The molding and packaging technique is well known in the semiconductor field. As shown in FIG. 1, the molding and packaging technique enables forming a packaging component 30P on at least a partial surface of a semiconductor element 10P and at least a partial surface of a encapsulated component 20P, so as to integrally bond the semiconductor element 10P to the encapsulated component 20P by means of the packaging component 30P. In addition, the molding and packaging technique also enables forming the packaging component 30P on at least a partial surface of the semiconductor element 10P, the packaging component 30P can embed at least the partial surface of the semiconductor element 10P, so as to protect the semiconductor element 10P, as shown in FIG. 2.
Taking the instance shown in FIG. 2 as an example, a concrete process of packaging the semiconductor element 10P by using the molding and packaging technique is as follows. As shown in FIG. 3, the semiconductor element 10P is first placed in a forming mold 40P in such a manner that a to-be-packaged surface of the semiconductor element 10P is exposed to a forming space 41P of the forming mold 40P. Next, as shown in FIG. 4, a forming material 50P in fluid form is introduced into the forming space 41P of the forming mold 40P, so that the forming material 50P fills up the forming space 41P of the forming mold 40P, and thus embeds the surface of the semiconductor element 10P that is exposed to the forming space 41P of the forming mold 40P. As shown in FIG. 5, after curing of the forming material 50P in the forming space 41P of the forming mold 40P and removal of the forming mold 40P, the forming material 50P can form the packaging component 30P encapsulated to at least a part of the surface of the semiconductor element 10P, where a first adjoining surface 31P of the packaging component 30P and a second adjoining surface 11P of the semiconductor element 10P correspond to each other.                To ensure that the semiconductor element 10P and the packaging component 30P can be encapsulated together more firmly and prevent the packaging component 30P from falling off from the semiconductor element 10P, a baking process needs to be carried out for the semiconductor element 10P encapsulated with the packaging component 30P after demolding, to achieve more reliable encapsulated between the packaging component 30P and the semiconductor element 10P. However, because the semiconductor element 10P and the packaging component 30P are made of different materials, the semiconductor element 10P and the packaging component 30P have different thermal expansion coefficients. In addition, because the polymerization and shrinkage of the material of the packaging component 30P continue during the baking, the semiconductor element 10P and the packaging component 30P undergo different degrees of deformation due to heat in the baking process. Specifically, referring to FIG. 5, the packaging component 30P is formed by curing of the forming material 50P introduced into the forming space 41P of the forming mold 40P. The packaging component 30P contracts inwardly fairly extensively when being heated in the baking process, and will further contract during cooling after baking. As a result, the first adjoining surface 31P of the packaging component 30P experiences a fairly extensive deformation. Theoretically, the second adjoining surface 11P of the semiconductor element 10P experiences a deformation to a smaller extent during cooling of the semiconductor element 10P after being heated, because the semiconductor element 10P has a smaller thermal expansion coefficient.        
Because the first adjoining surface 31P of the packaging component 30P is integrally encapsulated to the second adjoining surface 11P of the semiconductor element 10P, the first adjoining surface 31P of the packaging component 30P, when experiencing a fairly extensive deformation, generates a pull force acting on the second adjoining surface 11P of the semiconductor element 10P. Due to the pull force, the extent of the deformation of the second adjoining surface 11P of the semiconductor element 10P is greater than a theoretical extent of the deformation of the second adjoining surface 11P of the semiconductor element 10P. In FIG. 5, a solid line 100P represents an actual extent of deformation of the semiconductor element 10P due to the contraction and deformation of the packaging component 30P, and a dashed line 200P represents a theoretical extent of deformation of the semiconductor element 10P. As a result of this, undesirable phenomena such as cracking, deformation, and fatigue occur on at least a part of the surface of the semiconductor element 10P. Once undesirable phenomena such as cracking, deformation, and fatigue occur on the surface of the semiconductor element 10P, electrical and other properties of the semiconductor element 10P will be greatly affected. It should be understood that, the adjoining surfaces of the packaging component 30P and the packaged component 20P are also encapsulated together, and therefore, the adjoining surface of the packaging component 30P, when experiencing a fairly extensive deformation, also generates a pull force acting on the adjoining surface of the packaged component 20P. As a result, the extent of the deformation of the adjoining surface of the packaged component 20P is greater than a theoretical extent of deformation of the packaged component 20P.
Undesirable phenomena such as cracking and deformation of the surface of the semiconductor element 10P caused by the fairly extensive contraction and deformation of the packaging component 30P in the baking process will greatly affect the product yield of the semiconductor element 10P. Especially for the semiconductor element 10P used for photosensitive, it is requisite that the surface of the semiconductor element 10P be intact and as flat as possible. However, phenomena such as cracking and deformation of the surface of the semiconductor element 10P caused by the contraction and deformation of the packaging component 30P in the baking process greatly affects the product yield of the semiconductor element 10P, and even may directly lead to rejection of the semiconductor element 10P. Consequently, the molding and packaging technique cannot be applied to the packaging of the semiconductor element 10P used for photosensitive.
USPTO Backgrounds
USPTO Backgrounds