JPH0455784B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention utilizes the sharp directivity and high energy density properties of laser beams to create elaborate line drawings such as figures and characters on wood or synthetic resin boards. on how to engrave.

(Prior art) This type of engraving method using a laser beam is as follows:
A template is made by drilling holes in a pattern that corresponds to the processed shape in a metal plate that blocks the laser beam, such as brass or brass. There is a conventionally known method of machining a workpiece into the same pattern as the hole in the template by irradiating a laser beam from the hole and burning only the hole. , Japanese Unexamined Patent Publication No. 56-71000).

(Problem to be Solved by the Invention) However, in the conventional method using a template, a loop-shaped closed hole cannot be drilled because a part of the template falls off. When drilling through holes, a so-called bridge is required to keep the entire template in one piece.
Therefore, conventionally, it has been impossible to carve the entire outer edge of a character or figure onto the surface of a workpiece to form a perfect shape.

In this way, conventionally there were significant restrictions on the shapes that could be engraved. For example, even if you try to engrave kanji with many strokes on the surface of wood in cursive, you cannot engrave them unless you add the necessary bridges to the original characters and apply a certain design. had to have a different shape from the original text.

In view of the above circumstances, an object of the present invention is to improve the conventional template so as to engrave realistic line drawings exactly as in the original onto wood or the like using a laser beam.

(Means for Solving the Problems) In the present invention, first, a metal layer is laminated onto a corrosion-resistant base film, and a photoresist film is laminated on the surface of the metal layer to form a mask material. Then, a negative film on which the original has been photographed is superimposed on the photoresist film of the mask material, and the metal layer of the mask material is punched out using the photoetching method, thereby removing the negative film held on the flat base film. A laser mask is formed leaving a metal layer with the same pattern as the film. Next, the laser mask is placed on the surface of a workpiece such as wood, and the entire surface of the laser mask is irradiated with a laser beam from above to remove the base film, leaving a portion blocked by the metal layer. , embossing the pattern formed by the metal layer on the surface of the lower workpiece;

(Function) When the metal layer of the mask material is photo-etched using a negative film, the metal layer is etched in the same pattern as the negative film, but this metal layer is backed by a corrosion-resistant base film. Therefore, the metal layer is held integrally on the base film without separating into pieces.

When the workpiece is covered with the laser mask obtained in this way and a laser beam is irradiated from above, the surface of the workpiece other than the part blocked by the metal layer of the laser mask is evaporated to a certain depth. This results in a state where the metal layer is burnt and shaved, and the same pattern as the metal layer remains on the processed surface, creating an embossed pattern.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

1 is made of a corrosion-resistant material that will not corrode by etching, such as polyester, and has a thickness of 20 μm or more.
A base film of approximately 50 μm in thickness is integrally laminated with a metal layer 2 of less than 100 μm in thickness made of metal such as iron, copper, or brass, which can be etched. A resist film 3 is laminated to form a mask material m.

The photoresist film 3 is formed by laminating a film resist on the surface of the metal layer 2 by heating and applying pressure, or by applying a liquid resist.

On the other hand, a manuscript is prepared, for example, with a name written in dark ink on white paper, and this is photographed using a plate-making camera. The photosensitive film used for photography is preferably a high-contrast lithium-type film, as it is necessary to clearly display the contrast between black and white.

The photographed film is developed to obtain a negative film 4. In FIG. 1, 4a indicates a portion that has been developed and turned black.

Next, the negative film 4 is used as a photomask and is superimposed (masked) on the mask material m for photoetching.

To do this, the emulsion side of a negative film is superimposed on the photoresist film 3 of the mask material m, and after close exposure using vacuum printing (FIG. 1), the mask material m is immersed in a developer and developed. After development, the dissolved resist residue in the non-photosensitive area is washed away with water (Figure 2), and the metal layer 2 exposed from the resist film is corroded away by being sent to a corrosive machine (not shown) and sprayed with an etching solution. (chemical blanking) to form a laser mask LM on the base film 1, leaving a metal layer with the same pattern as the negative film 4 of the photomask (FIG. 3).

Next, this laser mask LM is closely attached to the surface of a workpiece 5 such as a synthetic resin such as acrylic resin or wood, and a laser beam L such as a carbon dioxide laser is irradiated onto the front surface from above (FIG. 4). In this case, by scanning the laser beam L by moving the workpiece 5 and the laser beam L relatively in the X-axis and Y-axis directions that intersect with each other, the laser beam can be accurately irradiated over the entire surface of the laser mask LM. Can be irradiated.

When the laser beam L is irradiated, the laser beam L is blocked by the metal layer 2 and evaporates only the photoresist film 3 of the laser mask LM, but in the exposed part of the base film 1, the workpiece 5 is evaporated together with the base film 1. The surface is evaporated (sublimated by high heat) to a certain depth (1 mm to 3 mm) and a recess 6 is carved (Fig. 5). As a result, a pattern identical to the pattern of the metal layer 2 is formed on the surface of the workpiece 4. A pattern, ie, the same pattern as the negative film 4, remains on the processed surface, and the name of the original is embossed in dark ink.

