JPH0342515B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application This invention relates to a screen printing apparatus used for printing electrodes of thick film integrated circuits, etc.

B. Prior Art For example, one of the important processes in the production of thick film integrated circuit devices is the process of applying solder paste onto various patterns of a thick film integrated circuit substrate. This solder paste application is currently mainly performed by either the following dispenser method or screen printing method.

FIG. 1 shows the former dispenser method, in which solder paste 3 is applied onto a substrate 1 by a dispenser nozzle 2 in the form of a collection of dots or spots. FIG. 2 shows a screen printing method, in which a screen printing mask 4 is positioned and placed on the substrate 1, and the solder paste 3 supplied onto the mask 4 is spread with a squeegee 5 onto the substrate 1 through the mask 4. This is a method in which it is applied to the surface.

By the way, the dispenser method has the versatility of being able to adapt to changes in the solder application pattern on the board 1, but normal solder application patterns can be of various shapes, such as square or round, and have different areas, as shown in Figure 3. There are many patterns P ₁ , P ₂ ..., and when applying solder paste 3 to a particularly large area pattern among these various patterns P ₁ , P ₂ ... using a dispenser method, it is necessary to apply the solder paste 3 to the entire surface of the pattern. It takes a lot of time to do this, resulting in low work efficiency, and it is also extremely difficult to adjust the amount of application, making it unsuitable.

On the other hand, in the screen printing method, _the work efficiency is not affected even if the shape or area of the solder application patterns _{P 1 ,} P ₂ . Since the paste is applied all at once and the squeegee 5 is used, it has the advantage that the amount of application can be easily adjusted. However, if there is a change in the solder application pattern, it cannot be easily followed, resulting in poor flexibility, and especially in high-mix, low-volume production, many types of masks must be prepared, which is uneconomical. In addition, it is difficult to make adjustments such as partially varying the moving speed of the squeegee 5 that slides on the mask 4 to perform screen printing at the best squeegee speed according to various solder application patterns P ₁ , P ₂ .
There was still room for improvement in the finish.

C. Purpose of the Invention The present invention takes into consideration the drawbacks of both the dispenser method and the screen method, takes advantage of the advantages of each, and enables printing of many different printing patterns without having to prepare many types of printing masks. An object of the present invention is to provide a screen printing device capable of selectively printing.

D. Structure of the Invention The present invention is an apparatus using a screen printing method, which includes a vertically disposed outer ring formed by a plurality of screen printing masks for each of a plurality of types of screen printing patterns arranged integrally in a series in the circumferential direction; an outer ring drive unit that intermittently rotates the outer ring in the circumferential direction; a coating material replenishing unit that uses the rotation of the outer ring to deposit and supply a coating material for screen printing onto the inner surface of the mask of the outer ring in a fixed direction; The inner ring is arranged so as to be rotatable coaxially with the outer ring and pushes out the coating material adhering to the inner surface of the lower mask of the outer ring to the outer surface of the same mask when rotated, and an inner ring drive section that rotates the inner ring independently. The outer ring selectively rotates so that a mask corresponding to a change in the screen printing pattern on the printing material is placed at the bottom, and the printing material is screen printed with the selected mask at the bottom by rotation of the inner ring. If there are N types of printing patterns on the printing material, the outer ring rotates N times accordingly.
The printing material is selectively printed N times using N masks. By doing so, the high workability of ordinary screen printing can be utilized, and changes in printing patterns can be easily followed, and the versatility of the dispenser method can also be achieved.

E. Example The present invention is applied to a solder screen printing apparatus for the substrate 1, and will be explained from FIGS. 4 and 5.
Reference numeral 6 denotes a flexible outer ring rotatably installed vertically at a predetermined position above the horizontal conveyance path 7 for the substrate 1, and selectively rotates intermittently in a long oblong orbit up and down. 8,8...
denotes a plurality of screen printing masks integrated in series forming the peripheral surface of the outer ring 6, each having a different screen printing pattern Q ₁ , Q ₂ . Reference numeral 9 denotes an outer wheel drive unit that rotates the outer ring 6 intermittently, and includes, for example, an outer ring rotating roller 10 that is connected to the upper part of the outer ring 6 and feeds the outer ring 6, and a first motor 11 that rotates the roller. Reference numeral 12 denotes a coating material replenishing part which is disposed at a fixed position inside the outer ring 6 and supplies solder paste 3, which is a coating material for printing, from a fixed direction to the inner surfaces of a series of masks 8, 8, over the entire width direction. A part of the solder supply pipe 13 having an oval opening at the tip is shown. 14 is an inner ring disposed coaxially within the lower part of the outer ring 6, 15 is an inner ring drive unit that independently rotates the inner ring 14, and the drawing shows one second motor 16. The inner ring 14 has four squeegees 17, 17... elastically supported by spring members 18, 18... on the outer periphery at 90° intervals so as to protrude in the axial direction, and each squeegee 17, 17... The mask 8 is placed at the bottom of the mask 8 and slides on the inner surface of the mask 8 in a light and elastic manner. Reference numerals 19 and 19 denote a cover that is placed between the inner ring 14 and the outer ring rotating roller 10 and also serves as a guide rail for regulating the movement direction of both ends of the outer ring 6. Reference numeral 20 indicates a wiping roller that sandwiches the upper part of the outer ring 6 with the outer ring rotating roller 10. The solder paste 3 attached to the outer surface of the mask 8 that has come to the upper part is wiped off by being connected to the outer wheel drive section 9 and rotating in the opposite direction to the outer ring 6.

