JP2005170055A - Screen mask, its manufacturing method and wiring foundation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a gap between patterns formed by screen printing of one time 40 μm or under. <P>SOLUTION: A positive pattern part 14 and a negative pattern part 16 are provided. A mask material (an emulsion film) is formed in the negative pattern part 16. In a screen mask 10 for screen printing transferring printing ink to a base body via a mesh opening 20 in the positive pattern part 14, a plating layer is formed selectively on a mesh 12 of the negative pattern part 16, and the mesh opening degree of the negative pattern part 16 is composed by lessening the mesh opening degree of the negative pattern part 16 than the opening degree of the positive pattern part 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention includes a screen mask for screen printing having a positive pattern portion and a negative pattern portion, and transferring a printing ink member to a substrate through a mesh opening in the positive pattern portion, and a method for producing the screen mask, The present invention relates to a wiring board on which a wiring pattern having at least a capacitor element is formed by screen printing.

  In general, screen printing is a method of printing using a screen mask in which a mesh is stretched on a frame and the mesh opening of a negative pattern portion is closed with a resin (for example, a photosensitive emulsion film). In this method, the squeegee is slid on the upper surface of the mask, and the ink member is extruded and printed on the substrate side through the mesh openings in the positive pattern of the screen mask.

  In this screen printing, since the screen mask is flexible and the printing pressure is low, it is possible to print on a wide range of printing materials such as paper, cloth, plastic, glass, and metal. Further, since the pattern of the ink member can be thickened, it is also applied to the manufacture of electronic parts such as thick film ICs (hybrid ICs), printed wiring boards, resistors and capacitors.

JP 51-48735 A

  Incidentally, the screen mask is usually manufactured by patterning a photosensitive emulsion film coated on a mesh by a photolithography technique. Alternatively, it is manufactured by selectively etching a metal film by a photolithography technique to form a mesh pattern.

  For example, a portion where the ink member is formed on the base material through the mesh becomes a desired pattern, and a portion corresponding to the photosensitive emulsion film formed on the mesh or a portion corresponding to the non-mesh portion in the metal film is a gap between the patterns. It becomes.

  In this case, the mesh opening of the screen mask is about 100 μm even in the fine type. For example, an emulsion film having a width of 40 μm or less is insufficiently supported by the mesh. For this reason, the emulsion film formed on the mesh cannot withstand the force applied by sliding the squeegee during screen printing, and may fall off the mesh.

  Further, the screen mask made of a metal film originally lacks the strength of the metal film, and cannot withstand the force applied by the sliding of the squeegee when the width of the non-mesh portion is 80 μm or less.

  In other words, conventionally, even if an attempt is made to reduce the gap between patterns to 40 μm or less by a single screen printing, the formation of the emulsion film in the screen mask and the strength of the metal film are insufficient, making it difficult to form. There is a problem.

  Therefore, a method of reducing the gap between patterns to 40 μm or less by performing screen printing in a plurality of times is considered. However, the difference between the film thickness of the odd number pattern and the film thickness of the even number pattern is 10%. When the above-described large variations occur, for example, when the pattern is a wiring pattern, the electrical characteristics of these wiring patterns may vary, which may cause a new problem that desired device characteristics cannot be obtained. is there.

  The present invention has been made in consideration of such problems, and the gap between patterns formed by one screen printing can be made 40 μm or less, and a fine pattern can be formed using inexpensive screen printing. An object is to provide a screen mask that can be formed.

  Another object of the present invention is to provide a method for producing a screen mask that can easily produce a screen mask capable of making a gap between patterns formed by one screen printing to be 40 μm or less. It is in.

  Another object of the present invention is to provide a wiring board in which a gap between patterns formed by screen printing is 40 μm or less.

  The present invention relates to a screen mask for screen printing that has a positive pattern portion and a negative pattern portion, a mask material is formed in the negative pattern portion, and a printing ink member is transferred to a substrate through a mesh opening in the positive pattern portion. The mesh opening degree of the negative pattern portion of the mesh is selectively made smaller than the opening degree of the positive pattern portion.

  By reducing the mesh opening degree of the negative pattern portion, the width of each mesh of the negative pattern portion is increased, and the contact area between the mask material and the mesh is increased. For example, a mask material having a width of 40 μm or less is sufficiently retained. be able to.

  As a result, the mask material formed on the mesh can sufficiently withstand the force applied by the sliding of the squeegee during screen printing and does not fall off the mesh. This leads to narrowing and high reliability of the pattern gap by screen printing, and the width of the gap formed on the substrate by the negative pattern portion can be made 40 μm or less. That is, a fine pattern can be formed using inexpensive screen printing, and the manufacturing cost of pattern formation can be greatly reduced.

