JP5094467B2 - Manufacturing method of ceramic substrate - Google Patents

Description

  The present invention relates to a method for manufacturing a ceramic substrate in which a conductor layer is formed on the surface of a ceramic sintered body.

  2. Description of the Related Art Conventionally, many electronic devices are incorporated in electronic devices such as mobile communication devices such as mobile phones. Such communication devices such as mobile phones have been rapidly reduced in size in recent years, and ceramic substrates mounted thereon are also required to be reduced in size and thickness.

  Such a ceramic electronic component contains a metal powder after forming a ceramic green sheet (hereinafter also referred to as a green sheet) with a doctor blade or the like by adding an organic binder, a plasticizer, a solvent, and the like to the ceramic powder to form a slurry. After forming a conductor pattern layer on the green sheet by printing a conductor paste, etc., and then stacking and pressing the green sheet on which a plurality of conductor pattern layers are formed, this laminate is obtained. It is obtained by firing the body.

In general, these ceramic substrates are subjected to R chamfering on the ridge line portion by barrel-polishing the ceramic sintered body in order to suppress the occurrence of cracks, chips and the like.
JP 2003-309343 A Japanese Patent Laid-Open No. 10-125565

  However, when barrel polishing is performed on a ceramic substrate having a conductor layer formed on the surface, the polishing stone is ground in direct contact with the conductor layer, so that the conductor layer formed on the surface of the ceramic substrate disappears. There was a problem.

  The present invention has been devised to solve the conventional problems as described above, and its purpose is to process the ceramic substrate without losing the conductor layer formed on the surface of the ceramic substrate. Another object is to provide a method for manufacturing a ceramic substrate.

  The method for manufacturing a wiring board according to the present invention includes a preparation step of preparing a ceramic sintered body having a conductor layer provided on a surface thereof, and an adhesive layer is formed so as to cover the conductor layer on the surface of the ceramic sintered body. Forming step, connecting step of connecting a ceramic member to the ceramic sintered body through the adhesive layer inside the ceramic sintered body in plan view, and the ceramic sintered body to which the ceramic member is connected And a removal step of removing the ceramic member and the adhesive layer by melting the adhesive layer.

  Preferably, in the method for manufacturing a ceramic substrate, the ceramic member is made of the same material as the ceramic sintered body.

  Preferably, the ceramic member has an inclined surface that spreads toward the ceramic sintered body.

  Preferably, after the removing step, the ceramic sintered body has a cleaning step of cleaning the surface on which the conductor layer is formed.

  Preferably, the adhesive layer is made of an adhesive sheet.

  According to the method for manufacturing a ceramic substrate of the present invention, it is possible to realize a method for manufacturing a ceramic substrate that enables processing of the ceramic substrate without losing the conductor layer formed on the surface of the ceramic substrate.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram showing an example of a method for manufacturing a ceramic substrate according to an embodiment of the present invention. In FIG. 1, 1 is a ceramic sintered body, 2 is a conductor layer, 3 is an adhesive layer, 4 is a ceramic member, and 11 is a ceramic substrate having a chamfered edge.

  The manufacturing method of the ceramic substrate 11 according to the present embodiment includes a preparation step of preparing the ceramic sintered body 1 having the conductor layer 2 provided on the surface, and the conductor layer 2 covered on the surface of the ceramic sintered body 1. The forming step for forming the adhesive layer 3, the connecting step for connecting the ceramic member 4 to the ceramic sintered body 1 via the adhesive layer 3 inside the ceramic sintered body 1 in plan view, and the ceramic member 4 connected A polishing step of polishing the ceramic sintered body 1 and a removal step of melting the adhesive layer 3 and removing the ceramic member 4 and the adhesive layer 3.

  This will be specifically described below. First, as shown to Fig.1 (a), the ceramic sintered compact 1 with which the conductor layer 2 was provided in the surface is prepared. This ceramic sintered body 1 is obtained as follows. For example, an organic binder, a plasticizer, an organic solvent, and the like are mixed with the ceramic inorganic component powder to obtain a slurry, and a ceramic green sheet is manufactured therefrom by a doctor blade method, a rolling method, a calendar roll method, or the like.

  Next, a conductor metal paste that becomes the conductor layer 2 by firing is applied to the required number of ceramic green sheets by screen printing, gravure printing, or the like. This conductive metal paste is prepared by mixing a conductive metal component powder with an organic binder, a plasticizer, an organic solvent, and the like.

  Next, these ceramic green sheets are laminated and heat-pressed to produce a ceramic green sheet laminate. The ceramic green sheet laminate is fired in the air or in a humidified nitrogen atmosphere to produce a ceramic sintered body 1.

