JP2533244B2 - How to clean a green sheet via hole - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning the inside of a via hole formed in a green sheet. Generally, a ceramic wiring board is manufactured through the steps shown in FIG.

First, in a green sheet forming step 1, a green sheet 10 is formed as shown in FIG. 9 (A). On one surface (upper surface) 10a of the green sheet 10, a Mylar (trade name) film 1 that functions as a waist plate
1 is sticky. The mylar film 11 is adhered only by viscous force of the green sheet 10 itself.

Next, a via hole forming step 2 is performed. This isゝ, as shown in FIG. 9 (B), a green sheet 10 by the punch 12 is punched out from the Mylar film 11 side, to form the via holes 13 and 14.

Next, a via forming step 3 is performed. This isゝ, as shown in FIG. 9 (C), the copper paste 16 filled from Mylar film 11 side via holes 13, 14 by the squeegee 15, to form a via 17 and 18.

Then, an inner layer conductor pattern forming step 4 is performed. Here, as shown in FIG. 9D, the mylar film 11 is peeled off, and the inner layer conductor patterns 19 and 20 are formed on the surface 10a of the green sheet 10 by printing.

After that, step 5 of stacking the green sheets on which the vias 17 and 18 and the inner layer conductor patterns 19 and 20 are formed, step 5 of baking the stacked sheets 6, and a surface conductor on the surface of the ceramic substrate obtained by baking. The ceramic printed wiring board is manufactured through the step 7 of forming.

In recent years, there has been a demand for higher density in a ceramic printed wiring board, and the diameter d of the vias 17, 18 has been reduced to about 100 μm, and higher reliability is required for the vias 17, 18. Is coming.

In order to improve the reliability of the via hole, it is necessary to fill the via hole 1 before the copper paste is filled with the copper paste.
It is necessary to perform cleaning surely so that there is no residue of chips, dust, etc. in the parts 3 and 14.

For this reason, as shown in FIG. 8, after the via hole forming step 2, a step 8 of blowing high pressure air to the green sheet to clean residual chips and scrap residue remaining in the vias 13 and 14 is performed. After that, a cleaning finishing step 9 is performed in which the adhesive tape is once attached and then peeled off to remove almost all the chips and debris that are missing.

Here, it is necessary that the cleaning step 8 should not adversely affect the next step of forming a via.

[0011]

2. Description of the Related Art In a conventional cleaning step 8, as shown in FIG. 10, a green sheet 30 having a via hole is formed, as shown in FIG.
In the orientation with the mylar film 11 as the upper surface, the 180-mesh support net 31a of the support jig 31 shown in FIG.
In this state, the operator uses the air nozzle 32 to blow high-pressure air 33 onto the upper surface side.

[0012]

The high-pressure air 33 is blown into the via holes 13 and 14 well, and when the chips remain in the via holes 13 and 14, the chips are removed from the via holes 13 and 14. 14 is pushed toward the lower openings 13a, 14a, pushed downward by the lower openings 13a, 14a, and collected by the dust collector 34.

Green sheet 1 of mylar film 11
Since the adhesive force to 0 is weak originally, and the mylar film 11 is not pressed down at all, the turbulent flow of the high-pressure air 33 in the via hole 13 causes the upper openings 13b, 14 of the via holes 13, 14 of the mylar film 11 to flow.
As shown by reference numerals 35 and 36 in FIG. 12, relatively large peeling occurs at the portion facing b.

When this peeling occurs, in the via forming step 3 shown in FIG. 8, the copper paste 16 is removed as shown in FIG.
It permeates into the gaps 37 and 38 between the peeled portions 35 and 36 of the mylar film 11 and the green sheet 10. As a result, as shown in FIG. 14, the diameter of the upper surface 10a of the green sheet 10 of the vias 17 and 18 becomes d ₁ , which is considerably larger than the predetermined diameter d ₀ .

The larger-diameter via portion 18a of the via 18 is unnecessarily electrically connected to the inner layer conductor pattern 19, resulting in a short circuit failure of the ceramic printed wiring board.

According to the present invention, by covering the upper surface of a green sheet having a via hole formed therein with a holding net and pressing the mylar film, it is possible to prevent the mylar film from peeling off during cleaning while blowing a high pressure error. The purpose is to provide a method for cleaning a via hole.

