JPH08204321A - Method and apparatus for printing solder - Google Patents

Abstract

PURPOSE: To miniaturize and enhance in accuracy a print by printing with high quality and easily altering a print pattern. CONSTITUTION: An electrostatic drum 12 made of an optical semiconductor is provided, and freely rotated in a direction of an arrow A. A charger 13 for uniformly charging the surface of the drum 12 at a predetermined potential, a laser beam emitting unit 14 for emitting a laser beam to the surface of the drum based on the data of a predetermined print pattern to a board 17 to form an electrostatic latent image, a powder solder supply unit 15 for adhering the fine particlelike powder solder 18 to the surface of the drum 12 corresponding to the image, and a transfer unit 16 for transferring the solder 18 by bringing the board 17 into contact with the drum 12 in a direction of an arrow B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder printing method and apparatus for printing solder on a substrate in a predetermined printing pattern.

[0002]

2. Description of the Related Art As a device for printing solder on a printed circuit board, a cream solder printing device has been conventionally provided which applies cream solder to a printed circuit board through a screen mask. As shown in FIG. 2, the printed circuit board 2 placed on the backup unit 1 has a predetermined pattern of pores 3a (FIG. 3) on the upper surface thereof.
(Refer to FIG. 3) is arranged, and an appropriate amount of cream solder 4 is supplied onto the screen mask 3 to move the squeegee 5 while pressing the squeegee 5 against the screen mask 3. The cream solder 4 was printed through.

[0003]

However, the conventional cream solder printing apparatus described above has the following problems. That is, in the case where the screen mask 3 is used, as shown in FIG. 3, the cream solder 4 is likely to remain on the edges of the pores 3a, and the cream solder 4 applied on the printed circuit board 2 by the subsequent printing operation. There is a possibility that the quality of the product may deteriorate due to whom. Then, when changing the print pattern of the solder, it is necessary to replace the screen mask 3, and the setup change is troublesome.

In addition, with the recent miniaturization and higher precision of electronic equipment, there is a demand for finer and higher precision solder printing patterns as well.
In the cream solder printing apparatus using the above, there is a limit to finer printing and higher accuracy. In addition, there is a demerit of using the cream solder 4 itself such that the cream solder 4 needs to be stirred before use.

The present invention has been made in view of the above circumstances. An object of the present invention is to perform high-quality printing without solder dripping, etc., and to easily change a print pattern. The present invention is to provide a solder printing method and an apparatus therefor capable of finer printing and higher accuracy.

[0006]

A solder printing method according to the present invention is a method for printing solder on a substrate in a predetermined printing pattern, wherein data of the printing pattern is printed on a charged photoconductor. A step of forming an electrostatic latent image on the photoconductor by shining light on the basis of the light; a step of adhering fine-particle powder solder corresponding to the electrostatic latent image on the photoconductor; The method is characterized in that the step of transferring the powdered solder attached to the body to the substrate is executed.

The solder printing apparatus of the present invention is an apparatus for printing solder on a substrate in a predetermined printing pattern, and includes a photoconductor, a charging unit for uniformly charging the photoconductor, and Exposure means for applying light to the photoconductor charged by the charging means based on the data of the print pattern to form an electrostatic latent image, and fine particles corresponding to the electrostatic latent image on the photoconductor. The present invention is characterized in that it comprises a developing means for adhering the powdered solder of 1) and a transfer means for transferring the powdered solder adhered on the photoconductor to the substrate.

[0008]

The present inventor replaces the paste-like cream solder used in the conventional solder printing with the fine solder powder in the form of fine powder so that the solder used in the copying machine, the printer, etc. The present invention has been accomplished by confirming that they can be handled in the same manner and can be printed by using the same principle as the electrophotographic process.

That is, according to the solder printing method of the present invention, by applying the light to the charged photoconductor, the solder is printed on the photoconductor by utilizing the property that the charge is discharged only in the exposed part. An electrostatic latent image corresponding to the print pattern to be formed can be formed, and if fine particle powder solder is attached to the electrostatic latent image, a pattern of the powder solder corresponding to the print pattern is formed on the photoconductor. Can be formed,
Furthermore, by transferring the powdered solder to the substrate, the solder can be printed on the substrate in a predetermined print pattern.

