JPH0334929Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to a printing device for a board with through holes, and in particular, the thickness of the ink coated on the inner circumferential surface of the through holes is kept constant. can be formed into The present invention relates to a printing device for a board having through holes.

(Prior Art) As shown in FIG. 5, a conventional printing apparatus for a board having through holes includes a printing table main body 5 having a table surface 5a on which a board 1 is set.
A gap 6 formed in the printing table main body 5 communicates with the gap 6, and the table surface 5
an air intake hole 7 opened at a position communicating with the through hole 2 of the substrate 1 placed on the substrate 1;
and a suction pump (not shown) that sucks the air inside the cavity 6 to create a predetermined negative pressure in the cavity 6. After the substrate 1 is set on the table surface 5a, the suction pump is operated. Therefore, at present, the ink 4 is sucked and applied to the inner peripheral surface of the through hole 2 of the substrate 1.

To explain the application state of the ink 4 in more detail based on FIGS. 6A to C, first, the silk screen 8 coated with the ink 4 is placed on the core 1a.
Placed on the surface of the enamel coating layer 3 coated with
Next, by printing the surface of the silk screen 8 with a squeegee 9, the ink 4 is applied to the silk screen 8.
As shown in Figure 6A,
Ink 4 is applied to the surface of enamel coating layer 3 . At this time, since the suction pump is operating, air is sucked directly below the through hole 2, and as shown in FIG. 6B, the ink 4 applied to the periphery of the through hole 2 is absorbed. The ink 4 flows down along the inner circumferential surface of the through hole 2 due to atmospheric pressure, and as shown in FIG.

(Problems with the Prior Art) However, in the above conventional printing device having through holes, when the ink 4 is sucked by the suction pump, air is forced into the through holes 2.
Because of the forced suction directly below the air, turbulence tends to occur in the airflow flowing through the through hole 2, which has a generally drum-shaped cross section.As a result, as shown in FIG. A reservoir 4a of ink 4 is formed.

Further, when applying the ink 4 to the front and back surfaces of the substrate 1 in the same manner as the above method, as shown in FIG.
A reservoir 4a of the ink 4 is formed approximately at the center of the inner peripheral wall surface of the through hole 2.

Therefore, it is difficult to maintain the hole diameter of the through hole 2 with high precision, and it is also difficult to make the ink film thickness uniform, making it easy to cause cracks and sagging, making it difficult to maintain the long-term stability of the board quality. However, there were various problems such as a decrease in the reliability of the product.

This invention was devised in view of the current situation, and its purpose is to rectify the air flowing inside the through-hole by an extremely simple means, thereby maintaining the diameter of the through-hole with high precision. In addition, we would like to provide a printing device for a board having through-holes that can stabilize the product quality over a long period of time by uniformizing the thickness of the ink applied inside the through-holes, and greatly improve the reliability of the product. That is.

(Means for solving the problem) In order to achieve the above object, in this invention, a circuit is printed on the surface of a board in which a through hole is formed, and the inner periphery of the through hole is printed by suction pressure. A rectifying jig for rectifying the intake air flow along the inner peripheral surface of the through hole is installed in a printing device for a substrate having a through hole configured to suck and apply ink to a surface of the through hole. It is characterized in that it is arranged and configured to stand directly below.

(Function) Therefore, in the printing device for a board having through-holes according to this invention, the rectifying jig is installed directly below the through-hole, and air is directed along the outer peripheral surface of the rectifying jig. The ink is applied uniformly to the inner peripheral surface of the through hole by suction.

(Example) Hereinafter, this invention will be described in detail based on an example shown in the accompanying drawings.

As shown in FIGS. 1 to 4, a printing device 10 for a substrate 1 having a through hole 2 according to this embodiment includes a printing table main body 11, a gap 12 opened in the printing table main body 11, An intake hole 13 that communicates with the cavity 12 and the through holes 2 of the substrate 1, and a plurality of rectifying jigs 14 disposed directly below each of the through holes 2.
, a rectifying jig fixture 15 that holds the rectifying jig 14 upright, and a suction pump (not shown) that sucks the air in the cavity 12 to create a predetermined negative pressure in the cavity 12. , is composed of.

Examples of the substrate 1 to which this invention is applied include a hollow substrate having a through hole 2 whose surface is coated with a hollow coating layer 3 on the surface of a core 1a, and various other circuit boards.

