JPH0478038B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method of manufacturing a multilayer ceramic substrate using a sheet lamination method, and particularly to a lamination method that accurately positions sheets in lamination.

[Background of the invention]

As a method for manufacturing multilayer ceramic substrates, there is a so-called sheet lamination method in which a large number of green sheets are laminated and bonded together by drilling holes in the green sheets, filling the holes with conductors, and printing wiring patterns. In order to manufacture a substrate with an ultra-high density wiring pattern using this method, the key point is to accurately perform various positionings during the manufacturing process.

Conventionally, positioning has been carried out by abutting the end surface of the green sheet against a positioning block, or by inserting guide holes punched in the green sheet into guide pins of a positioning table for each process.

FIG. 1 shows a method for manufacturing a multilayer ceramic substrate using the latter positioning method.

First, guide holes 2 are punched in the green sheet 1 as shown in a. Next, as shown in b, the guide holes 2 of the sheet 1 are inserted into the guide pins 4 of the lower die 3 of the via hole punching die for positioning, and via holes 5 are punched out at predetermined positions of the sheet 1. Figure b shows the state after the via holes are punched out. In addition to punching with a die, via holes can be formed by drilling holes at predetermined positions using an NC drilling machine, and the positioning method is also the same as in this example.

Next, the via hole is filled with conductive paste. The conductive paste used is a paste obtained by adding an organic binder and a solvent to Mo or W powder. Filling with conductor paste is done by screen printing method,
This is done using a well-known method such as a vacuum suction method. Taking the screen printing method as an example, it is necessary to position the screen and the sheet so that the via holes to be filled with conductive paste match the openings of the screen. Conventionally, positioning was performed by inserting the guide hole 2 of the sheet 1 into the guide 7 of the positioning table 6 of the conductor filling device. c is
A state in which the sheet 1 is set on the positioning table 6 and filled with conductive paste 8 is shown. (In the figure,
(The screen, the main body of the conductor filling device, etc. are not shown.) Next, the wiring pattern 9 is printed using the same screen printing method as used for filling the conductor. Figure d shows the state after printing.

Next, a predetermined number of sheets on which wiring patterns have been printed are laminated and then heated and pressed to adhere and integrate them. At this time, in order to position each sheet as shown in e, the guide pin 1 of the laminating jig 10 is
This is done by inserting the guide hole 2 of the sheet 1 into the hole 1. Next, the guide hole 13 of the sheet 12 integrated by adhesive is inserted into the guide pin 1 of the lower die 15 of the product punching die.
4, and punch out a product part 17 whose outline is indicated by the dotted line 16 at f in FIG. After that, sintering is performed using a well-known method, and the front and back conductors are plated with Ni or Au to complete the board.

As described above with reference to FIG. 1, in the conventional manufacturing method, positioning has been performed by inserting guide holes punched in a green sheet into guide pins of a positioning table in each process. However, as is well known, green sheets are made by bonding ceramic raw material powders such as alumina with an organic binder and forming them into a sheet shape, so they are easily deformed during the process, and the guide holes and guide pins are easily formed. By repeatedly inserting and removing the guide hole, the guide hole also loses its shape. For this reason, the positioning accuracy is ±0.1
The limit is on the order of mm, and this poor positioning accuracy has been an obstacle when manufacturing large multilayer substrates with ultra-high density.

There are problems with the guide hole method in each process, but here we will discuss the problems with lamination adhesion as an example.

Figure 2 shows problems during stacking, which occur due to deformation of guide holes, printing position accuracy, position accuracy of via holes from guide holes, deformation of sheets, etc. Due to a misalignment between sheets 1', conductivity could not be established between via hole 8 of sheet 1 and via hole 8' of sheet 1', resulting in an open failure (defective location 19).
occurs. Moreover, due to the misalignment between the sheets 1' and 1'', a shot defect (defective spot 18) occurs between the via hole 8'' of the sheet 1'' and the wiring line 9' of the sheet 1'.

[Purpose of the invention]

An object of the present invention is to provide a lamination method that greatly improves the positioning accuracy of green sheets in the process of laminating multilayer substrates using a sheet lamination method, and allows manufacturing of ultra-high density multilayer substrates.

[Summary of the invention]

In the present invention, a sheet positioning position and a stacking position are provided separately, and sheets that are accurately positioned at the positioning positions are accurately conveyed to the stacking position to perform the stacking operation.

