TW201631712A - Sealing paste, brazing material and production method thereof, sealing lid member and production method thereof, and package sealing method - Google Patents

Abstract

This sealing paste contains a starting material powder and a binder, the starting material powder containing 5-40 mass% of a low melting point metal powder having a 0.5-20.0 [mu]m average particle diameter and a melting point or liquidus temperature of less than 240 DEG C, 40-90 mass% of an Ag powder having an average particle diameter of 0.1-10.0 [mu]m, and 5-50 mass% of a Cu powder having an average particle diameter of 0.1-10.0 [mu]m. The sealing paste can easily form a brazing material, the alloy composition of said brazing material can be changed easily, and the sealing paste can reliably seal a package hermetically without resulting in cracking.

Description

Sealing paste, hard soldering material, manufacturing method thereof, sealing cover material, manufacturing method thereof, and package sealing method

The present invention relates to a sealing paste, a hard soldering material, and a package sealing method, and more particularly to a sealing paste and a hard soldering material using a mixed powder paste having a high degree of freedom in supply and easy composition control. And a manufacturing method thereof, a lid material for sealing, a method for producing the same, and a method for sealing a package.

The case is based on the special request 2014-222900 filed on October 31, 2014, the special offer 2015-164700 applied for on August 24, 2015, and the special offer 2015-213467 applied on October 29, 2015. No., claiming priority, hereby invoke its contents.

Generally, the material for sealing is a solder having a melting point of less than 450 ° C, or a brazing material having a melting point of 450 ° C or higher. Further, in order to seal the package with a lid material, a sealant called a seal ring described in Patent Document 1 may be used as a sealing material, and Ni (nickel) plating may be applied to the seal portion of the lid material or the package. The processor or the Ni plating is applied to the sealing portion of the seal ring itself. Other, sometimes using glass or The resin acts as a sealing material.

A lead-free solder material such as Pb (lead) - 63% by mass of Sn (tin) or Sn - 3 mass % Ag (silver) - 0.5% by mass of Cu (copper), Pb - 10% by mass of Sn or Au can be used for the solder material. (Gold) -20% by mass of Sn high temperature solder. The brazing material can mainly be Ag brazed, for example, Ag-28 mass% Cu as a material head, and contains Ag-22 mass% Cu-17 mass% Zn(zinc)-5 mass% Sn, or Cd (cadmium) or Ni. Ag brazing alloy. Cobalt or a 42 alloy or the like is attached to the seal ring or the cover material, and Ni plating treatment is applied thereto.

In the sealing method using a seal ring, when a solder material is used, a solder plate processed into a ring shape may be interposed between the cap material and the package together with the seal ring, melted/sealed using a furnace or an oven, or a solder paste or the like may be used. The lid material is formed into a ring-shaped solder frame, and thereafter sealed with the package. On the other hand, when Ag brazing is used, a ring-shaped Ag brazing sheet is punched out, and is interposed between the cap material and the package together with the sealing ring, and is sealed only by a seam welding machine or a laser welding machine. The portion is locally formed in a high temperature state, and Ag is hard-welded or Ni-plated formed on the seal ring is melted and sealed.

Since the sealing ring using the seal ring is a cushioning material, it is possible to use a seam welding method or the like to alleviate thermal shock or mechanical stress during sealing.

However, when Ag brazing and a Ni-plated sealing ring are used for sealing by a welding method, it is necessary to break between the lid member and the package to perform sealing, and the efficiency such as alignment is poor, which is very troublesome.

Therefore, it has been proposed to form a powder using an Ag brazing alloy. It is paste-formed, printed on a cover material, and heat-treated to form a sealing frame.

In the metal paste for sealing, which contains a metal powder and an organic solvent, the metal powder has a purity of 99.9% by weight or more and an average particle diameter of 0.1 μm to 1.0 μm. A metal paste for sealing prepared by mixing a metal powder composed of silver powder, platinum powder or palladium powder in an amount of 85 to 93% by weight and an organic solvent of 5 to 15% by weight. In the sealing method using the metal paste, it is described that the metal paste applied to the paste member or the lid member is dried at 80 to 300 ° C to form a sintered metal powder, and the metal is heated. A method in which a powder sintered body pressurizes a paste member or a cap member.

The metal paste described in Patent Document 2 is a metal powder of gold powder, silver powder, platinum powder or palladium powder, and is not a metal alloy.

Patent Document 3 discloses a silver brazing clad material comprising a base material composed of a low thermal expansion metal and a low temperature type silver brazing material layer bonded to at least one surface of the base material. The silver brazing material layer is formed by mixing a paste composed of a solvent and a binder with a metal powder composed of a low-temperature silver brazing material, and then heating the metal powder to heat the metal powder. After melting, it is rapidly cooled and solidified, and further formed by rolling. Specific examples of the silver brazing material include silver-copper-tin alloy, silver-copper-indium alloy, and silver-copper-zinc alloy. The silver brazing clad material is subjected to die cutting or the like to be processed into a predetermined size, whereby a lid material for encapsulating the package is formed.

It has been disclosed in Patent Document 4 that it is not a silver brazing. a paste-like brazing material composition containing Au and Sn is printed on one surface of the cap body, and then heat-treated at a temperature equal to or lower than the melting point of Au above the melting point of Au, thereby forming a fusion Au Sn A cap body of a brazing material in which a cap body is superposed on a package body to be fused.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Publication No. 9-293799

Patent Document 2: JP-A-2008-28364

Patent Document 3: Japanese Laid-Open Patent Publication No. 2006-49595

Patent Document 4: Japanese Laid-Open Patent Publication No. 2003-163299

However, in the case of the Ag brazing paste, it is necessary to heat-treat at a high temperature higher than the melting point of Ag brazing in forming the sealing frame, and thereafter, the welding process is again performed at the time of sealing. Further, since the powder of the Ag brazing alloy is pulverized, it is necessary to re-alloy the alloy and pulverize the powder when it is desired to have a different alloy composition, which is very troublesome.

Further, when the seam is welded by a so-called direct seam sealing method without using a seal ring or when sealing is performed by a laser welding method or an electron beam welding method, only the sealing portion is locally high-temperature and sealed, so that thermal shock is accompanied. Or mechanical stress is liable to cause cracks in the bonding layer or the package.

In the present invention, it is an object to provide an easily formed A hard-welded material, which can easily change the alloy composition of the hard-welded material, and a sealing paste, a hard-welded material, a method for producing the same, and a seal for reliably sealing the package without cracking Cover material and its manufacturing method, and package sealing method.

The sealing paste of the present invention comprises a raw material powder containing a raw material powder and a binder, and the raw material powder contains a low melting point metal powder having an average particle diameter of 0.5 μm or more and 20.0 μm or less and a melting point or a liquidus temperature of less than 240 ° C. Ag powder of 40% by mass or more and 40% by mass or less and 90% by mass or less of the Ag powder having an average particle diameter of 0.1 μm or more and 10.0 μm or less and 5% by mass or less and 50% by mass or less of the Cu powder having an average particle diameter of 0.1 μm or more and 10.0 μm or less.