  In this case, a plating layer may be formed on the mesh of the negative pattern portion to reduce the mesh opening degree of the negative pattern portion. The thickness of the plating layer is preferably 1 to 20 μm in consideration of plating processing time, emulsion film holding power, and the like.

  The present invention also provides a screen mask for screen printing having a positive pattern portion and a negative pattern portion, and transferring a printing ink member to a substrate through a mesh opening in the positive pattern portion. The opening degree is 0.

  That is, since the negative pattern portion is completely blocked, it is not necessary to form a mask material on the negative pattern portion, and the process can be simplified. In addition, since it is not necessary to consider dropping off of the mask material, it is possible to achieve narrowing and high reliability of the pattern gap by screen printing, and the gap formed on the substrate by the negative pattern portion The width can be set to 40 μm or less.

  In this case, a plating layer may be formed on the mesh of the negative pattern portion so that the mesh opening degree of the negative pattern portion is zero.

  Next, the present invention is for screen printing, which has a positive pattern portion and a negative pattern portion, a mask material is formed on the negative pattern portion, and the printing ink member is transferred to the substrate through a mesh opening in the positive pattern portion. In the method of manufacturing a screen mask, the mesh of the negative pattern portion is selectively plated in advance, and the mesh opening degree of the negative pattern portion is made smaller than the opening degree of the positive pattern portion. .

  Thereby, the width of each mesh of the negative pattern portion is increased, the contact area between the mask material and the mesh is increased, and even a mask material having a width of, for example, 40 μm or less can be sufficiently retained.

  As a result, the width of the pattern gap by screen printing is reduced and the reliability is improved, and the width of the gap formed on the substrate by the negative pattern portion can be 40 μm or less.

  In the method, after the plating treatment, at least a surface of the screen on which the squeegee slides may be polished to provide flatness. Further, before the plating process, a plating mask material may be formed on the surface of the screen on which the squeegee slides so that the plating layer is not formed on the surface.

  The plated layer is preferably made of a material that has a lower hardness than the screen and is easy to polish.

  Next, according to the present invention, in a wiring board on which a pattern having at least a passive element such as a capacitor element or an active element such as an electromechanical conversion element is formed by screen printing, a gap between the patterns is 40 μm or less. And

  In the present invention, the pattern may be formed by a single screen printing.

  Conventionally, since a fine gap screen mask cannot be obtained, when a gap of 40 μm or less is formed, a plurality of screen printings are indispensable, but inevitably the first printing pattern and the second printing pattern However, since the same printing conditions are not used, the film thickness is difficult to be uniform.

  However, in the present invention, since all patterns can be formed by one screen printing, the film thickness can be made uniform. In this case, when a plurality of patterns are formed in parallel, the difference between the average thickness of the odd-numbered pattern and the even-numbered average thickness is 5% or less of the total average thickness.

  The screen mask used in the screen printing has a positive pattern portion and a negative pattern portion, a mask material is formed on the negative pattern portion, and a printing ink member is formed through a mesh opening in the positive pattern portion. A material having a mesh opening degree of the negative pattern portion of the mesh smaller than that of the positive pattern portion may be used.

  Further, a plating layer may be formed on the mesh of the negative pattern portion in the screen mask. In this case, the thickness of the plating layer is preferably 1 to 20 μm.

  As described above, according to the screen mask of the present invention, the gap between patterns formed by one screen printing can be reduced to 40 μm or less, and a fine pattern can be formed using inexpensive screen printing. can do.

  In addition, according to the method for manufacturing a screen mask according to the present invention, a screen mask that can make the gap between patterns formed by one screen printing 40 μm or less can be easily manufactured.

  Further, according to the wiring board according to the present invention, the gap between patterns formed by screen printing is 40 μm or less, and the manufacturing cost of the wiring board can be reduced.

  Embodiments of a screen mask, a manufacturing method thereof, and a wiring board according to the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the screen mask 10 according to the present embodiment has a positive pattern portion 14 and a negative pattern portion 16 on a mesh 12, and a photosensitive emulsion film 18 (see FIG. 6B) and is a screen mask for screen printing in which ink is transferred to the substrate through the mesh openings 20 in the positive pattern portion 14.

  In particular, the screen mask 10 according to this embodiment is configured such that the mesh opening degree of the negative pattern portion 16 in the mesh 12 is selectively smaller than the mesh opening degree of the positive pattern portion 14. Specifically, the mesh opening degree of the negative pattern portion 16 is reduced by forming a plating layer 22 (see FIG. 6B) on the mesh 12 of the negative pattern portion 16.

