JPS6235911B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application) The present invention relates to a screen printing device, and particularly to a screen printing device that can easily and accurately align a printing screen with respect to a substrate to be printed. It is related to.

(Prior art) As is well known, in the production of thick film hybrid ICs, a method is widely adopted in which patterns of conductors, dielectrics, resistors, etc. are formed in one or multiple layers by screen printing. ing.

In this case, as devices become smaller,
The alignment between each pattern and between each layer, and therefore the alignment of a printing screen with respect to a substrate to be printed, increasingly requires high precision.

At present, the alignment of the printing screen with respect to the substrate to be printed is performed visually by an operator.

However, as the pattern on the printing screen becomes finer, alignment within acceptable tolerances becomes virtually possible, and after several prints with one printing screen, the pattern on the substrate can be seen through the apertures in the screen. The extreme difficulty in seeing the pattern again makes alignment with sufficient accuracy impossible.

Therefore, not only does it take a long time and skill to align the printing screen to the substrate to be printed, and there are large individual differences, but in practice, it is difficult to determine the required accuracy unless you actually make a test print. The disadvantage was that it was not possible to align the position. Additionally, this has the disadvantage that work efficiency tends to decrease.

(Objective) The present invention was made in order to eliminate the above-mentioned drawbacks, and its object is to easily and accurately align a printing screen to a printed substrate with high precision without relying on visual inspection. The objective is to provide a screen printing device that can

(Summary) In order to achieve the above object, the present invention provides a pair of alignment pins so that the printed substrate has a fixed position relative to a specified position of the printed substrate on a stage, and a pair of positioning conductive protrusions electrically connected to each other are provided at positions on the printing screen opposite to the positioning pins when the printing screen is aligned with sufficient accuracy; By detecting the conduction state between the pair of alignment pins,
The present invention is characterized in that it is configured to determine whether or not the alignment of the printing screen with respect to the substrate to be printed is completed.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a plan view showing a state in which a substrate to be printed is placed at a prescribed position on a stage in an embodiment of the present invention, and FIG. 2 is a sectional view taken along line A-A' in FIG. 1. It is.

As is clear from Figure 1, at stage 9,
Positioning pins 2, 3 and 4 are planted.
By placing the printed substrate 1 on the stage 9 and bringing its two sides into contact with the alignment pins 2, 3, and 4, the printed substrate 1 is correctly aligned on the stage 9.

2 and 3 of the alignment pins 2, 3, 4
also serves as an electrode for positioning the printing screen 8 with respect to the printed substrate 1 according to the present invention.

For this purpose, they are made of electrically conductive material and, as best shown in FIG. 2, these alignment pins 2 and 3 are insulated from the stage 9 by an insulating layer 5.

Lead wires 2A and 3A are connected to the lower ends of the alignment pins 2 and 3, respectively, and a means (in this example, a power supply E, a protection resistor R, and a series circuit of an ammeter M) are connected.

In order to improve the accuracy of alignment, it is preferable to process the tips of these alignment pins 2 and 3 into a tapered shape so that the area of the top surface thereof is narrowed.

FIG. 3 is a bottom view of the printing screen in the embodiment of the present invention. A support frame 10 having sufficient mechanical strength is provided around the printing screen 8, and a desired printing pattern (or opening) 12 is bored in a portion of the printing screen 8.

A rectangular area indicated by a two-dot chain line 15 corresponds to the printed substrate 1 in FIG. 1, and the printed pattern 12 is formed within this area.

Further, conductive projections 6 and 7 for alignment are formed downward at positions corresponding to the alignment pins 2 and 3 in FIG. 1 on the printing screen 8. In this example, it is assumed that the printing screen 8 is a metal screen made of a thin metal film, so
The alignment conductive protrusions 6 and 7 and the printing screen 8 are electrically connected.

As will be described in detail later, when the printing screen 8 is correctly placed in the normal position, the tips of the conductive projections 6 and 7 for positioning are aligned with the positioning pins 2 and 3.
Because the positioning of the printing screen 8 with respect to the printed substrate 1 is performed by this, the positioning conductive projections 6, 7
It is desirable to make the cross-sectional area of the tip as small as possible.