In the paste for sealing of the present invention, the average particle diameter of the low-melting-point metal powder is preferably 1 time or more and 10 times or less the average particle diameter of the Ag powder, and 1 or more times and 10 times the average particle diameter of the Cu powder. the following.

In the paste for sealing of the present invention, the average particle diameter of the low-melting-point metal powder is preferably larger than the average particle diameter of the Ag powder and the average particle diameter of the Cu powder.

In the sealing paste of the present invention, the mixing ratio of the binder is preferably 2% by mass or more and 50% by mass or less.

In the paste for sealing of the present invention, the low melting point metal powder may be selected from the group consisting of Su, In, Sn-Ag-Cu solder alloy, and Sn-Cu solder. One or more of alloys, Sn-Bi solder alloys, and Sn-In solder alloys.

The method for producing a hard-welded material according to the present invention includes: a paste application step and a heat treatment step of applying the paste for sealing onto a carrier; and the heat treatment step is to apply the seal to the carrier Heating the liquid phase of the low melting point metal between the Ag powder and the Cu powder by heating at a melting temperature of the low melting point metal, and then solidifying and solidifying the liquid phase of the low melting point metal, thereby forming and forming the Ag powder and the Cu powder. A hard-welded material having a porosity of 10% or more in which the bonding layer composed of the low-melting-point metal is bonded. Further, in order to secure strength and sealing properties, the hard-welded material is preferably formed to have a porosity of 35% or less.

The hard-welded material of the present invention has Ag powder having an average particle diameter of 0.1 μm or more and 10.0 μm or less, Cu powder having an average particle diameter of 0.1 μm or more and 10.0 μm or less, and a melting point or a liquidus temperature of less than 240. a bonding layer in which the Ag powder and the Cu powder are bonded to each other, and a porosity of 10% or more, and the mass ratio is 40% by mass or more and 90% by mass or less of the Ag powder, and the Cu powder is 5 mass% or more and 50 mass% or less, and the said bonding layer is 5 mass % or more and 40 mass % or less.

The method for producing a lid material for sealing according to the present invention includes: a paste application step of applying the paste for sealing onto a surface of a lid body; and a heat treatment step; and the heat treatment step is applied to the lid body The sealing paste is heated at a melting temperature of the low melting point metal, and a liquid phase of the low melting point metal is infiltrated between the Ag powder and the Cu powder, followed by cooling and solidifying, thereby forming the Ag powder and the foregoing The Cu powder is a hard-welded material having a porosity of 10% or more by a bonding layer composed of the low-melting-point metal. Further, the hard-welded material is preferably formed to have a porosity of 35% or less.

In the method for producing a sealing cap material of the present invention, after the heat treatment step, the binder removing step of removing the binder remaining in the hard solder material may be provided, and the binder removing step may have The washing step of washing the hard-welded material with the washing liquid, and the baking treatment of the hard-welded material after the washing treatment.

In the method for producing a sealing cover material, the sealing paste is applied to a surface of a sheet material having a plurality of the lid bodies formed in the paste applying step, and after the heat treatment step, The sheet is divided into individual sheeting steps of the aforementioned cover.

The sealing cover material of the present invention has a lid body and the above-mentioned hard-welded material provided on the surface of the lid body.

In the package sealing method of the present invention, the package body and the cover body are joined by a brazing alloy, and have a paste coating step, a heat treatment step, and an alloying step; the paste coating step is for the sealing a paste applied to the surface of the lid body; the heat treatment step of heating the paste for sealing applied to the lid body at a melting temperature of the low melting point metal between the Ag powder and the Cu powder After the liquid phase of the low-melting-point metal is infiltrated and then solidified by cooling, the Ag powder and the Cu powder are bonded to each other by a bonding layer composed of the low-melting-point metal, and the porosity is 10% or more; The alloying step is performed by superposing the lid body on the package body to form the hard solder joint material. The material is heated and melted and alloyed, and formed into the aforementioned brazing alloy. Further, the hard-welded material is preferably formed to have a porosity of 35% or less in order to secure strength and sealing properties.

In the package sealing method of the present invention, between the heat treatment step and the alloying step, there may be a binder removing step of removing the binder remaining in the hard solder material, and the binder removing step is The cleaning treatment may be performed by washing the hard solder material with a cleaning liquid, and heat-treating the hard solder material after the cleaning treatment.

In the package sealing method of the present invention, the sealing paste is coated on the surface of the sheet material which can form a plurality of the lid bodies in the paste coating step, and after the heat treatment step, the sheet material is provided Divided into individual sheeting steps of the aforementioned cover.

In the package sealing method of the present invention, after the singulation step, a plating treatment step of applying a metal plating to the surface of the cover may be provided. The metal plating treatment is applied as a metallization of the lid body, and after being divided into a lid body and then subjected to metal plating treatment, metal plating can be applied to the side wall of the lid body, and corrosion and rust of the side wall can be effectively prevented.

The package sealing method of the present invention is characterized in that the package overlaps the cover and is joined by a brazing alloy, and performs a paste coating step, a heat treatment step, and an alloying step; the paste coating step is for the sealing The paste is applied to a carrier; the heat treatment step is performed by heating the paste for sealing applied to the carrier at a melting temperature of the low melting point metal to form the low melting point between the Ag powder and the Cu powder. Metallic After the liquid phase is infiltrated and then solidified by cooling, the Ag powder and the Cu powder are bonded to each other by a bonding layer composed of the low melting point metal, and the porosity is 10% or more. The alloying step is After the hard solder material is laminated between the package and the lid, the hard solder material is heated and melted and alloyed to form the brazing alloy. Further, the hard-welded material is preferably formed to have a porosity of 35% or less.

The raw material mixture to be mixed with the sealing paste of the present invention contains a low melting point metal powder having a melting point or a liquidus temperature of less than 240 ° C, and Ag powder and Cu powder having a melting point higher than that of the low melting point metal powder. Then, as described above, the average particle diameter or the amount of each metal powder, the amount of the binder, and the controlled sealing paste are heated at a melting temperature of the low melting point metal, whereby the obtained hard solder joint material is also in the heat treatment step. The obtained hard-welded material is such that when the low-melting-point metal powder is melted, most of the Ag powder and the Cu powder which are higher than the melting point of the low-melting-point metal are directly left as a solid, and between the solid Ag powder and the Cu powder The liquid phase of the low-melting-point metal penetrates and cools and solidifies, whereby the bonding layer of the Ag powder and the Cu powder composed of the low-melting-point metal is bonded to each other. At this time, a large number of voids are formed at the portion having the low-melting-point metal powder before the heating in the heat treatment step, whereby the hard-welded material is formed into a porous structure having a porosity of 10% or more.