In this case, since the powdered solder is transferred from the photosensitive member to the substrate, no solder dripping or deviation occurs, and no screen mask is used. Therefore, when changing the printing pattern. No troublesome replacement work is required, just change the data when shining light. Further, as compared with the case where a screen mask is used, finer printing and higher accuracy can be achieved.

Further, according to the solder printing apparatus of the present invention, the photosensitive member charged by the charging unit is irradiated with light from the exposing unit based on the data of the printing pattern to form an electrostatic latent image. . Then, the developing means attaches the fine powder solder to the electrostatic latent image on the photoconductor to form a pattern of the powder solder corresponding to the print pattern on the photoconductor. Then, the powder solder on the photoconductor is transferred to the substrate by the transfer means, so that the solder is printed on the substrate in a predetermined print pattern.

In this case, since the powdered solder is transferred from the photosensitive member to the substrate, no solder dripping or misalignment occurs, and no screen mask is used. No troublesome replacement work is required, just change the data when shining light. Further, as compared with the case where a screen mask is used, finer printing and higher accuracy can be achieved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 schematically shows a main part configuration of a solder printing apparatus 11 according to the present embodiment. Here, the solder printing apparatus 11 is roughly divided into an electrostatic drum 12 as a photoconductor and a peripheral portion thereof. , Charger 1 as charging means
3, a laser beam irradiation device 14 as an exposure device, a powder solder supply device 15 as a developing device, a transfer device 16 as a transfer device, and the like.

Of these, the electrostatic drum 12 has its outer peripheral surface exhibiting insulation (high resistance) in a state where it is not exposed to light,
It is composed of a photoconductor that exhibits conductivity when exposed to light, and is freely rotated in the direction of arrow A in the figure by a drive mechanism (not shown). The charger 13 is configured to uniformly charge the surface of the electrostatic drum 12 at a predetermined potential by, for example, corona discharge.

The laser light irradiation device 14 is provided ahead of the charger 13 in the rotation direction of the electrostatic drum 12,
Although not shown in detail, for example, a semiconductor laser oscillator, a modulator, a deflector including a polygon mirror, a lens, and the like are provided. Then, the surface of the electrostatic drum 12 is irradiated with laser light based on data of a predetermined print pattern (data of a position where solder printing should be performed) on the substrate 17.

The powder solder supply device 15 is provided ahead of the laser beam irradiation device 14 in the rotation direction of the electrostatic drum 12, and a container 19 for accommodating the powder solder 18 in the form of fine particles.
And an attachment mechanism 20 including a plurality of rollers for applying an electric charge to the solder powder 18 from the container 19 and attaching the charge to the surface of the electrostatic drum 12.

Then, the transfer device 16 transfers the substrate 17 in the horizontal direction (direction of arrow B) to the substrate transfer mechanism 21, and the substrate 17 is placed on the opposite pole to the powder solder 18 attached to the electrostatic drum 12. A transfer charger 22 for charging is provided. At this time, the substrate 17 comes into contact with the electrostatic drum 12 at a position ahead of the attachment mechanism 20 in the rotation direction of the electrostatic drum 12, and the electrostatic drum 12 relatively rolls on the substrate 17 without slipping. It is designed to move.

Although not shown, the solder printing device 11 further includes a powder solder 18 printed on the substrate 17.
A fixing mechanism for fixing the toner, a cleaning mechanism for cleaning the electrostatic drum 12, and the like are provided. Further, each of the above-mentioned mechanisms is controlled by a control device such as a microcomputer (not shown). At this time, the data of the above-mentioned print pattern is not shown in the CA.
It is provided by the D system.

Next, by the solder printing device 11 described above,
A procedure for printing the powdered solder 18 on the substrate 17 will be described. In printing the powdered solder 18 on the substrate 17 in a predetermined print pattern, first, a step of forming an electrostatic latent image on the electrostatic drum 12 is executed. In this step, the charger 13 is rotated while rotating the electrostatic drum 12 in the direction of arrow A.
The electrostatic drum 12 is uniformly charged by the laser beam irradiation device 14, and the charged portion of the electrostatic drum 12 is irradiated with the laser beam by the laser beam irradiation device 14 based on the data of the print pattern given from the CAD system. Done by. As a result, the charge is discharged only on the portion of the electrostatic drum 12 which is exposed to the laser beam, and an electrostatic latent image corresponding to the print pattern for printing the solder is formed on the electrostatic drum 12. .

