JP2849607B2 - Method of manufacturing ceramic substrate having metallized metal layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a metallized metal bath used for a semiconductor element housing package for housing a semiconductor element, a circuit board on which a semiconductor element, a resistor, a capacitor, etc. are mounted and connected. The present invention relates to a method for manufacturing a ceramic substrate having a large area ceramic body as a starting material, and more particularly to a method for obtaining as many ceramic substrates having a metallized metal layer having a small area as possible as much as possible and with high productivity. is there.

(Prior Art) Conventionally, a ceramic substrate used for a package for housing a semiconductor element, a circuit board or the like is made of a high melting point metal powder such as tungsten or molybdenum as a wiring conductor on a top surface of a substrate made of an electrically insulating material such as alumina ceramic. Has a structure in which a large number of metallized metal layers are bonded, and such a conventional ceramic substrate is generally considered in terms of its mass productivity,
It is manufactured by the method shown in FIG.

That is, first, as shown in FIG. 2A, a large-area ceramic body 11 having a metallized metal layer 12 as a wiring conductor bonded to the upper surface is prepared.

Next, as shown in FIG. 2 (b), on the exposed outer surface of the metallized metal layer 12 bonded to the ceramic body 11, the metallized metal layer 12 A metal layer 13 made of nickel, gold, or the like is deposited by plating in order to strengthen the electrical connection with a semiconductor element, a resistor, a capacitor, and the like.

And finally, the ceramic body 11 is metallized metal layer.
By cutting the ceramic body 11 with a dicing machine or the like, the ceramic body 11 is separated into a plurality of small areas, and a large number of ceramic substrates 14 having a metallized metal layer 12 on the surface are collectively manufactured at one time.

(Problems to be Solved by the Invention) However, according to this conventional manufacturing method, the metal layer 13 made of nickel, gold or the like deposited on the exposed outer surface of the metallized metal layer 12 is soft. When the wide-area ceramic body 11 is cut by a dicing machine or the like together with the metallized metal layer 12 and separated into small-area ceramic substrates 14, a large amount of burrs are formed in the cut portions 13a of the metal layer 13,
Many metallized metal layers 12, close to ceramic substrate
In the case where the burrs are bonded to the surface of the semiconductor device, the burrs cause a short circuit between the adjacent metallized metal layers 12 and have a drawback that the burrs cannot be used for a semiconductor element storage package, a circuit board, or the like.

Further, when the ceramic substrate manufactured by the above method is used for a circuit board on which an optical semiconductor element is mounted, when the burrs are located on the optical axis of the optical semiconductor element, the light is scattered by the burrs or cut off, and as a result, There is also a disadvantage that the characteristics of the optical semiconductor element are significantly deteriorated.

(Object of the Invention) The present invention has been devised in view of the above-mentioned drawbacks. The object of the present invention is to cut a wide-area ceramic body having a metallized metal layer joined to a surface thereof using a dicing machine or the like to form a small-area ceramic substrate. Even if it is separated, it does not cause burrs at the cut portion of the plated metal layer deposited on the exposed outer surface of the metallized metal layer, and it can be suitably used as a package for storing semiconductor elements, a circuit board, and the like. An object of the present invention is to provide a method for manufacturing a ceramic substrate having a metallized metal layer.

(Means for Solving the Problems) According to the method for manufacturing a ceramic substrate having a metallized metal layer of the present invention, a part of the ceramic body and the metallized metal layer is formed on a large-area ceramic body having a metallized metal layer bonded to the surface. Applying a strip-shaped insulating layer so as to cover; applying a plated metal layer to an exposed outer surface of the metallized metal layer joined to the surface of the ceramic body; and attaching the ceramic body joined to the metallized metal layer. Cutting from the portion of the insulating layer to which the insulating layer is applied, and separating the insulating substrate into a plurality of small-area ceramic substrates.

Example Next, a method for manufacturing a ceramic substrate having a metallized metal layer according to the present invention will be described in detail with reference to an example shown in FIG.