When the raw material powder mixed in the sealing paste is used as the silver brazing alloy powder, it is necessary to heat the molten soldering material to a melting temperature (liquidus temperature) of the silver brazing alloy or more. The hard soldering material of the present invention utilizes liquid phase sintering of a low melting point metal powder to a low melting point metal Since the melting temperature (less than 240 ° C) is heated to form, the furnace or the like must be used at a high temperature, and is related to energy saving.

Then, when the package body and the lid body are sealed by using the hard-welded material of the present invention, even a sealing method in which only the sealing portion is locally formed in a high temperature state using a seam welding method, a laser welding method, an electron beam welding method or the like is used. In the middle, the porous structure of the hard-welded material can alleviate thermal shock or mechanical stress, thereby preventing cracking of the joint layer or the package. Further, the hard-welded material is heated to a melting temperature of the Ag powder and the Cu powder to alloy the Ag and Cu with the low-melting-point metal, whereby the package and the lid can be hermetically sealed.

Further, the sealing paste of the present invention can be applied to the surface of the carrier or the lid by printing or the like, so that a hard solder joint (sealing frame) having a desired shape can be easily formed. When the hard soldering material of the present invention is formed on the surface of the lid body, the hard solder material is fixed on the surface of the lid body by the molten low melting point metal, so that the hard solder joint material can be easily formed on the surface of the lid body. When the cover is processed, no hard welded material is peeled off. Moreover, the alloying step is carried out by sandwiching the hard-welded material to which the sealing cover material is bonded, and the alloying step is performed in a state of being superposed on the package, so that the alloying and sealing of the hard-welded material can be performed at the same time, which is very efficient.

The raw material powder to be mixed in the sealing paste of the present invention is a combination of a plurality of metal powders, so that the amount or combination of each metal powder can be easily changed, and the alloy composition can be easily changed.

When the average particle diameter of the Ag powder and the Cu powder mixed in the sealing paste is less than 0.1 μm, the porosity of the formed hard-welded material is If it is less than 10%, it is difficult to obtain the effect of mitigating thermal shock or mechanical stress. On the other hand, when the average particle diameter of the Ag powder and the Cu powder exceeds 10 μm, the porosity of the formed hard-welded material increases, and the sealing property is deteriorated. The hard-welded material of the present invention has a porosity of 10% or more and preferably 35% or less. If the porosity of the hard-welded material exceeds 35%, there is a problem that the sealing property is lowered.

Even if the average particle diameter of the low-melting-point metal powder is less than 0.5 μm, the porosity of the formed hard-welded material becomes less than 10%, and it is difficult to obtain an effect of alleviating thermal shock or mechanical stress, and the average particle diameter of the low-melting-point metal powder exceeds At 20 μm, the porosity of the formed hard-welded material becomes large, and the sealing property is deteriorated.

When the content ratio of the Ag powder in the entire raw material powder is less than 40% by mass, the eutectic composition of Ag, Cu, and the low melting point metal largely deviates, so that the sealing property is lowered, and when it exceeds 90% by mass, it is removed. When the binder residue is washed, there is a peeling of the lid body to which the hard-welded material is bonded, and the amount of Ag is more expensive, so the cost is high.

When the content ratio of all the Cu powders of the raw material powder is outside the range of 5 mass% or more and 50 mass% or less, that is, when it is less than 5% by mass or more than 50% by mass, the eutectic from Ag, Cu, and a low melting point metal The composition is largely deviated, so the sealing property is lowered.

When the content ratio of the low-melting-point metal powder of the raw material powder is less than 5% by mass, the formation of the bonding layer is insufficient, and when it is washed, it is peeled off from the lid body to which the hard-welded material is bonded, and when it exceeds 40% by mass, The excess low melting point metal is also sealed (after alloying) and has a eutectic temperature higher than that of Ag, Cu and a low melting point metal (for example, Ag-Cu-Sn The low melting point temperature region of the melting point where the eutectic temperature is low is generated in the sealing portion, so at least a melting point of 450 ° C or higher is expected, and conversely, a part of the sealing portion is at the melting point of the low melting point metal (below the melting temperature of the hard bonding material) There is melting enthalpy. In addition, when the content ratio of the low-melting-point metal powder exceeds 40% by mass, the eutectic composition of Ag, Cu, and a low-melting-point metal greatly deviates, and the sealing property also decreases.

When the binder is less than 2% by mass or the binder exceeds 50% by mass, even if it is kneaded with the raw material powder, it is difficult to form a paste suitable for the printing method. In addition, when the amount of the binder exceeds 50% by mass, the binder of the Ag powder and the Cu powder is softened by heat and the shape cannot be maintained, and it is difficult to form the hard-bonded material into a desired shape.

According to the present invention, the brazing alloy composition can be easily changed, and the hard welded material having a porous structure does not cause cracking, and the package can be hermetically sealed.

1‧‧‧ cover

2‧‧‧ plates

3‧‧‧ Carrier

4‧‧‧hard welded materials

5‧‧‧Package

6‧‧‧Seal cover material

11‧‧‧roll electrode

20‧‧‧Seal paste

21‧‧‧Ag powder

22‧‧‧Cu powder

23‧‧‧Low-melting metal powder

24‧‧‧Combination layer

25‧‧‧Adhesive

41‧‧‧ gap

Fig. 1A is a schematic view showing the configuration of a sealing paste of the present invention.

Fig. 1B is a schematic view showing the constitution of the hard-welded material of the present invention.

Fig. 2 is a plan view showing a state in which a paste for sealing is applied to the surface of a carrier according to the present invention.

Figure 3 relates to the invention, showing the formation of a hard weld on the surface of the cover material A plan view of a sealing cover material made of a composite material.

Fig. 4 is a perspective view showing an important part of a sheet material in a state in which a paste for printing and applying a seal is printed.

Fig. 5A is a front elevational view showing a step of laminating a lid member for sealing to a package body according to the present invention.

Fig. 5B is a front elevational view showing the step of joining the laminated cover material to the package in accordance with the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Composition of sealing paste>

First, the sealing paste 20 of the present invention used in the method for producing a hard-welded material of the present invention or the sealing method will be described.

The sealing paste 20 is obtained by mixing a binder 25 in a raw material powder, and the raw material powder contains a low melting point metal powder 23 having a melting point or a liquidus temperature of less than 240 ° C, and a melting point as shown in FIG. 1A. The Ag powder 21 and the Cu powder 22 are higher than the low melting point metal powder 23.