  When screen printing is performed on a substrate such as a ceramic substrate using the screen mask 10 of FIG. 1, the planar shape is rectangular and the corners are rounded as shown in FIG. A pattern P arranged in a matrix is formed.

  When the paste used for forming a shape retention layer such as a piezoelectric / electrostrictive layer or an antiferroelectric layer is used as an ink for screen printing, for example, as shown in FIG. The wiring board 32 in which the actuator unit 30 composed of the electromechanical conversion element functioning as an array can be configured.

  The wiring board 32 includes a base body 34 made of, for example, ceramics, and the actuator section 30 is disposed on the base body 34 in a matrix, for example. The base body 34 is provided with a space 38 for forming a vibration part 36 at a position where the actuator part 30 is formed.

  Of the base body 34, the portion where the void 38 is formed is thin, and the other portion is thick. The thin part functions as the vibration part 36 with a structure that is susceptible to vibration with respect to external stress, and the part other than the void 38 functions as a fixing part 40 that is thick and supports the vibration part 36. It is like that.

  Each actuator unit 30 includes a shape retaining layer 42 such as a piezoelectric / electrostrictive layer and an antiferroelectric layer directly formed on the vibrating portion 36, and the shape retaining layer, in addition to the vibrating portion 36 and the fixed portion 40. The actuator section 30 is displaced upward or downward by applying a predetermined voltage to the pair of electrodes 44. The actuator section 30 has a pair of electrodes 44 (row electrode 44 a and column electrode 44 b) formed on the upper surface of 42. It is like that. FIG. 3 shows an example in which the actuator unit 30 is displaced upward.

  Next, a method for manufacturing a screen mask according to this embodiment will be described with reference to FIGS. 4A to 6B.

  First, as shown in FIG. 4A, for example, a commercially available stainless steel screen mesh having a normal mesh 12 is prepared.

  Thereafter, as shown in FIG. 4B, a photoresist film 50 is formed on the entire surface, and then selectively etched to expose the mesh 12 in the negative pattern portion 16.

  Thereafter, as shown in FIG. 4C, a plating process is performed to form a plating layer 22 having a thickness t of about 1 to 20 μm on the mesh 12 in the negative pattern portion 16.

  Next, as shown in FIG. 5A, the remaining photoresist film 50 is removed by etching to expose the entire mesh 12.

  Thereafter, as shown in FIG. 5B, both sides of the mesh 12 are buffed to remove and flatten the plating layer 22 protruding from both sides of the mesh 12.

  6A, after forming a photosensitive emulsion film 18 on one side of the mesh 12, the negative pattern portion 16 is selectively exposed using a mask 52, whereby the emulsion film of the negative pattern portion 16 is formed. 18 is solidified.

  Then, as shown in FIG. 6B, the screen mask according to the present embodiment in which the mask material (emulsion film) 18 is formed in the negative pattern portion 16 by removing the emulsion film 18 that has not been solidified by development. 10 is completed.

  Next, a processing operation in the case of performing screen printing (for example, planar printing) using the screen mask 10 according to the present embodiment will be described.

  First, as shown in FIG. 7A, the base 34 is placed and fixed on the printing base 60. Thereafter, the frame 64 of the screen mask 10 is rotatably fixed to a fulcrum part 62 provided on the printing base 60, and the holding adjustment mechanism at the fulcrum part 62 is adjusted to position the screen mask 10 and the base 34. .

  After that, as shown in FIG. 7B, the ink 66 (paste for forming the shape retaining layer 42) is supplied to the entire surface of the screen mask 10, and then the squeegee 68 is slid under pressure on the screen mask 10. As the squeegee 68 slides, the ink 66 enters the substrate 34 side through the mesh openings 20 in the positive pattern portion 14 of the screen mask 10.

  Then, as shown in FIG. 7C, when printing is completed, a pattern along the shape of the positive pattern portion 14 on the substrate 34, for example, a large number of rectangular shape holding layers 42 as shown in FIG. A pattern P arranged in a pattern is formed.

  At this time, by sliding the squeegee 68 while raising the frame 64 corresponding to the fulcrum portion 62, the ink 66 can be separated from the positive pattern portion 14 through the mesh opening 20. In particular, in this embodiment, since the emulsion film 18 is formed on the mesh 12 of the negative pattern portion 16, the edge of the pattern P formed on the substrate 34 becomes sharp, and a highly accurate pattern along the design pattern P can be formed.

