIG. 2B is a printing process, and FIG. It shows after wet film formation. 2A to 2C, the semiconductor substrate 10 is normally in a wafer state, but only a part is shown for convenience.

  As shown in FIG. 2A, an electrode forming step is first performed. A silicon oxide film 20 which is a first insulating film is formed on the surface of the semiconductor substrate 10 by, for example, a CVD method, and electrodes 31 and 32 (in the drawing, by an evaporation method, for example, using Al on the silicon oxide film 20). Comb electrode portions 31b and 32b and a pad 31c are formed). In the present embodiment, in this step, a silicon nitride film 40 as a second insulating film is formed by, for example, a plasma CVD method so as to cover the electrodes 31 and 32 and between the electrodes 31 and 32.

  Next, as shown in FIG. 2B, a printing process for forming the moisture sensitive film 50 is performed. In this printing step, the semiconductor substrate 10 on which the electrodes 31 and 32 are formed is transported to a screen printing apparatus, and screen printing is performed using a paste 110 containing a polymer material that is a constituent material of the moisture sensitive film 50.

  Specifically, a screen mask 120 in which a mesh screen 122 (for example, a 250 mesh stainless steel screen) is coated with the emulsion 123 is prepared so that a pattern hole 121 corresponding to the formation region of the moisture sensitive film 50 is provided. The screen mask 120 is brought into contact with the surface of the semiconductor substrate 10 (on the side where the electrodes 31 and 32 are formed). Then, a paste 110 made of a polyimide precursor (a moisture sensitive film precursor having a polyamic acid as a basic skeleton) is supplied onto the screen mask 120, and the squeegee 130 is slid to pass through the pattern hole 121. A paste 110 is printed on the silicon nitride film 40 which is the outermost surface of the semiconductor substrate 10. Furthermore, when the printed paste 110 is heated at a predetermined temperature and cured (imidized) after the printing step, a moisture sensitive film 50 made of polyimide is formed as shown in FIG. Then, it is cut into chips by a dicing process (not shown).

  By the way, in the capacitive humidity sensor 100 described above, the positional accuracy of the moisture sensitive film 50 is required as the sensor size is reduced, and it is necessary to accurately align the screen mask 120 and the semiconductor substrate 10. ing.

  On the other hand, conventionally, screen printing is first performed by bringing a screen mask 120 into contact with a dummy substrate (for example, the semiconductor substrate 10 on which the electrodes 31, 32, etc. are not formed). The position is detected using an imaging device such as a CCD camera. Then, the semiconductor substrate 10 is positioned on the stage so that the detected print area and the moisture sensitive film formation area (the area where the moisture sensitive film 50 is to be formed) in the semiconductor substrate 10 are substantially in the same position. Was printing.

  However, in the case of screen printing, it is difficult to make the film thickness of the paste 110 (that is, the moisture sensitive film 50) printed on the surface of the semiconductor substrate uniform (for example, due to a saddle phenomenon in the end region). Therefore, as shown in FIG. 3, by providing a pattern hole 121 (region in a broken line in FIG. 3) of the screen mask 120 larger than the moisture sensitive film forming region 50a in the semiconductor substrate 10, the film thickness of the paste 110 is increased. An effective area that is substantially uniform is arranged in the moisture sensitive film forming area 50a.

  In the case of screen printing, since the paste 110 is printed by sliding the squeegee 130, the shape and / or size of the print area that is actually printed due to the elongation of the mesh screen 122 or the like is slightly different from the pattern hole 121. And will be different. Therefore, for example, as shown in FIG. 3, there is a large difference in shape and / or size between the moisture sensitive film forming region 50a of the semiconductor substrate 10 and the printed region 50b printed on the dummy substrate. Even if the semiconductor substrate 10 is positioned as a reference, the moisture sensitive film 50 cannot be formed with high positional accuracy. FIG. 3 is a schematic diagram for explaining conventional positioning. In FIG. 3, for convenience, the shape of the printing region 50b is the same as that of the pattern hole 121 (and the moisture sensitive film forming region 50a).

