Elastic wave device and method for manufacturing the same

Abstract

This provides a new structure that can appropriately improve the integration between the device chip and pillar that constitute an elastic wave device. [Solution] The pad 10 is provided with a pillar 7 formed in a through hole 15 that penetrates the support layer 5 and the roof layer 6 and positions the pad 10 at the bottom of the hole, with the base portion 7a fixed to the second metal layer 4 on the pad 10. The second metal layer 4 on the pad 10 has a recess 4a and a protrusion 4b adjacent to the recess 4a, and the base portion 7a of the pillar 7 has a protrusion 7e that fits into the recess 4a, which is complementary to the recess 4a, and a recess 7f that receives the protrusion 4b, which is complementary to the protrusion 4b.

Claims

1. A device chip having a functional surface composed of a piezoelectric material on one side, A first metal layer formed on the functional surface, comprising a circuit pattern including a plurality of resonators, a plurality of pads, inter-resonator wiring connecting the resonators, and external connection wiring connecting the resonators and the pads, In the area where the first metal layer is formed, a second metal layer is formed on the first metal layer and covers at least a portion of the inter-resonator wiring, the external connection wiring, and the pad, A support layer formed in a region other than the resonator formation region on the functional surface, A roof layer formed on the support layer and working in cooperation with the functional surface and the support layer to form a sealing space for the resonator, The pad comprises a pillar formed in a through hole that penetrates the support layer and the roof layer and positions the pad at the bottom of the hole, with the base of the pillar fixed to the second metal layer on the pad. An elastic wave device wherein the second metal layer on the pad has a recess and a protrusion adjacent to the recess, and the base of the pillar has a protrusion that complements the recess and fits into the recess, and a recess that complements the protrusion and receives the protrusion.

2. The recess has a first surface portion that is connected to the side surface of the convex portion, and a second surface portion that is on the side opposite to the first surface portion and forms the lowest part of the recess between it and the first surface portion, The elastic wave device according to claim 1, wherein the second surface is inclined such that the distance between the second surface and the surface of the second metal layer gradually increases as it approaches the bottom.

3. The elastic wave device according to claim 2, wherein the recess has a cross-sectional contour shape that is arc-shaped at any position on the imaginary line segment connecting the starting end of the second surface, located on the upper side of the inclination of the second surface, to the lowest part, and the recess has a cross-sectional contour shape that is perpendicular to the imaginary line segment connecting the starting end of the second surface, located on the upper side of the inclination of the second surface, to the lowest part.

4. The elastic wave device according to claim 1, wherein the convex portion is formed to have a top portion that protrudes in an overhang shape above the lowest part of the concave portion.

5. A method for manufacturing an elastic wave device according to any one of claims 1 to 4, The steps include forming the first metal layer in each region of the wafer that will become one of the device chips, For each of the aforementioned regions, the step of forming the second metal layer after forming the first metal layer, A method for manufacturing an elastic wave device, comprising the steps of: for each region, after the formation of the second metal layer, performing a characteristic inspection by bringing a probe pin into contact with the second metal layer on the pad, and plastically deforming a part of the second metal layer with the probe pin to form the recess and the convex portion.

6. The method for manufacturing an elastic wave device according to claim 5, wherein the plastic deformation is caused by pressing the tip of the probe pin against the surface of the second metal layer such that the central axis of the probe pin forms an acute angle between the surface and the central axis of the second metal layer.

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