JPH11129640A - Mask for printing and its manufacture, and manufacture of circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit board having a fine wiring conductor by a method wherein the area of an opening on the lower surface of a printing pattern comprising a single sheet where a past for printing is pressed into the upper surface, and is discharged from the lower surface, is made wider than the area of the opening on the upper surface. SOLUTION: This printing mask 10 comprises a single sheet 12, and the edge parts of a printing pattern are made sharper by eliminating an end part opening and a central opening. Also, the area of an opening on the mask lower surface is made wider than the area of an opening on the mask upper surface. By this method, the amount of a paste to be printed is limited when being pressed in from the mask upper surface, and in the meantime, a printing of which the thickness is made thinner in advance is performed by the paste which is limited in advance and pressed in, from the wide part on the mask lower surface, and a printing of a fine wiring pattern is made possible. By this method, the printing initial setup manhours due to a plate replacement for the mask can be reduced, and at the same time, a cost reduction can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing mask for printing various pastes on a printing medium by screen printing and a method for manufacturing the same, and more particularly to a method for forming a fine printing pattern having a width of 50 μm or less. The present invention relates to a printing mask and a method of manufacturing the same.

[0002] The present invention further relates to a method of manufacturing a circuit board, and more particularly to a method of manufacturing a circuit board which enables formation of an inner wiring or a surface wiring having a wiring conductor width of 50 μm or less by screen printing.

[0003]

2. Description of the Related Art Conventionally, as a method of forming a wiring conductor, a screen printing method, a photo etching method, and the like are well known.

[0004] The photo-etching method in which the width of the wiring conductor can be easily reduced to 50 μm or less includes a step of attaching a conductive material such as vapor deposition, sputtering, and plating to the base, and a step of masking with a resist in accordance with the wiring pattern. Or a step of removing a conductive portion by etching, or masking the negative region of the wiring pattern with a resist in advance, forming a conductive layer thereon by the above-described vapor deposition, sputtering, etc., and then removing the masked resist portion. There is a method of forming a removed wiring pattern. However, in these methods, the equipment cost of the necessary equipment is high, the maintenance cost of the equipment to be used and the necessary consumable materials are expensive,
Furthermore, since the number of steps is basically increased, there is a disadvantage that the production cost is significantly increased in terms of both running cost and fixed cost.

On the other hand, the conventional screen printing method cannot make the width of a wiring conductor printable in an actual production line to 50 μm or less, and is inferior in dimensional accuracy as compared with the above-described photo etching method. Since the equipment cost and the running cost are low, it is widely used today as a method for forming conductor wiring on a circuit board for mounting electronic components.

When a wiring pattern of a conductive paste is printed by a screen printing method, as a usual printing mask, a photosensitive emulsion film is formed on a mesh made of a metal wire or a polymer wire, and a portion where the conductive paste is passed is formed. A mesh screen is used in which the wiring pattern is formed by removing the emulsion by etching.

If the intersection of the mesh screen mesh exists at the end of the wiring pattern without emulsion, that is, near the wall of the emulsion, the intersection of the mesh screen of the mesh screen and the end of the wiring pattern formed of the emulsion is formed. The opening in the enclosed area (hereinafter referred to as an end opening) is smaller than the opening in the mesh screen (hereinafter referred to as the center opening) surrounded by the intersection of the meshes adjacent to the mesh screen. The paste is easily clogged.

When the width of the printed wiring conductor is sufficiently large compared to the end opening, clogging of the paste at the end opening can be ignored. The clogged area near the opening of the part cannot be ignored, and the printed pattern has irregularities and sometimes the pattern is cut, resulting in poor printing.

On the other hand, as an improvement of the screen printing method,
There is a printing mask made of a plate made of a metal material or a resin-based material and having a through hole formed therein and having no mesh screen mesh and an aperture ratio of 100%. This printing mask is generally called a metal mask because a metal mask is generally used in many cases. The metal mask has an aperture ratio of 100%, and there is no mesh that obstructs the passage of the paste. Therefore, the paste is excellent in the discharge property of the paste. On the contrary, the discharge amount of the paste is large, and the printing becomes blurred. In addition, the printed pattern is likely to have irregularities, and is not suitable for printing with a narrow wiring conductor width.

Further, when this metal mask is used for a print mask in which several long linear print patterns are arranged in parallel, the strength of a narrow portion sandwiched between the parallel print patterns is reduced.
It becomes relatively weaker than the strength of the wide part that is not sandwiched between parallel printing patterns, and by repeated printing operation,
In some cases, the printed pattern was deformed and the shape became unstable, and it was sometimes difficult to continuously obtain a stable shape of the printed paste. Due to this fact, the metal mask is hardly used for printing circuit wiring having many linear wiring patterns, but is used for printing simple shapes such as circular conductor patterns.

[0011] The aperture ratio is also referred to as opening here, but in a plane perpendicular to the paste discharge direction, the screen area is calculated based on the total area of the screen with respect to the entire area of the screen. It is the ratio of the area after subtracting the area, in other words, it indicates the ease with which the paste passes through the screen, and the value is 100%
It can be said that it is easier to pass nearer to.

[0012]

With the recent downsizing of portable electronic devices such as computers, there has been a demand for smaller, lighter, and more power-saving circuit boards on which electronic components are mounted. In addition, the selling price of such electronic devices has been greatly reduced, and the cost of electronic components used for such electronic devices has also been required to be reduced. For this reason, circuit boards used for electronic circuits are required to realize high-density wiring for miniaturization and weight reduction, to reduce signal transmission loss for power saving, and to reduce manufacturing costs for cost reduction. Various reviews were considered,
There is a demand for a technology that can form fine wiring conductors with a simpler process.

When a fine wiring pattern is required,
Although somewhat expensive, vapor deposition, sputtering, plating, photoresist, and the like have been used. However, these methods require high equipment costs for the necessary equipment, high maintenance costs and necessary materials for the equipment to be used, and basically require many steps. Has a drawback that becomes extremely high.

[0014] In the case of a ceramic substrate alone, these methods capable of fine wiring, such as the vapor deposition method, can be applied only to a fired substrate, and include an inner wiring provided for patterning on a green sheet, and a surface layer formed by a simultaneous firing method. There is a problem that it cannot be applied to wiring patterning. Therefore, in order to perform patterning on a green sheet, there is currently no suitable method other than the screen printing method, and a technique capable of forming fine wiring by the screen printing method is required.

On the other hand, there is a demand for a technology that can form a finer wiring pattern at a lower cost even for a resin circuit board.