First, as shown in FIG. 1A, a wide-area ceramic body 1 having a metallized metal layer 2 bonded to the upper surface is prepared.

The ceramic body 1 is made of an aluminum oxide sintered body, an aluminum nitride sintered body, or the like. For example, when the ceramic body 1 is made of an aluminum oxide sintered body, methyl methacrylate, a raw material powder of alumina, silica, calcia, magnesia, or the like is used. An organic solvent such as ethyl acrylide and a solvent such as toluene are added and mixed to form a slurry, and a ceramic green sheet (ceramic green sheet) is formed by employing a doctor blade method or a calender roll method. Thereafter, the ceramic green sheet is manufactured by punching the ceramic green sheet into an appropriate shape and firing at a high temperature (about 1600 ° C.).

The metallized metal layer 2 bonded to the upper surface of the ceramic body 1 is made of a high melting point metal powder such as tungsten, molybdenum, etc., and is obtained by adding a suitable organic solvent and solvent to the metal powder such as tungsten, molybdenum, etc. The metal paste is printed and applied in a predetermined pattern on the upper surface of a ceramic green sheet serving as the ceramic body 1 by a conventionally known screen printing method, and is applied in a reducing atmosphere for about 16 hours.
The ceramic green sheet and the metal paste are sintered and integrated at a temperature of 00 ° C. to be joined to the upper surface of the ceramic body 1.

Next, as shown in FIG. 1 (b), a band-shaped insulating layer 3 is coated on the upper surface of the ceramic body 1 to which the metallized metal layer 2 is bonded so as to cover the ceramic base 1 and a part of the metallized metal layer 2. To wear.

The insulating layer 3 is made of, for example, an aluminum oxide sintered body, and is obtained by adding and mixing an organic solvent such as methyl methacrylate and ethyl acrylate and a solvent such as toluene to raw material powder such as alumina, silica, calcia and magnesia. The insulating paste is applied to the upper surface of the ceramic body 1 in a band shape by a conventionally known screen printing method, and is baked at a temperature of about 1600 ° C. in a reducing atmosphere to be applied to a predetermined position of the upper surface of the ceramic body 1. You.

The insulating layer 3 effectively prevents a large amount of burrs from being generated in the cut and separated portions of the ceramic substrate when the ceramic body 1 described below is cut and separated into a plurality of ceramic substrates. Acts as a mark indicating

Note that the insulating layer 3 is not limited to the above-described aluminum oxide sintered body, but may be another electric insulating material, specifically, an organic material such as an epoxy resin or a silicon resin. However, when the insulating layer 3 is formed of the same material as the ceramic body 1, when the insulating layer 3 is applied to the ceramic body 1, a stress caused by a difference in thermal expansion coefficient between the ceramic body 1 and the insulating layer 3 is caused. This is completely eliminated, and the ceramic body 1 and the insulating layer 3 can be extremely firmly adhered. Therefore, in order to adhere the insulating layer 3 and the ceramic body 1 firmly, it is preferable that both are formed of the same material.

When the thickness of the insulating layer 3 exceeds 0.05 mm, when electronic components such as semiconductor elements, resistors, capacitors, etc. are connected to the metallized metal layer 2 using an automatic machine, the insulating layer 3 hinders the automatic machine. Therefore, there is a risk that the electronic component cannot be connected well to the metallized metal layer 2. Therefore,
Preferably, the thickness of the insulating layer 3 is 0.05 mm or less. If the width of the insulating layer 3 is less than 0.15 mm, the ceramic body 1 is cut by a dicing machine or the like to be separated into a large number of ceramic substrates. In this case, the cutting area of the dicing machine or the like becomes larger than the width of the insulating layer 3, so that a large amount of burrs are generated in the cut and separated portion of the ceramic substrate.
, And it becomes difficult to connect electronic components such as semiconductor elements, resistors, and capacitors to the metallized metal layer 2. Therefore, it is preferable that the width of the insulating layer 3 is set in the range of 0.15 to 1.0 mm.

