JP2002321337A - Screen printing device, screen printing method and mask plate for screen printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen printing device, a screen printing method and a mask plate for screen printing that secures good snap off property even if different size of electric parts are put together. SOLUTION: In a mask plate 7 for screen printing used for the screen printing that prints a cream solder on a substrate, a pattern hole 7b for an ordinary size of part penetrated in the thickness direction having the same shape as a first opening part 14 and a pattern hole for a fine pitch part having the cream solder crammed through a second opening hole 15 and an escape part preventing touch with the inside of the pattern hole 7a below a second opening hole 15 formed with smaller size than the first opening hole 14 are provided. Thereby, good snap off property is secured even if the different size of electric parts are put together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing apparatus for printing cream solder on a substrate on which electronic components are mounted, a screen printing method, and a mask plate for screen printing.

[0002]

2. Description of the Related Art In mounting electronic components by soldering, a screen printing method is widely used as a method for supplying solder to electrodes on a substrate. In this method, cream solder is printed on the electrode surface through the pattern holes by moving a squeegee on the mask plate using a mask plate provided with pattern holes according to the electrode arrangement.

[0003] By the way, there are various kinds of electronic components mounted by soldering. In recent years, BGAs are mounted on the same mounting substrate.
Increasingly, large electronic components such as (Ball Grid Array) and micro-sized chip-type components are mixedly mounted. When manufacturing a mask plate used for screen printing on such a mounting board, first, the thickness of the mask plate is determined based on the amount of solder required for soldering a large electronic component, and the thickness of the mask plate on the board is determined. Pattern holes are arranged according to the electrode arrangement of these electronic components. When providing pattern holes for printing cream solder on the electrodes for solder bonding of the microchip on the same mask plate, the pattern holes are formed based on an appropriate amount of solder for soldering these microelectronic components. The opening size is determined.

[0004]

However, since the proper amount of solder for soldering a small chip is smaller than the amount of solder for a large component, the appropriate amount of solder is small for the pattern holes provided in the mask plate of the same thickness. The opening size is smaller than that of the related art, so that the ratio of the opening size to the thickness dimension in the pattern hole for a microchip becomes smaller. As a result, after the cream solder is printed on the substrate through the pattern holes, there is a problem in that the print-out property when separating the substrate from the mask plate is deteriorated, and good printing cannot be performed.

Accordingly, an object of the present invention is to provide a screen printing apparatus, a screen printing method, and a mask plate for screen printing, which can ensure good plate removal when electronic components of different sizes are mixedly mounted. And

[0006]

According to a first aspect of the present invention, there is provided a screen printing apparatus for printing cream solder on a substrate on which an electronic component is mounted, through a pattern hole provided in a mask plate. A substrate positioning portion that holds the substrate and positions it with respect to the mask plate, and a squeegee that pushes cream solder into the pattern holes by sliding on the mask plate,
Moving means for sliding the squeegee on the mask plate, wherein the mask plate has a first opening formed in the upper surface of the mask plate and having the same shape as the first opening and penetrating in the thickness direction. Opening type pattern holes,
A second opening formed in a size smaller than the first opening;
A second opening type pattern hole in which a relief portion for preventing contact between the cream solder pushed through the second opening portion and the inner surface of the pattern hole is formed below the second opening portion; Is provided.

According to a second aspect of the present invention, there is provided a screen printing apparatus for printing cream solder through a pattern hole provided in a mask plate on a substrate on which electronic components are mounted. A substrate positioning portion for positioning with respect to the mask plate, a squeegee for pushing cream solder into the pattern holes by sliding on the mask plate, and a moving means for sliding the squeegee on the mask plate. A first opening type pattern hole having the same shape as an opening shape of a first opening portion formed on an upper surface of the mask plate and penetrating in a thickness direction; A second opening formed in a smaller size than the hole, having a solder introduction portion having the same shape as that of the second opening and having a predetermined penetration depth; A second opening types of the pattern holes relief portion is formed to prevent contact with the inner surface of the cream is pushed through the solder inlet portion solder and pattern holes are provided in.

According to a third aspect of the present invention, there is provided a screen printing method for printing cream solder on a substrate on which an electronic component is mounted via a pattern hole provided in a mask plate. A substrate positioning step of positioning with respect to the mask plate, and a squeezing step of pushing cream solder into the pattern holes by sliding a squeegee on the mask plate, wherein the mask plate includes A first hole type pattern hole having the same shape as the first hole portion formed on the upper surface and penetrating in the thickness direction, and a second hole formed in a size smaller than the first hole portion. An escape portion is formed below the opening of the pattern hole to prevent the cream solder pushed in through the second opening from coming into contact with the inner surface of the pattern hole. A second opening types of the pattern holes are formed.

According to a fourth aspect of the present invention, there is provided a screen printing method for printing cream solder on a substrate on which an electronic component is mounted via a pattern hole provided in a mask plate. A substrate positioning step of positioning with respect to the mask plate, and a squeezing step of pushing cream solder into the pattern holes by sliding a squeegee on the mask plate, wherein the mask plate includes A first opening type pattern hole having the same shape as the opening shape of the first opening portion formed in the upper surface and penetrating in the thickness direction, and a second opening formed in a size smaller than the first opening portion. 2 has a solder introduction portion having the same shape as the opening shape of the opening portion and having a predetermined penetration depth, and is inserted under the solder introduction portion through the solder introduction portion. A second opening types of the pattern holes is provided with relief portion to prevent contact with the inner surface of the chromatography solderless and pattern holes are formed.

A screen printing mask plate according to a fifth aspect of the present invention is a screen printing mask plate used for screen printing for printing cream solder on a substrate on which electronic components are mounted, and is formed on an upper surface of the mask plate. A first hole type pattern hole having the same shape as the first hole portion formed and penetrating in the thickness direction, and a second hole formed in a size smaller than the first hole portion. A second opening type pattern hole provided with a relief portion for preventing contact between the cream solder pushed in through the second opening portion and the inner surface of the pattern hole is provided below the portion. ing.

The mask plate for screen printing according to claim 6 is a mask plate for screen printing used for screen printing for printing cream solder on a substrate on which electronic components are mounted, and is formed on the upper surface of the mask plate. A first opening type pattern hole having the same shape as the opening shape of the first opening portion penetrated in the thickness direction, and a second opening formed in a size smaller than the first opening portion. A solder introduction portion having the same shape as the opening shape of the hole portion and having a predetermined penetration depth is provided. Prevention of contact between the cream solder pushed in through the solder introduction portion below the solder introduction portion and the inner surface of the pattern hole. And a second hole type pattern hole in which a relief portion is formed.

According to the present invention, there is provided an opening-type pattern hole for a large component having the same shape as the opening on the upper surface of the mask plate and penetrating in the thickness direction, and the opening provided below the opening. By providing, on the same mask plate, an opening-type pattern hole for a microchip in which a relief portion for preventing contact between the cream solder pushed in through the inside and the inner surface of the pattern hole is formed. Even in a case where electronic components are mixedly mounted, it is possible to secure a good plate removal property.

[0013]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a front view of a screen printing apparatus according to one embodiment of the present invention, FIG. 2 is a partial cross-sectional view of the screen printing apparatus according to one embodiment of the present invention, and FIG. 3 is screen printing according to one embodiment of the present invention. FIGS. 4, 5, and 6 are partial cross-sectional views of a mask plate for screen printing, illustrating the shape of pattern holes in a mask plate for screen printing according to an embodiment of the present invention.

First, a screen printing apparatus will be described with reference to FIG. In FIG. 1, the substrate positioning unit 1
A Y-axis table 2, an X-axis table 3, and a Z-axis table 4 are stacked, and a substrate 6 is held by a clamper 5 of a substrate holding unit provided on the Z-axis table 4. FIG. 1 shows a state where the Z-axis table 4 is raised and the substrate 6 is in contact with the lower surface of the mask plate 7.

Above the mask plate 7, a squeegee head 10 is provided. The squeegee head 10 has two cylinders 12 arranged in a vertical position on a horizontal base portion 11, and a lower end of two rods 12a protruding downward.
The squeegees 13A and 13B are held respectively. The squeegee head 10 is moved in the horizontal direction by moving means (not shown), and the squeegees 13A and 13B are raised and lowered by driving the cylinder 12, and the squeegees 13A and 13B are pressed against the upper surface of the mask plate 7 in the lowered state.

While one of the squeegees 13A, 13B is pressed against the mask plate 7, the squeegee head 10
Are moved in the respective squeegee directions of the squeegees 13A and 13B (see arrows a and b) to push the cream solder into the pattern holes formed in the mask plate 7. Then, the cream solder is transferred to the electrodes formed on the substrate 6 to perform screen printing on the substrate 6.

Next, pattern holes provided in the mask plate 7 will be described. As shown in FIG. 2, the mask plate 7 has two types of pattern holes 7a and 7 having different shapes.
b is provided. As shown in FIG.
Reference numerals a and 7b have different shapes for printing cream solder on the electrodes 6a and 6b to which different types of electronic components are to be soldered, and the electrode 6b requires a relatively large amount of solder for soldering. Types of electronic components and the electrodes 6
Electronic components with a small amount of solder, such as fine pitch chip-type components, are soldered to a.