  An internal wiring conductor layer that electrically connects the conductor layers 2 may be formed inside the ceramic sintered body 1 as necessary. Moreover, you may produce the ceramic sintered compact 1 in which the conductor layer 2 was formed by apply | coating a conductor metal paste to the surface of the ceramic sintered compact 1 sintered by baking beforehand, and heat-processing.

  Next, as shown in FIG. 1B, the adhesive layer 3 is formed on the surface of the ceramic sintered body 1 so as to cover the conductor layer 2 by a dispensing method, a screen printing method, or the like, The ceramic member 4 that is smaller than the ceramic sintered body 1 as viewed is connected to the ceramic sintered body 1 through the adhesive layer 3. Here, as shown in FIG. 2, the ceramic member 4 is connected to the ceramic sintered body 1 inside the ceramic sintered body 1 so that the corners of the ceramic sintered body 1 are not covered in a plan view. .

  As the type of the adhesive layer 3, a paste adhesive such as epoxy, acrylic, or urethane, or a sheet adhesive can be used.

  Here, when an adhesive sheet is used to form the adhesive layer 3, the adhesive layer 3 can be formed uniformly, so that when the ceramic member 4 is connected, the adhesive layer 3 is ceramic sintered. The ceramic substrate 11 can be prevented from protruding to the side surface of the body 1 and the unevenness of the R chamfering of the edge portion during polishing is further reduced.

  As the type of the ceramic member 4, oxide ceramics such as alumina ceramics and glass ceramics, and non-oxide ceramics such as aluminum nitride and silicon carbide can be used. Here, when the material of the ceramic member 4 and the material of the ceramic sintered body 1 are formed of the same material, the ceramic member 4 ground during polishing is re-applied to the surface of the ceramic sintered body 1. The occurrence of deterioration of insulating properties due to adhesion can be further reduced.

  In addition, as shown in FIG. 3, when the ceramic member 4 has a shape having an inclined surface that spreads toward the ceramic sintered body 1, the polishing stone and the abrasive are edge portions of the ceramic sintered body during polishing. Therefore, the ceramic substrate 11 can be obtained in which the edge chamfering process can be performed on the edge portion in a short time and the processing irregularity of the R chamfering process is further reduced.

  Next, as shown in FIG. 1 (c), the ceramic sintered body 1 to which the ceramic member 4 is connected is polished to round the edge portion.

  As a polishing method, a ceramic sintered body 1 is put in a polishing container containing a polishing stone, an abrasive, and a polishing solution, and the ceramic sintered body 1 is rotated or vibrated. A so-called blast polishing process or the like that is sprayed onto the bonded body 1 can be used.

  Further, by polishing in a state where the ceramic sintered body 1 and the ceramic member 4 are integrated, for example, even when the thickness of the ceramic sintered body 1 is thin, the ceramic member 4 is made of the ceramic sintered body 1. Since the strength can be reinforced, the ceramic sintered body 1 can be prevented from cracking or cracking during polishing.

  Next, as shown in FIG. 1D, the adhesive layer 3 is melted to remove the ceramic member 4 and the adhesive layer 3 from the ceramic sintered body 1. As a removing method, for example, the ceramic sintered body 1 is heated to 500 to 1000 ° C. to melt and decompose the adhesive layer 3 to remove the ceramic member 4. Thereby, the ceramic substrate 11 can be obtained.

  In addition, after removing the adhesive layer 3 and the ceramic member 4, you may perform the washing | cleaning process of wash | cleaning the ceramic sintered compact 1 in which the conductor layer 2 was formed in the surface. In that case, since the residue of the adhesive layer 3 on the surface of the ceramic sintered body 1 and the conductor layer 2 can be removed, the ceramic substrate 11 with higher insulation reliability can be obtained.

  When a semiconductor chip or chip component is mounted on the surface of the conductor layer 2, a nickel layer and a gold layer are sequentially deposited on the surface by a plating method or the like in order to strengthen the bonding with solder or the like. You may keep it.

  Furthermore, the conductor layer 2 is not limited to the one formed only on one side of the ceramic sintered body 1. The conductor layer 2 is formed on both sides of the ceramic sintered body 1, and the adhesive layer 3, the ceramic member 4, May be connected.

  The ceramic member 4 may be a ceramic sintered body similar to the ceramic sintered body 1. In this case, the surfaces on which the conductor layers 2 of the two ceramic sintered bodies 1 are formed may be opposed to each other and the surfaces may be connected via an adhesive. In this case, the two ceramic sintered bodies 1 can be processed simultaneously, and the working efficiency can be improved.

  According to the method for manufacturing a ceramic substrate as described above, the conductor layer 2 provided on the surface of the ceramic sintered body 1 is polished without directly contacting a polishing stone or an abrasive during polishing. For this reason, the conductor layer 2 provided on the surface of the ceramic sintered body 1 is polished and peeled, and the metal component in the ground conductor layer 2 is reattached to the surface of the ceramic sintered body 1, thereby Degradation of the insulating properties of the substrate 11 can be suppressed.