[0017]

According to a first aspect of the present invention, a synthetic resin film is adhered to one surface of a green sheet in which a via hole is formed and a via hole is formed. In a method for cleaning a via hole in which gas is blown to remove chips and / or debris remaining in the via hole, the green sheet on which the via hole has been formed is oriented with the synthetic resin film as an upper surface. The lower surface of the hole formed green sheet is supported by a mesh support net that does not block the lower opening of the via hole, and the synthetic resin film on the upper surface of the via hole formed green sheet is A structure in which a high-pressure gas is blown from the side of the holding net while it is held by a large mesh holding net. Is.

[0018]

The supporting net supports the green sheet on which the via holes have been formed, and does not prevent chips and debris remaining in the via holes from coming out from the lower opening of the via holes.

The presser net does not prevent air from being blown into the via hole through the upper opening of the via hole, and also prevents the synthetic resin film from peeling off.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram illustrating a method for cleaning a green sheet via hole according to an embodiment of the present invention.

FIG. 2 shows an apparatus for carrying out the method for cleaning a via hole according to the present invention.

In FIG. 2, reference numeral 50 denotes a gantry, and an X-direction moving mechanism 52 for moving the nozzle 51 back and forth in the directions of arrows X ₁ and X _{2 on} the upper surface, and a nozzle 52 also reciprocating in the directions of arrows Y ₁ and Y _2. A Y-direction moving mechanism 53 for moving is provided.

Two green sheet sandwiching jigs 54 shown in FIG. 3 are set side by side on the gantry 50.

In this jig 54, an opening / closing frame 58, in which a 70-mesh support net 56 is stretched around a frame-shaped main body 55 and a 100-mesh holding net 57 is stretched, has one end hinged to the main body 55 by a hinge 59. The structure is supported so that it can be opened and closed.

The specifications of the 70 mesh support net 56 are as follows:
Wire diameter 70μm, thickness 125μm, opening 2
92 μm, opening area 65%, transmission volume 8
1 cm ³/ m²Is.

The specifications of the 100-mesh holding net 57 are as follows: wire diameter 70 μm, thickness 125 μm, opening 183 μm, opening area 52%, permeation volume 65 cm ³ / m ² .

These specifications apply to the via holes 13 and 14
Diameter d ₀ of 90 [mu] m, the pitch p of the via hole 13 and 14 are determined in response to a 0.45 or 0.9 mm.

Reference numeral 60 denotes a dust collector, which is provided below the pedestal 50.

Cleaning of the via hole is performed as described below.

First, as shown in FIG. 3, the opening / closing frame 58 of the jig 54 is opened, and the green sheet 30 with the via holes is formed.
In the direction with the mylar film 11 as the upper surface, and the arrow A
The green sheet side is placed on the support net 56, and the frame 58 is closed. As a result, the green sheet 30 is sandwiched between the support net 56 and the presser net 57, is supported on the support net 56 and presses the mylar film 11 on the upper surface, as shown in FIG.
It is pressed by 7.

Since 70 mesh is used as the support net 56, the via holes 13 and 14 and the support net 56 are the lower openings 13 of the via holes 13 and 14.
It is in a state in which a and 14a are hardly blocked by the wire rod 56b of the support net 56.

Further, since the holding net 57 is made of 100 mesh, the holding net 57 holds the Mylar film 11 around the upper openings 13b and 14b of the via holes 13 and 14. Become.

In FIG. 1, the nozzle 51 has an orifice diameter of 1.9 mm and is arranged 5.0 to 10.0 mm away from the upper surface of the green sheet 30.

The above devices 52 and 53 operate simultaneously, and the nozzle 51 moves in a zigzag shape as indicated by reference numeral 61 in FIG.

At this time, as shown in FIG. 1, the pressure is 4.
High-pressure air of 0 to 5.0 kg / cm ² is jetted from the nozzle 51 as indicated by reference numeral 62, and 0.5 to 0.5 is applied to the green sheet 30.
Spray at a passing wind speed of 1.0 m / s.

The high pressure air 62 from the nozzle 51 passes through the opening 57a of the holding net 57 and the via hole 1
4, the opening 56a of the support net 56
It blows out through the via hole 14 through and through the inside of the via hole 14.

When reaching a position facing the nozzle 51 and the via hole 13, the high pressure air from the nozzle 51 blows through the via hole 13 as described above.

