JPS58170040A - Low temperature sealing member - Google Patents

Abstract

PURPOSE:To form a sealing member capable of sealing at a low temperature with high reliability of sealing characteristic in an excellent mass production by glazing a low melting point glass on one side surface of a supporting member and plating gold on the other side surface. CONSTITUTION:A supporting member 12 made of ceramic formed in a frame shape is formed at a sealing member 10. A metallized layer 14 made of metal such as tungsten, molybdenum or the like is baked on the lower surface of the member 12, a nickel is plated on the layer 14, and a low melting point glass 20 is glazed on the upper surface of the member 12. This glass 20 is coated and glazed on the surface after plated. In order to form a low melting point glass 20 layer, low melting glass powder is formed in a paste state with acryl resin and nitrocellulose as an organic binder and terpineol or the like as a solvent, and coated by a screen printing on the upper surface of the member 12. Subsequently, it is dried at 80-150 deg.C, and then glazed at 300-450 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing member for low temperature sealing, and more specifically,
The present invention relates to a sealing member suitable for use in low-temperature sealing of a package for enclosing a solid-state image sensor and a light-transmitting window member.

Area sensors, that is, solid-state imaging devices such as CCDs coated with organic color separation filters, are sensitive to heat, so in order to encapsulate them in a package, the temperature between the package and the light-transmitting window member is generally 200°C. The following low temperature seals are required.

Although resins are used as sealing materials for low-temperature seals, resins are not preferred because they are moisture permeable.

There is also a seam welding method in which the window component is sealed at high temperature (around 400°C) to a metal support frame using low melting point glass, and this metal support frame is welded to the package. Cracks tend to occur in low-melting glass and light-transmitting window members due to thermal stress, which not only raises concerns about airtightness, but also has poor productivity, as the manufacturing process is complicated and it is difficult to seal multiple pieces at the same time. There is a drawback that the cost is high.

In addition, sapphire is used as a window member, metallized at high temperature, and fused to the package using soft solder, but these are expensive.

The present invention has been made to solve the above-mentioned difficulties, and its purpose is to provide a sealing member that is excellent in mass production, has highly reliable sealing properties, and is capable of low-temperature sealing, and has the following characteristics: The problem lies in that one side of the support member is glazed with low melting point glass to form the welded part of the light transmitting window member, and the other side is plated with gold to form the sealed part by soft solder.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a sealing member IO. In the figure, reference numeral 12 denotes a support member made of ceramic and formed into a frame shape.

Reference numeral 14 denotes a metallized layer made of metal such as tungsten or monopden, which is fired on the lower surface of the support member 12.

16 is a nickel plating layer applied to the metallized layer 14;
8 is a gold plating layer.

The thickness of the gold plating layer 18 is required to be 3 to 5 mm.

This is because, as will be described later, the processing temperature when glazing low melting point glass is as high as approximately 400°C, so the nickel layer 16 diffuses into the gold plating layer 18 and oxidizes, worsening solder leakage. Depending on the thickness required. Note that the thickness of nickel plating may be about 27 layers.

20 is a low melting point glass, and the upper surface of the support member 12 is glazed.

This low melting point glass 2o is applied after the above plating process,
Glazed.

This is because if the low melting point glass 20 is applied first and then plating is performed, the low melting point glass 20 is chemically extremely unstable and deteriorates during the plating process, and also because it absorbs moisture during the process. This is because it causes negative effects on the solid-state image sensor after being sealed, and because impurities are mixed into the plating bath, the bath life is significantly reduced, making it difficult to put it into practical use.

To form the 20 layers of low-melting point glass, first, low-melting point glass powder is made into a paste using acrylic resin, nitrocellulose, etc. as an organic binder and terpineol, etc. as a solvent, and this is pasted onto the supporting member 12 by screen printing or the like. Apply to the top surface.

Next, dry this at 800C~l 5000 and then
Glazing treatment is carried out at a temperature of 450°C to 450°C.

As described above, by forming a sealing member in advance by depositing gold plating and low-melting point glass on the supporting member, the low-melting point glass was conventionally applied by screen printing onto the optical glass, which is a light-transmitting window member. Compared to conventional methods, there is no need to place optical gas molten gas on a jig, which prevents scratches, and low-melting glass powder scatters on the light-transmitting part of the optical glass, causing it to be glazed as it is. Generation of defective products is prevented.

