JPH08191184A - Manufacture of printed wiring board and manufacturing equipment - Google Patents

Abstract

PURPOSE: To provide a method wherein high reliable filling of conducting paste for through holes is obtained and its manufacturing equipment. CONSTITUTION: A sheet 2 having elasticity and ventilation is laid on a suction stage 1, and an object to be printed wherein through holes 7 are perforated in previously specified portions is set on the sheet 2. Conducting paste 5 supplied on the object to be printed is printed with a squeegee 6 while the object is sucked with the suction stage 1, and the through holes 7 are filled with the conducting paste 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a printed wiring board for mounting semiconductor LSIs, chip parts, etc., and interconnecting them, and a manufacturing apparatus therefor.

[0002]

2. Description of the Related Art In recent years, with the miniaturization and high density of electronic equipment, there has been a strong demand for a board capable of high-density wiring not only in the industrial field but also in the consumer field.

A conventional method for manufacturing a double-sided circuit board will be described below. FIGS. 3 (A) to 3 (G) are cross-sectional views of products in each manufacturing process of a conventional double-sided circuit board, in which 10 is a prepreg sheet, for example, a nonwoven fabric of aromatic polyamide fiber and a thermosetting epoxy resin. A base material made of an impregnated composite material is used. Reference numeral 11 denotes a plastic sheet coated with a Si-based release agent on one side, and for example, polyethylene terephthalate (hereinafter referred to as PET sheet) is used. Reference numeral 12 is a through hole, and is filled with a conductive paste 13 that is electrically connected to a metal foil 14 such as copper attached to both surfaces of the prepreg sheet 10.

First, as shown in FIG. 3 (B), a plurality of through holes 12 are formed at predetermined positions of the prepreg sheet 10 having the PET sheets 11 attached to both sides thereof, as shown in FIG. 3 (B). Then, as shown in FIG. 3C, the through holes 12 are filled with the conductive paste 13. A printing apparatus for filling the conductive paste 13 is shown in FIG. Spread the paper sheet 17 on the suction stage 18, set the prepreg sheet 10 on it,
The conductive paste 13 supplied on the PET sheet 11 is printed with a squeegee 19. The conductive paste 13 enters and is filled in the through holes 12.

Next, as shown in FIG. 3 (D), the PET sheet 11 is peeled off, and as shown in FIG. 3 (E), a metal foil 14 such as a copper foil is formed on both surfaces of the prepreg sheet 10. Pile up. By heating and pressurizing with a hot press in this state, as shown in FIG. 3 (F), the prepreg sheet 10 and the metal foil 14 are
Are adhered, and the metal foils 14 on both sides are electrically connected to the through holes 12 provided at predetermined positions by the filled conductive paste 13. Then, as shown in FIG. 3 (G), the metal foil 14 on both sides is
Is selectively etched to form a circuit pattern 15, and a double-sided circuit board 16 is obtained.

[0006]

However, in the above-mentioned conventional printing apparatus, the suction stage 18 has the prepreg sheet.
Since the entire surface of 10 is fixed by suction, when the size of the prepreg sheet 10 to be printed becomes large, the suction stage 18
It becomes difficult to maintain the uniformity of the flatness. Therefore, the pressure distribution of the squeegee 19 will vary within the prepreg sheet 10, and the filling amount of the conductive paste 13 will vary, resulting in a defective resistance value.

When the diameter of the through hole 12 becomes smaller, the filling pressure must be increased in order to fill the conductive paste 13. However, the variation in the pressure distribution of the squeegee 19 makes the filling amount more unstable, It is expected that quality problems will often occur.

Further, the conductive paste is transmitted through the paper sheet 17.
Since 13 adheres to the suction stage 18, there is a problem in that the suction ability is deteriorated, printing failure may occur, and it is necessary to wash the stage from time to time.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems of the prior art, and provides a method of manufacturing a printed wiring board and a manufacturing apparatus therefor in which a highly reliable through-hole can be filled with a conductive paste. To aim.

[0010]

In order to achieve the above object, a method for manufacturing a printed wiring board according to the present invention comprises (1) a step of preparing a substrate having one or more through holes preliminarily drilled; , A step of laying a sheet having elasticity and breathability and setting a substrate on the sheet, and a step of filling the through holes with the conductive paste while sucking from the lower surface of the sheet. .

Further, (2) a step of preparing a substrate having one or more through holes preliminarily drilled, and laying a sheet having elasticity and breathability and a paper sheet on the suction stage in sequence, It is characterized in that it comprises a step of setting a substrate thereon and a step of filling the through-hole with a conductive paste while sucking with a suction stage.

Next, in the printed wiring board manufacturing apparatus of the present invention, (3) a sheet having elasticity and breathability on which a printed substrate is placed, and the printed substrate set on this sheet It is characterized by comprising suction means for sucking from the lower surface to fix and set, and means for printing on the substrate to be printed.

Further, (4) a suction stage, a sheet and a paper sheet having elasticity and breathability which are sequentially placed on the suction stage, and means for printing on the substrate to be printed which is set on the paper sheet and sucked by the suction stage It consists of and.

