JPH0466386B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a semiconductor device package made of ceramic for supporting a semiconductor device having an extremely large number of electrodes, such as a high-density integrated circuit, and a method for manufacturing the same. It is.

(Prior art) On the surface of the package for semiconductor elements, there are many extremely thin linear electrodes called finger patterns for connecting to the many electrodes of the semiconductor element, and for connecting the package for semiconductor elements to the circuit board. Many electrodes are formed on ceramic green sheets, and conventionally these electrodes were made of Mo,
It was formed by printing and firing a conductive paste containing a metal with a high melting point such as W. However, with the recent remarkable improvement in the degree of integration of semiconductor devices, there are many devices with a large number of terminals, such as 100 or more, and their overall size is becoming smaller and smaller. As a result, the dimensional accuracy required for the electrodes has become extremely high, and due to uneven firing shrinkage that inevitably occurs when ceramic green sheets are fired, the dimensional accuracy required for the electrodes cannot be satisfied, and conventional methods cannot It has become difficult to manufacture packages for such highly integrated semiconductor devices.

(Problems to be solved by the invention) The present invention solves these conventional problems,
It was completed with the aim of developing a new package for semiconductor devices and its manufacturing method that can fully meet the dimensional accuracy required to support highly integrated semiconductor devices with a large number of electrodes, exceeding 100. It is something that

(Means for Solving the Problems) In the present invention, a metallized layer for electrodes fired on a ceramic sheet is coated with a photosensitive electric insulating layer having an opening formed by photoetching, and an electrode inside the opening is coated with a photosensitive electrical insulating layer having an opening formed by photoetching. A first invention relating to a package for a semiconductor element, characterized in that a metal layer having excellent affinity with solder is formed on a metallized layer for use, and a ceramic green in which a metallized layer for electrodes is formed in required parts. After firing the sheet, a photosensitive electrical insulating layer is formed on the entire surface of the part including the electrode metallized layer, and this is photoetched to form openings at precise positions.
For semiconductor devices, characterized in that an external metal lead is brazed and then plated with a metal that has excellent affinity with solder to form a metal layer for soldering on the metallized layer for electrodes in the opening. A second invention relating to a method for manufacturing a package, in which a ceramic green sheet with a metallized layer for electrodes formed on required portions is fired, and external metal leads such as terminal pins are brazed to the portions containing the metallized layer for electrodes. A photosensitive electrical insulating layer is applied to the entire surface of the electrode, and then this photosensitive electrical insulating layer is photoetched to form openings communicating with the electrode metallized layer at precise locations. A third aspect of the present invention relates to a method for manufacturing a package for a semiconductor device, characterized in that a metal layer for soldering is formed on the metallized layer in the opening by plating with metal.

(Example) Next, the present invention will be described in detail with regard to an example of a wire bonding tab type shown in the drawings.

1 to 4 show the manufacturing process of an embodiment of the second invention of the present application. First, as shown in FIG. 1, a semiconductor element is mounted on the surface of an unfired ceramic green sheet 1 using a conventional technique. A metallized layer 2 for electrodes is formed on the ceramic green sheet 1, and a metallized layer 3 for electrodes in a finger pattern is connected to a large number of electrode terminals of a semiconductor element by wire bonding. A through hole 5 filled with a conductor 4 for connecting the terminal pin 9 to the terminal pin 9 is provided. Such a ceramic green sheet 1 is then fired by a conventional method to become a ceramic sheet 1, but at this time, firing shrinkage occurs and the dimensional accuracy of the metallized layer 3 for electrodes in particular is disturbed, as is the case with the conventional method. be. Therefore, in the present invention,
A photosensitive electrical insulating layer 6 is applied to the entire surface of the ceramic sheet 1 including the electrode metallized layer 3 as shown in FIG. This photosensitive electrical insulating layer 6 must have heat resistance that can withstand subsequent processes such as brazing (about 800°C), soldering (about 200°C), and die mounting of semiconductor elements (about 450°C). Yes, it is preferable to use an inorganic paint. Next, the photosensitive electrical insulating layer 6 is photo-etched to form an opening 7 with high precision at the exact position where the electrode metallized layer should originally be. This photoetching is carried out very precisely by optical means, independent of firing shrinkage of the ceramic sheet. Thereafter, electroless plating and brazing plating are applied as needed, and as shown in FIG. 5
A base plating layer 8 is formed, and then pins 9 for terminals are formed.
After brazing external metal leads such as Ni, Cu, etc.
If plating is performed with a metal that has excellent affinity with solder, such as Au or Ag, the electrode metallized layer 3 and metallized layer 2 in the opening 7 will be made of a metal suitable for soldering, as shown in FIG. Layer 10 will be formed.