  After the printing is completed, as shown in FIG. 7D, the squeegee 68 is separated from the screen mask 10 and the base 34 is removed from the printing base 60. Thereafter, the ink return plate 70 is lowered and slides toward the fulcrum portion 62 to perform ink return.

  By repeating this series of operations, a desired pattern P is screen-printed on a large number of substrates 34.

  As described above, in the screen mask 10 according to the present embodiment, the plating layer 22 is selectively formed on the mesh 12 of the negative pattern portion 16 and the mesh opening degree of the negative pattern portion 16 is set to the mesh of the positive pattern portion 14. Since the opening is made smaller than the opening degree, the width of each mesh 12 of the negative pattern portion 16 is widened, and the contact area between the emulsion film 18 which is a mask material and the mesh 12 is increased. For example, the width d (FIG. 6B) can be sufficiently retained.

  As a result, the emulsion film 18 formed on the mesh 12 can sufficiently withstand the force applied by the sliding of the squeegee 68 during screen printing and does not fall off the mesh 12. This leads to narrowing and high reliability of the pattern gap by screen printing, and the gap width g (see FIG. 2) of the pattern P (pattern of the shape retention layer 42) formed on the substrate 34 by the negative pattern portion 16. Reference) can be 40 μm or less.

  The thickness of the plating layer 22 is preferably 1 to 20 μm in consideration of the plating processing time, the holding power of the emulsion film 18 and the like.

  In particular, in the screen mask 10 and the method for manufacturing the same according to the present embodiment, after the plating process, both sides of the mesh 12 are polished to provide flatness. There is no problem with sliding. Therefore, the plating layer 22 is preferably made of a material having a hardness lower than that of the mesh 12 and easy to polish.

  In the above example, a case where a pattern with a gap g of 40 μm or less is formed by one screen printing is shown. Of course, a pattern with a gap g of 40 μm or less may be formed by a plurality of screen printings. .

  Conventionally, since a fine gap screen mask cannot be obtained, when a gap of 40 μm or less is formed, a plurality of screen printings are indispensable. Since the printing conditions are not the same as the pattern, the film thickness is difficult to be uniform.

  However, in this embodiment mode, all patterns can be formed by one screen printing, so that the film thickness can be made uniform. In this case, when a plurality of patterns are formed in parallel, the difference between the average thickness of the odd-numbered pattern and the even-numbered average thickness can be 5% or less of the total average thickness.

  As a result, when the pattern P formed by screen printing is equivalent to a wiring pattern having a capacitor element as shown in FIGS. 2 and 3, there is no variation in the electrical characteristics of these element patterns. Desired device characteristics can be obtained.

  In the above embodiment, both sides of the mesh 12 are polished. However, as shown in FIG. 8A, at least the surface on which the squeegee 68 slides is polished to give flatness to the surface. Good. In this case, as shown in FIG. 8B, when the emulsion film 18 is formed in the negative pattern portion 16, the contact area between the plating layer 22 and the emulsion film 18 is greatly increased, and the anchor effect drawn from the shape of the plating layer 22 is obtained. Thus, the emulsion film 18 can be held more firmly.

  Further, in the above embodiment, the plated layers 22 are formed on both surfaces of the mesh 12 in the negative pattern portion 16, but in addition, as shown in FIG. By covering the surface on which the squeegee 68 slides with the mask film 72, in the subsequent plating process, the surface on which the squeegee 68 of the mesh 12 in the negative pattern portion 16 slides is plated as shown in FIG. 9B. The layer 22 is not formed, and the time required for the subsequent polishing process can be shortened.

  In the above embodiment, the plating layer 22 is formed on the mesh 12 of the negative pattern portion 16 by 1 to 20 μm so that the mesh opening degree of the negative pattern portion 16 is smaller than the opening degree of the positive pattern portion 14. However, as shown in FIG. 10, the opening of the negative pattern portion 16 may be completely closed with the plating layer 22, that is, the mesh opening degree of the negative pattern portion 16 may be set to zero.

  In this case, since the negative pattern portion 16 is completely blocked, it is not necessary to form a mask material (emulsion film 18) on the negative pattern portion 16, and the process can be simplified. In addition, since it is not necessary to consider the omission of the mask material (emulsion film 18), it is possible to achieve a narrow pattern gap and high reliability by screen printing. The width g of the gap formed in can be set to 40 μm or less.

  In the above example, the case where the actuator unit 30 having the shape retaining layer 42 is screen-printed on the base 34 has been shown. However, the present invention can also be applied to the case where metal wiring is formed on a substrate, for example.

  Of course, the screen mask, the manufacturing method thereof, and the wiring board according to the present invention are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention.