Then, as shown in FIG.
To effectively prevent the metallized metal layer 2 from being oxidized and corroded on the exposed outer surface of the metallized metal layer 2 joined to the upper surface of the metallized metal layer, and to firmly connect a semiconductor element, a resistor, a capacitor and the like to the metallized metal layer 2. Is deposited.

The metal layer 4 is excellent in corrosion resistance of nickel, gold, etc.
In addition, a metal having good conductivity is used, and is layered on the exposed outer surface of the metallized metal layer 2 by a conventionally well-known electrolytic plating method.

If the thickness of the metal layer 4 is less than 0.05 μm, the metal layer 4 cannot completely cover the exposed outer surface of the metallized metal layer 2, and the metallized metal layer 2 may be oxidized and corroded. The connection strength between the layer 2 and the semiconductor element, the resistor, the capacitor, etc. becomes weak, and
If it exceeds 20.0 μm, the ceramic substrate as a product becomes extremely expensive. Therefore, it is preferable that the thickness of the metal layer 4 be in the range of 0.05 to 20.0 μm.

Finally, the ceramic body 1 to which the metallized metal layer 2 has been bonded is cut at the portion of the insulating layer 3 adhered to the upper surface thereof by using a mechanical cutting device such as a dicing machine. As shown in (d), a large number of ceramic substrates 5 as a product having the metallized metal layer 2 on the surface are intensively manufactured at one time.

When the ceramic body 1 is cut by a mechanical cutting device such as a dicing machine, the cutting of the ceramic body 1 is a portion where the insulating layer 3 is applied, and the cut portion has an outer surface of the metallized metal layer 2. Since the metal layer 4 deposited on the metallized metal layer 4 does not exist, no burrs are generated on the metal layer 4, and as a result, the metallized metal layer 2 adjacent to the metallized metal layer 2
There is no short circuit between them, and no burrs are located on the optical axis of the optical semiconductor element, and the characteristics of the optical semiconductor element are not degraded. , A resistor, a capacitor, etc., can be used very suitably for a circuit board.

(Effects of the Invention) According to the method for manufacturing a ceramic substrate having a metallized metal layer of the present invention, a band-shaped insulating layer is adhered to the upper surface of a large-area ceramic body to which the metallized metal layer is bonded, and the ceramic body is attached. By cutting a large number of small-area ceramic substrates at once by cutting from the part where the insulating layer is attached, the ceramic substrate obtained is extremely inexpensive and the metallized metal layer Burr does not occur in the metal layer deposited on the outer surface, and the metallized metal layer adjacent to the metallized metal layer is short-circuited by the burr generated in the metal layer, or the burr is located on the optical axis of the optical semiconductor element, The characteristics of the optical semiconductor element are not degraded. Therefore, the ceramic substrate manufactured by the manufacturing method of the present invention is extremely suitably used for a semiconductor element housing package for housing a semiconductor element such as an optical semiconductor element or a circuit board on which a semiconductor element, a resistor, a capacitor and the like are mounted and connected. It becomes possible.

[Brief description of the drawings]

FIGS. 1 (a), 1 (b), 1 (c) and 1 (d) are cross-sectional views for respective steps for explaining a method of manufacturing a ceramic substrate having a metallized metal layer according to the present invention, and FIGS. 2 (a) and 2 (b). (C) is a sectional view for each step for explaining a conventional method of manufacturing a ceramic substrate having a metallized metal layer. DESCRIPTION OF SYMBOLS 1 ... Ceramic body 2 ... Metallized metal layer 3 ... Insulating layer 4 ... Metal layer 5 ... Ceramic substrate

Claims (1)

(57) [Claims] A step of applying a strip-shaped insulating layer to a large-area ceramic body having a metallized metal layer bonded to a surface thereof so as to cover the ceramic body and a part of the metallized metal layer; A step of layering a plated metal layer on the exposed outer surface of the bonded metallized metal layer, and cutting the ceramic body bonded with the metallized metal layer from a portion where the insulating layer is applied, and forming a plurality of small-area Separating the ceramic substrate into a ceramic substrate.