To position the sheet at the positioning position, use an image pickup tube to project a reference hole accurately drilled in the sheet onto the cathode ray tube of a monitor television, and place the sheet reference hole at the fixed position specified by vertical and horizontal cursor lines on the cathode ray tube. Finely adjust and lock the X, Y, and θ tables to which the sheet is fixed so that the hole images match.

Next, the sheet is sucked by the conveyance mechanism (adsorbed in close contact with the positioning table), moved to the stacking table, and stopped. This stop position can be accurately positioned by mechanical methods. At the lamination position, adhesive is applied, a new guide hole is drilled, lamination is performed at an accurate position, temporary adhesion is performed, and this lamination position is also monitored to confirm accuracy.

As described above, according to the present invention, the end surface of the green sheet is brought into contact with the positioning block of the device,
Alternatively, there is no need to insert the guide hole of the green sheet into the guide pin of the device, and even if the guide hole etc. is damaged, stacking is possible, and position confirmation is always possible, so there is no need to insert defective products due to sheet deformation. This makes it possible to remove layers, etc., allowing for highly accurate lamination.

[Embodiments of the invention]

Examples of the present invention are shown in FIGS. 3 to 6. FIG. 3 shows an overall view of the laminating device. FIG. 4 shows the sheets before lamination. Positioning reference holes 35A to 35D are punched simultaneously with the via holes 5 in the sheet before lamination using a punching die, NC drilling machine, or the like. This positional accuracy can be suppressed to within ±0.01mm. In the example, a via hole 5 with a diameter of 0.2 mm and a reference hole 35 with a diameter of 0.2 mm are created using an Nc drilling machine.
A, 35B, 35C, and 35D were simultaneously drilled at the four corners of a 0.3 mm thick green sheet, and the positional accuracy between the holes immediately after drilling was ±0.01 mm.

After drilling, filling printing of via holes 5 and wiring pattern printing are performed using a screen to obtain a state before lamination.

The lamination work uses the apparatus shown in Fig. 3. For lamination, the sheet 1 is set on the positioning table 25, and the sheet 1 is fixed by vacuum suction. At this time, the approximate positioning is performed by inserting the conventional guide hole 2 into the guide pin of the positioning table 25. Next, as shown in Fig. 5, the reference holes 35A, 35B, 35C,
On 35D, image pickup tubes 22A, 22B, 22C, 2
2D and insert the reference holes 35A, 35B, 35
C, 35D are displayed on the monitor television 20. Reference holes 32A, 32 on monitor TV 20
Cursor lines 33, 3 for B, 32C, 32D
4 to the reference holes 32A, 32B, 32C, 3
Surround 2D. With this work, the image pickup tubes 22A, 22
B, 22C, 22D and the cursor lines 33, 34 of the monitor television 20 are fixed.

Next, the sheet conveyance mechanism table 24 is accurately moved onto the alignment table 25. The alignment table 25 is raised to bring the sheet 1 into close contact with the conveyance table 24, and the conveyance table 24 is vacuumed, and at the same time, the vacuum suction of the alignment table 25 is stopped. The alignment table 25 is lowered and stopped at the original position.

The conveyance table 24 is accurately moved onto the stacking table 27 while the sheets are being sucked. The stacking table 27 is raised and a new guide hole 37 is drilled (the guide hole 37 is used to prevent the entire stack from tilting during hot pressing during main bonding), and at the same time, it is brought into close contact with the transport table. At the same time as vacuum suction is performed on the stacking table 27, suction on the transport table 24 is stopped. The stacking table 27 is lowered. At this lowering stop position, the position sensor 36 detects the upper end of the sheet and stops.

The transport table 24 is moved to an intermediate position between the alignment table 25 and the stacking table 27 (a position that does not interfere with work).Then, the image pickup tube 23 is moved to project the reference hole 32 on the monitor television 21, and the cursor line is Move 33 and 34 to the reference hole 32
Assume that the position is fixed.

For the second and subsequent sheets, the alignment table 25
The sheet is set at , and while watching the monitor television 20, the positioning table 25 is moved in X, Y, and θ, and the sheet is positioned within the cursor lines 33 and 34.

Adhesive is applied to the first sheet with a brush or spray, and the second sheet is moved to the stacking table 27 and stacked in the same manner as the first sheet. The TV monitors on the stacking table constantly check their positions after stacking, and if there is a problem, they can be stacked again. The third and subsequent sheets are sequentially stacked in the same manner as the second sheet. FIG. 6 shows the state of completed lamination. The positional accuracy in this embodiment is such that a 100x image is projected on a 12-inch cathode ray tube, and the cursor lines 33 and 34 are approximately 0.6 mm on the cathode ray tube, and the resolution is 0.006 mm.
Therefore, the position of the reference hole can be fixed on the cathode ray tube with an accuracy of ±0.01mm.