The intake hole 13, which is formed approximately at the center of the printing table body 11, is sized to communicate with all the through holes 2 of the substrate 1 when the substrate 1 is set on the surface of the printing table body 11a. has been done.

The rectifying jig 14, as shown in FIG. The outer circumferential surface 17a is formed into a substantially conical shape with a curve that matches the curvature of the inner circumferential surface of the through hole 2, which is formed in a substantially drum-shaped cross section, and connects the lower half of the inner circumferential surface of the through hole 2 with the flow regulator. The air intake/outflow passages 18 formed by the outer peripheral surfaces 17a of the air intake/outflow passages 17 are set so as to maintain the same spacing.

As shown in FIGS. 3 and 4, the rectifying jig fixture 15 is configured in a flat plate shape, and is arranged in the gap 1.
When the rectifying jig 14 is set in the jig holding stepped portion 12a of No. 2, a holding hole 19 for erecting the shaft rod 16 of the rectifying jig 14 is opened at a position directly below each through hole 2. ing. In addition, at a predetermined position of the rectifying jig fixture 15 (a position that does not interfere with the upright installation of the rectifying jig 14), there is a hole for supplying the air sucked from the through hole 2 to an intake pump (not shown). A plurality of holes 20 are provided to penetrate through the hole 20 .

Therefore, when applying the ink 4 into the through hole 2 of the substrate 1 using the printing apparatus 10 according to this embodiment, the ink 4 is first applied as shown in FIG. 6A. A silk screen 8 consisting of
is strained out from the surface of the silk screen 8, and as shown in FIG. 6A, the ink 4 is applied to the surface of the enamel coating layer 3.

At this time, since the suction pump is operating, air is sucked directly below the through hole 2, and as shown in FIG. The air that flows into the formed intake/outflow path 18 is rectified by the outer circumferential surface 17a of the straightening jig 14 and flows, so that the air that has been applied to the peripheral edge of the through hole 2 is The ink 4 is uniformly flowed along the inner peripheral surface of the through hole 2 due to the above-mentioned suction pressure, and the ink 4 is spread over almost the entire inner peripheral surface of the through hole 2.
is applied with a uniform thickness.

In the above embodiment, the case where the rectifying jig 14 is held upright by the rectifying jig fixture 15 has been explained as an example, but this invention is not limited to this. Instead, the rectifying jig may be held by fitting into a holding hole formed at the bottom of the cavity.

(Effects of the invention) As explained above, in the printing device for a board having through-holes according to this invention, a rectifying jig is installed directly below the through-hole formed in the board, and the rectifying jig is installed directly below the through-hole formed in the board. By sucking air along the outer circumferential surface of the tool, the air flowing inside the through hole is rectified and the ink is applied to the inner circumferential surface of the through hole, making it easy to reduce the thickness of the ink inside the through hole. As a result, the diameter of the through-hole can be maintained with high accuracy, the product quality can be stabilized over a long period of time, and the reliability of the product can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional perspective view showing a printing device for a board having through-holes according to an embodiment of the invention, FIG. 2 is a sectional view showing an enlarged main part of the printing device, and FIG. 4 is a perspective view of a rectifying jig fixture, FIG. 5 is a partially sectional perspective view showing a conventional printing device for a board with through holes, and FIGS. 6A to C are FIG. 7 is a cross-sectional explanatory diagram showing the steps of forming an ink layer on the inner circumferential surface of a through hole of a substrate. FIG. 7 is a cross-sectional explanatory diagram showing a first example of an ink layer formed by a conventional printing device. FIG. FIG. 7 is an explanatory cross-sectional view showing a second example of an ink layer formed by a conventional printing device. Explanation of symbols, 1... Board, 2... Through hole, 4... Ink, 10... Printing device, 11
...Printing table main body, 12...Gap portion, 13...
...Intake hole, 14... Rectifier jig, 15... Rectifier jig fixture.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A circuit is printed on the surface of a board in which a through hole is formed, and ink is drawn and applied to the inner circumferential surface of the through hole using suction pressure. The printing apparatus includes a rectifying jig that rectifies the intake air flow along the inner circumferential surface of the through hole, and the rectifying jig is installed in a direction directly below the through hole. 1. A printing device for a board having through holes. (2) The rectifying jig is installed upright in a hole of a rectifying jig fixture that is set concentrically beneath the through hole, as set forth in claim 1 of the utility model registration claim. Printing equipment for boards with through holes.