JPH0221673B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention The present invention relates to a ceramic substrate manufacturing method that is optimal when manufacturing a multilayer ceramic substrate using a sheet lamination method, and in particular to a ceramic substrate manufacturing method that takes into consideration improved positioning accuracy in the manufacturing process. The present invention relates to a substrate manufacturing method.

BACKGROUND ART 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 after 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 in the manufacturing process.

Conventionally, this positioning has been performed 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 FIG. 1a. Next, as shown in FIG. 1b, the guide holes 2 of the sheet 1 are inserted into the guide pins 4 of the lower mold 3 of the via hole punching die for positioning, and via holes 5 are punched out at predetermined positions on the sheet 1. *In addition to punching with a mold, a well-known method for forming a via hole is to use an NC drilling machine to drill holes in a predetermined position, and the positioning method is 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, as shown in FIG. The via holes to be filled with the conductive paste (not shown) were arranged so as to match the positions of the via holes to be filled with the conductive paste 8 and filled with the conductive paste 8.

Next, as shown in FIG. 1d, a wiring pattern 9 is printed using the screen printing method as in the case of filling the conductor.

Next, as shown in FIG. 1e, a predetermined number of sheets with wiring patterns printed thereon are laminated and then heated and pressed to bond and integrate them. At this time, in order to position each sheet, the guide pin 11 of the lamination jig 10
This is done by inserting the guide hole 2 of the sheet 1.

Next, as shown in FIG. 1f, the guide hole 13 of the sheet 12 integrated by adhesive is inserted into the guide pin 16 of the lower die 15 of the product punching die, and a product part 18 whose outline is indicated by the dotted line 17 is punched out. . 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 conductor.

As described above with reference to FIG. 1, in the conventional manufacturing method, guide holes punched in a green sheet are inserted into guide pins of a positioning table in each process to perform positioning. However, as is well known, green sheets are produced by supplying ceramic raw material powder such as alumina with an organic binder.
Since it is formed into a sheet shape, it is easily deformed during the process, and the guide hole also loses its shape by repeatedly inserting and removing the guide pin into the guide hole.

For this reason, the positioning accuracy is limited to approximately ±0.1 mm, and this poor positioning accuracy has been an obstacle in manufacturing large-sized laminated substrates with ultra-high density.
For example, in a via hole conductor filling process using a screen printing method, if a misalignment occurs between the opening of the screen and the via hole position of the sheet, the filling with the conductive paste will not be completed completely. That is, as shown in FIG. 2, when the guide hole 2 of the sheet 1 is deformed 19 and the sheet 1 is set in a position misaligned with respect to the positioning table 3 of the hole filling device, the screen 20 A positional shift occurs between the opening 21 of the sheet 1 and the via hole 5 of the sheet 1. In this state, the conductive paste 8 is moved through the opening 2 of the screen 20 by moving the squeegee 22.
If the conductive paste is discharged through the conductor paste 1 into the via hole 5 of the sheet 1, a sufficient discharge amount will not be obtained and the conductive paste will stop midway through the via hole. It is clear that such an incompletely filled conductor paste 23 causes an open failure of the substrate after lamination bonding and sintering.

Next, an example of a case where a problem occurs due to misalignment between sheets in the lamination adhesion process is shown below.
It is shown in Figure 3. That is, sheet 1 and sheet 1A
Due to the misalignment between the two, conductivity could not be established between the via hole 24 of sheet 1 and the via hole 24A of sheet 1A, resulting in an open defect (defective location 2).
5) occurs. Also, due to the misalignment between the sheets 1A and 1B, the via hole 24 of the sheet 1B
A shot defect (defective point 27) occurs between the wiring line 26A of the sheet 1A and the wiring line 26A of the sheet 1A.

Purpose of the Invention The purpose of the present invention is to fill conductors in via holes of multilayer ceramic substrates by lamination method, print wiring patterns,
The object of the present invention is to provide a method for manufacturing a ceramic substrate that greatly improves the positioning accuracy of green sheets in a lamination bonding process and can manufacture an ultra-high-density multilayer substrate.

General Description of the Invention In the ceramic substrate manufacturing method of the present invention, images of reference marks provided at at least two locations on a sheet mounted on a table at a positioning position are projected on a monitor television, and the images of the reference marks are displayed at a predetermined position on the television. After finely adjusting the table and fixing it, the table is then moved to the working position to perform work such as filling conductors into the sheet via holes, printing wiring patterns, and laminating and bonding, thereby accurately positioning the sheet during various operations. I'm starting to do that.