  The ceramic substrate 11 produced by the method as described above should be highly reliable, with the R edge chamfering processed uniformly on the edge ridge line portion without losing the conductor layer 2 on the surface. it can.

  EXAMPLES Hereinafter, although the Example is given and the manufacturing method of the wiring board of this invention is demonstrated in detail, this invention is not limited only to a following example.

  First, 90 parts by mass of alumina powder as a ceramic inorganic component, and 100 parts by mass of ceramic powder prepared by combining silica, magnesia, and calcia as sintering aids at a ratio of 10 parts by mass, acrylic resin 15 parts by mass as an organic binder Parts were prepared, and toluene and ethyl acetate as an organic solvent were mixed by a ball mill to prepare a ceramic slurry. This ceramic slurry was applied by a doctor blade method and dried to form an alumina ceramic green sheet having a thickness of 100 μm.

  Next, after adding 10 parts by mass of acrylic resin and 1 part by mass of α-terpineol as an organic solvent to 100 parts by mass of tungsten powder on the surface of the alumina ceramic green sheet, and thoroughly mixing with a stirring deaerator, A conductor metal paste sufficiently kneaded with three rolls was applied to a thickness of 20 μm in a 1 mm × 1 mm square shape by screen printing, and dried at 70 ° C. for 30 minutes.

  Next, the alumina ceramic green sheets were stacked and thermocompression bonded at a pressure of 20 MPa and a temperature of 50 ° C. to produce a laminate of alumina ceramic green sheets.

  Next, this alumina ceramic green sheet laminate is fired in a humidified nitrogen atmosphere at 1600 ° C. for 1 hour to form a ceramic sintered body 1 having a 5 mm × 5 mm square shape with a conductor layer 2 provided on the surface and a thickness of 1 mm. Was made.

  Next, a ceramic member 4 having a square shape of 4 mm × 4 mm and a thickness of 0.5 mm was produced in the same manner except that the conductor layer 2 was not formed on the surface.

  Next, an adhesive layer 3 having a thickness of 100 μm was formed by dispensing an epoxy adhesive so as to cover the conductor layer 2 formed on the surface of the ceramic sintered body 1. The ceramic member 4 was placed via the adhesive layer 3 and connected by being cured by heating at 100 ° C. for 30 minutes.

  Next, the ceramic sintered body 1 was put into a barrel tank together with a zirconia polishing stone, a silicon carbide polishing material, and a water polishing solution, and was polished by rotating at 50 rpm for 12 hours.

  Next, the polished ceramic sintered body 1 was heated in a nitrogen atmosphere at 500 ° C. for 1 hour to melt the adhesive layer 3 and remove the ceramic member 4 from the ceramic sintered body 1. Thus, the ceramic substrate 11 was produced.

  Next, as a comparative example, a ceramic substrate 11 was produced in the same manner as above except that the ceramic member 4 was not connected.

  Regarding the obtained ceramic substrate 11, when the appearance of the surface of the conductor layer 2 was observed with a 50-fold microscope, the ceramic substrate 11 of the example had no scratches or peeling on the conductor layer 2, and the ceramic substrate 11 The edge portion was chamfered. On the other hand, in the ceramic substrate 11 of the comparative example, the conductor layer 2 was scratched and peeled from the ceramic sintered body 1.

It is a figure which shows an example of the manufacturing method of the ceramic substrate by embodiment of this invention. It is a top view which shows the ceramic sintered compact to which the ceramic member was connected. It is sectional drawing which shows the ceramic sintered compact to which the ceramic member was connected.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ceramic sintered compact 2 ... Conductor layer 3 ... Adhesion layer 4 ... Ceramic member 11 ... Ceramic substrate

Claims (5)

A preparation step of preparing a ceramic sintered body provided with a conductor layer on the surface;
Forming a bonding layer so as to cover the conductor layer on the surface of the ceramic sintered body;
A connecting step of connecting a ceramic member to the ceramic sintered body via the adhesive layer inside the ceramic sintered body in plan view;
A polishing step of polishing the ceramic sintered body to which the ceramic member is connected;
And a removing step of removing the ceramic member and the adhesive layer by melting the adhesive layer.   The method for manufacturing a ceramic substrate according to claim 1, wherein the ceramic member is made of the same material as the ceramic sintered body.   The method for manufacturing a ceramic substrate according to claim 1, wherein the ceramic member has an inclined surface that spreads toward the ceramic sintered body.   The method for manufacturing a ceramic substrate according to any one of claims 1 to 3, further comprising a cleaning step of cleaning a surface of the ceramic sintered body on which the conductor layer is formed after the removing step.   The method for manufacturing a ceramic substrate according to claim 1, wherein the adhesive layer is made of an adhesive sheet.

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