The raw material powder contains the Ag powder 21 in an average particle diameter of 0.1 μm or more and 10.0 μm or less and 40% by mass or more and 90% by mass or less, and the Cu powder 22 contains an average particle diameter of 0.1 μm or more and 10.0 μm or less and 5% by mass or more and 50% by mass or less. The low-melting-point metal powder 23 has an average particle diameter of 0.5 μm or more and 20.0 μm or less and 5% by mass or more and 40% by mass or less, and the Ag powder 21, the Cu powder 22, and the low melting point metal are used. The powder 23 is suitably mixed in the above numerical range. Moreover, the respective content ratios of the Ag powder 21, the Cu powder 22, and the low melting point metal powder 23 are ratios with respect to the raw material powder.

The low-melting-point metal powder 23 may be one or more selected from the group consisting of Sn, In, Bi, Sn-Ag-Cu solder alloy, Sn-Cu solder alloy, Sn-Bi solder alloy, and Sn-In solder alloy. Further, any of the Sn-Ag-Cu solder alloy, the Sn-Cu solder alloy, the Sn-Bi solder alloy, and the Sn-In solder alloy used as the low-melting-point metal powder 23 may contain Sn, for example, 96.5 mass%. Sn-3.0% by mass Ag-0.5% by mass Cu, 99.3% by mass Sn-0.7% by mass Composition ratio of Cu or the like.

The binder 25 is composed of at least one of rosin, an active agent, a solvent, a rocking agent, and other additives.

The sealing paste 20 is formed by mixing the binder 25 at a ratio of 2% by mass or more and 50% by mass or less (ratio in the paste) to the raw material powder.

When the average particle diameter of the Ag powder 21 and the Cu powder 22 is less than 0.1 μm, the porosity of the hard-welded material formed using the sealing paste 20 is less than 10%, and it is difficult to obtain thermal shock or mechanical stress relaxation. effect. On the other hand, when the average particle diameter of the Ag powder 21 and the Cu powder 22 exceeds 10 μm, the porosity of the formed hard-welded material increases, and the sealing property is deteriorated.

Further, even if the average particle diameter of the low-melting-point metal powder 23 is less than 0.5 μm, the porosity of the formed hard-welded material is less than 10%, and it is difficult to obtain an effect of alleviating thermal shock or mechanical stress. Low melting point metal powder When the average particle diameter of 23 exceeds 20 μm, the porosity of the formed hard-welded material increases, and the sealing property is deteriorated.

The average particle diameter of the low-melting-point metal powder 23 is in the range of 0.5 μm or more and 20.0 μm or less, and is preferably the same as the average particle diameter of the Ag powder 21 and the Cu powder 22, or more preferably. Specifically, the average particle diameter of the low-melting-point metal powder 23 is preferably 1 time or more and 10 times or less the average particle diameter of the Ag powder 21 and the Cu powder 22, more preferably 1 time or more and 5 times or less, and more preferably 1.25 times or more. The following is better.

When the content ratio of the Ag powder 21 in the entire raw material powder is less than 40% by mass, the sealing property is lowered. When the content exceeds 90% by mass, peeling occurs during washing for removing the binder residue, and the cost is further increased. In addition, when the content ratio of the Cu powder 22 is outside the range of 5 mass% or more and 50 mass% or less, that is, when it is less than 5% by mass or more than 50% by mass, the sealing property is lowered. Further, when the content ratio of the low-melting-point metal powder 23 is less than 5% by mass, peeling occurs during washing, and when it exceeds 40% by mass, a low melting point temperature region is generated and the molten portion of the brazing alloy is not melted. Hey. When the content ratio of the low-melting-point metal powder 23 exceeds 40% by mass, the sealing property also decreases.

When the content ratio of the binder to the sealing paste 20 is less than 2% by mass or more than 50% by mass, even if it is kneaded with the raw material powder, it is difficult to form a paste suitable for the printing method. In particular, when the binder exceeds 50% by mass, when the hard-welded material is formed, the binder completely removes the Ag powder and the Cu powder, and it is difficult to form the hard-bonded material into a desired shape.

<Composition and manufacturing method of hard solder joint material>

A method of manufacturing the hard-welded material 4 using the above-described sealing paste 20 will be described with reference to Fig. 2 .

The method for producing the hard-welded material 4 includes a paste application step of printing and applying the above-described sealing paste 20 onto the carrier 3; and the sealing paste 20 applied to the carrier 3 as a low-melting-point metal a heat treatment step of heating the melting temperature of the powder 23; and a binder removal step of removing the binder after the heat treatment step.

[paste coating step]

The carrier 3 such as a ceramic substrate to which the brazing material is not suitable is prepared, and the above-described sealing paste 20 is printed and applied on a surface of the carrier 3 in a desired shape, for example, in a shape of a peripheral portion overlapping the package on the surface of the lid. Frame or sheet (Figure 2). The sealing paste 20 can also be supplied to the carrier 3 by discharging it by a dispenser or the like.

[heat treatment step]

The carrier 3 coated with the paste for sealing 20 is subjected to a low temperature reflow process to form a hard solder material 4. Specifically, the sealing paste 20 applied to the carrier 3 is heated in a nitrogen atmosphere to a melting temperature of the low melting point metal powder 23 contained in the sealing paste 20, that is, the melting point or liquid of the low melting point metal powder 23. a low melting point metal powder having a temperature equal to or higher than the phase line temperature and not higher than the melting point of Ag and Cu, and the Ag powder 21 and the Cu powder 22 are not melted. The last 23 melts. This heat treatment is sufficient as long as the low-melting-point metal powder 23 is melted, and therefore it can be carried out by reflow (heat treatment) using a furnace or an oven of a general solder material. More specifically, when the low-melting-point metal powder 23 is a Sn powder, it is a low-melting-point metal in a temperature range of a melting point (232° C.) or more of Sn, a melting point of Ag (961° C.), and a melting point of Cu (1083° C.). Heat treatment is carried out at a temperature of +10 ° C to 30 ° C.

When the low-melting-point metal powder 23 is melted, the liquid phase of the low-melting-point metal is covered between the Ag powder 21 and the Cu powder 22 which are not melted at the temperature of the heat treatment. Then, the liquid phase of the low melting point metal is infiltrated between the Ag powder 21 and the Cu powder 22, and then cooled to solidify the low melting point metal. Thereby, as shown in FIG. 1B, the bonding layer 24 forming the low melting point metal is connected to the high melting point metal. A hard-welded material 4 in the state of a powder (Ag powder 21 and Cu powder 22). At this time, a part of the low-melting-point metal and the high-melting-point metal may be alloyed, but most of the high-melting-point metal remains directly in the original powder, so that a large gap is formed in the portion having the low-melting-point metal powder 23 by heat treatment before heating. 41. The hard-welded material 4 is formed into a porous structure having a porosity of 10% or more.

In the heat treatment step, the Ag powder 21 and the Cu powder 22 composed of the high melting point metal in the sealing paste 20 are melted and the liquid is in a liquid state to invade the high melting point metal powder 21, 22 In the middle, liquid phase sintering is performed. Thereby, the hard solder material 4 can be formed at a low heat treatment temperature. At this point, it does not become a brazing alloy of a low melting point metal and a high melting point metal.

