JPH0760263B2 - Laser marking method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for marking a surface of a package mold or the like in a semiconductor device with characters such as a product classification symbol, quality or trademark by using a laser. It is a thing.

[Conventional technology]

Conventionally, as one of the methods for marking characters on the surface of a package mold in a semiconductor device using laser light, two masks made of a light shielding plate such as a stainless steel plate are used, and the first mask 10a is As shown in FIG. 6, a character forming light-shielding pattern 1 connected by narrow connecting pieces 12a on one or both of the upper side and the lower side of the character.
A pair of translucent patterns 13 to the left and right of the character, leaving 1a
While the a and 13a and the translucent pattern 14a for the inside of the character are punched out, the second mask 20a is formed on the second mask 20a as shown in FIG.
A pair of translucent patterns 21a, 21 for the upper and lower sides of the character
The laser light that has been punched out of a and transmitted through the transparent patterns 13a and 14a of the first mask 10a and the laser light that has transmitted through the transparent pattern 21a of the second mask 20a is produced as product 3
There is one in which the character 31a is marked on the surface of the product 30a as shown in FIG. 8 by irradiating the same position on the surface of 0a and changing the irradiation position of the laser light.

[Problems to be Solved by the Invention]

However, in this conventional laser marking method, if there is a positional deviation during setting between the first mask 10a and the second mask 20a, the marked character 31a will have a deformed shape.

That is, when the setting positions of the both masks 10a and 20a are displaced in the vertical direction of the character, the character 31a is displayed on one or both of the lower side and the upper side of the character 31a as shown in FIGS. 9 and 10. While a part is missing, the first mask 10 is formed on one or both of the upper side and the lower side of the character 31a.
Since the protrusion 31a 'by the narrow connecting piece 12a in a is a deformed character, the protrusion 31a' formed on one or both of the upper side and the lower side lowers the commercial value. , The character 31a may be misread as another character.

Therefore, in the conventional laser marking method, the character 31
In order to prevent a from becoming a deformed character with the protrusion 31a ', it is necessary to set the first mask 10a and the second mask 20a by strictly aligning them so that there is no displacement. So to this setting,
It requires a lot of trouble and skill, is very inefficient,
This brought about a significant increase in cost.

The present invention provides a laser marking method which solves the above-mentioned problems in the conventional laser marking method.

[Means for Solving the Problems]

In order to achieve this object, the present invention leaves a character forming light-shielding pattern connected to the first mask by a connecting piece on either one or both of the upper side and the lower side of the character,
At least a pair of translucent patterns for the left and right sides of the character are punched out, while a pair of translucent patterns for at least the upper side and the lower side of the character are punched out in the second mask, and the laser light transmitted from the translucent patterns in these two masks is cut off. In the laser marking method of irradiating the same place on the surface of the product, the character is formed into a character pattern drawn in a straight line, while the width dimension of the connecting piece in the first mask is set to the light shielding pattern in the first mask. It has a wide width equal to the width dimension of.

[Operation and effect of invention]

In this way, when the characters are formed in the character pattern drawn in a straight line, and the width dimension of the connecting piece in the first mask is configured to be as wide as the width dimension of the light shielding pattern,
When setting both masks, when the two masks are displaced in the vertical direction, the character has a wide upper side and a narrower lower side, or a narrower upper side and a wider lower side. Therefore, it is possible to prevent the protrusion from being formed on one or both of the upper side and the lower side of the character due to the narrow width connecting piece as in the conventional case described above.

Therefore, according to the present invention, for products such as semiconductor devices,
This has the effect of marking beautiful characters without causing misreading.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.
In the figure, reference numeral 10 denotes a first mask made of a light shielding plate such as a stainless steel plate, and reference numeral 20 in FIG. 2 denotes a second mask also made of a light shielding plate such as a stainless steel plate.

In the first mask 10, the light-shielding pattern 11 for forming the outer peripheral contour of the character is left, and the light-transmitting patterns 13 and 13 and the light-transmitting pattern 14 for the inside of the character are punched out. , For example, while forming a character pattern drawn in a straight line, such as a character used in a calculator, the width of the connecting pieces 12, 12 for one or both of the upper side and the lower side of the light-shielding pattern 11. The dimension S1 is set to be as wide as the width dimension S of the light shielding pattern 11.

On the other hand, in the second mask 20, as in the conventional case, a pair of translucent patterns 21, 21 for the upper and lower sides of a character are punched out.

Then, the translucent patterns 13 and 14 in the first mask 10
The more transmitted laser light and the laser light transmitted from the light transmitting pattern 21 of the second mask 20 are applied to the same portion on the surface of the product 30.

Then, on the surface of the product 30, as shown in FIG. 3, it is possible to mark characters 31 in a pattern drawn in a straight line as used in a so-called calculator.

In this case, the connecting piece in the first mask 10
By configuring the width dimension S1 of 12, 12 to be as wide as the width dimension S of the light-shielding pattern 11, when the setting positions of both masks 10, 20 are displaced in the vertical direction of the character, the character 31 As shown in FIG. 4, the width of the upper side is wide and the width of the lower side is narrow, or, as shown in FIG. 5, the width of the upper side is narrow and the width of the lower side is wide. It is possible to prevent the protrusion 31a 'from being formed on the upper side and / or the lower side of the character 31a due to the narrow connecting piece 12a as in the conventional case described above.

It should be noted that the above embodiment has shown the case of marking a number, but it goes without saying that the present invention can be applied not only to the case of this number but also to marking a character such as an alphabet. Further, the translucent pattern 14 for the inside of the character may be provided on the second mask 20 instead of being provided on the first mask 10 as in the above embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG. 5 show an embodiment of the present invention, and FIG.
Plan view of the mask, FIG. 2 is a plan view of the second mask, FIG.
FIG. 4, FIG. 5 and FIG. 5 are views showing the form of the marked characters, FIG. 6 to FIG. 10 show the conventional case, FIG. 6 is a plan view of the first mask, and FIG. Plan view of the mask, 8th
FIG. 9, FIG. 9 and FIG. 10 are views showing the forms of marked characters. 10 …… First mask, 11 …… Shading pattern, 12 …… Connecting piece, 13 …… Transparent pattern, 20 …… Second mask, 21 …… Transparent pattern, 30 …… Product, 31 …… Character.

Claims (1)

[Claims] 1. A pair of light-transmitting patterns for at least the left and right sides of a character are punched out while leaving a character forming light-shielding pattern connected to a first mask by a connecting piece on one or both of the upper side and the lower side of the character. On the other hand, a laser marking method in which a pair of translucent patterns for at least the upper side and the lower side of a character are punched out on the second mask and the laser light transmitted from the light shielding patterns of these two masks is applied to the same position on the surface of the product. In addition, while forming the character in a character pattern drawn by a straight line, the width dimension of the connecting piece in the first mask is configured to be a wide width equal to the width dimension of the light shielding pattern in the first mask. And laser marking method.