FIG. 2 shows another embodiment.

This embodiment is the same as the embodiment described above except that a rhodium plating layer 17 is further formed on the nickel plating 16 as a base for the gold plating 18, so a description thereof will be omitted.

In addition to the same effects as described above, this embodiment can also reduce the gold plating thickness to about 0.5% mN and 1.5 mm, resulting in a significant cost reduction.

Furthermore, since the gold plating layer 18 is formed thinly, its mechanical strength is low when it is sealed into a ceramic package etc. via solder (Sn-Pb), as will be described later.
It is difficult to form an n-Pb-Au alloy, which is advantageous in terms of strength.

The reason why the gold plating layer 18 can be formed so thin is that rhodium acts effectively as a barrier to diffusion in the nickel nose layer, and rhodium itself forms intermetallic compounds with gold.
Furthermore, because it is difficult to oxidize, it is stable even under the above-mentioned high temperature conditions during glazing.

The rhodium plating thickness is not particularly limited, but is 0.1 mm to 0.
．． 5. It is effective at about Jm.

FIG. 3 shows the sealing member 10 heat-sealed to an optical glass 30 serving as a light-transmitting window member.

This heat sealing involves applying a high temperature of around 400° C. to weld with low melting point glass.

The present invention is also provided as a lid with a light transmitting window in which the sealing member 10 is heat-sealed to the optical glass 30.

Note that the sealing member 10 can also be provided as a lid with a window for light transmission, in which a soft solder such as solder is applied to the gold plating layer 18 of the sealing member 10 in advance. - FIG. 4 shows an example of the ceramic package 31.

32 is a solid-state image sensor, and 34 is its color separation filter.

A sealing portion Nihametallized layer 36 is formed on the upper end surface of this ceramic package 31, a nickel plating layer 38 is formed on this metallized layer, and a gold plating layer 40 is further formed on this metallized layer.

1 Therefore, the gold plating layer 18 of the sealing member 16 and the gold plating layer 40 of this ceramic package 31
A low-temperature seal is applied between the two and a soft solder such as solder.

In addition to ceramics, the support member for the aluminum member may be a member having a coefficient of thermal expansion almost the same as that of low-melting glass, such as Kovar (Fe-Ni, -Co alloy).

An IF e -Ni alloy or the like may also be used, and the metallized layer described above does not necessarily need to be formed as long as it is a conductive member and can be directly plated on the surface thereof.

As described above, according to the present invention, since it can be provided in advance as a sealing member, operations such as applying low melting point glass directly to the light-transmitting window member as in the conventional method can be omitted, and the light-transmitting window member is not damaged or soiled. In addition to the above, the rhodium layer has various other advantages such as being able to form a thin gold plating layer, which is extremely advantageous in terms of cost.

Although the present invention has been variously explained above with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. It is.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views showing different embodiments of the sealing member according to the present invention, FIG. 3 is a cross-sectional view of the sealing member welded to optical glass, and FIG. 4 is a cross-sectional view showing an example of a ceramic package. It is a diagram. 10.8. Seal member, 12. ,,Supporting member. 149. , metallized layer, 16. , Niranal plating layer, 18. ．． ．． Gold plating layer, 20. , , low melting point glass, 17,0. Rhodium plated layer. 30. Optical glass 31. ,,ceramic package,32,0. Solid-state image sensor. 341.1 Color separation filter, 36. ,,metalized layer, 3B,,, nickel plating layer. 4'O1, plating layer. Patent applicant Shinko Electric Industry Co., Ltd. Representative Takekio Mitsunobu Figure 4 32 34

Claims (1)

[Claims] 1. Low-temperature glass made by glazing low melting point glass on one side of a support member having a coefficient of thermal expansion approximately equal to that of the low melting point glass and gold plating on the other side of the support member. Seal member for sealing. 2. Glaze low melting point glass on one side of a support member that has a coefficient of thermal expansion that is approximately the same as this low melting point glass, and plate the other side of the support member with gold using a diffusion prevention material such as rhodium as a base. A sealing member for low-temperature sealing made of 3. A sealing member made by glazing low melting point glass on one side of a support member having a coefficient of thermal expansion approximately equal to that of the low melting point glass and gold plating on the other side of the support member for light transmission. A lid body with a light-transmitting window, characterized in that the low-melting point glass is sealed at an appropriate position of a window member.