[Binder removal step]

As described above, the binder 25 is mixed in the sealing paste 20. Therefore, after the heat treatment step, the residue of the binder 25 remaining in the hard-welded material 4 is removed by the cleaning liquid (washing treatment). At this time, after the hard solder material 4 is peeled off from the carrier, the hard solder material 4 is separately washed. As the cleaning liquid, a precision parts cleaner (Pine Alpha Series) manufactured by Arakawa Chemical Industries Co., Ltd., or the like can be used.

After the residue of the binder 25 is removed by the cleaning liquid (washing treatment), a treatment for reducing the organic component remaining inside the hard-welded material 4 may be performed as needed. In the treatment, for example, the hard-welded material 4 is subjected to heat treatment at 300 ° C or more and 1200 ° C or less for 0.1 hour or longer and 24 hours or shorter, and is preferably a heat treatment at 600 ° C for 9 hours to vaporize and remove the organic component.

<Configuration and Manufacturing Method of Sealing Cover Material>

In the method of manufacturing the hard-welded material 4 described above, the case where the sealing paste 20 is applied to the carrier 3 and the hard-welded material 4 is separately manufactured is described, but the sealing body 5 and the lid 1 are sealed. The hard-bonded material 4 (see FIGS. 5A and 5B) is formed in advance on the surface of the lid body 1, and may constitute a lid member 6 for sealing in which the lid body 1 and the hard-weld material 4 are integrated.

A method of manufacturing the sealing cover member 6 will be described with reference to Fig. 3 .

The manufacturing method of the sealing cover material 6 is the aforementioned hard soldering material 4 The carrier 3 in the manufacturing method (Fig. 2) is replaced with the lid 1 except for the method of manufacturing the hard solder material 4, and has a paste for applying the sealing paste 20 to the surface of the lid 1. a coating step; a heat treatment step of heating the sealing paste 20 applied to the lid body 1 at a melting temperature of the low melting point metal powder 23; and removing the binder 25 after the hard solder material 4 is formed on the surface of the lid body 1 Adhesive removal step.

[paste coating step]

The material of the lid body 1 can be Ni plating (metal plating) on the surface by using cobalt, a 42 alloy or the like. The sealing paste 20 described above is printed on the surface of the lid body 1 in a frame shape conforming to the shape of a peripheral portion overlapping the package body, for example. Moreover, at this time, the discharge supply is performed by a dispenser or the like, and the sealing paste 20 can be applied to the lid 1.

[heat treatment step]

Next, the lid body 1 to which the sealing paste 20 is applied is subjected to a low temperature reflow treatment. Specifically, the lid body 1 to which the sealing paste 20 is applied is heated in a nitrogen atmosphere to a melting temperature of the low melting point metal powder 23 contained in the sealing paste 20, that is, the melting point of the low melting point metal powder 23. The low-melting-point metal powder 23 is melted at a temperature equal to or higher than the liquidus temperature and not higher than the melting point of Ag and Cu, and the Ag powder 21 and the Cu powder 22 are not melted. Then, the liquid phase of the low melting point metal is infiltrated between the Ag powder 21 and the Cu powder 22, and then cooled to solidify the low melting point metal. Thereby, the sealing cover material 6 provided with the hard-welded material 4 can be formed on the surface of the lid body 1 and hard. The welded material 4 has a porous structure in which the porosity of the Ag powder 21 and the Cu powder 22 is 10% or more by the bonding layer 24 composed of a low melting point metal. Since the hard-welded material 4 thus formed is fixed to the surface of the lid body 1, the lid member 6 for sealing is not peeled off from the lid body 1 when the lid member 6 for sealing is operated.

[Binder removal step]

As described above, the adhesive 25 is mixed in the sealing paste 20. Therefore, the residue of the binder 25 remaining after the heat treatment step is removed by the cleaning liquid.

Even at this time, as needed, after the cleaning treatment of the binder, a step of reducing the organic component remaining inside the hard-welded material 4 may be performed (for example, applying 300 ° C or more to 1200 ° C to the hard-welded composite material) Hereinafter, the heat treatment of 0.1 hour or longer and 24 hours or shorter is preferably a baking treatment in which the organic component is vaporized and removed by heat treatment at 600 ° C for 9 hours.

<Manufacturing method of a plurality of sealing cover materials>

In the method for producing the lid member for sealing 6, the heat treatment is applied to the lid member 1 for applying the sealing paste 20, and as shown in Fig. 4, the remaining sheets are prepared in advance to form a plurality of lids 1. After the plurality of hard-welded materials 4 are formed on the surface of the sheet material 2, the sheet material 2 is divided into a plurality of sheets 1 into a plurality of sheets, whereby a plurality of sealing lid materials 6 can be produced at one time.

In this case, the method for producing a sealing cover material includes a paste application step of printing and applying the sealing paste 20 on the surface of the sheet material 2, and a sealing paste 20 applied to the sheet material 2 as a low melting point metal powder 23 a heat treatment step of heating the molten solder material 4 to form a hard solder material 4; a binder removal step of removing the binder 25 after forming the hard solder material 4 on the surface of the sheet material 2; and cutting the sheet material 2 to divide into a sealing lid material 6 The chipping step. Further, a plating treatment step of applying metal plating to the surface of the sealing cover member 6 may be provided after the individual sheeting step, as needed.

[paste coating step]

The sheet material 2 having a size in which a plurality of lids 1 are formed is prepared, and the sealing paste 20 is placed on the surface of the sheet material 2 so as to be aligned with the peripheral portion of the package 5 which is superposed on the surface of the lid sheet 6 for sealing. The position is printed and printed in a frame shape (not shown). At this time, the sealing paste 20 can be applied to the sheet material 2 by the discharge supply by a dispenser or the like. The material of the sheet material 2 can be Ni plating (metal plating) on both sides or one side of the surface using cobalt, a 42 alloy or the like.

[heat treatment step]

The sheet material 2 (the lid body 1) to which the sealing paste 20 is applied is subjected to a low temperature reflow treatment. Specifically, the sheet material 2 to which the sealing paste 20 is applied is heated in a nitrogen atmosphere to a melting temperature of the low melting point metal powder 23 contained in the sealing paste 20, that is, the melting point of the low melting point metal powder 23 or Above the liquidus temperature and below the melting point of Ag and Cu, Ag powder 21 The low-melting-point metal powder 23 is melted at a temperature at which the Cu powder 22 does not melt. Then, the liquid phase of the low melting point metal is infiltrated between the Ag powder 21 and the Cu powder 22, and then cooled to solidify the low melting point metal. Thereby, a hard solder material 4 (FIG. 4) can be formed on the surface of the sheet material 2 (the lid body 1), and the hard solder joint material 4 has a combination of Ag powder 21 and Cu powder 22 by a low melting point metal. The layer 24 has a porous structure in which the porosity is 10% or more. Since the hard-welded material 4 thus formed is fixed to the surface of the sheet material 2 (the lid body 1), the sheet material 2 (the lid body 1) is not peeled off from the lid body 1 when it is processed.