Examples of the invention Examples of the present invention are shown in FIGS. 4-10.

FIG. 4 shows the green sheet 1 in which via holes have been punched. Drilling is by punching die or NC
This is done using a drilling machine, etc. Hole position accuracy is ±0.01mm
It is possible to suppress it within At this time, holes that will serve as reference holes for positioning in the next process are also drilled at the same time. In the example, a diameter of 0.2 mm was used using an NC drilling machine.
via hole 5 and a diameter of 0.2mm as a reference mark.
The reference holes 28A, 28B, 28C, 28D are 0.3
Perforations were simultaneously made in the four corners of a mm-thick green sheet. The positional accuracy between holes is ±0.01mm.

Next, FIG. 5 shows the main parts of an apparatus for carrying out the method of filling conductor paste into via holes according to an embodiment of the present invention.
A seat is mounted on the top surface of the seat and can be moved for fine adjustment in the X, Y, and O directions, and can be fixed after adjustment. For this purpose, for example, a table base 129 on which the table 29 is placed is used.
The table 29 can be relatively movable for fine adjustment. Note that the table 29 is configured such that a sheet can be suctioned and fixed to the top surface of the table by a vacuum suction device (not shown) (in FIG. 5, a dummy sheet 30 is suctioned and fixed on the table 29).

Further, the table base 129 is guided by the guide rail 31 whose axis is horizontal, and is moved rightward from the positioning position a shown in FIG. 5 to the working position b.
It is now possible to move up to In this working position b, it is placed directly below the screen 32 that is moved up and down,
The screen 32 is lowered and brought into close contact so that the opening 132 matches the via hole of the sheet, and the conductive paste 33 is forced through the opening 32 into the via hole of the sheet by the lateral movement of the squeegee 34.
The openings 132 of the screen 32 have the same pattern as the via holes 5 and reference holes 28A to 28D in FIG. 4.

Above the table 29 at the positioning position, four image pickup tubes 35A to 35D are arranged so as to be able to move slightly in the X and Y directions so as to project the reference mark on the sheet of the table 29 onto the cathode ray tube of the monitor television 36. Images from the four image pickup tubes 35A to 35D are divided into four parts and displayed on the cathode ray tube. Two cursor lines 39 are provided on each of the four divided cathode ray tubes 37A to 37D in the horizontal and vertical directions and can be moved separately in the vertical and horizontal directions.

Next, a method for filling a via hole with a conductive paste according to an embodiment of the present invention will be described with reference to FIG. First, a method for detecting the screen position will be described. A dummy sheet 30 for detecting the position of the screen 32 is mounted on the positioning table 29 stopped at the sheet positioning position a,
It is fixed to the table 29 by vacuum suction. next,
The table 29 is sent to the working position b along the guide rail 31 of the conductor filling device. Next, squeegee 3
4, apply the conductive paste 33 to the screen 32.
is printed on the dummy sheet 30 through the opening 132, and the table 29 is returned to the position a again.

Next, the positioning reference hole 28 which is a reference mark
Image pickup tubes 35A, 35B, 35C, 35 for position detection are placed above the print patterns 34A, 34B, 34C, 34D corresponding to A, 28B, 28C, 28D.
Let D come. Image pickup tubes 35A, 35B, 3
Print patterns 34A and 3 captured in 5C and 35D
Images 38A and 3 of 4B, 34C, and 34D, respectively.
8B, 38C, 38D are areas 37A, 37B, which are divided into four on the cathode ray tube of the monitor television 36.
The positions of the image pickup tubes 35A, 35B, 35C, and 35D are individually adjusted in the X and Y directions so that they are located approximately in the center of the tubes 37C and 37D, and then locked. Next, two horizontal and two vertical cursor lines 39 provided for each area 37A, 37B, 37C, and 37D on the cathode ray tube are moved, and the print pattern images 38A, 3
Surround 8B, 38C, and 38D from the top, bottom, left, and right. In this embodiment, a 100x image is projected on a 12-inch cathode ray tube. The spacing between scanning lines on a cathode ray tube is approximately 0.6 mm, so the resolution is 0.006
mm, and the position of the printed pattern of the reference hole can be fixed with a cursor line on the cathode ray tube with an accuracy of ±0.01 mm.