[0014]

According to the above construction, the flatness of the stage does not directly affect the squeegee or the substrate by laying a sheet having elasticity and breathability under the substrate to be printed, and the pressure of the squeegee is applied to the entire surface of the substrate. It is kept uniform. Further, the conductive paste does not come into contact with the stage by entering between the stage and the substrate.

[0015]

Embodiments will be described in detail below with reference to the drawings. FIG. 1 shows an embodiment of the present invention, in which 1 is a suction stage for fixing and setting a prepreg sheet, and 2 is a sheet having elasticity and breathability, for example, thick filter paper. 3 is a prepreg sheet, 4 is a PET sheet attached to both sides of the prepreg sheet 3, 5 is a conductive paste, and 6 is a squeegee for printing the conductive paste 5 and filling the through holes 7 formed in the prepreg sheet 3. .

The through hole 7 can be opened by laser processing or the like. The sheet 2 used had a thickness of 0.4 mm. As the prepreg sheet 3, an aramid epoxy resin base material to which the PET sheet 4 was attached was used.

Next, the printing operation of this embodiment will be described. First, a prepreg sheet 3 having a plurality of through holes 7 formed in advance is prepared. Therefore, a sheet having elasticity and breathability, here a sheet 2 is laid on the suction stage 1, and the prepreg sheet 3 is set on the sheet.
Then, the conductive paste 5 supplied onto the prepreg sheet 3 is printed with a squeegee 6 while being sucked by the suction stage 1, and the through holes 7 are filled with the conductive paste 5.

In the present embodiment constructed as described above, the thick sheet 2 works so as to alleviate the slight difference in the unevenness of the suction stage 1, and has the air permeability so as not to reduce the suction force, and it is electrically conductive. The liquid component of paste 5 is absorbed. Since the difference in the unevenness is relaxed, the variation in the filling force of the conductive paste 5 can be reduced, so that the filling amount of the conductive paste 5 into the through holes 7 becomes constant.

FIG. 2 shows another embodiment of the present invention, in which the same reference numerals as those in FIG. 1 denote the same elements.
Further, 8 is a sheet having elasticity and breathability, for example, polyurethane, and 9 is a paper sheet, for example, thin paper. The sheet 8 used had a thickness of 1 cm.

The printing operation is the same as in the embodiment of FIG. Also in this embodiment, the sheet 8 works so as to alleviate a slight difference in the unevenness of the suction stage 1. In addition, there is no problem with the air permeability, and the suction force sufficient to fix the prepreg sheet 3 is produced. The reason why the paper sheet 9 is used is to make it easier to absorb the liquid component of the conductive paste 5. It is also used as a means for moving the prepreg sheet 3.

[0021]

As described above, according to the present invention,
First, on a sheet having elasticity and breathability, a print object having through holes previously set at predetermined positions is set,
A method of filling the through holes with the conductive paste while sucking from the lower surface of the sheet. Secondly, a sheet having elasticity and air permeability and a paper sheet are sequentially laid on the suction stage, and the sheet is preliminarily predetermined. By filling the through-hole with conductive paste while setting the printing object with through-holes drilled at the locations and sucking with the suction stage, the filling of the through-hole with conductive paste is highly filled. By the way, it is carried out stably, and as a result, the resistance value defect in the double-sided conductive holes of the printed wiring board is reduced, so that the printed wiring board with a high yield can be obtained, and the adhesion of the conductive paste to the suction stage is almost eliminated. Therefore, the suction stage can be used permanently, the maintainability and reliability are high, and the production cost can be reduced. Door can be.

[Brief description of drawings]

FIG. 1 is a diagram showing a printing method according to an embodiment of the present invention.

FIG. 2 is a diagram showing a printing method according to another embodiment of the present invention.

FIG. 3 is a diagram showing a cross section of a product in each manufacturing process of a conventional double-sided circuit board.

FIG. 4 is a diagram illustrating a conventional printing method.

[Explanation of symbols]

1 ... Suction stage, 2, 8 ... Elastic and breathable sheet, 3 ... Prepreg sheet, 4 ... PET sheet, 5 ... Conductive paste, 6 ... Squeegee, 7 ... Through hole, 9 ... Paper sheet.

Claims (4)

[Claims] 1. A step of preparing a substrate having one or more through-holes formed in advance, a step of laying a sheet having elasticity and breathability, and setting the substrate on the sheet.
A method of manufacturing a printed wiring board, comprising the step of filling the through holes with a conductive paste while sucking from the lower surface of the sheet. 2. A step of preparing a substrate having one or more through holes preliminarily drilled, and a sheet having elasticity and breathability and a paper sheet are sequentially laid on the suction stage, and the sheet is laid on the sheet. A method of manufacturing a printed wiring board, comprising: a step of setting the substrate; and a step of filling the through hole with a conductive paste while sucking with the suction stage. 3. A sheet having elasticity and breathability for mounting a substrate to be printed, suction means for sucking and fixing and setting the substrate to be printed set on the sheet from the lower surface of the sheet, An apparatus for manufacturing a printed wiring board, comprising: means for printing on a printed substrate. 4. A suction stage, and an elastic and breathable sheet and a sheet which are sequentially placed on the suction stage,
An apparatus for manufacturing a printed wiring board, comprising: means for setting on the paper sheet and printing on the substrate to be printed sucked by the suction stage.