Although it depends on other factors such as machine accuracy and alignment accuracy with respect to the cursor line on the cathode ray tube, it is possible to perform laminated bonding with the positional deviation error between sheets controlled to ±0.01 to ±0.02 mm.

When the stacking is completed, the vacuum of the stacking table 27 is stopped, and the guide punching pin 29 is lowered to take out the sheet. In this state, it is temporarily bonded with adhesive, and a pin is set in the new guide hole to prevent the entire piece from tilting, and then it is set in the hot press jig (see Fig. 2). Thereafter, they are heated and pressed using a hot press device to integrate them.

After this, the board is completed through processes such as cutting, sintering, Ni plating, and Au plating.

〔Effect of the invention〕

According to the present invention, the positioning of the laminated adhesive can be adjusted to ±0.01
This can be done with an accuracy of ~±0.02mm. Therefore,
There are no open defects, short defects, etc. due to lamination, and it has become possible to manufacture multilayer ceramic substrates with ultra-high density patterns.

In addition, during lamination, the position of the reference hole is constantly checked on the cathode ray tube, and if the position of the reference hole is misaligned due to deformation of the sheet, it can be eliminated as a defective product before starting the work. In addition, checks are made during lamination, and if alignment is poor due to malfunction or the like, lamination can be performed again, making it possible to prevent defects.

Even if the sheet changes over time or is deformed due to printing, if the reference hole position is within the allowable range, adjust the deviation of the four corner reference holes from the set position on the cathode ray tube (up, down, left, right). By distributing it evenly, positional deviation errors can be minimized. With the conventional guide hole method and guide pin method, it was impossible to eliminate positional errors caused by parallel movement or rotation of the entire sheet in one direction, but with this equipment, position errors caused by parallel movement, rotation, etc. Positioning errors can be minimized because the position is confirmed on the cathode ray tube.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of a conventional method for manufacturing a multilayer ceramic substrate. Figure 1a shows a green sheet with guide holes punched out, Figure 1b shows a green sheet with via holes punched out, Figure 1c shows the state in which the via holes are filled with conductors, Figure 1d shows the state in which wiring pattern printing has been completed, Figure 1e shows the state in which sheets are laminated for lamination adhesion, and Figure 1f shows the product. Figure 2 shows the state in which the adhesively bonded sheet is set in the lower mold of the punching die for punching.
3 is an overall view of a stacking apparatus according to an embodiment of the present invention; FIG. 4 is a perspective view of sheets before stacking; FIG. 5 is an explanatory diagram of the sheet positioning method; FIG. 6 is a perspective view showing the sheet state after lamination. 1... Green sheet, 2... Guide hole, 3...
... Via hole punching die (lower die), 4... Guide pin of via hole punching die, 5... Via hole, 6
... Positioning table of conductor filling device, 7 ... Guide pin of positioning table of conductor filling device, 8
...Conductor paste filled in via hole, 9...
...Wiring pattern printed on green sheet, 1
0... Lamination jig, 11... Guide pin of the lamination jig, 12... Green sheet after lamination bonding, 13
...Guide hole of green sheet after lamination adhesion, 1
4...Guide pin of product punching die, 15...Product punching die (lower die), 16...Outline of product, 17
……product.

Claims (1)

[Scope of Claims] 1. A method of laminating sheets of multilayer ceramic substrates, which allows for slight movements in at least X, Y, and θ in a method of laminating sheets in which via holes of the sheets have been filled with conductors, wiring patterns have been printed, etc. A positioning table and a laminated table capable of at least Z movement are separately provided, and in the positioning table, two or more reference holes of each sheet are processed on a first image monitor, and an image of the reference holes is processed. After each sheet is mounted and fixed at a predetermined position, each sheet is suctioned and fixed by a conveying mechanism and moved to the stacking table, stacked on the stacking table, and the second image is formed in the reference hole. A laminating method characterized in that processing is performed using a monitor to confirm that each of the sheets has been laminated normally. 2. After each sheet is moved by the transport mechanism,
2. The lamination method according to claim 1, wherein each sheet is provided with a guide hole for lamination. 3. The laminating method according to claim 1 or 2, characterized in that, after laminating the respective sheets, if a defect in the laminating position of each of the sheets is detected, the defective sheet is removed and lamination is performed again. .