An object of the present invention is to provide a circuit board having fine wiring conductors, which cannot be realized by a printing mask in a conventional screen printing method using a mesh screen, a metal mask, or the like. It is an object of the present invention to provide a printing mask that can be formed, a method of manufacturing the same, and a method of manufacturing a circuit board at low cost using the printing mask.

[0017]

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and the gist of the present invention is to provide a mask provided with a printing pattern which presses a printing paste into an upper surface and discharges the printing paste from a lower surface. , The printing pattern is:
A printing mask comprising a single sheet, wherein the area of the opening on the lower surface is larger than the area of the opening on the upper surface.

In a specific mode, the print pattern of the mask includes an unpenetrated portion that does not penetrate at least from the lower surface of the mask to the upper surface of the mask. Another specific mode is that the print pattern of the mask is Is characterized by comprising a penetrating portion penetrating from the mask upper surface to the mask lower surface, and a non-penetrating portion extending from the mask lower surface and not penetrating the mask upper surface. By providing such a non-penetrating portion, the strength of the printing mask is improved. Is secured. In each case, the width of the printed pattern of the wiring is preferably 50 μm or less, more preferably 40 μm or less, and most preferably 30 μm or less.

According to the present invention, the method of manufacturing a mask for wiring printing is characterized in that a laser beam is irradiated from one surface of a sheet constituting a mask body to form a print pattern.
When opening a through hole penetrating from the lower surface of the mask to the upper surface of the sheet, sequentially reduce the output of the laser, so that the area of the opening on the lower surface of the mask is larger than the area of the opening on the upper surface of the mask, Alternatively, an opening that penetrates from the lower surface to the upper surface of the mask according to the printing pattern is formed in the sheet, and the laser output is reduced in a part of the area according to the printing pattern as compared with the time of the penetration processing. Is to provide a non-penetrating part.

From another aspect, the method of manufacturing a wiring printing mask according to the present invention provides a method for forming a printed pattern on only one surface of a metal sheet, and a method for etching the entire surface of the metal sheet. After the application, by etching only from one side, the area of the opening on the lower surface of the mask is larger than the area of the opening on the upper surface of the mask. A printing pattern is formed on the surface by a resist film, and a resist film is formed on the other surface so that a part of the printing pattern remains as a bridge, and then the etching is performed to provide a non-penetrated portion in the metal sheet. Is a method of manufacturing a mask for use.

From another aspect, in the present invention, a predetermined printing pattern sheet having a bridge provided at an appropriate position is prepared, and then a photosensitive resin film is formed on one side of the sheet, and the printing pattern sheet is exposed and developed. Is to remove a portion of the photosensitive resin film corresponding to.

According to the present invention, by using the printing mask thus obtained, it is possible to form wiring having a wiring conductor width of 50 μm or less, more preferably 40 μm or less, and most preferably 30 μm or less. Circuit board can be obtained by inexpensive means. In addition, according to the present invention, by using the above-described mask, printing and firing on a ceramic substrate, the width of the wiring conductor is 50 μm or less, 40 μm or less in a more preferred embodiment, and 30 μm or less in the most preferred embodiment. After printing on a ceramic circuit board or ceramic green sheet, and laminating a predetermined number of the obtained ceramic green sheets,
A multilayer ceramic circuit board having a width of 50 μm or less, more preferably 40 μm or less in a more preferred embodiment, and 30 μm or less in the most preferred embodiment can be manufactured by inexpensive means.

In addition, when the above-mentioned printing mask is used, the width of the wiring conductor is 50 μm or less, more preferably 40 μm or less, and most preferably 30 μm or less.
m or less, a resin circuit board, and a laminated resin circuit board, and a printed pattern is printed on the resin board, a circuit pattern is formed, and a resin film formed of an insulating layer is formed on the obtained resin circuit board, By repeating the formation of a circuit pattern by printing and the formation of a resin film consisting of an insulating layer,
A laminated resin circuit board having a width of 50 μm or less, more preferably 40 μm or less in a more preferred embodiment, and 30 μm or less in the most preferred embodiment can be manufactured by an easy means.

In the ceramic circuit board, the resin circuit board, the laminated ceramic circuit board, or the laminated resin circuit board according to the present invention, the above-mentioned problem is solved, and cost reduction and high-density wiring are realized.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, referring to the attached drawings,
The form of the printing mask according to the present invention will be described.

FIGS. 1 (a) and 1 (b) are schematic illustrations of the configuration of a printing mask according to the present invention. FIG. 1 (a) is a plan view, and FIG. FIG. 1 is a sectional view taken along line 1-1.

As shown in FIG. 1A, the mask 10 is a sheet
The main body is composed of 12 and has a printing pattern 14. In FIG. 1B, an area 16 shown in white represents a print pattern 14, which includes a penetrating portion 18 and a non-penetrating portion 11, and an upper portion of the non-penetrating portion 11 constitutes a bridge 13.

In a preferred embodiment of the present invention, the width L of the wiring conductor formed by the printed pattern 14 is 50 μm or less, and the distance E between the non-penetrated portions 11 is 100 μm to
The bridge width X is 200 μm or less, and the bridge width X is 50 μm or less, and the thickness of the bridge, that is, the thickness of the convex portion of the non-penetrated portion 11 is 50 μm. The dimensions of these elements may be set as appropriate according to the width of the wiring conductor and the length of the print pattern. The strength of the print pattern only needs to be able to maintain a predetermined rigidity when the squeegee passes during printing. Table 1 shows an example of such dimensions.

[0029]

[Table 1]

The printing mask sheet material composed of a single sheet is not particularly limited as long as it is a flexible material. Generally, a metal material or a resin-based material is used. In metal materials, stainless steel materials that are not easily rusted and are relatively easy to process are preferable, but are not particularly limited thereto. Titanium-based materials or aluminum-based materials that can be processed by ordinary metal, such as, What is necessary is just to select suitably according to the case.

Resin-based materials have the drawback that it is difficult to determine the conditions during printing because they have higher ductility than metals, but they are relatively suitable for low printing pressure conditions where the viscosity of the printed paste is low. It is often used because it has the advantage of not having to worry about rust like metal
Specifically, a material that is durable even if the thickness is reduced, such as nylon, polyethylene, or a fluororesin, is appropriately selected.

By the way, as described in the section of the prior art, the amount of paste that passes through a printing mask having an aperture ratio of 100% is the largest. In other words, aperture ratio 1
“00%” means that the opening area of the mask upper surface and the opening area of the mask lower surface are the same, and the paste pressed into the mask opening is printed as much as it is pressed. The amount of paste applied is the largest. Therefore, if the paste applied more than the printed line width has sufficient viscosity and thixotropy, the paste thickness at the time of printing can be maintained and fine wiring is possible, There is no paste with high viscosity and thixotropy enough to hold a fine wiring pattern with a line width of 50 μm or less, so the thickness of the printed paste is
By increasing the width, the thickness is reduced, and at this time, if the original paste has a uniform thickness, the spread of the width is uniform, and the mask can be manufactured while predicting the spread in advance. However, even a slight difference causes fatal non-uniform spread of the fine pattern, so that a target fine wiring pattern cannot be formed with a conventional print mask having an aperture ratio of 100%.