Next, the operation of the above device will be explained. For example, when applying solder in one pattern _P1 on the board 1,
Screen printing pattern that fits this pattern P ₁
Selectively rotate the outer ring 6 so that one mask 8 having Q ₁ is at the bottom. During this rotation, the selection mask 8 is passed near the tip of the solder supply pipe 13,
During this time, the solder paste 3 is applied to the inner surface of the selection mask 8 through the solder supply pipe 13. On the other hand, the board 1 is carried to a fixed position near the bottom of the outer ring 6, and the pattern of the board 1 is
Align the surface to be soldered corresponding to P ₁ with the pattern Q ₁ of the selection mask 8. After that, the inner ring 14 is rotated and the selection mask 8 is sequentially pressed onto the substrate ₁ using the squeegees 17, 17, .
Apply printing on top. When one printing is completed, the inner ring 14 is stopped and the substrate 1 is separated from the outer ring 6.
A mask 8 of pattern Q ₂ matching the next selected pattern P ₂ of substrate 1 is selected and sent to the bottom. Thereafter, by repeating the same operations as described above, each pattern P ₁ , P ₂ ... on the substrate 1 is made into a corresponding mask 8, 8 ...
But then I started screen printing one by one.

Note that the present invention is not limited to the above-mentioned embodiments. For example, the present invention is not limited to the above-mentioned embodiments. It is also possible to sequentially feed the printing materials downward. Further, structurally, the outer ring can be configured as a circular drum-shaped outer ring 6', as shown in FIG. 6, for example.

F. Effects of the Invention As described above, according to the present invention, it is possible to combine the productivity of the screen printing method and the versatility of the dispenser method, and to print multiple masks without having to prepare many types of printing masks. The outer ring, in which a plurality of printing masks for each type of printing pattern are arranged in series in the same direction, is selectively and intermittently fed in the circumferential direction so that the printing mask corresponding to the desired printing pattern is placed at the bottom. Therefore, it is possible to provide a screen printing device that can selectively print many different printing patterns and has great implementation effects. Furthermore, by making the rotational speed of the inner ring variable in accordance with the mask used for screen printing the outer ring, it is possible to perform the best screen printing according to the mask, thereby improving the quality of screen printing.

[Brief explanation of drawings]

1 and 2 are schematic side views of a conventional solder applicator, FIG. 3 is a plan view of a printing material, and FIGS. 4 and 5 are partially sectional perspective views showing an embodiment of the present invention. Side view FIG. 6 is a side view showing another embodiment of the present invention. 6, 6... Outer ring, 8... Mask, Q ₁ , Q ₂ ...
Screen printing pattern, 9... Outer wheel drive section, 1
2... Application material (solder paste), 14... Inner ring,
15...Inner wheel drive section.

Claims (1)

[Claims] 1. An outer ring formed by arranging multiple screen printing masks for each of multiple types of screen printing patterns in a series in the same direction, and a printing mask corresponding to the selected printing pattern by vertically disposing the outer ring at the bottom. an outer ring drive unit that selectively and intermittently rotates in the circumferential direction so as to rotate the outer ring intermittently; and a coating material supply unit that supplies screen printing coating material from a fixed direction to the inner surface of the mask of the outer ring;
an inner ring which is rotatably disposed within the lower part of the outer ring and which, when rotated, extrudes and applies coating material adhering to the inner circumferential surface of the mask at the lower part of the outer ring onto a screen printed substrate disposed on the outer surface of the mask; and an inner ring which is independent of the inner ring. A screen printing device characterized by comprising a rotating inner wheel drive section.