JPH02133936A - Semiconductor device - Google Patents

Abstract

PURPOSE:To sharply enhance reliability of a semiconductor device by a method wherein a gap material is added to an adhesive and particles whose coefficient of thermal expansion and elastic modulus are nearly identical with each other are distributed uniformly in a bonding part of a semiconductor element and a substrate. CONSTITUTION:A terminal 3 formed at a circuit board 2 is coated with an adhesive 5 containing a conductive particle 4. Then, when a semiconductor element 1 is mounted, the adhesive 5 coated in order to prevent the conductive particle 4 from being forced out from the terminal 3 is hardened. After that, the circuit board 2 is coated with an adhesive 6 containing a gap material 7; the semiconductor element 1 is mounted on it after an electrode 8 of the semiconductor element 1 has been aligned with the terminal 3 of the circuit board; the adhesive 6 is hardened by applying proper heat and a proper pressure. In this semiconductor device, a gap material whose coefficient of thermal expansion and elastic modulus are nearly identical to those of the conductive particle is added to a part, between the semiconductor element and the board, where the conductive particle does not exist; an internal stress whose magnitude is identical to that of the conductive particle is generated; thereby, the internal stress is dispersed uniformly over the whole semiconductor element; it is possible to restrain an exfoliation, a displacement, a crack and the like from being caused.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a structure in which a semiconductor element is mounted face-down on a circuit board.

[Prior Art] In conventional semiconductor devices, when a semiconductor element is wirelessly bonded onto a circuit board, an adhesive containing conductive particles is placed on the terminal corresponding to the electrode of the semiconductor element of the Cao Chi substrate, as shown in Fig. 2. The structure was such that an adhesive was selectively applied, an electrical connection was established with the electrodes of the semiconductor edge element, and the substrate and the semiconductor element were fixed with an adhesive.

[Problems to be Solved by the Invention] However, in a conventional semiconductor device having the structure shown in FIG. be. The adhesive and the conductive particles have different coefficients of thermal expansion and elasticity. Therefore, when thermal stress or mechanical stress is applied to the semiconductor device,
There are regions where conductive particles are present and regions where only adhesive is present, resulting in uneven internal stress within the semiconductor element. As a result, there are five problems such as peeling of the semiconductor element, deviation of the semiconductor element, and cracking in two. The present invention is intended to solve these problems, and aims to equalize the internal stress in the adhesive and provide high reliability.

[Means for Solving the Problems] The semiconductor device of the present invention provides electrical continuity between the electrodes of the semiconductor element and the substrate via conductive particles, and also connects the substrate and the semiconductor element using an adhesive. A semiconductor device having a bonding structure is characterized in that a gap material is mixed into the adhesive.

[Embodiment] FIG. 1 is a cross-sectional view of an embodiment of the present invention. Reference numeral 1 denotes a semiconductor element whose active surface faces a circuit board 2. In FIG. As the circuit board 2, a glass board or a glass board is used depending on the purpose. The terminals 3 are formed on the circuit board 2 by metal vapor deposition. 4 is a conductive particle made of fine resin particles coated with N1 plating, etc., which connects the electrode 8 on the active surface of the semiconductor element 1 and the terminal 6 of the circuit board 2.
There is electrical continuity between the The adhesive α5 containing the conductive particles 4 and the adhesive b6 containing the gap material 7 have the role of fixing the electrodes 8 of the semiconductor element 1 and the terminals 3 of the circuit board 2 so that their positions do not shift. Furthermore, by using the same adhesive for the adhesive α5 and the adhesive h6, it is possible to prevent differences in internal stress depending on the position due to different adhesives.

7 is a gap material having a spherical, elliptical, bicylindrical, etc. shape. The material is made of the same resin as the conductive particles 4, and the thermal expansion coefficient and elastic modulus are almost the same as the conductive particles.

First, adhesive 5 containing conductive particles 4 is applied onto terminals 5 formed on circuit board 2 . Next, when mounting the semiconductor element 1, the applied adhesive 5 is cured in order to prevent the conductive particles 4 from protruding from the terminals 3. After that, an adhesive 6 containing a gap material 7 is applied on the circuit board 2,
The semiconductor element 1 is mounted thereon with the electrodes 8 of the semiconductor element 1 and the terminals 3 of the circuit board aligned, and appropriate heat and pressure are applied to harden the adhesive 7. In a semiconductor device constructed using this method, a gap material whose coefficient of thermal expansion and elasticity is almost the same as that of the conductive particles is mixed into a region between the semiconductor, element, and substrate where there are no conductive particles. By generating an internal stress of a certain magnitude, it is possible to construct a semiconductor device in which the internal stress is uniform over the entire surface of the semiconductor element.As a result, when heat or mechanical stress is applied to the semiconductor device, the The large difference in the internal stress of the adhesive between areas where conductive particles are present and areas where conductive particles are not present, as in the conventional semiconductor device shown, can be significantly reduced, and the internal stress can be uniformly applied to the entire semiconductor element. It can be dispersed and prevent the occurrence of cracking and cracking in two.

[Effects of the Invention] - As explained above, the present invention mixes a gap material into the adhesive, and uniformly distributes particles with substantially the same coefficient of thermal expansion and elasticity in the bonded area between the semiconductor element and the substrate. By doing so, it becomes possible to reduce the deviation of internal stress depending on the position, and the reliability of the semiconductor device can be greatly improved.

[Brief explanation of the drawing]

Figure 1 shows a cross-sectional view of an embodiment of the present invention. Figure 2 shows a cross-sectional view of a conventional semiconductor device.
・Semiconductor element...Circuit board...Terminal...Conductive particles...Adhesive α...・・・・・・Adhesive b ・・・・・・Gap material・・・・・・More than electrode

Claims (1)

[Claims] In a semiconductor device having a structure in which an electrode of a semiconductor element and a circuit board are electrically connected through conductive particles, and the substrate and the semiconductor element are bonded using an adhesive, a gap material is mixed into the adhesive. A semiconductor device characterized by: