JPH0929931A - Flux printing apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flux printing apparatus easy to print even flux extremely high in viscosity on precoated solder. SOLUTION: A flux printing apparatus is equipped with the mask 4 superposed on a base plate 3 and having pattern apertures 4a permitting flux F to pass bored therein, the squeegee 14 sliding on the mask 4 to scrape up the flux F to print the same on the base plate 3 through pattern apertures 4a, the support plate 9 supporting the squeegee 14, the motor 7 moving the support plate 9 horizontally and the nozzle 21 and lamps 22, 23 heating the fronts of squeegees 14, 15 in the moving direction thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flux printing apparatus suitable for printing flux on solder precoated on electrodes of a substrate.

[0002]

2. Description of the Related Art Conventionally, there is a flux printing apparatus which pre-coats electrodes on a substrate with a solder pre-coating method and prints a flux on the solder. Here, after the flux is printed by this flux printer,
Electronic components are mounted on the solder. However, the surface of the pre-coated solder has a curved surface, and when the electronic component is mounted, the electronic component may slip on the solder and cause a positional shift.

[0003]

In order to prevent this displacement, it is advisable to increase the viscosity of the flux to be printed and to suppress the movement of electronic parts by the adhesive force of the flux.

Here, in the conventional flux printing apparatus,
The flux is printed directly on the precoated solder. Therefore, if the viscosity of the flux is increased in order to prevent the displacement of the electronic components, printing cannot be performed. Therefore, at present, a flux of about 1,000,000 cps is used.

However, there is a problem in that such a viscosity cannot effectively prevent the above-mentioned displacement of the electronic component.

[0006] Therefore, an object of the present invention is to provide a flux printing apparatus that is easy to print on precoated solder even if the flux has a very high viscosity.

[0007]

SUMMARY OF THE INVENTION A flux printing apparatus according to the present invention comprises a mask which is superposed on a substrate and has a pattern hole through which the flux passes, and a flux which is slid on the mask to pull the flux through the pattern hole. A squeegee that prints the flux on the substrate, a support plate that supports the squeegee, a moving unit that horizontally moves the support plate, and a heating unit that heats the front side in the moving direction of the squeegee are provided.

[0008]

With the above structure, the flux is printed on the substrate through the pattern holes formed in the mask.
At this time, the flux squeezed by the squeegee is heated by the heating means, and the viscosity of the flux is considerably reduced from the viscosity at room temperature, and printing becomes easy. Therefore, even if a flux having a very high viscosity is used at room temperature, it is possible to print smoothly on the substrate.

[0009]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a side view of a flux printer according to an embodiment of the present invention. In FIG. 1, 1 is a box provided to surround the entire flux printing apparatus from the outside, 2 is a substrate holder provided under the box 1 for holding a substrate 3, and 4 is superposed on the upper surface of the substrate 3 from above. It is a mask, and the mask 4 has a pattern hole 4a formed at a position where the flux F should be applied. Pattern hole 4a
The flux F is printed on the substrate 3 via the. A mask holder 5 supports the mask 4.

A horizontal feed screw 6 is rotatably supported on the upper portion of the box 1, and 7 is a motor as a moving means for rotating the feed screw 6. Reference numeral 8 is a feed nut which is screwed into the feed screw 6 and whose lower portion is connected to a horizontal support plate 9. Therefore, when the motor 7 is driven, the support plate 9
Can be moved in the horizontal direction (arrow N) in FIG.

Numerals 10 and 11 are cylinders which are erected on the support plate 9 with a certain space therebetween.
Vertical rods 12 and 13 are vertically inserted into each of them. Reference numerals 14 and 15 denote squeegees fixed to the lower portions of the rods 12 and 13 so as to incline, and in FIG. 1, the squeegee 14 descends and slides on the upper surface of the mask 4 to scrape the flux F. . In addition, 1
Reference numerals 6 and 17 are stoppers that are fixed to the upper portions of the rods 12 and 13, and their lower portions contact the cylinders 10 and 11, thereby defining the lower limit positions of the rods 12 and 13, that is, the squeegees 14 and 15.

Reference numeral 18 denotes a hot air generating section provided outside the box 1 for discharging hot air. The hot air is sent to the squeegee 14 from the hot air generating section 18 through the pipe 19, the joint 20 on the support plate 9 and the nozzle 21. Flux F
Is injected in the immediate vicinity of and the flux F is directly heated. Reference numeral 22 denotes a lamp which is disposed below the support plate 9 between the nozzle 21 and the rod 13 and which directly irradiates the flux F attracted by the squeegee 14 with heat rays.
Similarly, when the squeegee 15 descends and draws the flux F, the lamp 23 arranged symmetrically with the lamp 22.
The heat ray is irradiated from the above to heat the flux F.

Here, the flux F is usually 7 ° C to 8 ° C.
When the temperature rises, the viscosity becomes half, and when heated from the normal temperature of 25 ° C to about 50 ° C, the viscosity decreases to about 1/10. Therefore, even if a flux having a viscosity much higher than a flux having a viscosity of about 1,000,000 cps (a flux that can be used in a conventional flux printer) is used,
By blowing hot air from the nozzle 21 and radiating heat rays from the lamp 22 to raise the temperature of the flux F,
The viscosity of the flux F, which has a very high viscosity at room temperature, is remarkably lowered, and printing can be smoothly performed in this state. Here, as the heating means, only the nozzle 21 or only the lamp 22 may be adopted, and the flux F may be heated only by the nozzle 21 or only the lamp 22.

Of course, the substrate 3 is taken out of the flux printing apparatus after the printing of the flux is completed,
Since the temperature of the substrate returns to about room temperature, when electronic components are mounted in the subsequent process, the viscosity of the flux becomes a very high level again, and the displacement of the electronic components can be sufficiently suppressed.

[0016]

According to the flux printing apparatus of the present invention, a mask is provided on the substrate, which is superposed on the substrate and has a pattern hole through which the flux passes. Since the squeegee for printing, the support plate for supporting the squeegee, the moving means for horizontally moving the support plate, and the heating means for heating the front side in the moving direction of the squeegee are provided, the flux to be printed on the substrate is effectively It can be printed by heating it to a reduced viscosity. Therefore, it is possible to perform printing using a flux having a very high viscosity at room temperature, and it is possible to effectively prevent the displacement of the electronic component when the electronic component is mounted on the substrate in a subsequent process.

[Brief description of drawings]

FIG. 1 is a side view of a flux printer according to an embodiment of the present invention.

[Explanation of symbols]

 3 Substrate 4 Mask 4a Pattern Hole 7 Motor 9 Support Plate 14 Squeegee 21 Nozzle 22 Lamp 23 Lamp F Flux

Claims (4)

[Claims] 1. A mask having a pattern hole formed on a substrate for allowing flux to pass therethrough, a squeegee that slides on the mask to attract flux to print the flux on the substrate through the pattern hole, and the squeegee. A flux printing apparatus, comprising: a support plate that supports the squeegee, a moving unit that horizontally moves the support plate, and a heating unit that heats the front side in the moving direction of the squeegee. 2. The heating means is connected to a hot air generating section,
3. A nozzle for ejecting hot air is included.
The described flux printing device. 3. The flux printing apparatus according to claim 1, wherein the heating means includes a lamp for irradiating the flux attracted to the squeegee with heat rays. 4. A flux printing method in which a mask is superposed on a substrate, a squeegee is slid on the mask, and a flux is printed on the substrate through a pattern hole formed in the mask, the flux being scraped onto the squeegee. A method of printing flux, comprising heating the flux as described above.