In a printing mask using a mesh screen, if the intersection of the mesh of the mesh screen exists near the end of the wiring pattern formed of the emulsion, the end opening is smaller than the center opening. Then, the paste is easily clogged. If the width of the printed wiring conductor is sufficiently large compared to the end opening, clogging of the paste at the end opening can be neglected. A nearby clogged area cannot be ignored, and a pattern to be printed has irregularities, and sometimes the pattern is cut, resulting in poor printing. Further, since the aperture ratio of these mesh screens is at most about 70% at present, the area of the central opening is inevitably reduced, and naturally the end opening is also reduced, so that clogging is more likely to occur. Under the circumstances, the desired fine wiring pattern could not be formed.

The printing mask according to the present invention is different from a mesh screen mask or a metal mask in that the printing mask is formed of a single sheet, and the edges of the printing pattern are sharpened by eliminating the end opening and the center opening. Further, the area of the opening on the lower surface of the mask is larger than the area of the opening on the upper surface of the mask. In this way, the amount of paste to be printed is limited when being pressed from the upper surface of the mask, and from the widening portion of the lower surface of the mask, the paste is reduced in advance and the thickness is reduced by the previously pressed paste. The printing mask according to the present invention makes it possible to print a fine wiring pattern, even if the printing is performed so that the paste does not have sufficient viscosity and thixotropy.
Such a relationship between mask sizes is preferably under the following conditions. When the thickness of the penetrating portion is T, the thickness of the non-penetrating portion is t, the distance between the penetrating portions is E, the width of the penetrating portion is L, and the width of the non-penetrating portion is X, 0.2 ≦ t / T ≦ 0.8 0.15 ≦ Preferred dimensions are obtained when L / (E−X) ≦ 1.05. 0.2 ≦ t / T is necessary for maintaining the strength of the mask, and if it is less than 0.2, the mask is easily damaged during printing. If it exceeds 0.8, it is difficult for the paste to wrap around the unpenetrated portion, and the wiring is broken. In the range of L / (EX), less than 0.15 or
If it exceeds 1.05, the mask will be damaged during printing.

In the case where a number of fine wiring patterns are provided in parallel, in a printing mask having the above-described structure, the adjacent printing patterns sometimes have low durability in repeated printing steps. In some cases, the printing accuracy may deteriorate.

In such a case, a method of making the area of the opening on the lower surface of the mask wider than the area of the opening on the upper surface of the mask can be realized by providing a part of the upper surface of the mask that does not penetrate. . Such a portion that does not penetrate is also referred to as a bridge as one form, and the mode in which this bridge is provided is effective when there are many parallel fine print patterns. The effect of this bridge is, firstly, to make the areas of the openings on the upper surface and the lower surface of the mask different, secondly, to limit the amount of paste that passes at the time of printing, and thirdly, to print in parallel. An object of the present invention is to provide a pattern with a mechanical strength to suppress the deterioration of a printing mask in a repeated printing operation. In other words, even if several long print patterns are formed in parallel, the portion sandwiched between the print patterns has a structure that is connected to the adjacent portion in a bridge shape, so there is sufficient mechanical strength and repeated It can withstand printing operation. Also, the paste is not supplied directly from the upper surface of the mask at the portion where the bridge is provided, but the printed paste is cut off by the bridge because the paste flows around in the space between the bridge and the lower surface of the mask. Without printing. Note that the pitch of the bridges (the distance between adjacent bridges) needs to be smaller than a certain level. This is because the paste is not supplied to the bridge, but if the pitch is less than a certain level, the paste will wrap around to the lower surface of the bridge mask, so it is possible to print a fine wiring pattern without breaks Becomes The pitch is
It is appropriately selected by trial and error depending on the viscosity of the paste and various conditions at the time of printing.

That is, in the printing mask according to the present invention, the aperture ratio is larger than that of a printing mask using a normal mesh, the paste discharge property is excellent, and the printing mask is compared with a conventional mesh screen or a metal mask. It is possible to print complicated and complicated wiring patterns, especially 50 μm
Even with a wiring pattern having the following wiring conductor width, printing can be performed with high repeatability.

FIGS. 2 to 5 are schematic illustrations of a printing mask manufacturing method according to another embodiment of the present invention and a printing pattern obtained by the method.

First, as shown in FIGS. 2 (a) and 2 (b), an unprocessed metal sheet or resin sheet 24 is formed at a predetermined interval along a required print pattern 21 by an etching method or a laser processing method. , A through hole 22 is formed. A metal sheet may be formed by a plating method for growing a metal film on a portion other than the through-hole, and any forming means may be used as long as a sheet having through-holes at predetermined intervals can be obtained. Further, nylon, polyethylene, fluorine resin, or the like can be used for the resin sheet.

Next, as shown in FIGS. 3 (a) and 3 (b), a photosensitive resin film 31 is formed on one surface of the sheet provided with through holes at predetermined intervals. Since an organic solvent is usually used for cleaning the printing mask at the time of printing, the photosensitive resin is preferably a photosensitive polyimide which is chemically very stable.

Then, as shown in FIGS. 4 (a) and 4 (b), the photosensitive resin film is exposed to ultraviolet light by using a photomask 41 that transmits light to the print pattern. Next, development is performed with a developing solution, and non-developed portions along the print pattern are removed with an etching solution that does not damage the sheet.

If the surface of the sheet having through holes formed at predetermined intervals in this way is not in contact with the resin film, and the surface of the resin film not in contact with the sheet is the mask lower surface,
A printing mask combining a pattern penetrating from the mask upper surface to the mask lower surface and a pattern not penetrating from the mask lower surface to the mask upper surface can be obtained. By using a photosensitive resin film, the accuracy of the photomask can be obtained as it is,
Even fine wiring patterns can be manufactured without any problems. Further, since the accuracy of the thickness of the photosensitive resin film is good, it is easy to control the amount of paste to be applied, thereby enabling a more difficult wiring pattern. In addition, even if the precision of the resin sheet or metal sheet prepared first is rough, the precision of the photosensitive resin part can be sufficiently obtained, so a mask that absorbs the rough precision of the sheet and can withstand sufficient use is manufactured. it can.