FIG. 4 is a schematic configuration diagram for explaining the operation when aligning the printing screen with respect to the substrate to be printed according to the present invention. In this figure, the same reference numerals as in FIGS. 1 to 3 represent the same or equivalent parts.

As described above, the two positioning conductive protrusions 6 and 7 are electrically connected to each other. Therefore, as is clear, in FIG. 4, only when the alignment pin 2 and the alignment conductive protrusion 7 are in contact with each other, and the alignment pin 3 and the alignment conductive protrusion 6 are in contact with each other, The circuit of power supply E is closed, and the ammeter M
A current flows through.

Therefore, by detecting this current and driving a notification means (by sound, light, etc.) based on the result, it is possible to indicate the completion of alignment.

Furthermore, if the current detection signal is used to prevent the relative movement of the printed substrate 1 or the stage 9 and the printing screen 8 and to fix them, the labor of the operator can be saved. Accurate alignment can be performed semi-automatically.

Further, a guide capable of accurately positioning one side of the printing screen 8 is provided, for example, on the stage 9, and the printing screen 8 is configured to automatically slide along this guide. If the sliding of the printing screen 8 is stopped and fixed based on the detection signal, it is possible to automate the alignment.

In the present invention, the alignment conductive protrusions 6 and 7 provided on the printing screen 8 are located outside the area 15 corresponding to the printed substrate 1, and the height of the alignment pins 2 to 4 is adjusted to the printed substrate. If the thickness is selected to be lower than 1, the printing operation by the printing screen 8 will not be affected.

The present invention can be modified and implemented as follows.

(1) The alignment pins 2 and 3 are provided independently without serving as alignment pins for the printed substrate 1 with respect to the stage 9.

(2) Instead of the conductive projections 6 and 7 for positioning, use springs, needle-like contact pieces, or cut and raised pieces.

(3) A non-conductive mesh screen is used as the printing screen 8. In this case, it is necessary to connect the positioning conductive projections 6 and 7 with a suitable conductive material (for example, a conductive support frame).

(Effects) As is clear from the above description, according to the present invention, the following effects are achieved.

(1) Since the alignment of the printing screen with respect to the substrate to be printed is determined mechanically, alignment work is simplified and streamlined. At the same time, individual differences and variations in alignment accuracy are eliminated, resulting in uniform screen printing.

(2) It also becomes possible to automate or semi-automate the alignment of the printing screen to the substrate to be printed.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a state in which a printed substrate is placed at a prescribed position on a stage, FIG. 2 is a sectional view taken along line A-A' in FIG. 1, and FIG. Bottom view of printing screen in one embodiment, No. 4
The figure is a schematic configuration diagram for explaining the present invention. 1... Printed board, 2, 3... Alignment pin,
5... Insulating layer, 6, 7... Conductive projection for positioning,
8...Printing screen, 9...Stage, 10
...Support frame, 12...Print pattern.

Claims (1)

[Scope of Claims] 1. a stage; alignment pins fixed on the stage for positioning the printed substrate; and when the printed substrate is positioned on the stage, the printed substrate a pair of alignment electrodes fixed so that the tips are lower than the height of the substrate and electrically insulated from the stage; means for detecting conduction between the alignment electrodes; and printing. a pair of electrodes that are electrically conductively connected to each other and are located in such a position that they come into contact with each of the alignment electrodes when a pattern to be printed is formed on the substrate and are aligned correctly with respect to the substrate to be printed; 1. A screen printing device comprising: a printing screen provided with conductive projections for positioning. 2. The screen printing apparatus according to claim 1, wherein the alignment electrode is also used as an alignment pin for positioning a substrate to be printed. 3. The screen printing apparatus according to claim 1 or 2, wherein the alignment electrode is processed into a tapered shape so that the area of the top surface thereof is narrowed. 4. Claim 1, wherein the printing screen is a metal screen.
The screen printing device according to item 1, 2 or 3. 5. The screen printing apparatus according to claim 1, 2 or 3, wherein the printing screen is a non-conductive mesh screen. 6. The screen printing apparatus according to any one of claims 1 to 5, wherein the stage is provided with a guide for positioning one side of the printing screen.