The shapes of these pattern holes will be described. As shown in FIG. 3, the pattern holes 7b are formed on the upper surface of the mask plate 7 having a thickness T by opening holes 14 having a hole diameter D1.
The first opening portion has the same shape as the first opening portion and is formed so as to penetrate in the thickness direction (first opening type). In contrast,
The pattern hole 7a has a hole diameter D1 as shown in FIG.
It has a shape having a large diameter portion 16 formed with a hole diameter D3 larger than D2 below an opening portion 15 (second opening portion) formed with a smaller hole diameter D2 (second hole). Opening type).

At the time of screen printing, FIG.
As shown in the figure, the cream solder 8 pushed in through the opening 15 by the squeegee 13 is pushed out into the large-diameter portion 16 and then descends without contacting the inner surface of the large-diameter portion 16. It reaches the surface of the electrode 6a. That is, the large diameter portion 1
Reference numeral 6 denotes an escape portion for preventing the cream solder 8 pushed in through the opening 15 at the time of printing from coming into contact with the inner surface of the pattern hole 7a.

With this arrangement, after the squeegee, the substrate 6 is separated from the lower surface of the mask plate 7 and the cream solder 8 in the pattern hole 7a is transferred to the electrode 6a. There is no plate dropout defect that remains with the toner attached. That is, when the normal size component and the fine pitch component are mixed and loaded, even when the hole diameter D2 is set to be smaller than the thickness T of the mask plate 7, it is possible to secure a good plate removal property.

As a second hole type, the pattern hole 7a 'may have a shape as shown in FIG.
Here, a solder introduction portion 18 having the same shape as the opening shape of the opening portion 17 (second opening portion) formed with the hole diameter D2 smaller than the hole diameter D1 and having a predetermined penetration depth T1 is formed. A shape having a large-diameter portion 16 ′ formed with a hole diameter D3 larger than D2 below the introduction portion 18 (second opening type). Here, the penetration depth T1 is set in relation to the hole diameter D2 so as to optimize the introduction of the cream solder 8 during squeezing.

At the time of screen printing, FIG.
As shown in the figure, the cream solder 8 pushed in by the squeegee 13 via the solder introduction part 18 is
The shape is maintained when descending, and after being extruded into the large diameter portion 16 ', it descends without losing its shape and reaches the surface of the electrode 6a. Also in this case, the large diameter portion 16 ′
It serves as a relief portion for preventing the pushed cream solder 8 from coming into contact with the inner surface of the pattern hole 7a '.

Thus, as in the case described above, the cream solder 8 is provided on the inner surface of the pattern hole 7a 'when the plate is removed.
Can be prevented, and the solder introduction section 18 can prevent the cream solder 8 from breaking down, so that the amount of solder transferred to the electrode 6a can be set accurately.

As shown in FIG. 6, a plurality of pattern holes 7a may be provided for one electrode 6a. In this case, the arrangement of the pattern holes 7a is as shown in FIG.
As shown in (c), a matrix arrangement or a staggered arrangement can be used. By employing such an aperture type, the amount of solder can be set with high accuracy.

[0025]

According to the present invention, an opening-type pattern hole for a large part, which has the same shape as the opening on the upper surface of the mask plate and penetrates in the thickness direction, and a squeegee below the opening. Since the pattern hole of the opening type for the micro chip, in which a relief part for preventing the pushed cream solder and the inner surface of the pattern hole from contacting with each other, is formed on the same mask plate, Even in a case where electronic components are mixedly mounted, it is possible to secure a good plate removal property.

[Brief description of the drawings]

FIG. 1 is a front view of a screen printing apparatus according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the screen printing apparatus according to one embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a mask plate for screen printing according to an embodiment of the present invention.

FIG. 4 is an explanatory view of a shape of a pattern hole of a mask plate for screen printing according to an embodiment of the present invention.

FIG. 5 is an explanatory view of a shape of a pattern hole of a mask plate for screen printing according to an embodiment of the present invention.