Another method of manufacturing a printing mask according to the present invention, not shown, will be described below. A single sheet of a mask sheet made of a metal sheet or a resin sheet is placed on a plate frame of a predetermined size, and is processed by a laser from a surface that hits a lower surface of the mask. By moving the laser while gradually reducing the laser output, the area in the thickness direction from the surface corresponding to the lower surface of the mask to the surface corresponding to the upper surface of the mask can be gradually reduced. Alternatively, a desired printing mask can be obtained by alternately forming a penetrating pattern and a non-penetrating pattern by setting the laser output to two stages. Since the output of the laser can be changed easily and the depth and size of the processing can be changed freely, it is preferable for the production of a mask having a finer line width of 50 μm or less, and the program for the production of the pattern is also preferable. Since it can be manufactured only by using the mask, the lead time is short, and the pattern can be easily changed. In the laser processing, holes are formed by melting, so that the processed edge is rounded. As a result, the resistance of the resist or paste to pass is reduced, the opening on the upper surface of the mask can be reduced, and the strength of the mask itself can be increased. Further, the surface melted by the laser is modified, so that the wettability to the resist and the paste is improved, so that the resist and the paste can be applied even with a finer wiring pattern without any loss.

As another aspect of the method of manufacturing a printing mask according to the present invention, there is a method of processing a single metal sheet by etching. This utilizes the effect that the etching proceeds almost uniformly in the direction of the surface and the depth direction where the etching solution is in contact with the passage of time. It is possible to form a printing mask having a pattern such that the area becomes smaller in the thickness direction. Furthermore, if a method using a half-etching method is used, a pattern in which a bridge is left and a pattern which is not left are aligned on both sides of the mask, and patterning is performed in advance with a resist, and then etching is performed on both sides of the mask. A bridge can be provided by immersing in a liquid and performing etching. This is possible because the etching speed is controllable. The method of manufacturing a print mask using these etchings does not require a large device, and can be manufactured relatively inexpensively.

The etching treatment is mainly performed with an acid. According to this, the state of the etching interface of the metal sheet is oxidized, and the wettability of both the penetrated portion and the unpenetrated portion is improved.
As a result, a fine wiring pattern of paste or resist is applied without loss. Further, as in the case of the laser, the processing edge portion is rounded, so that the passage resistance of the resist and the paste is reduced, and the opening on the upper surface of the mask can be made smaller, thereby increasing the strength of the mask itself.

According to these manufacturing methods of a printing mask, a printing mask suitable for printing a fine wiring having a non-penetrated portion in a printing pattern, in other words, a bridge can be obtained.

The printing screen manufactured in this manner has a structure in which even if several long printing patterns are formed in parallel, the metal part sandwiched between the printing patterns is connected to the adjacent metal part in a bridge shape. Therefore, it can withstand the printing process. In the bridge, the paste is not supplied directly from the upper surface of the mask, but the paste flows around in the space between the bridge and the lower surface of the mask. Printed on

That is, in the printing mask manufactured according to the present invention, the aperture ratio is larger than that of a printing mask using a normal mesh, and the paste discharging property is excellent, and a conventional mesh screen or metal mask is used. It is possible to print complicated wiring patterns compared to
Even a wiring pattern having a wiring conductor width of m or less can be printed with high repeatability.

Here, according to a further aspect of the present invention,
By using the above-described printing mask, a ceramic circuit board having a wiring conductor width of 50 μm or less can be easily manufactured by a simple means of a printing method. Hereinafter, such a manufacturing method will be described.

One of ceramic powder or glass powder such as alumina, mullite, aluminum nitride, cordierite, glass (borosilicate glass, cordierite glass, anorthite glass, etc.) having a particle size of 0.1 to 10 μm; Two or more kinds of mixed powders, an acrylic resin, a butyral-based organic resin, an organic solvent such as toluene, xylene, acetone, and butanol, and a small amount of additives are mixed by a ball mill and defoamed.
Create a green sheet with a thickness of 20 to 300 μm.

After punching holes for forming vias in the green sheet and filling with a conductive paste, the inner layer wiring is printed. When the surface wiring is formed by the simultaneous firing method, the surface wiring printing is also performed. The paste for the inner layer wiring, the paste for the surface layer wiring, and the paste for the via are 0.01 to 5 μm of W, Mo, Au, and A.
g, Cu, Ag-Pd or other metal powder, or CuO, Cu ₂ O or other softened metal powder, mixed with an organic resin such as ethyl cellulose, an organic solvent such as theopineol, and a small amount of other additives Is done. The conductor paste to be used is determined by the temperature at which the solid content of the ceramic green sheet is sintered. For example, if it is a green sheet having a solid content of alumina, W, Mo having a melting point equal to or higher than its sintering temperature.
Is used as the solid content. It is a green sheet having glass as a solid content. If sintering is possible at about 900 ° C., a paste containing Ag and Cu as solid contents will be used.

When the surface wiring is formed by a post-installation method, the green sheet on which the inner wiring and the via are formed is laminated and pressed, followed by firing, printing of the surface wiring paste, and the solid content contained in the paste is fired. Re-bake at the sintering temperature.

The printing mask according to the present invention used for the inner layer wiring printing and the surface wiring printing is made of a metal material or a resin-based material, and the pattern formed as the mask is different from the pattern penetrating from the mask upper surface to the mask lower surface. ,
This is a combination with a concave pattern that does not penetrate from the mask lower surface to the mask upper surface.

Such a printing mask according to the present invention has a larger aperture ratio than a printing mask using a normal mesh, is excellent in the discharge property of the paste, and has a larger aperture ratio than a conventional mesh screen or metal mask. It is also possible to print a circuit pattern of a complicated wiring, and it is also possible to print a wiring pattern having a wiring conductor width of 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less. It is possible to manufacture a ceramic circuit board having an inner wiring or a surface wiring.

According to a further aspect of the invention from another aspect, the use of a printing mask as described above allows the use of a printing mask of 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less.
A resin circuit board having the following wiring conductor width can be easily manufactured by a simple means called a printing method. Such a manufacturing method will be described below.

A resin substrate to be a circuit board is prepared, and a copper layer is uniformly formed on the resin substrate by electroless plating or the like so as to have a thickness of several μm to several tens μm. Any material may be used as long as it is a good conductor, and a copper-based, silver-based, or gold-based metal or alloy is preferable from the viewpoint of cost and ease of handling.

