JP2571795Y2 - Resin-sealed electronic components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to an electronic component in which elements such as a piezoelectric element, a capacitor, and a positive temperature coefficient thermistor are sealed with a resin.

(Prior Art) For example, a thermosetting epoxy-modified resin is used as an exterior resin of an electronic component in which a lead terminal is connected to a piezoelectric element, dipped in a sealing resin solution and resin-sealed.
When mounting resin-sealed electronic components, such as piezoelectric components, on a printed circuit board, these electronic components are held on tape at a fixed pitch, and taping is automatically supplied to the printed circuit board, etc. .

(Problem to be Solved by the Invention) In a conventional electronic component packaged with a thermosetting epoxy-modified resin, there is a problem that a crack is generated in the package resin when taping is automatically inserted by an automatic supply device at the time of mounting.

Therefore, an object of the present invention is to improve the impact resistance of a resin-sealed electronic component so as to prevent a crack or the like from occurring in an exterior resin even during automatic taping or the like.

(Means for Solving the Problems) In the present invention, the resin layer encapsulating the electronic element is provided with an inner resin layer in contact with the electronic element, and a resin layer formed on the outer periphery of the inner resin layer and having higher toughness than the inner resin layer. The structure includes a high outer resin layer.

Here, toughness indicates the tenacity of a material, and refers to the property of being hardly broken by impact.

(Embodiment) FIG. 1 shows an embodiment, and FIG. 2 shows a piezoelectric resonator element as an example of an electronic element used in the embodiment.

Reference numeral 2 denotes a piezoelectric resonator element using an energy trapping type thickness longitudinal vibration mode, and vibrating electrodes 6 and 6 are provided on the main surface on the front side and the main surface on the back side of a piezoelectric substrate 4 such as a piezoelectric ceramic substrate.
Are arranged at positions facing each other with the piezoelectric substrate 4 interposed therebetween. On both main surfaces, terminal electrodes 8, 8 connected to the vibrating electrodes 6, 6 are arranged at ends opposite to each other.
Lead terminals 10, 10 are connected to the respective terminal electrodes 8, 8 by soldering.

The resin for sealing the piezoelectric resonator element 2 has a two-layer structure. Reference numeral 12 denotes an inner resin layer, and the element 2 is sealed with a vibration space 16 by the inner resin layer 12. Inner resin layer 12
Is used as a porous epoxy resin. Vibration space 16
Is a space for preventing the vibration of the vibrating portion provided with the vibrating electrodes 6, 6 from being suppressed by the sealing resin.

Inside resin layer outside the inside resin layer 12 as an exterior resin layer
An epoxy resin layer 14 having higher toughness than 12 is covered.

To manufacture the piezoelectric component of the present embodiment, the lead terminals 10, 1
A wax is applied so as to cover the vibrating portion of the piezoelectric resonator element 2 to which the piezoelectric resonator element 0 is attached, and after the wax is cured, the piezoelectric resonator element 2 is immersed in an epoxy resin liquid containing air bubbles. 2 is covered with a porous epoxy resin layer 12.
Thereafter, when the porous epoxy resin 12 is cured by heating, the wax in the vibrating portion evaporates and is released to the atmosphere via the porous epoxy resin layer 12 or the porous epoxy resin 12
To form a space 16 therein. Thereafter, the element 2 is immersed in a highly tough epoxy resin liquid to form a highly tough epoxy resin layer 14 on the exterior, and thermally cured.

 FIG. 3 shows another embodiment.

Compared with the embodiment of FIG. 1, a silicon resin layer 18 is formed between the inner porous epoxy resin layer 12 and the outer high-toughness epoxy resin layer 14. Since the silicon resin layer 18 is softer than the epoxy resin layer, the silicon resin layer 18 absorbs stress even when the high-toughness epoxy resin layer 14 of the exterior contracts during molding or is gripped by an automatic supply device. However, it is possible to prevent a stress from being applied to the inner epoxy resin layer 12 and the piezoelectric resonator element 2, and to further improve the impact resistance.

(Effects of the Invention) In the present invention, the resin layer sealing the electronic element is formed of an inner resin layer in contact with the electronic element, and an outer resin layer formed on the outer periphery of the inner resin layer and having higher toughness than the inner resin layer. Because of this, the impact resistance as an electronic component is improved, accidents such as occurrence of cracks in the exterior resin during automatic taping are less likely to occur, and reliability is improved.

Further, since the inner resin layer having lower toughness than the outer resin layer is arranged between the electronic element and the outer resin layer having high toughness, even if the outer resin layer having high toughness is molded and contracted, its stress is reduced. The stress applied to the electronic element by being absorbed by the inner resin layer can be reduced, and a highly reliable electronic component can be provided also in this regard.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing one embodiment, FIG. 2 is a perspective view showing an electronic element sealed in the same embodiment, and FIG. 3 is a vertical sectional view showing another embodiment. 2,20 ... electronic element, 4 ... piezoelectric substrate, 6 ... vibrating electrode,
8 ... terminal electrode, 10 ... lead terminal, 12, 18 ... inner resin layer, 14 ... epoxy resin layer.

Claims (1)

(57) [Scope of request for utility model registration] In an electronic component in which an electronic element having lead terminals is exposed and sealed with a resin, a resin layer sealing the electronic element has an inner resin layer in contact with the electronic element; A resin-sealed electronic component comprising: an outer resin layer formed on the outer periphery of the inner resin layer and having a higher toughness than the inner resin layer.