Thereafter, the metal layer 2 may be removed together with the base film 1 from the surface of the workpiece 5, but adhesive may be applied to the entire back side of the base film 1 in advance and release paper is applied to the outside before laser beam irradiation. If the laser mask LM is peeled off and adhered to the surface of the workpiece 5, the position of the laser mask LM will not shift during laser irradiation, and at the same time as the predetermined pattern is embossed, the surface of the embossed pattern will be completely attached to it. A high-gloss metal layer with the same contour can be applied in one step.
In this case, instead of applying adhesive to the back side of the base film 1, the base film 1 and the workpiece 5 are
Needless to say, a double-sided adhesive sheet may be interposed between the two to bond the metal layer.

In addition, if a photoresist film of a type that becomes soluble when exposed to light is used and the metal layer 2 is etched into a pattern that is a negative tape compared to the above-mentioned embodiment, the unevenness on the surface of the workpiece 5 will be exactly opposite to that shown in FIG. The name of the manuscript is engraved in dark ink on the processed surface.

Alternatively, if you write something in dark ink on white paper and print it onto photographic paper, inverting the black and white, and making a negative film from it, the negative film will turn black, just as the dark ink does. Therefore, if you use this negative film to photo-etch a popular type of photoresist film that becomes insoluble when exposed to light, you can obtain a laser mask in which the metal layer of the characters is punched out, and then the laser beam can be applied from above. By irradiating it, it is possible to engrave dark ink letters on the surface of the workpiece.

(Effect of the invention) In short, in the present invention, the laser mask LM
Since the corrosion-resistant base film 1 is laminated on the mask material m, which is the material for making the mask, even if the metal layer 2 is punched out by photo-etching, the metal layer will be retained on the base film 1 and will not remain in pieces. Do not separate. Therefore, there is no need for a bridge to keep the template integral as in the past, so there are no design restrictions when making laser masks.In addition to this advantage, the present invention uses negative film 4 Since the laser mask LM is made by masking the image on the mask material m and using the photoetching method, it is possible to form a laser mask LM that is extremely faithful to the original.

Therefore, when this laser mask LM is placed on the workpiece and irradiated with a laser beam, the base film 1 exposed from the metal layer 2 and the surface of the workpiece under it are removed due to high heat, and the metal layer 2 The effect is that an extremely realistic pattern relief, just like the original, can be obtained on the blocked part of the workpiece.

In particular, in the present invention, the base film exposed from the metal layer of the laser mask LM is instantly removed by laser irradiation, so the upper part of the workpiece on the lower surface is completely opened during laser irradiation. Therefore, combustion gas from the workpiece due to laser irradiation can quickly diffuse outside the laser mask LM, and combustion gas does not enter between the workpiece and the laser mask LM. Therefore, in the present invention, even if the laser mask with a base film is superimposed on the surface of the workpiece, the combustion gas of the workpiece may displace the metal layer of the laser mask LM, or the surface of the workpiece may No soot,
It also has the effect of producing precise and beautiful engravings.

In this way, according to the present invention, line drawings such as characters can be embossed or engraved exactly as in the manuscript, so in the case of manuscripts written with a brush, even minute ink marks on the tip of the brush can be faithfully reproduced. It can be engraved, making it ideal for decorating the surface of the box with Chinese poems and sutras, or for engraving a handwritten name on a nameplate. In addition, the difference in light and shade can be widely used for engraving manuscripts, not only for letters but also for rubbings, fish prints, and ukiyo-e woodblocks.For example, a so-called handprint made by applying ink on a hand and stamping it on paper is used as a manuscript and then engraved with a laser beam. Then, even the minute wrinkles of the palm can be clearly reproduced and engraved on the processed surface.

[Brief explanation of the drawing]

1 to 5 are cross-sectional views showing each step of the engraving method according to the present invention. 1 is a base film, 2 is a metal layer, 3 is a photoresist film, 4 is a negative film, 5 is a workpiece, m
is the mask material, LM is the laser mask, and L is the laser beam.

Claims (1)

[Claims] 1 Form a mask material by laminating a photoresist film on the front surface of the metal layer and a corrosion-resistant base film on the back surface, and place a negative film on which a document has been photographed in advance on the photoresist film of the mask material. The metal layer of the mask material is punched out by photo-etching after being stacked on top of each other, thereby forming a laser mask in which a metal layer with the same pattern as the negative film held on the flat base film remains, and then the laser mask is is superimposed on the surface of the workpiece, and a laser beam is irradiated from above to remove the base film leaving the pattern formed on the metal layer, and at the same time, the pattern embossed on the surface of the workpiece is placed on the bottom surface. An engraving method using a laser beam characterized by forming.