Next, a photosensitive resist is applied uniformly by a spin coater or the like and dried on a substrate, and the above-mentioned mask having a printed pattern opposite to a wiring pattern is formed by using a resin paste that does not transmit light as a printing paste. Print using. And the part where the photosensitive resist of the wiring pattern part is hardened by light and hidden by light is removed in the subsequent uncured part resist removing step while remaining uncured, and the exposed metal layer part is removed by etching, A desired circuit pattern is formed on the resin substrate. Alternatively, a photosensitive resist is directly printed on the resin substrate on which the conductive metal layer is formed using the mask so as to form a circuit pattern, and after drying, the resist is cured by irradiating light, and then the etching solution is applied. A resin circuit board can also be formed by immersing the resin board and reacting an etchant with a portion where the resist is not applied to remove unnecessary conductor portions in the circuit pattern.

As another method, there is a means for forming a circuit pattern directly on a resin substrate by printing, drying, and curing using a conductive paste with the conductive mask.

In these well-known methods of forming a wiring conductor, whether to use a positive type or a negative type is appropriately selected depending on the specifications, material restrictions, and other various conditions. .

In this way, a resin circuit board can be manufactured. In addition, through holes and via holes are formed in this board to establish conduction between the main surfaces of the resin circuit board. When a plurality of the above-mentioned resin circuit boards are laminated and bonded, a laminated resin circuit board can be manufactured.

According to still another aspect, after the above-mentioned resin circuit board is obtained, an insulative resin is applied on the board by a roll coater or a spin coater, and the resin is cured. In the same way as the method of obtaining the substrate,
If another circuit pattern is formed and repeated, another laminated resin circuit board can be obtained.

At this time, a conductor to be a necessary via may be formed by using a print mask according to the present invention, and then an insulating film may be applied and formed. Alternatively, after applying and drying an insulating resin, the print mask according to the present invention may be used. Alternatively, a shielding resist may be applied so as to be hardened except for the via portion, and the via portion may be formed into a hole, and a conductor may be buried to form the hole.

The insulating resin used here is made of at least one material selected from the group consisting of epoxy, acrylic, silicon, polyimide and polyamide. As long as it has properties and can be applied by a spin coater or a roll coater, it can be appropriately selected regardless of the material. Further, the form of the insulating resin may be an adhesive or a resist, regardless of its form. Any type can be used as long as a uniform and good insulating layer can be formed.

The above-described printing mask for manufacturing a resin circuit board has a larger aperture ratio than a printing mask using a normal mesh, is excellent in the discharge property of the paste, and has a conventional mesh screen or metal mask. It is also possible to print a circuit pattern of a complicated wiring as compared with a wiring pattern having a wiring conductor width of 50 μm or less, and it is possible to print a fine inner layer wiring or a surface wiring having a wiring conductor width of 50 μm or less. It is possible to manufacture a resin circuit board having the following. Circuit boards made by these methods have a more uniform and uniform wiring conductor width, and therefore have excellent electrical characteristics such as frequency characteristics and insulation, and high quality that can take electromagnetically designed values. It can be an article.

Of course, it goes without saying that the printing mask according to the present invention may be used for printing circular conductor patterns and the like in addition to wiring patterns. Hereinafter, embodiments according to the present invention will be described.

[0066]

【Example】

Example 1 A sheet of nylon resin having a thickness of 0.1 mm was prepared, and the sheet was attached to an aluminum frame having an inner size of 220 × 200 mm while applying a tensile force without any gap. Prepare a laser device that can change the spot diameter every 10 μm in the range of 10 to 50 μm, and adjust the laser output so that the amount of engraving is about 20 μm at a time on this pasted sheet. Starting with a spot diameter of 40
Printing masks were prepared by engraving 0, 20, and 10 μm, each with a thickness of about 20 μm. Since the engraving amount cannot be secured unless the laser output is changed as the spot diameter becomes smaller, the pattern is adjusted so that the optimum output is obtained as appropriate, and the width of the mask upper surface is approximately 10 μm and the width of the mask lower surface is approximately 50 μm. A printing mask was used.

An alumina substrate and a green sheet prepared by mixing an alumina powder and an organic resin were used as the printing medium. The paste contains Cu and Ag powder as solids 2
In each case, a paste of 400000 cps was used under the conditions of a BHT type viscometer at 10 rpm and 25 ° C.

When printing was performed by the screen printing method using a rubber squeegee, printing without disconnection and short-circuiting was possible even under all combinations of conditions ((mask 2) × (substrate 2) × (paste 2) = 8 conditions). Met.

The change in the pattern of the printing mask before printing and after printing 200 times was examined using an optical microscope.
Neither the wiring width nor the wiring interval changed so small as to be unobservable. Furthermore, when the laser-processed portion of the mask was observed with an optical microscope, it was found that the contact angle of the water droplet was smaller than that of the unprocessed surface, and the surface was modified by laser processing, and the wettability was improved. . Also,
Since the printing pressure was lower than when the same paste was used for the conventional mesh screen printing (0.5 to 1 kg / c for the conventional mesh screen printing).
In printing mask according to the present invention with respect to it was m ² 0.
It was 1 kg / cm ² . ), The printing mask according to the present invention,
It turned out to be suitable for finer wiring patterns.

Example 2 A sheet of stainless steel having a thickness of 0.1 mm was prepared, a 10 μm-thick photosensitive resist was applied to both sides by a spin coater, dried, and then one side was exposed to the entire surface, and the other side was exposed. Is exposed using a photomask on which a print pattern is printed. Thereafter, development is performed to expose the print pattern portion of the stainless sheet, and the print pattern portion is etched away using an etchant. Since the etching proceeds uniformly from the portion facing the etching solution over time, the width tends to be wider than the mask printing pattern. In this embodiment, the wiring width of the photomask is set to 20 μm. After performing the etching process,
The wiring conductor width of the obtained printing mask was 30 μm. 220 x 200m
An aluminum frame having an inner dimension of m was attached to a combination type in which a stainless steel outer frame portion was surrounded by a resin sheet to produce a printing mask.

An alumina substrate and a green sheet prepared by mixing an alumina powder and an organic resin were used as the printing medium. The paste contains Cu and Ag powder as solids 2
In each case, a paste of 400000 cps was used under the conditions of a BHT type viscometer at 10 rpm and 25 ° C.

When printing was performed by a screen printing method using a rubber squeegee, printing without disconnection and short-circuiting was possible even under all combinations of conditions ((mask 2) × (substrate 2) × (paste 2) = 8 conditions). Met.

The change in the pattern of the printing mask before printing and after printing 200 times was examined with an optical microscope.
Neither the wiring width nor the wiring interval changed so small as to be unobservable. Furthermore, when the etched part of the mask was observed with an optical microscope, it was found that the contact angle of the water droplet was smaller than that of the unprocessed surface, and the surface was modified by the oxide film by etching, and the wettability was improved. I was In addition, since the printing pressure can be performed at a lower printing pressure than when the same paste is used for the conventional mesh screen printing (in contrast to 0.5 to ¹ kg / cm ² in the conventional mesh screen printing). It was 0.1 kg / cm ² for the printing mask according to the present invention.) It was found that the printing mask according to the present invention was suitable for finer wiring patterns.