  Therefore, in the present embodiment, the above-described printing process (FIG. 2B) is performed by the following method. This will be described with reference to FIGS. 4 (a) to 4 (c) and FIGS. 5 (a) to 5 (d). 4A to 4C are diagrams for explaining the reference pattern hole and the alignment pattern. 5A and 5B are diagrams for explaining the printing process shown in FIG. 2B in more detail. FIG. 5A shows printing on a dummy substrate, FIG. 5B shows reference pattern position detection, and FIG. ) Indicates the positioning of the semiconductor substrate 10, and (d) indicates printing on the semiconductor substrate 10.

  In the present embodiment, as shown in FIG. 4A, a reference pattern hole 124 serving as an alignment reference between the screen mask 120 and the semiconductor substrate 10 is provided in the screen mask 120. Specifically, a plurality of circular reference pattern holes 124 having a diameter in the range of 100 μm or more and 1000 μm or less (for example, 300 μm) are arranged at positions facing each other across the pattern hole 121 for forming the moisture sensitive film 50 (total). 4) provided.

  Further, as shown in FIG. 4B, in the planar direction of the semiconductor substrate 10, substantially the same as the reference pattern 60a printed through the reference pattern hole 124 (the region within the broken line in FIG. 4B). An alignment pattern 60b having a shape and a size is formed on the semiconductor substrate 10 as shown in FIG. 4C in accordance with the positional relationship between the pattern hole 121 and the reference pattern hole 124. Specifically, in the chip forming the capacitive humidity sensor 100, the silicon nitride film 40 is deposited in a predetermined region, and the silicon nitride film is also formed at a predetermined position in a chip region different from the chip forming the capacitive humidity sensor 100. 40 was deposited to form an alignment pattern 60b. The alignment pattern 60b may be formed based on a shape printed in advance on the semiconductor substrate 10 (the state where the silicon nitride film 40 is formed) through the reference pattern hole 124, or may be formed on the dummy substrate in advance. You may form based on the shape printed through the hole 124. FIG.

  Then, with the screen mask 120 and the semiconductor substrate 10 (the silicon nitride film 40 and the alignment pattern 60b formed by the silicon nitride film 40 formed) having the above-described configuration prepared, first, as shown in FIG. Then, the dummy substrate 200 (the semiconductor substrate 10 on which the electrodes 31, 32, etc. are not formed) was temporarily positioned and fixed on the stage 140 of the screen printing apparatus. Thereafter, the stage 140 was sent to the installation position of the screen mask 120, the screen mask 120 was brought into contact with the dummy substrate 200, and the paste 110 to be the moisture sensitive film 50 was printed. At this time, the printing conditions of the dummy substrate 200 and the semiconductor substrate 10 to be described later are substantially the same. In the present embodiment, the height of the stage 140 is adjusted, and in the set state before printing, the distance between the lower surface of the screen mask 120 and the surface of the dummy substrate 200 is such that the lower surface of the screen mask 120 and the surface of the semiconductor substrate 10 are It was made to become substantially equal to the interval. In addition, a dummy substrate 200 having a thickness substantially the same as that of the semiconductor substrate 10 may be applied.

  Next, with the stage 140 returned from the installation position of the screen mask 120 to the substrate installation position, the CCD camera 300 installed above the substrate installation position images the reference pattern 60a printed on the dummy substrate 200, The position (coordinates) of the reference pattern 60a with respect to the stage 140 was detected. Specifically, the coordinates of the reference pattern 60a are defined by a scaler (two in the x direction and two in the y direction) displayed on the monitor so as to overlap the image of the reference pattern 60a.

  After defining the position of the reference pattern 60 a, the dummy substrate 200 was removed from the stage 140 and the semiconductor substrate 10 was positioned and fixed on the stage 140. Specifically, as shown in FIG. 5C, the alignment pattern 60b is imaged by the CCD camera 300, and the position of the semiconductor substrate 10 is adjusted so that the alignment pattern 60b matches the position previously defined by the scaler. Adjusted.

  Then, in this positioning state, the stage 140 is sent to the installation side of the screen mask 120, and as shown in FIG. 5D, the paste 110 that becomes the moisture sensitive film 50 by bringing the screen mask 120 into contact with the semiconductor substrate 10 is provided. Printed. FIG. 5D corresponds to FIG. 2B. 5C and 5D, for convenience, the electrodes 31 and 32 on the semiconductor substrate 10 are omitted, and only the alignment pattern 60b is illustrated.