FIG. 6 is an explanatory view of a shape of a pattern hole of a mask plate for screen printing according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate positioning part 6 Substrate 6a, 6b electrode 7 Mask plate 7a, 7a ', 7b Pattern hole 8 Cream solder 13, 13A, 13B Squeegee 14, 15, 17 Opening part 16, 16' Large diameter part 18 Solder introduction part

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) H05K 3/34 505 H05K 3/34 505C 505D F term (reference) 2C035 AA06 FA27 FA31 FB24 FC08 FD01 FD19 FE01 FF00 2H084 AA26 BB01 BB02 BB13 CC10 CF03 CF06 2H114 AA04 AB11 AB15 AB17 EA04 EA08 5E319 AA03 AB05 AC01 AC11 BB05 CC33 CD29 GG15

Claims (6)

[Claims] 1. A screen printing apparatus for printing cream solder through a pattern hole provided in a mask plate on a substrate on which electronic components are mounted, wherein the screen printing device holds the substrate and positions the substrate with respect to the mask plate. A substrate positioning portion, a squeegee for pushing the cream solder into the pattern hole by sliding on the mask plate, and moving means for sliding the squeegee on the mask plate; A first opening type pattern hole having the same shape as the first opening portion formed on the upper surface of the mask plate and penetrating in the thickness direction, and having a size smaller than the first opening portion; A relief portion is formed below the second opening to prevent contact between the cream solder pushed through the second opening and the inner surface of the pattern hole. Screen printing apparatus characterized by a second opening types of the pattern holes are formed. 2. A screen printing apparatus for printing cream solder through a pattern hole provided in a mask plate on a substrate on which electronic components are mounted, wherein the screen printing device holds the substrate and positions it with respect to the mask plate. A substrate positioning portion, a squeegee for pushing the cream solder into the pattern hole by sliding on the mask plate, and moving means for sliding the squeegee on the mask plate; A first opening type pattern hole having the same shape as the opening shape of the first opening portion formed on the upper surface of the mask plate and penetrating in the thickness direction, and having a size smaller than the first opening portion; A solder introduction portion having the same shape as the opening shape of the formed second opening portion and having a predetermined penetration depth is inserted below the solder introduction portion through the solder introduction portion. Screen printing apparatus characterized by a second opening types of the pattern holes relief portion is formed to prevent contact with the inner surface of the chromatography solderless and pattern holes are formed. 3. A screen printing method for printing cream solder on a substrate on which an electronic component is mounted via a pattern hole provided in a mask plate, wherein the substrate is held and positioned with respect to the mask plate. Substrate positioning step, including a squeezing step of pushing cream solder into the pattern hole by sliding a squeegee on the mask plate, wherein the mask plate,
A first opening type pattern hole having the same shape as the first opening portion formed on the upper surface of the mask plate and penetrating in the thickness direction, and having a size smaller than the first opening portion; A second opening type in which a relief portion is formed below the second opening to prevent contact between the cream solder pushed through the second opening and the inner surface of the pattern hole. A screen printing method characterized by having pattern holes. 4. A screen printing method for printing cream solder through a pattern hole provided in a mask plate on a substrate on which electronic components are mounted, wherein said substrate is held and positioned with respect to said mask plate. Substrate positioning step, including a squeezing step of pushing cream solder into the pattern hole by sliding a squeegee on the mask plate, wherein the mask plate,
A first opening type pattern hole having the same shape as the opening shape of the first opening portion formed on the upper surface of the mask plate and penetrating in the thickness direction, and having a size smaller than the first opening portion; A solder introduction portion having the same shape as the opening shape of the formed second opening portion and having a predetermined penetration depth, the cream solder pushed in through the solder introduction portion below the solder introduction portion and the inner surface of the pattern hole; With a relief part to prevent contact with
And a pattern hole of the opening type. 5. A mask plate for screen printing used for screen printing for printing cream solder on a substrate on which an electronic component is mounted, wherein a shape of a first opening formed on an upper surface of the mask plate is determined. A first hole-type pattern hole having the same shape and penetrating in the thickness direction, and a second hole formed below a second hole formed with a size smaller than the first hole. A second opening-type pattern hole provided with a relief portion for preventing contact between the cream solder pushed in through the hole and the inner surface of the pattern hole. Mask plate. 6. A mask plate for screen printing used for screen printing for printing cream solder on a substrate on which electronic components are mounted, wherein an opening shape of a first opening formed on an upper surface of the mask plate. A first hole type pattern hole penetrating in the thickness direction with the same shape as that of the first hole portion, and a predetermined hole having the same shape as the opening shape of the second hole portion formed with a size smaller than the first hole portion; A second opening having a solder introduction portion having a depth, and a relief portion formed under the solder introduction portion to prevent contact between the cream solder pushed through the solder introduction portion and the inner surface of the pattern hole. A mask plate for screen printing characterized by having a pattern hole of a type.