Example 3 A sheet of nylon resin having a thickness of 0.1 mm was prepared, and the sheet was attached to an aluminum frame having an inner dimension of 220 × 200 mm while applying a pulling force without any gap. Was. Next, a laser device having a spot diameter of 50 μm is prepared, and the laser output is adjusted so that the engraving amount is about 100 μm and 50 μm at a time on the attached sheet. Laser output, 50 for unpenetrated part
Processing was performed with a laser output corresponding to μm to create a printing mask.

An alumina substrate and a green sheet prepared by mixing an alumina powder and an organic resin were used as the printing medium. The paste contains Cu and Ag powder as solids 2
In each case, a paste of 400000 cps was used under the conditions of a BHT type viscometer at 10 rpm and 25 ° C.

When printing was performed by a screen printing method using a rubber squeegee, printing without disconnection and short-circuiting was possible even under all combinations of conditions ((mask 2) × (substrate 2) × (paste 2) = 8 conditions). Met.

Changes in the pattern of the printing mask before printing and after printing 200 times were examined with an optical microscope.
Neither the wiring width nor the wiring interval changed so small as to be unobservable. Furthermore, when the laser-processed portion of the mask was observed with an optical microscope, it was found that the contact angle of the water droplet was smaller than that of the unprocessed surface, and the surface was modified by laser processing, and the wettability was improved. . Also,
Since the printing pressure was lower than when the same paste was used for the conventional mesh screen printing (0.5 to 1 kg / c for the conventional mesh screen printing).
In printing mask according to the present invention with respect to it was m ² 0.
It was 1 kg / cm ² . ), The printing mask according to the present invention,
It turned out to be suitable for finer wiring patterns.

Example 4 A stainless steel sheet having a thickness of 0.1 mm was prepared, and a photosensitive resist having a thickness of 10 μm was applied to both sides by a spin coater and dried. Exposure is performed using a baked photomask, and the other side is exposed using a baked photomask with a printed pattern. Thereafter, development is performed to expose the print pattern portion of the stainless sheet, and the print pattern portion is etched away using an etchant. Since the etching proceeds uniformly from the portion facing the etching solution over time, the width tends to be wider than the mask printing pattern. In this embodiment,
Since the etching is performed from both sides of the metal sheet, the etching time is about half as compared with the case of the second embodiment.
The thickness was 5 μm. After performing the etching treatment, the width of the wiring conductor of the obtained printing mask was 30 μm. The printing mask thus produced was pasted on a combination type in which a stainless steel outer frame was surrounded by a resin sheet on an aluminum frame having an inner size of 220 × 200 mm to produce a printing mask.

An alumina substrate and a green sheet prepared by mixing an alumina powder and an organic resin were used as the printing medium. The paste contains Cu and Ag powder as solids 2
In each case, a paste of 400000 cps was used under the conditions of a BHT type viscometer at 10 rpm and 25 ° C.

When printing was performed by the screen printing method using a rubber squeegee, printing without disconnection and short-circuiting was possible even under all combinations of conditions ((mask 2) × (substrate 2) × (paste 2) = 8 conditions). Met.

Changes in the pattern of the printing mask before printing and after printing 200 times were examined with an optical microscope.
Neither the wiring width nor the wiring interval changed so small as to be unobservable. Furthermore, when the etched part of the mask was observed with an optical microscope, it was found that the contact angle of the water droplet was smaller than that of the unprocessed surface, and the surface was modified by the oxide film by etching, and the wettability was improved. I was In addition, since the printing pressure can be performed at a lower printing pressure than when the same paste is used for the conventional mesh screen printing (in contrast to 0.5 to ¹ kg / cm ² in the conventional mesh screen printing). It was 0.1 kg / cm ² for the printing mask according to the present invention.) It was found that the printing mask according to the present invention was suitable for finer wiring patterns.

Example 5 A hole of 70 μm × 20 μm as shown in FIG.
A bridge having a width of 30 μm is formed. Next, as shown in FIG. 3, a photosensitive polyimide film having a thickness of 50 μm is formed on the entire surface of one surface of the stainless steel sheet, exposed to ultraviolet light using a photomask having a print pattern as a mask, exposed, and developed. The portion of the photosensitive polyimide film corresponding to the printing pattern was removed, and a printing mask as shown in FIG. 4 having a printed wiring conductor width of 20 μm was prepared.

An alumina substrate and a green sheet prepared by mixing an alumina powder and an organic resin were used as the printing medium. The paste contains Cu and Ag powder as solids 2
In each case, a paste of 400000 cps was used under the conditions of a BHT type viscometer at 10 rpm and 25 ° C.

When printing was performed by the screen printing method using a rubber squeegee, printing without disconnection and short-circuiting was possible even under all combinations of conditions ((mask 2) × (substrate 2) × (paste 2) = 8 conditions). Met.

When the change in the print pattern of the printing mask before and after printing 200 times was examined by an optical microscope, it was found that both the wiring width and the wiring interval were so small as to be unobservable.

Example 6 Cordierite (MgO-Al2O3-SiO2) having an average particle size of 1 μm
A mixed powder of 50:50 (weight ratio) of a system glass powder and an alumina powder, an acrylic binder as an organic resin, xylene as an organic solvent, and a small amount of other additives are mixed by a ball mill to form a slurry, which is then defoamed. A green sheet having a thickness of 200 μm was prepared by a blade method.

The surface layer wiring Ag paste is applied to the green sheet,
Laser printing made of the resin material shown in Pattern 1 of FIG. 1 manufactured in Example 3 was performed using a printing mask provided with a non-penetrated portion, and the green sheet having the surface wiring was printed.
Fired at 900 ° C. Thus, a ceramic circuit board having a surface wiring having a wiring conductor width of 45 μm was obtained.

When the circuit board was electrically examined, the variation in the resistance value of each wiring was 0.4% or less, which was very small and good.

Example 7 Cordierite (MgO-Al2O3-SiO2) having an average particle size of 1 μm
A mixed powder of 50:50 (weight ratio) of a system glass powder and an alumina powder, an acrylic binder as an organic resin, xylene as an organic solvent, and a small amount of other additives are mixed by a ball mill to form a slurry, which is then defoamed. A green sheet having a thickness of 30 μm was prepared by a blade method.

