JPH0286495A - Construction of mask for printing semi-liquid material - Google Patents

Abstract

PURPOSE:To obviate deflection of a squeegee and enable a desired quantity of a solder cream to be printed with favorable reproducibility by providing a squeegee support member at a window hole of a mask. CONSTITUTION:An opening part 2, namely a window hole, of a solder cream printing mask 1 is provided with squeegee support members 3 along the directions in which a squeegee 4 is moved. The squeegee 4 is moved in the directions of arrows, whereby a solder cream 5 is printed. In this case, the squeegee 4 is pressed against the mask 1 with a predetermined pressure, but the squeegee support members 3 disposed at the window hole 2 ensure that the squeegee 4 is hardly deflected. Therefore, a desired quantity of the solder cream is printed with favorable reproducibility.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to the structure of a semi-liquid printing mask, and more specifically, it relates to the structure of a semi-liquid printing mask, and more specifically, it relates to the structure of a semi-liquid printing mask. When printing semi-liquid materials such as shaped sealing resin and solder cream.

This invention relates to an improvement in the shape of a mask opening.

[Conventional technology 1] For example, when surface-mounting electronic components are soldered or mounted on a printed circuit board, solder cream is printed on the connection terminals of the printed circuit board in a corresponding position, shape, and amount. After the electrodes are brought into contact, the solder cream is heated and melted using a reflow device or the like, and the electrodes of the electronic component and the terminals on the printed circuit board are joined by soldering.

The method for printing the solder cream at this time is to use a mask l made of stainless steel or the like, which has mask openings 2, or window holes, for printing the solder cream at positions corresponding to the terminals of the printed circuit board, as shown in Figure 2. The usual method is to use a squeegee 4 made of resin or rubber to extrude solder cream from the window hole of the mask and print on the printed circuit board.

[Problems to be Solved by the Invention] In the conventional technology, as shown in FIG. 2, one opening in a mask for printing solder cream is provided for one application area. It was printed using a mask. When printing highly viscous solder cream using this method, it was necessary to increase the pressure of the squeegee to prevent blurring.

However, if the pressing force of the squeegee is high, the squeegee bends at the mask opening and scrapes off the solder cream, making it impossible to print the required amount of cream and causing variations due to repetition, making it difficult to control the amount of printing. Ta.

In addition, to prevent this phenomenon, the mask opening should be bent (
When using a rigid squeegee.

Since the squeegee is hard and requires high pressing pressure, the mask may be damaged or the mask and squeegee may wear against each other, resulting in durability problems.

[Means for Solving the Problems 1] The structure of the semi-liquid material printing mask of the present invention is characterized in that a squeegee holding member is provided in the opening of the mask in the same direction as the moving direction of the squeegee.

[Example] An example of the present invention will be described below based on one drawing. In FIG. 1, a squeegee holding member 3 is disposed in the opening 2, that is, the window hole, of the mask l for the solder cream marking portion 11 in the direction in which the squeegee moves. Squeegee 4 in the direction of the arrow
moves and the solder cream 5 is printed. At this time,
Although the squeegee 4 is pressed against the mask L with a certain specified pressure, the squeegee holding member 3 disposed in the window hole 2 makes it difficult for the squeegee to bend, so that the desired amount of solder cream can be printed with good reproducibility. Ru.

Here, FIG. 1(a) is a perspective view showing the state before the squeegee 4 is placed on the mask window hole 2, and FIG. 1(b) is a cross-sectional view showing the state where the squeegee is on the mask window hole. It is a diagram.

In addition, since the mask holding member 3 also has the effect of reinforcing the mask window hole 2, the mask can withstand twisting, pulling, and bending forces of the mask caused by malfunctions in the pressing force of the squeegee or carelessness in handling the mask. It also works to prevent deformation and damage to window holes.

Furthermore, the structure of the mask of the present invention is as described above.

In addition to being used for solder cream printing for reflow soldering, it can also be widely applied to semi-liquid printing in general, such as semi-liquid resin printing for resin sealing, and the same effect can be obtained.

[Effect of the invention 1] As explained above, the structure of the mask of the present invention is such that the squeegee holding member is provided in the mask window hole, so that the squeegee does not bend, and the desired amount of solder cream can be printed with good reproducibility. Now I can do it. This reduces the number of soldering defects such as solder bridges and solder ovens due to the amount of solder, and reduces the number of man-hours required to correct them, which has a great effect on improving the quality of electronic devices and reducing costs.

In addition, due to the effect of reinforcing the mask window hole of the squeegee holding member,
The mask is less likely to break, extending its lifespan.
Running costs are lower, which also has the effect of reducing product-specific development costs.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the mask structure of the present invention, with FIG. 1(a) being a perspective view and FIG. 1(b) being a sectional view. Second
Figures (a) and (b) are diagrams showing conventional mask structures. Mask Mask opening (window hole) Squeegee holding member Squeegee solder cream and above Applicant Seiko Epson Co., Ltd. Agent Patent attorney Kizobe Suzuki (and 1 other person) Notebook diagram (α-ridge? Cb) Notebook 2m (Q) Atsushi 2 flashes

Claims (1)

[Claims] In the structure of a semi-liquid material printing mask for coating and printing a semi-liquid material onto a flat plate such as a printed circuit board by a squeegee extrusion method, a squeegee holding member is provided in the opening of the mask in the same direction as the moving direction of the squeegee. A structure of a semi-liquid printing mask characterized by the following.