As a result, the chips and scraps 63 in the via holes 13 and 14 are blown outside the via holes, and the via holes 13 and 14 are cleaned well.

Further, in FIG. 1, the wire rods 57b and 57c constituting the presser net 57 are pressed into the via hole 14 because the part facing the upper opening 14b of the via hole 14 which is easy to peel off is pressed. Although the high pressure air 62 exerts a force in the peeling direction,
Peeling of the mylar film 11 hardly occurs.

Similarly, the portion of the mylar film 11 facing the upper opening 13a of the via hole 13 is also pressed by the other wire members 57d and 57e forming the pressing net 57, and peeling hardly occurs at this portion as well.

Therefore, the bayer hole 1 after cleaning
The portions 3 and 14 are as shown in FIG. 4, and the mylar film 11 is hardly peeled off.

Therefore, when the copper paste is filled in the via forming step 3 shown in FIG.
Without exuding between 0 and mylar film 11,
This is normally performed as shown in FIG.

Therefore, as shown in FIG. 6, the via holes 17 and 18 have the upper openings 13 and 1 of the via holes 13 and 14, respectively.
Also in the portion of No. 4, it is formed without particularly increasing the diameter. Therefore, as shown in FIG. 7, the inner layer conductor 19 is normally formed without short-circuiting the via 18.

High-pressure nitrogen may be used instead of high-pressure air.

[0045]

As described above, according to the first aspect of the invention, the via hole can be cleaned without unnecessarily peeling the synthetic resin film.

Therefore, the via hole can be cleaned without adversely affecting the subsequent steps.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a method for cleaning a via hole of a green sheet according to an embodiment of the present invention.

FIG. 2 is a schematic view of an apparatus for performing a method for cleaning a green sheet via hole according to an embodiment of the present invention.

FIG. 3 is a view showing a green sheet sandwiching jig.

FIG. 4 is a diagram showing a state after cleaning a via hole by the method for cleaning a via hole in FIG.

FIG. 5 is a diagram showing a filled state of copper paste.

FIG. 6 is a diagram showing a formed viar.

FIG. 7 is a diagram showing that the inner layer conductor pattern does not short-circuit the via.

FIG. 8 is a diagram showing a manufacturing process of a ceramic printed wiring board.

9 is a diagram showing a state after each step of FIG.

FIG. 10 is a diagram showing an example of a conventional method for cleaning a via hole.

11 is a view showing a support jig used in the method of FIG.

12 is a diagram showing a state after cleaning the via hole by the method for cleaning a via hole in FIG.

FIG. 13 is a diagram showing a filled state of copper paste.

FIG. 14 is a diagram showing a formed viar.

FIG. 15 is a diagram showing that the inner conductor pattern is short-circuited with the via.

[Explanation of symbols]

 8 Cleaning Step 11 Micro Film 12 Punch 13,14 Bayer Hole 16 Copper Paste 17,18 Bayer 19,20 Inner Layer Conductor Pattern 30 Bayer Hole Formed Green Sheet 50 Frame 51 Nozzle 52 X Direction Moving Device 53 Y Direction Moving Device 54 Green Sheet Clamping jig 55 Frame body 56 Supporting net 56a Opening 57 Pressing net 57a Opening 57b-57e Wire rod 58 Opening / closing frame 59 Hinge 60 Dust collector 61 Nozzle moving path 62 High pressure air 63 Chips and dust

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-64-39098 (JP, A) JP-A-56-46600 (JP, A)

Claims (1)

(57) [Claims] 1. A high-pressure gas is blown to a green sheet having a via hole formed therein, in which a synthetic resin film is adhered on one surface, and a via hole is formed by making a hole, and the green sheet remains in the via hole. in via hole cleaning process for removing chips and / or shavings are, the via hole has been formed green sheet (30), and the synthetic resin film (11) was used as a top orientation, the via hole has been formed green The lower surface of the seat (30) is provided with a lower opening (13) of the via hole (13, 14).
a, 14a) mesh support net (56)
And the synthetic resin film (11) on the upper surface of the green sheet (30) on which the via holes have been formed by the pressing net (5) having a mesh larger than the supporting net (56).
7) A method for cleaning a green sheet via hole, characterized in that high-pressure gas is blown from the side of the holding net (57) while being pressed by 7).