A punch hole for forming a via was formed in the green sheet, an Ag paste for the via was filled and printed, and the Ag paste for the inner layer wiring was etched by a stainless steel sheet shown in Pattern 2 of FIG. Printing was performed using a printing mask provided with a non-penetrated portion. After laminating press the green sheet with inner layer wiring and via formed, 90
Baking was performed at 0 ° C., and the surface of the baked substrate was printed with an Ag-Pd paste for surface wiring using a printing mask similar to the above (different wiring pattern), and rebaked at 850 ° C. As a result, a laminated ceramic circuit board having an inner wiring having a wiring conductor width of 42 μm and a surface wiring was obtained.

The wiring board was electrically examined. As a result, there was no disconnection or short circuit, and the variation of the resistance value of each wiring was 0.4% or less, which was very good.

Example 8 A 1 mm thick resin substrate mainly composed of epoxy resin was prepared, and a circuit wiring pattern was directly formed on this resin substrate by using a conductive paste mainly composed of copper. 4
50μ with the printing mask shown in FIG.
m, a circuit pattern having a wiring width of 30 μm is printed,
After drying and curing, a base resin circuit board was manufactured. The viscosity of the conductive paste used was the same as in Example 1, but the type of the vehicle was different because the drying and curing methods were different. The thickness of the wiring pattern after drying and curing thus obtained was 20 to 35 μm, and no disconnection or short circuit was found at the time of manufacturing 20 sheets, and the resin circuit board had a fine wiring conductor width. The wiring board was electrically examined. As a result, there was no disconnection or short circuit, and the variation in the resistance value of each wiring was very good at 0.4% or less.

Example 9 An epoxy resin having a viscosity of 500 CPS (BHT type viscometer, 10 RPM, 25 ° C.) was placed on the resin circuit board obtained in Example 8.
Was applied by a spin coater and dried to form an insulating resin layer having a thickness of about 75 μm. Next, after curing with the exception of the via portion using a photosensitive mask, the resin in the via portion was removed to form a hole, and the conductor was embedded. Thereafter, in the same manner as the method of obtaining the resin circuit board,
Another circuit wiring pattern is formed by using a printing mask of a single metal sheet (stainless steel sheet) manufactured by the single-sided etching method similar to the second embodiment and the double-sided etching method similar to the fourth embodiment according to the present invention. And repeat this three times,
A three-layer laminated resin circuit board was obtained. When the obtained five laminated resin circuit boards were examined, a laminated resin circuit board having a fine wiring width without disconnection or short circuit was obtained. The wiring board was electrically examined. As a result, there was no disconnection or short circuit, and the variation in the resistance value of each wiring was very good at 0.4% or less.

Example 10 A resin substrate mainly made of epoxy resin and having a thickness of 0.5 mm and through holes provided in predetermined positions was prepared, and a circuit wiring pattern was directly formed on the resin substrate by using copper. Using a conductive paste as a main component, a circuit pattern having a wiring width of 50 μm is printed using a printing mask shown in FIG. 1 manufactured in Example 3 and dried and cured to form a base resin circuit board. Was made. The same conductive paste as that used in Example 1 was used.

Five layers of an epoxy-based adhesive were alternately laminated while precisely positioning the obtained resin circuit board and a predetermined position, and cured by heating in a dryer at 60 ° C. for 2 hours. A laminated resin circuit board of 2.7 mm was obtained. When the obtained laminated resin circuit board was examined, a laminated resin circuit board having a fine wiring width without disconnection or short circuit was obtained.
When this wiring board was electrically examined, there was no disconnection or short circuit, and the variation in the resistance value of each wiring was 0.2%.
Very good below.

Example 11 As shown in FIG. 5, holes of 80 μm × 25 μm were formed in a stainless steel sheet having a sheet thickness of 50 μm by etching.
A hole having a width of 20 μm is formed by forming the holes so that the holes are shifted by 50 μm from each other by 100 μm. Next, as shown in FIG. 3, a photosensitive polyimide film having a thickness of 30 μm was formed on the entire surface of one surface of the stainless steel sheet, exposed to ultraviolet light using a photomask having a printed pattern as a mask, exposed, and developed. The portion of the photosensitive polyimide film corresponding to the printed pattern is removed, and the width of the printed wiring conductor is 2
A printing mask having a thickness of 5 μm as shown in FIG. 5 was prepared.

An alumina substrate and a green sheet prepared by mixing an alumina powder and an organic resin were used as the printing medium. The paste contains Cu and Ag powder as solids 2
In each case, a paste of 400000 cps was used under the conditions of a BHT type viscometer at 10 rpm and 25 ° C.

When printing was performed by a screen printing method using a rubber squeegee, printing without disconnection and short-circuiting was possible even under all combinations of conditions ((mask 2) × (substrate 2) × (paste 2) = 8 conditions). Met.

When the change of the print pattern of the printing mask before and after the printing was completed 300 times was examined by an optical microscope, it was found that both the wiring width and the wiring interval were so small as to be unobservable. In this type, the strength of the mask is relatively improved because the adjacent pattern is shifted from the unpenetrated portion.

Comparative Example 1 As in Example 1, a metal mask of a wiring pattern having a wiring width of 50 μm and a wiring width of 30 μm was manufactured. Was not provided. Next, printing was performed on the green sheet of alumina, which is the same printing medium as in Example 1, under the conditions considered to be the best printing conditions. The paste bleeds in some places, causing a short circuit. Further, as the number of times of printing increases, the wiring interval increases, and after 20 times of printing, the wiring is distorted by 30 to 40% or the pattern is elongated. After continuing printing, about 60
The wiring gap was torn during the second printing.

[0101]

As described above in detail, in the printing mask according to the present invention, it is possible not only to print a finer wiring width, which has been conventionally difficult with the screen printing method, As for the printing mask, in addition to the low cost due to the ease of manufacturing of the screen printing method, the number of times that the printing can be performed is dramatically increased. Cost reduction can be realized.

In the method of manufacturing a printing mask according to the present invention, the accuracy of the photomask can be directly obtained by using a photosensitive resin film, and even a fine wiring pattern can be manufactured without any problem. Now you can do it. Further, since the accuracy of the thickness of the photosensitive resin film is good, it is easy to control the amount of paste to be applied, thereby enabling a more difficult wiring pattern. In addition, even if the precision of the resin sheet or metal sheet prepared at the beginning is rough, the precision of the photosensitive resin part can be sufficiently obtained, so a mask that absorbs the rough precision of the sheet and can withstand sufficient use is manufactured. it can.

