JPH0149038B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of the Invention] This invention relates to a method for manufacturing a multilayer wiring porcelain board, in which a conductive material is formed on one side of an unsintered porcelain sheet (hereinafter referred to as a "green sheet") with via holes formed therein. The present invention relates to a method and apparatus for printing a wiring pattern with paste and simultaneously filling the via hole with conductive paste.

[Background of the invention and prior art]

A multilayer wiring ceramic board is a wiring board that has a so-called three-dimensional wiring structure, in which multiple ceramic boards with a wiring pattern on one side are laminated, and the wiring patterns of the upper and lower layers are connected to each other with conductors filled in via holes in each layer. It is. There is a trend toward miniaturization and higher wiring density for this type of board, and at the same time, high processing precision is required to manufacture it.
High productivity is required.

In the manufacturing process of this multilayer wiring ceramic board,
It is necessary to print a wiring pattern using conductive paste on one side of a green sheet with via holes perforated therein, and to fill the via holes with conductive paste. Conventionally, this process has been carried out using the following method. It's here. First, a via hole is drilled,
and small pieces (for example, square with 10 cm on each side and thickness)
A raw sheet cut into 200μ) pieces is placed on a printing table, and conductive paste is screen printed on it. At this time, small holes are provided in the printing table corresponding to the positions of the via holes, and the conductive paste is sucked into the via holes through the small holes. In addition, several small holes are provided at positions corresponding to the periphery of the raw sheet on the printing table, and by maintaining a negative pressure in these holes, the raw sheet is attracted and held at the periphery of the raw sheet. The above negative pressure state is released when the is removed from the printing table.

However, in this conventional method, if the raw sheet is not carefully and correctly placed on the printing table, the printing pattern may be misaligned, or the via holes may be misaligned with the small holes on the printing table, resulting in The conductive paste is not filled into the inside of the battery and may leak. On the other hand, in order to prevent such a situation, the raw sheets must be set carefully and carefully, which makes it impossible to increase work efficiency. Furthermore, since raw sheets are easily deformed or damaged by external forces, it is very difficult to incorporate the process of setting and resetting them on the printing table into an automated mass production system.

[Purpose of the invention]

This invention was made to solve the above-mentioned problems in the conventional method, and it prints a wiring pattern on one side of a long raw sheet while intermittently feeding it, and at the same time prints a wiring pattern on one side of the raw sheet and simultaneously fills the via hole. The present invention provides a method and device for filling conductive paste, thereby improving productivity and promoting automation.

[Structure and Examples of the Invention]

First, the configuration of the apparatus according to the present invention will be explained based on the illustrated embodiment.A long raw sheet 12 is fed along the path along which the raw sheet 12 is fed in the longitudinal direction.
A printing press 15 and a mesh belt 1 are arranged above and below so as to sandwich the .

The printing machine 15 is usually a screen printing machine, and has a printing pattern corresponding to a predetermined wiring pattern and a via hole drilling pattern.

The mesh belt 1 consists of a mesh-shaped endless belt that is sufficiently wider than the raw sheet 12 wound between rollers 2 and 3, and is moved in the direction in which the raw sheet 12 is fed by the drive of these rollers 2 and 3. Driven intermittently. Located between the rollers 2 and 3,
A vacuum table 11 is provided below the mesh belt 1 to maintain negative pressure on the back side of the belt 1.

The mesh belt 1 is also equipped with a tape supply mechanism 14 that supplies a breathable tape 5 between the belt 1 and the raw sheet 12. This tape 5 is a long tape made of high-quality paper or the like, which is slightly narrower in width than the green sheet 12 and has a width sufficient to cover the via hole punching pattern described later. After passing through a tension roll 7 that is movable in the direction of the arrow in FIG. 1, it rides on the center of the mesh belt 1, and is conveyed along with the belt 1 from right to left in the figure while being attracted and held there. Furthermore, after leaving the mesh belt 1, the tape 5 passes through a tension roll 8 and a guide roll 9, which are movable in the direction of the arrow in FIG. 1, and then is wound onto a take-up roll 10.

This take-up roll 10 is connected to a motor (none of which is shown) via a half clutch, and a weak torque is applied in the direction of the arrow. Therefore, the tape 5 that is sequentially fed as the mesh belt 1 is driven is wound up as needed.