Next, a procedure for filling a product sheet with a via hole with a conductor will be described. Using the end surface of the product sheet or a guide hole (not shown), the product sheet is roughly positioned and mounted on the positioning table 29 at the positioning position a in FIG. 5, and fixed by vacuum suction. At this time, the reference holes 28A, 28B, 28 displayed on the cathode ray tube
The image of C, 28D is 40
A, 40B, 40C, and 40D, which are shifted from the center position of the corresponding cursor line 39. Next, in order to correct this deviation, images 40A, 40B, 40C, 40 of the reference holes are displayed on the cathode ray tube.
While looking at D, move the table 29 slightly so that it is in the center of the corresponding cursor line, and block when the positioning is completed. FIG. 7 shows an image of the state in which positioning is completed.

Next, the table 29 is transported to the conductor filling work position b, stopped at a fixed position, and conductor filling is performed. Subsequently, the table 29 is again conveyed to the positioning position a, and the sheet that has been filled with conductors is taken out. As described above, by adopting the positioning method of the present invention and suppressing the feeding accuracy of the table 29 within the range of 0.01, it became possible to align the screen and the sheet with an accuracy of ±0.01 mm.

Next, the wiring pattern is printed, but since the wiring pattern can be printed using exactly the same device as the conductor filling device (only the screen 32 has been changed), the wiring pattern can be printed within ± with respect to the standard position of the sheet.
Printing was possible with a positioning accuracy of 0.01mm.

This has made it possible to manufacture multilayer ceramic substrates with ultra-high density patterns in which the distance between the end faces of the via hole conductor and the adjacent wiring line is 0.1 mm.

Next, an example of the lamination adhesion method will be described with reference to FIGS. 8 to 10. This laminating device uses a positioning table 41 configured similarly to the conductor filling device,
This table 41 is similarly movable along the guide rail 31 from the positioning position a to the laminating work position b. In this working position b, base 4
The head portion 44 is guided by four guide posts 43 erected on the head portion 2 and vertically moves up and down. The lower surface 45 of this head portion 44 can attract a sheet by vacuum suction.

In addition, four image pickup tubes 35A~ are placed on the positioning position a.
The state in which the 35Ds are arranged and connected to the monitor television is the same as in each of the above embodiments.

Next, we will explain the laminating operation using this laminating device.The principle of positioning is the same as in the case of the conductor filling device.The sheets 1 are fixed one by one to the table 41 at the positioning position, and the reference holes 28A to 28D
The table 41 is imaged on a cathode ray tube, the table 41 is adjusted so that it is in a fixed position, and the table 41 is locked.The table 41 is then transported to the lamination work position b and laminated and bonded. To explain step by step, first, the first sheet 1 is placed on the positioning table 41 using its end surface or guide hole (not shown).
It is roughly positioned and mounted, and fixed to the table 41 by vacuum suction. Similar to the conductor filling device, image pickup tubes 35A, 35B, 35C, and 35D are placed above the reference holes 28A, 28B, 28C, and 28D of the sheet 1.
, respectively, and insert the reference holes 28A, 28B, onto the CRT (not shown) of the monitor TV.
Projects images of 28C and 28D. Next, the image of each reference hole is fixed on the cathode ray tube using two cursor lines in the vertical direction and two in the horizontal direction. Next, with the sheet 1 vacuum-suctioned, the positioning table 4
1 is transported to the laminating work position b and stopped at a fixed position as shown in FIG. Next, the head portion 44 of the laminating device is lowered along the guide post 43 and stopped with the lower surface 45 of the head lightly pressing against the upper surface of the sheet 1.

In this state, the vacuum suction by the table 41 is cut off, the head section 44 is brought into a vacuum suction state, and the sheet 1 is suctioned onto the lower surface 45 thereof. Subsequently, the head portion 44 is retracted upward, and the table 41 is retracted to the positioning position a.

Next, the means for positioning and stacking the second sheet under the first sheet will be described. Table 41 in position a for positioning the second sheet
Approximately position it on top and fix it. Brush or spray adhesive for temporary bonding onto the four corners of the sheet, preferably outside the product area. Next, project the images of the four reference holes on the sheet onto the cathode ray tube, and move the X, Y, O Finely adjust the table 41 in the direction and lock it. Next, move the table 41 to the stacking work position b.
The head 44 is lowered to the lower surface 45 of the head.
The lower surface of the first sheet, which has been sucked in, is stopped while lightly pressing the upper surface of the second sheet. In this state, when the vacuum suction of the table 41 is cut off and the head 44 is raised, the second sheet is adhered to the lower surface of the first sheet and is raised. Subsequently, the table 41 is transported to the positioning position a, and the third, fourth, etc. sheets are successively laminated and bonded using the same means as described above until a predetermined number of sheets have been attached.