Next, powder solder 18 is attached to the electrostatic drum 12.
The step of adhering is carried out subsequently. In this step, the powder solder supply device 15 applies an electric charge to the solder powder 18 with respect to the electrostatic drum 12 which is continuously rotated in the direction of the arrow A, so that an electrostatic latent image is formed on the surface of the electrostatic drum 12. Then, it is attached. As a result, the solder powder 18 is attached onto the electrostatic drum 12 according to the print pattern.

Then, the step of transferring the powdered solder 18 attached in a predetermined pattern on the electrostatic drum 12 to the substrate 17 is subsequently executed. In this step, the substrate transfer mechanism 21
While transferring the substrate 17 in the direction of arrow B in synchronism with the rotation of the electrostatic drum 12, the transfer charger 22 causes the substrate 17 to move.
Is charged, and in this state, the electrostatic drum 12 is relatively rolled on the substrate 17 without slipping. As a result, the powder solder 18 is printed on the substrate 17 in a predetermined print pattern.

The printing of the solder 18 on the board 17 is continuously performed on a plurality of boards 17.
Further, when the type of the substrate 17 (type of print pattern) is changed, the data when the laser beam is irradiated by the laser beam irradiation device 14 is changed.

As described above, according to this embodiment, the powder solder 1
Since 8 is transferred from the electrostatic drum 12 to the substrate 17, unlike the conventional cream solder printing apparatus using the screen mask 3, the solder 18 printed on the substrate 18 does not drip or shift. Absent. Also, the powdered solder 18
By using, it is possible to achieve finer printing and higher accuracy than in the case where the screen mask 3 is used.

Since the solder 18 can be printed by directly reading the data from the CAD system, it is not necessary to form the screen mask 3 according to the print pattern, and for example, on the substrate 17 of a small lot. In contrast, the solder printing work can be easily performed. In this case, when changing the print pattern,
Since it suffices to change the data when the light is applied by the laser light irradiation device 14, troublesome setup change work is not necessary, and the print pattern can be easily changed.

[0025]

As is apparent from the above description, according to the solder printing method and apparatus of the present invention, the solder printing method is used for printing the solder on the substrate in the predetermined printing pattern. It is possible to perform high-quality printing without equality, to easily change the print pattern, and to achieve the excellent practical effect of enabling finer printing and higher accuracy. is there.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention and is a diagram schematically showing a main part configuration of a solder printing apparatus.

FIG. 2 is a diagram showing a main part of a solder printing apparatus in a conventional example.

FIG. 3 is an enlarged vertical cross-sectional view showing how solder dripping occurs.

[Explanation of symbols]

In the drawings, 11 is a solder printing device, 12 is an electrostatic drum (photoreceptor), 13 is a charger (charging means), 14 is a laser beam irradiation device (exposure means), 15 is a powder solder supply device (developing means), 16 is a transfer device (transfer means), 17 is a substrate, 18
Is powder solder, 20 is an attachment mechanism, 21 is a substrate transfer mechanism, 2
Reference numeral 2 denotes a transfer charger.

Front page continuation (72) Inventor Akira Omori 1-24-30 Meieki Minami, Nakamura-ku, Nagoya, Aichi Prefecture Toshiba Chubu Branch Office

Claims (2)

[Claims] 1. A method for printing solder on a substrate in a predetermined print pattern, wherein light is applied to a charged photoconductor based on the data of the print pattern, and the photoconductor is printed on the photoconductor. A step of forming an electrostatic latent image on the photosensitive member, a step of adhering fine particle powder solder corresponding to the electrostatic latent image on the photoconductor, the powder solder adhered on the photoconductor to the substrate A solder printing method comprising performing a transfer step. 2. An apparatus for printing solder on a substrate in a predetermined print pattern, comprising a photoconductor, a charging unit for uniformly charging the photoconductor, and a photoconductor charged by the charging unit. An exposing means for irradiating light on the basis of the data of the print pattern to form an electrostatic latent image, and a developing means for adhering fine powder solder on the photoconductor corresponding to the electrostatic latent image. And a transfer means for transferring the powdered solder attached on the photoconductor to the substrate, the solder printing apparatus.