Abstract:
A diene rubber composition with excellent processability which reconciles fuel-saving performance with high road-holding performance and is excellent in tensile strength and wearing resistance; a diene rubber obtained by crosslinking the composition; and a process for producing the composition. The composition is characterized in that it comprises 100 parts by weight of a diene rubber having a molecular-weight distribution, which is represented by the ratio of the weight-average molecular weight to the number-average molecular weight, of 1.1 to 30, 20 to 200 parts by weight of silica, and a cationic polymer and that the amount of rubber components insoluble in toluene is 0.2 to 1 g per g of the silica. The process for producing the composition is characterized by reacting a rubber latex stabilized with an anionic emulsifying agent with an aqueous silica suspension containing a cationic polymer and co-coagulating the rubber contained in the rubber latex and the silica contained in the aqueous suspension in a specific pH range.
Abstract:
A process for producing a metallized ceramic substrate having a first conductive layer and a second conductive layer whose surface roughnesses are different from each other, which process comprises the steps of forming a first conductive paste layer containing metal powder on a substrate of sintered ceramic; forming a second conductive paste layer containing metal powder whose average particle diameter is different from that of the metal powder as constituent of the first conductive paste layer; and firing the first conductive paste layer and the second conductive paste layer to thereby form the first conductive layer and the second conductive layer. By the process, there is provided a metallized ceramic substrate that even when it is a multilayer substrate having multiple metallized layers, is capable of ensuring airtightness.
Abstract:
The present invention provides a metallized substrate having a novel structure. The metallized substrate comprising, disposed in the order mentioned: a ceramics substrate; a high-melting point metal layer; a base nickel plating layer; a layered nickel-phosphorous plating layer; a diffusion-inhibiting plating layer; and a gold plating layer, the base nickel plating layer being any one of a nickel plating layer, a nickel-boron plating layer, or a nickel-cobalt plating layer, the diffusion-inhibiting plating layer being any one of a columnar nickel-phosphorous plating layer, a palladium-phosphorous plating layer, or a palladium plating layer. According to the above composition, even after heating the semiconductor chips in a mounted state, it can make the connection strength of wire bonding favorable.
Abstract:
The present invention is to provide a diene rubber composition and a cross-linked diene rubber thereof excellent in tensile strength, wear resistance and processability, keeping compatibility of both good fuel efficiency and high gripping property, and a production method thereof. What is characterized in the composition is that the composition is comprised of 100 parts by weight of a diene rubber having a molecular weight distribution expressed in terms of the ratio of the weight-average molecular weight to the number-average molecular weight of 1.1 to 30, 20 to 200 parts by weight of silica and a cationic polymer, and that a toluene-insoluble rubber content per gram of the silica within the range from 0.2 to 1g, and diene cross-linked rubber thereof. What is characterized in the production method is that the method comprises steps of allowing rubber latex stabilized by an anionic emulsifying agent to react with an aqueous suspension of silica containing a cationic polymer and effecting co-coagulation of rubber in the rubber latex with the silica in the aqueous suspension within a specific pH range.
Abstract:
The present invention provides a method for manufacturing metallized aluminum nitride substrate, the method comprising: Step A for forming a high-melting point metal layer over a sintered aluminum nitride substrate; Step B for forming over the high-melting point metal layer an intermediate metal layer of at least one selected from the group consisting of: nickel, copper, copper-silver, copper-tin, and gold by plate processing; and Step C for forming a surface metal layer containing silver as a main component over the intermediate metal layer by coating a silver paste whose glass component content is 1 mass % or less and firing under nonoxidizing atmosphere. By this method, it is capable of forming a glass component-free silver layer which is adhered at a high degree of adhesion strength onto the high-melting point metal layer formed over the aluminum nitride substrate as a top face by thick-film method using a silver paste which makes thick-membrane forming easier.
Abstract:
The present invention is to provide a fabrication method for metallized ceramics substrate comprising the steps of: forming a first conductive paste layer containing metallic powder on a sintered ceramics substrate; forming a second conductive paste layer containing metallic powder of which average particle diameter is different from that of metallic powder constituting the first conductive paste layer; and forming a first conductive layer and a second conductive layer by firing the first conductive paste layer and the second conductive paste layer, wherein surface roughness of the first conductive layer and the second conductive layer is different. By this method, it is possible to secure airtightness of the metallized ceramics substrate even if it is a multilayered substrate having a plurality of metallized layers.