[Binder removal step]

As described above, the adhesive 25 is mixed in the sealing paste 20. Therefore, the residue of the binder 25 remaining after the heat treatment step is removed by the cleaning liquid (washing treatment). As the cleaning liquid, a precision parts cleaner (Pine Alpha Series) manufactured by Arakawa Chemical Industries Co., Ltd., or the like can be used.

Even in this case, after the residue of the binder 25 is removed by the cleaning liquid (washing treatment), a treatment for reducing the organic component remaining inside the hard-welded material 4 may be performed as needed. In the treatment, for example, the hard-welded material 4 is subjected to heat treatment at 300 ° C or more and 1200 ° C or less for 0.1 hour or longer and 24 hours or shorter, and is preferably a heat treatment at 600 ° C for 9 hours to vaporize and remove the organic component.

[segmentation step]

Next, the sheet 2 formed with the hard-welded material 4 is cut, and each cover is The body 1 (sealing cover material 6) is diced.

[plating treatment step]

As described above, Ni plating is applied to the surface of the sheet material 2, but the sheet material 2 of the hard-welded material 4 is cut and formed, and after the lid member 1 (sealing lid member 6) is diced, all of them may be used. Ni plating (metal plating) was applied. Thereby, Ni plating is applied to the cut surface (side surface) of the lid body 1 (sealing lid member 6), and corrosion or rusting of the side wall of the lid body 1 (sealing lid member 6) can be prevented. Ni plating can be formed by electroless plating or electrolytic plating, and the film thickness can be several μm. Further, other metal plating may be applied in addition to Ni plating.

<Package sealing method>

Next, a package sealing method for bonding a package to a package will be described with reference to FIGS. 5A and 5B.

This sealing method has a paste application step of printing and applying the above-described sealing paste 20 on the surface of the lid 1; and the sealing paste 20 applied to the lid 1 is melted at a low melting point metal powder 23 a heat treatment step of heating; a binder removal step of removing the binder 25 after the hard solder material 4 is formed on the surface of the lid body 1; and the lid body 1 after removing the binder 25 is superposed on the package body 5 to make the hard solder joint material 4 The alloying step of heating and melting to form a brazing alloy to bond the lid 1 to the package 5 is a configuration in which the alloying step is added to the method for producing the sealing lid 6 described above. The package sealing method has a sheeting step and a plating place as needed Steps. Therefore, in the description of the package sealing method, the description of the paste application step, the heat treatment step, the binder removal step, the singulation step, and the plating treatment step is omitted, and only the surface of the lid 1 is provided with a hard surface. An alloying step of bonding the package 5 and the lid 1 to the sealing cover material 6 of the welded material 4 is performed.

[alloying step]

As shown by an arrow in FIG. 5A, the sealing cover material 6 is superimposed so that the hard-welded material 4 contacts the package 5, and as shown in FIG. 5B, heating is performed by adding a predetermined pressure. The hard solder material 4 is melted, cooled and solidified, and the lid 1 is bonded to the package 5. The package 5 is made of ceramic or the like, and a gold plating layer is formed as a conductive metal layer on the bonding surface with the lid 1.

The heating method of the hard-welded material 4 includes a fusion method (heat sealing method), a seam welding method (resistance welding method), and a treatment using an oven or a conveyor belt furnace at a temperature higher than a melting point of a brazing material. Injection welding method, electron beam welding method, ultrasonic welding method, and the like.

For example, in the seam welding method, as shown in FIG. 5B, the sealing cover member 6 is superposed so that the package 5 contacts the hard bonding material 4, and the roller electrode 11 is abutted from above the lid body 1 of the sealing lid member 6. The current flows in a state in which a predetermined pressure is applied, and the roller electrode 11 is moved along the peripheral portion of the lid 1. When the hard-welded material 4 is partially melted by Joule heat corresponding to the current value of the roller electrode 11, by appropriately setting the current value, it is instantaneously heated to the high-melting-point metal powder (Ag powder 21 and Cu powder 22). The temperature above the melting point causes this to melt.

In the laser welding method or the electron beam welding method, although the illustration is omitted, the hard bonding material 4 can be instantaneously heated by irradiating the bonding surface with a laser or an electron beam in a state in which the sealing member 6 is sealed.

In this manner, by melting the high-melting-point metal powders 21 and 22, the low-melting-point metal is also contained, and all of the hard-welded materials 4 are in a molten state, and a brazing alloy is formed from each of the contained metals to complete the sealing. For example, in the hard solder material 4 containing Sn as, for example, Ag, Cu, or a low-melting-point metal, an Ag-Cu-Sn-based brazing alloy is used, and the lid 1 and the package 5 can be joined.

In the alloying step, when a heating method in which only a sealing portion is formed into a local high temperature state using a seam welding method, a laser welding method, an electron beam welding method, or the like, a part of the sealing portion is locally heated in order, so that it is heated. Partial and unheated parts generate thermal shock or mechanical stress. At this point, the hard-welded material 4 is a porous structure having a porosity of 10% or more inside the void, and the thermal shock or mechanical stress during welding can be alleviated. Therefore, cracking of the bonding layer or the package 5 between the package 5 and the lid 1 can be prevented, and the package 5 and the lid 1 can be hermetically sealed. Further, when the porosity of the hard-welded material 4 is increased, the sealing property is lowered, so that the porosity is preferably 35% or less.

The hard-welded material 4 is formed into a porous structure having voids therein, but when the hard-welded material 4 is heated to the melting temperature of the Ag powder 21 and the Cu powder 22, and Ag and Cu are melted and alloyed with the low-melting-point metal, , that is, along the peripheral portion of the cover 1 by various welding methods When the hard solder material 4 is heated, the molten portion of the hard solder material 4 is sequentially moved, so that the voids inside the hard solder material 4 are pushed out to the outside as the molten portion moves, so that the package 5 and the cover can be made. Body 1 is indeed hermetically sealed.

When the hard solder material 4 is used for, for example, bonding of a substrate and a mounted object, that is, different from the sealing use of the package 5, it is not necessary to have an alloying step when it is not required to be hermetically sealed. In the hard-welded material 4, Ag and Cu are not alloyed with the low-melting-point metal, or a part of the alloy is alloyed, and the porous structure may remain, and the substrate and the object to be mounted may be bonded.

Then, in such a manner, in the method of sealing the lid body 1 and the package 5, the hard solder material 4 is formed in advance on the lid body 1, so that the stable hard solder material 4 can be easily formed on the lid body 1. The surface of the sealing cover material 6 is not easily peeled off from the lid body 1 during the treatment of the lid member 6 for sealing, and is easy to handle. Further, as described above, the sealing paste 20 can be applied to the surface of the carrier 3 or the lid 1 by printing or the like, and the hard solder material 4 (sealing frame) having a desired shape can be easily formed. Then, the hard soldering material 4 can be formed by the heat treatment at a low temperature for the formation of the lid body 1, which is more efficient.