FIG. 10 shows a state in which the first sheet 1 and the second sheet 1A have been bonded and the third sheet 1B is mounted on the table 41 at the positioning position a. As can be seen from the above explanation, according to the present invention, positioning accuracy is determined by the positional accuracy of the reference hole, its resolution, the alignment accuracy with respect to the cursor line on the cathode ray tube, and the mechanical accuracy of the laminating device, and It is possible to perform laminated adhesion with the misalignment error controlled within ±0.01 to ±0.02mm.

After the sheets have been laminated and bonded, the vacuum suction of the head section 44 is cut off and the sheets are taken out from the lamination apparatus. In this state, they are temporarily bonded with adhesive, so they are integrated by heating and pressing using a hot press. Next, a product part is cut out using the reference hole as a guide and sintered in a sintering furnace. After that, surface treatments such as Ni plating and Au plating are applied to complete the board.

Thus, in each embodiment, it is not necessary to abut the end surface of the green sheet against the positioning block of the apparatus or to insert the guide hole of the green sheet into the guide pin of the apparatus. Therefore, positioning accuracy will not be deteriorated due to damage to the end face of the green sheet or the guide hole.

In addition, since the image of the reference hole of the green sheet is always projected on the cathode ray tube and the position is confirmed during work, if the reference hole position is incorrect due to sheet deformation, etc., we will mark it as a defective product before starting work. can be excluded.

In addition, if the reference hole position deviates from within the allowable range due to economical shrinkage of the sheet, we will install reference holes at the four corners of the sheet to equalize the deviation from the set position on the CRT. By allocating it to With the conventional guide hole 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 method, positioning by parallel movement, rotation, etc. The error is due to position confirmation on the cathode ray tube.
can be minimized.

Although the above embodiments have been explained in which the present invention is applied to filling conductors into via holes, wiring pattern printing, and lamination adhesion, it is natural that the present invention can be used only for any one of the above operations. It is possible.

Effects of the Invention As explained above, in the present invention, a table on which a sheet is mounted can be moved from a positioning position to a working position, and at the positioning position, images of reference marks provided at at least two places on the sheet are projected on a monitor television. The table is finely adjusted to be in the specified position on the TV, then fixed, and then moved to the working position to perform work such as filling conductors into the seat via holes, greatly improving the positioning accuracy of these tasks. , it has the effect of making it possible to obtain an ultra-high precision multilayer substrate.

[Brief explanation of drawings]

Figures 1 a to f are perspective views showing the conventional manufacturing method of ceramic substrates, Figure 2 is a cross-sectional view showing the conventional conductor filling process, Figure 3 is a cross-sectional view showing the conventional lamination bonding process, and Figure 4 is a cross-sectional view showing the conventional conductor filling process. A perspective view of a sheet used in an embodiment of the present invention, FIG. 5 is a schematic diagram showing a conductor filling method according to an embodiment of the present invention, FIG. Fig. 7 is an image of the sheet reference hole after positioning is completed, Fig. 8 is a perspective view showing the state in which the first sheet is mounted on a table using the lamination adhesion method of the embodiment of the present invention, and Fig. 9 is a photographic view of the first sheet. FIG. 10 is a perspective view showing the state in which the sheets of FIG. 1... Green sheet, 5... Beer hall, 2
9...Positioning table, 32...Screen,
33... Conductor paste, 35A to 35D... Image pickup tube, 36... Monitor TV, 37A to 37D...
Braun tube, 39... cursor line, 41... table, 44... head section.

Claims (1)

[Claims] 1. The table on which the sheet is mounted is movable from the positioning position to the working position, and at the positioning position, images of reference marks provided at at least two places on the sheet are displayed on a monitor television, and the table is moved to a predetermined position on the television. 1. A method for producing a ceramic substrate, which comprises: finely adjusting the substrate, fixing the substrate, and then moving to a working position to perform operations such as printing conductor-filling wiring patterns into sheet via holes and laminating and adhering the substrate.