  Thus, according to the screen printing method in the present embodiment, the alignment pattern 60b formed on the semiconductor substrate 10 and the reference pattern 60a printed on the dummy substrate 200 have substantially the same shape and size. Therefore, the semiconductor substrate 10 and the screen mask 120 can be positioned with high accuracy. Therefore, printing by the pattern hole 121 for forming the moisture sensitive film 50 can be performed with high positional accuracy on the moisture sensitive film forming region 50 a on the semiconductor substrate 10.

  The alignment pattern 60b is a portion serving as a reference for alignment between the screen mask 120 and the semiconductor substrate 10 in place of the moisture sensitive film forming region 50a where the paste 110 is to be printed on the semiconductor substrate 10 through the pattern holes 121. It is. Since the alignment pattern 60b is not fixed in shape and / or size in terms of characteristics like the moisture sensitive film formation region 50a, the shape of the reference pattern 60a printed through the reference pattern hole 124 is not necessary. And can have a shape and size substantially the same as the size.

  Moreover, in this embodiment, the example which provided the some alignment pattern 60b in the opposing position on both sides of the moisture sensitive film formation area | region 50a was shown. Therefore, even if the difference in shape and size between the reference pattern hole 124 and the printed reference pattern 60a differs depending on the position where the alignment pattern 60b is formed, printing with the pattern hole 121 can be performed with higher positional accuracy. .

  Further, as shown in the present embodiment, when the moisture sensitive film 50 is made of polyimide, the emulsion 123 constituting the screen mask 120 is required to have chemical resistance. Therefore, the resist thickness of the emulsion 123 needs to be increased. Therefore, if the size of the reference pattern hole 124 is less than 100 μm, the printed reference pattern 60a cannot be a fine pattern. However, in the present embodiment, the dimension (diameter) of the reference pattern hole 124 in the planar direction of the semiconductor substrate 10 is set in the range of 100 μm or more and 1000 μm or less, so that the reference pattern 60a printed on the dummy substrate 200 is A fine pattern can be formed, and the reference pattern 60a can be easily positioned.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  In the present embodiment, an example in which the semiconductor substrate 10 made of silicon is employed as the substrate and the electrodes 31 and 32 are formed on the semiconductor substrate 10 via the insulating film 20 has been shown. When the semiconductor substrate 10 is used as the substrate in this manner, the capacitive humidity sensor 100 can be formed by a general semiconductor process, so that the manufacturing cost can be reduced. However, an insulating substrate such as a glass substrate can also be applied as the substrate. The screen printing method of the present invention is not limited to the formation of the moisture sensitive film of the capacitive humidity sensor 100, and can be applied to, for example, printing a conductive paste on a printed board.

  In the present embodiment, an example in which the reference pattern hole 124 is circular is shown. When the shape is circular, the difference in shape between the reference pattern hole 124 and the reference pattern 60a printed through the reference pattern hole 124 is small, and since there is no corner, clogging or the like is unlikely to occur, and the pattern is printed on the dummy substrate 200. It is easy to define (detect) the position of the reference pattern 60a. However, since the alignment pattern 60b is also substantially circular, with one reference pattern hole 124 and alignment pattern 60b, the semiconductor substrate 10 may be displaced in the rotational direction with respect to the screen mask 120 with the alignment pattern 60b as the center. There is. On the other hand, for example, as shown in FIG. 6A, if the reference pattern hole 124 and the alignment pattern 60b are substantially L-shaped, the position of the semiconductor substrate 10 relative to the stage 140 (in the planar direction) (2 directions)) is easy to determine. The shape of the reference pattern hole 124 is not limited to the above example, and may be, for example, a polygon (for example, a rectangle shown in FIG. 6B). In particular, if it is a plurality, it is possible to perform alignment with high accuracy.

  Further, in the present embodiment, an example in which the alignment pattern 60b is provided separately from the formation region of the capacitive humidity sensor 100 of the semiconductor substrate 10 is shown. However, a portion of the capacitive humidity sensor 100 that is not covered with the moisture sensitive film 50 can be applied as the alignment pattern 60b. For example, the pads 31c and 32c may be used as the alignment pattern 60b. In this case, since it is not necessary to form the alignment pattern 60b separately, the sensor size can be reduced and the manufacturing cost can be reduced.