In the method using a laser, the output can be easily changed, and the depth and size of the processing can be freely changed, so that a mask having a finer line width can be manufactured, and the pattern can be formed. Since it is possible to fabricate a mask using only a program, the lead time is short, and the pattern can be easily changed. In the laser processing, holes are formed by melting, so that the processed edge is rounded. As a result, the resistance of the resist or paste to pass is reduced, the opening on the upper surface of the mask can be reduced, and the strength of the mask itself can be increased. Further, the surface melted by the laser is modified, so that the wettability to the resist and the paste is improved, and the resist and the paste are applied even with a finer wiring pattern without a defect.

In the method by etching, since the progress speed is controllable, a finer wiring pattern can be accurately formed on both sides or one side even with a finer wiring pattern. Thus, a large number of inexpensive masks having high dimensional accuracy can be manufactured. The etching process is mainly performed with an acid, but the state of the etching interface of the metal sheet is oxidized, and the wettability of both the penetrated portion and the non-penetrated portion is improved. You. Further, as in the case of the laser, the processing edge portion is rounded, so that the passage resistance of the resist and the paste is reduced, and the opening on the upper surface of the mask can be made smaller, thereby increasing the strength of the mask itself.

Further, in the method of manufacturing a circuit board according to the present invention, since the printing mask obtained according to the present invention is used, a circuit board having a fine conductor wiring pattern is manufactured. Accordingly, high-density wiring can be performed, and the size and weight of such electronic components can be further reduced. In addition, it has a more uniform and uniform wiring conductor width, so it has excellent electrical characteristics such as frequency characteristics and insulation properties, and can be made a high-quality product that can take electromagnetically designed values. The present invention is very useful in practical use, for example, by properly selecting the material of the wiring conductor to be formed, it is possible to reduce signal transmission loss and to save power.

[Brief description of the drawings]

FIG. 1 is a typical mask configuration diagram according to the present invention.

FIG. 2 is a configuration diagram of a sheet material of a typical mask of the present invention.

FIG. 3 is a diagram showing a typical mask in the process of being manufactured according to the present invention.

FIG. 4 is another representative mask configuration diagram according to the present invention.

FIG. 5 is a plan view of a print pattern.

[Explanation of symbols]

 Reference Signs List 21 mask sheet material 22 penetrating part 31 photosensitive resin 41 photosensitive resin 42 penetrating part 43 bridge

Claims (14)

[Claims] 1. A mask provided with a printing pattern which presses a printing paste into an upper surface and discharges the printing paste from a lower surface, wherein the printing pattern has an area of an opening on a lower surface larger than an area of an opening on an upper surface. A printing mask characterized by the following. 2. A mask provided with a printing pattern that presses a printing paste into an upper surface and discharges the printing paste from a lower surface, wherein the printing pattern includes a penetrating portion penetrating from the mask upper surface to the mask lower surface, and a mask extending from the mask lower surface and extending from the mask lower surface. And a non-penetrating part that does not penetrate the printing mask. 3. The printing mask according to claim 1, wherein the width of the printing pattern is 50 μm or less. 4. A method of forming a print pattern by irradiating a laser beam from one surface of a sheet constituting a mask main body, and sequentially forming through holes in the sheet from the lower surface of the mask to the upper surface thereof. A method for manufacturing a printing mask, characterized in that the output of a laser is reduced and the area of an opening on the lower surface of the mask is made larger than the area of an opening on the upper surface of the mask. 5. A mask on which a print pattern is formed only on one surface of a metal sheet and a film which is not etched on the other surface are applied to the other surface, and then etching is performed from only one surface, thereby forming a mask upper surface. A method for manufacturing a printing mask, characterized in that the area of the opening on the lower surface of the mask is larger than the area of the opening. 6. A laser beam is radiated from one surface of a sheet constituting the mask body to form an opening penetrating from the lower surface to the upper surface of the mask in accordance with the printing pattern, and forming an opening in accordance with the printing pattern. A method for manufacturing a printing mask, characterized in that an unpenetrated portion is provided in a region of a part by making the laser output smaller than that in the case of through processing. 7. A printing pattern is formed on one surface of a metal sheet by a resist film, and a resist film is formed on the other surface so that a part of the printing pattern remains as an unpenetrated portion, and then etching is performed. A method of manufacturing a printing mask, wherein a non-penetrated portion is provided in the print pattern. 8. A sheet having a predetermined print pattern provided with a bridge at an appropriate position is prepared, and then a photosensitive resin film is formed on one side of the sheet, and the portion corresponding to the print pattern is exposed and developed. A method for manufacturing a printing mask, comprising removing a photosensitive resin film. 9. The method for manufacturing a printing mask according to claim 4, wherein the width of the printing pattern is 50 μm or less. 10. The printing pattern width according to claim 3, wherein the width is 50 μm.
Prepare the following printing mask, then put the mask on the ceramic substrate and press the printing paste into the printing pattern from the mask upper surface, after printing the printing pattern on the ceramic substrate, simultaneously or individually The width of the wiring conductor is 50 μ
m or less. 11. The printing pattern width according to claim 3, wherein the width is 50 μm.
The following printing mask was prepared, and then the mask was placed on a ceramic green sheet, and the printing pattern was printed on the ceramic green sheet by pressing a printing paste from above the mask into the printing pattern, thereby obtaining A method of manufacturing a laminated ceramic circuit board having a wiring conductor width of 50 μm or less, comprising laminating a predetermined number of the obtained ceramic green sheets, pressing them together, and firing them simultaneously. 12. The print pattern width according to claim 3, wherein the width is 50 μm.
Prepare the following printing mask, then put the mask on the resin substrate and press the printing paste into the printing pattern from the mask upper surface, print the printing pattern on the resin substrate, the circuit pattern A method of manufacturing a resin circuit board having a wiring conductor width of 50 μm or less, characterized by being formed. 13. The print pattern width according to claim 3, wherein the width is 50 μm.
The following printing mask is prepared, and then the mask is placed on a resin substrate, and a printing paste is pressed into the printing pattern from the mask upper surface to print the printing pattern on the resin substrate to form a circuit pattern. A method for manufacturing a laminated resin circuit board having a wiring conductor width of 50 μm or less, wherein a predetermined number of the obtained resin boards are laminated. 14. The printing pattern width according to claim 3, wherein the width is 50 μm.
The following printing mask is prepared, and then the mask is placed on a resin substrate, and a printing paste is pressed into the printing pattern from the mask upper surface to print the printing pattern on the resin substrate to form a circuit pattern. A resin film serving as an insulating layer is formed on the obtained resin substrate, and a predetermined number of layers are laminated by repeating the circuit pattern formation and the resin film forming the insulating layer by printing. A method of manufacturing a laminated resin circuit board having a wiring conductor width of 50 μm or less.