Further, the sealing cover material 6 after the heat treatment step is subjected to an alloying step in a state in which the hard-welded material 4 is placed on the package 5, and the alloying and sealing of the hard-welded material 4 can be simultaneously performed. effectiveness.

Further, the raw material powder mixed in the sealing paste 20 At the end, since a plurality of metal powders are contained by combination, the amount or type of each metal powder can be easily changed, and the alloy composition can be easily changed.

When the raw material powder to be mixed in the sealing paste is a silver brazing alloy powder, it is necessary to heat the molten solder to a melting temperature (liquidus temperature) of the silver brazing alloy. The hard solder joint material 4 of the embodiment is formed by liquid phase sintering of a low melting point metal and heating by a melting temperature of a low melting point metal (less than 240 ° C), so that the furnace or the like does not need to use a high temperature specification, and the processing can be reduced. energy.

Further, the package sealing method may be a method in which a pre-formed hard-welded material 4 is laminated between the package 5 and the lid 1 and then the molten hard-welded material 4 is heated and alloyed (not shown). . That is, in the package sealing method, a paste coating step, a heat treatment step, and an alloying step are performed; the paste coating step applies a sealing paste 20 to the carrier 3; the heat treatment step The sealing paste 20 applied to the carrier 3 is heated at a melting temperature of the low melting point metal, and the liquid phase of the low melting point metal is infiltrated between the Ag powder 21 and the Cu powder 22, followed by cooling and solidifying, thereby forming a paste. The Ag powder 21 and the Cu powder 22 are bonded to each other by a bonding layer 24 composed of a low melting point metal, and have a porosity of 10% or more. The alloying step is to laminate the hard solder material 4 to the package. After the gap between the lid body 1 and the lid body 1, the hard solder material 4 is heated and melted and alloyed to form a brazing alloy.

Example

Examples 1 to 9 and Comparative Examples 1 to 11 are used in the real The samples of the package and the lid (sealing lid) were each 100. For the package system, a ceramic (aluminum oxide) having a plane size of 3.2 mm × 2.5 mm and a thickness of 0.5 mm was used, and a metal plating (metallization layer) was formed on the 5 μm Ni plating layer to form a 0.5 μm Au plating layer. As the lid system, a cobalt plate material having a plane size of 3.1 mm × 2.4 mm and a thickness of 0.1 mm was used, and a metal plating layer (metallization layer) was formed on a 5 μm Ni plating layer to form a 0.1 μm Au plating layer.

The sealing paste for forming the sealing cover materials of Examples 1 to 9 and Comparative Examples 1 to 10 was prepared by mixing the raw material powder and the binder in which the metal powders of the mixing ratio and the average particle diameter shown in Table 1 were mixed. Production. SAC 305 in Table 1 is a Sn-Ag-Cu solder alloy of Sn-3 mass% Ag-0.5 mass% Cu. Then, these sealing pastes are applied to the respective lids, and then subjected to a heat treatment at a maximum temperature of 240 ° C to form a hard-welded material to form a sealing lid member, and the sealing cover material is removed to remove the binder. .

For each metal powder, the median diameter (D50) of the particle diameter measured by the laser diffraction or scattering type particle size distribution measuring apparatus was used as the average particle diameter.

The hard-welded material of Comparative Example 11 was a rolled material (BAg-8: 72% by mass Ag-28% by mass Cu) of a silver brazing alloy having no porous structure.

The hard-welded composite material formed by the sealing cover materials of Examples 1 to 9 and Comparative Examples 1 to 11 has a theoretical density of the mixed powder (raw material powder) of the composition as ρ1, and the hard welded joint after washing. When the density of the material is ρ2 as measured by the Archimedes method, the porosity is calculated using a calculation formula of porosity (%) = (ρ1 - ρ2) / ρ1.

Further, the hard-welded materials of Comparative Example 7 and Comparative Example 10 were peeled off in the binder removal step. Further, the hard-welded material of Comparative Example 8 was broken in shape during the heat treatment step, and the shape could not be maintained. Therefore, in the hard-welded materials of Comparative Examples 7, 8, and 10, the porosity was not measured, and the porosity was described by "-".

Next, each cover (sealing cover material) is superposed on the package, and is subjected to seam welding to perform hermetic sealing.

Thereafter, the vicinity of the joint portion between the package and the lid was observed with a stereoscopic microscope (×50 times) to investigate the presence or absence of cracks. Then, the ceramic package in the vicinity of the joint portion was judged to be unacceptable (OK), and the crack was found to be unacceptable (NG) (Table 2).

Further, a hermetic sealing test of the He leakage test and the liquid foaming test was carried out for each of the 100 samples, and the airtight defect rate was examined in accordance with the number of leaks. The evaluation of the tightness is as follows: if the airtight defect rate is less than 2% in both the He leak test and the liquid foaming test, it is set to pass (OK), and the airtight defect rate is 2% in at least one of the tests. The above is assumed to be unqualified (NG) (Table 2).

The results of these are shown in Table 2.

As is apparent from Tables 1 and 2, the raw material powder is an Ag powder containing an average particle diameter of 0.1 μm or more and 10.0 μm or less and 40% by mass or more and 90% by mass or less, and Cu powder is used as an average particle diameter of 0.1 μm or more and 10.0. 5% or less and 5% by mass or more and 50% by mass or less, and the low-melting-point metal powder is a sealing paste having an average particle diameter of 0.5 μm or more and 20.0 μm or less and 5% by mass or more and 40% by mass or less, and has a porosity of 10%. In the above-described hard-welded composite material having a porous structure, none of the sealing cover materials of Examples 1 to 9 is cracked, and the package has high airtightness and can be satisfactorily sealed.

When the average particle diameter of the Ag powder and the Cu powder to be mixed in the sealing paste is less than 0.1 μm, and the average particle diameter of the low melting point metal powder is less than 0.5 μm (Comparative Example 9), the sealing paste is used. The formed hard solder joint has a porosity of less than 10%, and the joint between the package and the cover The layer or the package itself produces cracks. On the other hand, when the average particle diameter of the Ag powder and the Cu powder exceeds 10 μm (Comparative Example 1), the porosity of the formed hard-welded material increases, and the sealing property is deteriorated. When the average particle diameter of the low-melting-point metal powder exceeds 20 μm (Comparative Example 2), the porosity of the formed hard-welded material increases, and the sealing property is deteriorated.