It is a top view which shows the screen mask which concerns on this Embodiment. It is a top view which shows the pattern formed using the screen mask which concerns on this Embodiment. It is a longitudinal cross-sectional view of the pattern formed using the screen mask which concerns on this Embodiment. 4A to 4C are process diagrams (part 1) illustrating the method for manufacturing the screen mask according to the present embodiment. 5A and 5B are process diagrams (part 2) illustrating the method for manufacturing the screen mask according to the present embodiment. 6A and 6B are process diagrams (part 3) illustrating the method for manufacturing the screen mask according to the present embodiment. 7A to 7D are process diagrams showing processing operations when screen printing (for example, planar printing) is performed using the screen mask according to the present embodiment. FIG. 8A is an explanatory view showing a state where only one side of the mesh is polished, and FIG. 8B is an explanatory view showing a state where an emulsion film is formed on the negative pattern portion. FIG. 9A is an explanatory view showing a state in which a mask film is coated on one side of the mesh before the plating process, and FIG. 9B is an explanatory view showing a state in which the plating process is performed. It is explanatory drawing which shows the state which block | closed the opening of the negative pattern part with the plating layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Screen mask 12 ... Mesh 14 ... Positive pattern part 16 ... Negative pattern part 18 ... Photosensitive emulsion film 20 ... Mesh opening 22 ... Plating layer

Claims (16)

In a screen mask for screen printing that has a positive pattern portion and a negative pattern portion, a mask material is formed in the negative pattern portion, and a printing ink member is transferred to a substrate through a mesh opening in the positive pattern portion,
A screen mask, wherein the mesh opening degree of the negative pattern portion of the mesh is selectively made smaller than the opening degree of the positive pattern portion. The screen mask according to claim 1.
A screen mask, wherein a width of a gap formed on the substrate by the negative pattern portion is 40 μm or less. The screen mask according to claim 1 or 2,
A screen mask, wherein a plating layer is formed on the mesh of the negative pattern portion. The screen mask according to claim 3.
A screen mask, wherein the plating layer has a thickness of 1 to 20 μm. In a screen mask for screen printing that has a positive pattern portion and a negative pattern portion and transfers a printing ink member to a substrate through a mesh opening in the positive pattern portion,
The screen mask according to claim 1, wherein a mesh opening degree of the negative pattern portion is zero. The screen mask according to claim 5.
A screen mask, wherein a plating layer is formed on the mesh of the negative pattern portion. In a method of manufacturing a screen mask for screen printing, which has a positive pattern portion and a negative pattern portion, a mask material is formed in the negative pattern portion, and a printing ink member is transferred to a substrate through a mesh opening in the positive pattern portion. ,
A method of manufacturing a screen mask, wherein the mesh of the negative pattern portion is selectively plated in advance, and the mesh opening degree of the negative pattern portion is made smaller than the opening degree of the positive pattern portion. In the manufacturing method of the screen mask of Claim 7,
A method of manufacturing a screen mask, comprising: polishing at least a surface on which both squeegees slide, after the plating process, to impart flatness. In the manufacturing method of the screen mask of Claim 7 or 8,
A method for producing a screen mask, comprising: forming a plating mask material on a surface of a screen on which a squeegee slides before forming the plating layer so that a plating layer is not formed on the surface. In the manufacturing method of the screen mask of any one of Claims 7-9,
The method for manufacturing a screen mask, wherein the plating layer has a lower hardness than the screen and is easily polished. In a wiring board on which a pattern having at least a passive element such as a capacitor element or an active element such as an electromechanical conversion element is formed by screen printing,
A wiring board having a gap between the patterns of 40 μm or less. The wiring board according to claim 11,
A wiring board, wherein a plurality of patterns are formed in parallel, and a difference between an average thickness of an odd-numbered pattern and an even-numbered average thickness is 5% or less of a total average thickness. The wiring board according to claim 11 or 12,
The screen mask used in the screen printing has a positive pattern portion and a negative pattern portion, a mask material is formed on the negative pattern portion, and the printing ink member is transferred to the substrate through the mesh opening in the positive pattern portion. Which
The wiring board according to claim 1, wherein the mesh opening degree of the negative pattern portion of the mesh is smaller than the opening degree of the positive pattern portion. The wiring board according to claim 13, wherein
A wiring board, wherein a plating layer is formed on a mesh of the negative pattern portion in the screen mask. The wiring board according to claim 14,
A wiring board, wherein the plating layer has a thickness of 1 to 20 μm. In the wiring board according to any one of claims 11 to 15,
A wiring board, wherein the pattern is formed by one screen printing.

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