The process of printing the wiring patterns 16, 16, . . . on the raw sheet 12 using this apparatus and filling the via holes 13, 13, . . . with conductive paste is carried out as follows.

A raw sheet 12 in which via holes 13, 13, . . . have been previously punched in a predetermined pattern in a previous process.
is sent from right to left in synchronization with the driving of the mesh belt 1, as shown by the arrow in the figure, and rides on the center of the belt 1 so as to cover the tape 5. Here, a tape 5 with air permeability that is slightly narrower than the raw sheet 12 is supplied to the center of the mesh belt 1, so that the central part of the raw sheet 12 is attracted to the mesh belt 1 through this tape 5. Retained. In addition, since the peripheral portion of the coexisting sheet 12 is in direct contact with the mesh belt 1 without using the tape 5, it is attracted and held by the mesh belt 1 with a stronger suction force than the central portion. As a result, the raw sheet 12 is stably held flat on the mesh belt 1 without wrinkles or the like.

While the raw sheet 12 is being held on the mesh belt 1 in this way, when the belt 1 stops driving,
At the same time that the printing machine 15 prints the wiring patterns 16, 16, . . . with conductive paste on the green sheet, the conductive paste is filled into the via holes 13, 13, . In this case, stop positioning marks 17, 17... are previously placed on the raw sheet in a predetermined positional relationship with the perforation pattern of the via holes 13, 13... While reading the above belt 1 using the same marks 17,17...
It is appropriate to stop.

In this process, via holes 13, 13...
... is maintained at a negative pressure through the tape 5 by the suction action of the vacuum table 11, which helps filling the conductive paste. At this time, the suction force acting on the conductive paste within the via holes 13, 13, . Can be done.

In addition, the tape 5 has the effect of preventing the suction belt 1 from becoming dirty with conductive paste, and even if the belt 1 becomes dirty, a new tape 5 is supplied one after another, completely preventing the raw sheet 12 from getting dirty. be able to. Furthermore, due to the suction action of the vacuum table 11 through the tape 5, the conductive paste oozes between the raw sheet 12 and the tape 5, and the via hole 1
3,13...The surrounding area will not be polluted.

This tape 5 has pie holes 13, 13...
Even if the perforation pattern is different, it can be used as is as long as it has a width that covers the entire range of the same pattern. Therefore, there is no need to prepare a different one for each different perforation pattern as in the conventional printed table, and it can be used commonly for various perforation patterns.

In addition, the green sheet on which wiring patterns are printed and via holes are filled with conductive paste as described above is cut into predetermined small pieces in the subsequent process, laminated, and then crimped and then baked. This completes the multilayer wiring ceramic board.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to continuously print a wiring pattern on a raw sheet and fill the via holes with conductive paste while it is in a long state, so that a single piece of raw sheet in the form of a small piece can be printed. Compared to conventional means in which these steps are performed while setting and resetting the destination printing table, productivity can be greatly improved, and the process can be automated to a large extent.

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of the invention, and a plan view same as FIG. 2. FIG. 1... mesh belt, 5... tape, 11...
...Bakyum table, 12...Raw sheet, 13
... Via hole, 14 ... Tape supply mechanism.

Claims (1)

[Claims] 1. A method of printing a wiring pattern with conductive paste on a raw sheet for a multilayer wiring ceramic board having via holes perforated therein, and filling the via holes with the conductive paste intermittently in a predetermined direction. A raw sheet with via holes perforated is supplied onto the mesh belt being fed, and a breathable tape is supplied between the mesh belt and the raw sheet to maintain negative pressure on the back side of the mesh belt. A multilayer wiring porcelain characterized in that, while a tape and a raw sheet are held by suction on the raw sheet, when a mesh belt stops, a conductive paste is printed on the raw sheet and the conductive paste is filled into the via hole. Method for printing and filling conductive paste on raw sheets for substrates. 2. In a device that prints a wiring pattern using conductive paste on a green sheet for a multilayer wiring ceramic board with via holes punched therein, and also fills the via hole with the conductive paste, a long green sheet is fed in the longitudinal direction of the device. A printing machine and a mesh belt that is driven intermittently are placed above and below the same sheet on the path, and the mesh belt is
A raw sheet for multilayer wiring porcelain substrates, characterized in that it is equipped with a vacuum table that maintains a negative pressure on the back side thereof, and a tape supply mechanism that supplies a breathable tape between the belt and the raw sheet. conductive paste printing and filling equipment.