When the content ratio of the Ag powder was less than 40% by mass (Comparative Example 3), the sealing property was lowered, and when it exceeded 90% by mass (Comparative Example 10), peeling occurred in the binder removal step. When the content ratio of the Cu powder is outside the range of 5% by mass to 50% by mass, that is, when it is less than 5% by mass (Comparative Examples 4 and 10) or more than 50% by mass (Comparative Examples 5 and 7), The seal will be reduced. When the content ratio of the low-melting-point metal powder is less than 5% by mass (Comparative Examples 7 and 10), peeling occurs in the binder removal step, and when it exceeds 40% by mass (Comparative Example 6), the sealing property is lowered.

Further, the present invention is not limited to the above-described embodiments, and various modifications can be added without departing from the scope of the invention.

Industrial use possibility

The hard-welded material having a porous structure can be easily changed by the alloy composition of the hard-welded material, and cracks are not generated, so that the package can be hermetically sealed.

20‧‧‧Seal paste

21‧‧‧Ag powder

22‧‧‧Cu powder

23‧‧‧Low-melting metal powder

25‧‧‧Adhesive

Claims (18)

A paste for sealing comprising a raw material powder and a binder, wherein the raw material powder contains a low-melting metal powder having an average particle diameter of 0.5 μm or more and 20.0 μm or less and a melting point or a liquidus temperature of less than 240 ° C Ag powder of 40% by mass or more and 40% by mass or less and 90% by mass or less of the Ag powder having an average particle diameter of 0.1 μm or more and 10.0 μm or less and 5% by mass or less and 50% by mass or less of the Cu powder having an average particle diameter of 0.1 μm or more and 10.0 μm or less. The paste for sealing according to the first aspect of the invention, wherein the average particle diameter of the low-melting-point metal powder is 1 time or more and 10 times or less the average particle diameter of the Ag powder, and the average particle diameter of the Cu powder is at least 1 time. 10 times or less. The sealing paste according to claim 1, wherein the average particle diameter of the low melting point metal powder is larger than an average particle diameter of the Ag powder and an average particle diameter of the Cu powder. The sealing paste according to the first aspect of the invention, wherein the mixing ratio of the binder is 2% by mass or more and 50% by mass or less. The sealing paste according to claim 1, wherein the low melting point metal powder is selected from the group consisting of Sn, In, Sn-Ag-Cu solder alloy, Sn-Cu solder alloy, Sn-Bi solder alloy, and Sn-In solder. More than one type of alloy. A method for producing a hard-welded material, comprising: a paste coating step and a heat treatment step of applying the above-mentioned sealing paste according to claim 1 of the patent application to a carrier; In the heat treatment step, the sealing paste applied to the carrier is heated at a melting temperature of the low melting point metal, and the liquid phase of the low melting point metal is infiltrated between the Ag powder and the Cu powder, and then cooled and solidified. Thereby, a hard solder material having a porosity of 10% or more in which the Ag powder and the Cu powder are bonded by a bonding layer made of the low melting point metal is formed. A hard-welded material characterized by having Ag powder having an average particle diameter of 0.1 μm or more and 10.0 μm or less, Cu powder having an average particle diameter of 0.1 μm or more and 10.0 μm or less, and a melting point or a liquidus temperature of less than 240 a bonding layer in which the Ag powder and the Cu powder are bonded to each other, and a porosity of 10% or more, and the mass ratio is 40% by mass or more and 90% by mass or less of the Ag powder, and the Cu powder is 5 mass% or more and 50 mass% or less, and the said bonding layer is 5 mass % or more and 40 mass % or less. A method for producing a lid material for sealing, comprising: a paste application step of applying the paste for sealing according to claim 1 of the patent application to a surface of a lid body; and a heat treatment step; The sealing paste coated on the lid body is heated at a melting temperature of the low melting point metal, and a liquid phase of the low melting point metal is infiltrated between the Ag powder and the Cu powder, and then cooled and solidified, thereby forming the aforementioned The Ag powder and the Cu powder are a hard-welded material having a porosity of 10% or more which is connected by a bonding layer made of the low-melting-point metal. The method for producing a sealing cover material according to claim 8, wherein after the heat treatment step, a binder removal step of removing a binder remaining in the hard-bonded material is provided. The method for producing a sealing cap material according to claim 9, wherein the binder removing step includes a washing step of washing the hard solder material with a cleaning liquid, and a heat treatment after the washing treatment. Baking treatment of welded composite materials. The method for producing a sealing cover material according to the eighth aspect of the invention, wherein the sealing paste is coated on a surface of a sheet material capable of forming a plurality of the lid bodies in the paste coating step, and the heat treatment is performed After the step, there is a sheet forming step of dividing the sheet material into the lid body. A sealing cover material comprising: a cover body; and a hard-welded material according to item 7 of the patent application scope provided on the surface of the cover body. A package sealing method for bonding a package body and a cover body by a brazing alloy, and having: a paste coating step, a heat treatment step, and an alloying step; the paste coating step is as claimed in the patent application The sealing paste according to the first aspect is applied to the surface of the lid body; and the heat treatment step is performed by heating the paste for sealing applied to the lid body at a melting temperature of the low melting point metal to the Ag The liquid phase of the low melting point metal is infiltrated between the powder and the Cu powder, and then cooled and solidified, whereby the Ag powder and the Cu powder are formed by the former a hard-welded material having a porosity of 10% or more in which a bonding layer composed of a low-melting-point metal is bonded; wherein the alloying step heats and melts the hard-welded material by superposing the lid on the package It is alloyed and formed into the aforementioned brazing alloy. The package sealing method of claim 13, wherein the binder removal step of removing the binder remaining in the hard-bonded material is between the heat treatment step and the alloying step. The method of sealing a package according to claim 14, wherein the removing step of the adhesive has a cleaning process of washing the hard solder material with a cleaning liquid; and heat-treating the hard solder after the cleaning process. Baking treatment of composite materials. The method of sealing a package according to claim 13, wherein the sealing paste is coated on the surface of the sheet in which the plurality of the lids are formed in the paste coating step, and after the heat treatment step, There is a singulation step of dividing the aforementioned sheet material into the above-mentioned lid body. The package sealing method of claim 16, wherein after the singulating step, a plating treatment step of applying a metal plating to the surface of the cover is provided. A package sealing method is a method in which a package is overlapped with a cover and joined by a brazing alloy, characterized in that a paste coating step, a heat treatment step, and an alloying step are performed; the paste coating step is as claimed The aforementioned range of item 1 The sealing paste is applied to the carrier; the heat treatment step is such that the sealing paste applied to the carrier is heated at a melting temperature of the low melting point metal to form the aforementioned Ag powder and the Cu powder. a liquid-phase infiltration of a low-melting-point metal, followed by cooling and solidification, thereby forming a hard-welded material having a porosity of 10% or more in which the Ag powder and the Cu powder are bonded by a bonding layer composed of the low-melting-point metal; In the step of disposing the hard solder material between the package and the lid, the hard solder material is heated and melted and alloyed to form the brazing alloy.