  Further, in the present embodiment, an example in which the dimension of the reference pattern hole 124 provided in the screen mask 120 is set in the range of 100 μm or more and 1000 μm or less in the planar direction of the semiconductor substrate 10 is shown. However, in this embodiment, the paste 110 forms polyimide as the moisture sensitive film 50, and the resist thickness of the emulsion 123 is thick for chemical resistance, so the thickness is 100 μm or more. Therefore, since the resist thickness can be reduced depending on the type of paste 110, the dimension of the reference pattern hole 124 provided in the screen mask 120 may be set in the range of 50 μm to 1000 μm in the planar direction of the semiconductor substrate 10. When the thickness is less than 50 μm, it is difficult to make the reference pattern 60a printed from the mesh size constituting the screen mask 120 a fine pattern. Since the chip size on which the capacitive humidity sensor 100 is formed is usually about 1000 μm to 2000 μm, the maximum dimension is set to 1000 μm or less. The minimum dimension is a setting for a diameter in the case of a circle, and a setting for one side in the case of an L-shape or a polygon shown in FIG.

It is a figure which shows schematic structure of the capacitive humidity sensor of this invention, (a) is a top view, (b) is sectional drawing in the AA cross section of (a). It is sectional drawing according to process for demonstrating the outline of the manufacturing method of a capacitive humidity sensor, (a) is an electrode formation process, (b) is a printing process, (c) has shown after moisture-sensitive film formation. It is a schematic diagram for demonstrating the conventional positioning. It is a figure for demonstrating a reference pattern hole and an alignment pattern. FIGS. 3A and 3B are schematic cross-sectional views for explaining the printing process shown in FIG. 2B in more detail, in which FIG. 2A shows printing on a dummy substrate, FIG. 2B shows reference pattern position detection, and FIG. (B) shows the printing on the semiconductor substrate. (A), (b) is a figure which shows the modification of a reference | standard pattern hole.

Explanation of symbols

10 ... Semiconductor substrate (substrate)
20 ... Silicon oxide films 31, 32 ... Electrodes 31c, 32c ... Pad 40 ... Silicon nitride film 50 ... Moisture sensitive film 60a ... Reference pattern 60b ... Alignment pattern 100 ..Capacitive humidity sensor 110 ... Paste 120 ... Screen mask 121 ... Pattern hole 124 ... Reference pattern hole 140 ... Stage 200 ... Dummy substrate 300 ... CCD camera

Claims (8)

A screen printing method in which a screen mask provided with a desired pattern hole is brought into contact with a substrate, and a paste is printed on the substrate through the pattern hole,
The screen mask is provided with a reference pattern hole serving as an alignment reference between the screen mask and the substrate,
According to the positional relationship between the pattern hole and the reference pattern hole, the substrate has substantially the same shape and size as the reference pattern printed through the reference pattern hole in the plane direction of the substrate on the substrate. Forming an alignment pattern;
Printing the screen mask in contact with a dummy substrate, and detecting the position of the reference pattern printed on the dummy substrate;
And positioning the substrate so that the alignment pattern is substantially at the same position with respect to the detected position of the reference pattern, and printing by contacting the screen mask in this positioned state. A characteristic screen printing method.   The screen printing method according to claim 1, wherein a plurality of the alignment patterns are provided apart from each other.   The screen printing method according to claim 2, wherein the plurality of alignment patterns are provided at opposing positions across an area where the paste is printed on the substrate through the pattern holes. On the same plane on the substrate, a pair of electrodes are provided so as to be opposed to each other,
The pattern hole is provided corresponding to a formation region of a moisture sensitive film formed on the substrate so as to cover between the pair of electrodes and the pair of electrodes,
The screen printing method according to claim 1, wherein the paste includes a polymer material that is a constituent material of the moisture-sensitive film.   The screen printing method according to claim 4, wherein a portion of the substrate that is not covered with the moisture sensitive film is also used as the alignment pattern.   The screen printing method according to claim 4 or 5, wherein the reference pattern hole has an L-shape or a circular shape.   7. The screen printing method according to claim 4, wherein a dimension of the reference pattern hole in the planar direction of the substrate is set in a range of 50 μm to 1000 μm.   The said moisture sensitive film is a polyimide, The dimension of the said reference pattern hole in the plane direction of the said board | substrate is set in the range of 100 micrometers or more and 1000 micrometers or less, The any one of Claims 4-6 characterized by the above-mentioned. Screen printing method.

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