Patent EP-2280425-A2 (EP)
Inventor: NAGEL DR HENNING
IPC: H05K3/40
Filed: 2010-05-11
Abstract: The process comprises applying a moist material forming the contacts in a desired strip-like and/or point-like arrangement on an exterior surface of the semiconductor component, drying (12) the moist material by heating the semiconductor component to a temperature T 1with 350[deg] C= T 1= 480[deg] C over time t 1with 1 second= T 1= 600 seconds and keeping the semiconductor element at temperature T 1over a time t 1, and sintering (18) the dried material by heating the semiconductor component to a temperature T 2and keeping the semiconductor component at temperature T 2over a time t 2. The process comprises applying a moist material forming the contacts in a desired strip-like and/or point-like arrangement on an exterior surface of the semiconductor component, drying (12) the moist material by heating the semiconductor component to a temperature T 1with 350[deg] C= T 1= 480[deg] C over time t 1with 1 second= T 1= 600 seconds and keeping the semiconductor element at temperature T 1over a time t 1, sintering (18) the dried material by heating the semiconductor component to a temperature T 2and keeping the semiconductor component at temperature T 2over a time t 2, cooling (20) the semiconductor component to a temperature T 3that is equal or roughly equal to room temperature and keeping the semiconductor component at temperature T 3over a time T 3, cooling the semiconductor component to a temperature T 4, which is = -35[deg] C and keeping the semiconductor component at temperature T 4over a time T 4, and heating the semiconductor component to room temperature. After the application of the moist material at room temperature, the semiconductor component is kept over a time t awith 1 second= t a600 seconds at room temperature. After the application of the moist material on the semiconductor component, a base medium or a medium containing basic components is applied with a surfactant medium, which is used as the base medium, with water, which is used as a surfactant medium, anionic surfactants such as soap, fatty alcohol sulfates, alkyl benzolsulfonates and/or cationic surfactants such as invert soap, amphoteric surfactants and/or non-ionic surfactants like non-carboxylic acid esters of polyalcohols, or with the surfactant medium, which is applied in the form of a liquid or a foam in the area of the applied moist material onto the semiconductor component. The moist material is exposed to an oxidizing atmosphere A 1with a mixture of air, solvent and/or vapor and/or reaction products. The semiconductor component is heated in an oxidizing atmosphere A 2with a mixture of air and binders, resins and/or solvents or air with an enhanced oxygen content (>= 21 vol.%). The dried material is sintered at temperature T 2with 720[deg] C= T 2= 920[deg] C. The semiconductor component is kept at temperature T 2during the time t 2with 1 second= t 2= 120 seconds, where the sintering is done in air or in air with an enhanced oxygen content (>= 21 vol.%), and is kept at the temperature T 3over a time t 3with 1 second= t 3= 24 hours in air with normal humidity or in air with reduced humidity (less than 20 vol.%). The semiconductor component is cooled and kept at the temperature T 4in an inert atmosphere or in dry air with nitrogen or argon or a mixture of carbon dioxide. During cooling to the temperature T 4, the semiconductor component is subjected to an environment in which dry ice or alcohol such as methanol or ethanol is found. The semiconductor component is heated to a temperature T 7with 120[deg] C for connecting the contacts with electrically conducting strip-shaped connectors. The semiconductor component is interconnected with additional semiconductor components via connectors and then encapsulated with additional semiconductor components. During the encapsulation, alkaline components are added to the contacts, where the alkaline components include alkaline salts or alkaline earth carbonate. The electrically conducting contacts are in contact with polymers containing alkaline components for addition of the alkaline components. The contacts include an outermost layer of the sintered contact configured to have open pores, where a pore volume is 25 vol.%. The alkaline components are galvanically injected into the open pores, and then segments of the contacts are covered with a metallic layer. The moist material is applied to the surface of the semiconductor component in a pasty consistency or as a paste by compressing, dispensing, ink jet application or through a wet-chemical separation process. The semiconductor components have a material constant of K [J/cm 2>[deg] C] with 0.02= K= 0.06, where K=Ax dx rho x Cpx B, A is surface of the semiconductor component in cm 2>, d is thickness of the semiconductor component in cm, rho is density of the semiconductor component in g per cm 3>, Cp is thermal capacity of the semiconductor component [J/gK] and B is reference size to [1/cm 2>] of the particular semiconductor component to be treated and to attain a thermal content P with P=Kdelta Tdelta t, where delta T is the temperature difference to 0[deg] C. The interconnected semiconductor components have a material constant of K*[J/cm 2>[deg] C] with 0.9= K*= 1.6, where K*=A*x d*x rho *x Cp*x B*, A* is surface of the interconnected semiconductor component in cm 2>, d* is thickness of the interconnected semiconductor component in cm, rho * is density of the interconnected semiconductor component in g per cm 3>, Cp* is thermal capacity of the interconnected semiconductor component [J/gK] and B* is reference size to [1/cm 2>] of the interconnected semiconductor component such as a solar module. The semiconductor component experiences a thermal content P with 117000 Js/cm 2>= P= 460800 Js/cm 2>. An independent claim is included for a process for producing a composite of semiconductor components.