Next, the embodiment of the third invention of the present application will be described in detail with reference to FIGS. 5 to 8. First, as shown in FIG. 5, a semiconductor element is mounted on the surface of an unfired ceramic green sheet 1 by a conventional technique. A metallized layer 2 for electrodes is formed on the ceramic green sheet 1, and a metallized layer 3 for electrodes in a finger pattern is connected to a large number of electrode terminals of a semiconductor element by wire bonding. A through hole 5 filled with a conductor 4 for connecting the terminal pin 9 to the terminal pin 9 is provided. Such a ceramic green sheet 1 is then fired by a conventional method to become a ceramic sheet 1, but at this time, firing shrinkage occurs and the dimensional accuracy of the metallized layer 3 for electrodes in particular is disturbed, as is the case with the conventional method. be. Next, as shown in FIG.
A plating layer 8 for brazing is formed on the portion, and an external metal lead such as a pin 9 for a terminal is brazed thereto. Next, a photosensitive electrical insulating layer 6 is applied to the entire surface of the ceramic sheet 1 including the electrode metallized layer 3. For this photosensitive electrical insulating layer 6, an organic paint having heat resistance that can withstand subsequent soldering steps (approximately 200° C.), die mounting steps for semiconductor elements, etc. can be used. In addition,
If photosensitive polyimide, photosensitive glass, or the like is used as the material for the photosensitive electrical insulating layer 6, and it surrounds the semiconductor element, it has the effect of shielding alpha rays emitted from the alumina ceramic of the semiconductor element. Next, the photosensitive electrical insulating layer 6 is photo-etched as shown in FIG. 7, and an opening 7 is formed with high precision at the exact position where the electrode metallized layer should originally be. This photoetching is carried out very precisely by optical means, independent of firing shrinkage of the ceramic sheet. After that, by finishing plating with a metal that has excellent affinity with solder such as Ni, Au, or Ag, the surface of the electrolytic metallized layer 3 becomes the photosensitive electrical insulating layer 6, as shown in FIG. covered,
It is possible to obtain a package for a semiconductor device in which an opening 7 is formed using photoresist at a precise position in the photosensitive electrical insulating layer 6, and a metal layer 10 having excellent affinity with solder is formed inside the opening 7. becomes.

(Function) The package for semiconductor elements manufactured in this way is one in which solder or the like is poured into the opening 7 to directly connect semiconductor elements with terminals or TABs, etc., and when the ceramic green sheet is fired. Unavoidable ceramic sheet 1
Even if the dimensional accuracy of the electrode metallized layer 3 decreases due to firing shrinkage, the electrodes of the semiconductor element etc. connection can be made correctly. Therefore, according to the present invention, it is possible to easily manufacture a package for a highly integrated semiconductor device having more than 100 electrodes.

In the above explanation, the electrode metallized layer 3 is used for wire bonding, but in the case of a flip-chip type, the electrode metallized layer 3 corresponds to the dot-shaped electrode that directly contacts the electrode on the lower surface of the semiconductor element. Become something to do. In addition, in the case of a leadless type package, many dot-like electrodes are formed on the bottom surface of the package for connection with the circuit board, but in this case, these dot-like electrodes correspond to the electrode metallization layer 3. It goes without saying that the present invention can also be applied to the formation of these point-like electrodes.

(Effects of the Invention) As is clear from the above description, the present invention has succeeded in forming highly accurate electrodes by the photoresist method, despite the inevitable firing shrinkage of ceramic sheets. Therefore, the semiconductor device package suitable for supporting highly integrated semiconductor devices and its manufacturing method will greatly contribute to the development of industry.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views showing the manufacturing process of the embodiment of the second invention of the present application, and FIGS. 5 to 8 are sectional views of the third embodiment of the present invention.
FIG. 3 is a cross-sectional view showing the manufacturing process of the embodiment of the invention. 1: Ceramic sheet, 3: Electrode metallized layer, 6: Photosensitive electrical insulating layer, 7: Opening, 10:
metal layer.

Claims (1)

[Scope of Claims] 1. A photosensitive electrical insulating layer 6 having an opening 7 formed by photoetching is coated on an electrode metallized layer 3 fired on a ceramic sheet 1. A package for a semiconductor element, characterized in that a metal layer 10 having excellent affinity with solder is formed on a metallized layer 3. 2. After firing the ceramic green sheet on which the metallized layer for electrodes is formed in the required areas, a photosensitive electrical insulating layer is formed on the entire surface of the area including the metallized layer for electrodes, and this is photoetched to form openings at precise positions. A metal layer for soldering is formed on the electrode metallized layer in the opening by brazing the external metal lead and then plating with a metal that has excellent affinity with solder. Features: A manufacturing method for packages for semiconductor devices. 3. After firing the ceramic green sheet on which the metallized layer for electrodes is formed in the required parts, external metal leads such as terminal pins are brazed, and a photosensitive electrical insulating layer is applied to the entire surface of the part including the metallized layer for electrodes. This photosensitive electrical insulating layer is then photoetched to form an opening communicating with the electrode metallized layer at a precise location, and then plating is performed with a metal that has excellent affinity with solder to fill the inside of the opening. A method for manufacturing a package for a semiconductor device, comprising forming a metal layer for soldering on a metallized layer.