JP5493290B2 - Electronic component package - Google Patents

Description

  The present invention relates to an electronic component package in which two substrates are joined by a joining member, or a joining member and a spacer, and a joining method thereof.

  Conventionally, in a semiconductor acceleration sensor, a pressure sensor, or the like, at least one of a substrate having a first electrode formed on the surface and a substrate having a movable part (vibrating part) having a second electrode formed thereon is a bonding member, Alternatively, a bonding material and a spacer are provided, the first electrode and the second electrode are arranged to face each other and bonded via a bonding member or a spacer, and a physical quantity such as acceleration or pressure is obtained by displacement of the movable part. It is converted into an electrical signal and taken out.

  In such an electronic component package manufacturing method, suppressing variations in the gap between the first electrode and the second electrode suppresses variations in sensor quality. For this reason, it is desirable to keep the height of the spacer used for the joint as constant as possible between sensors or within one sensor.

  FIG. 9 shows a conventional capacitive pressure sensor described in Patent Document 1 and a manufacturing method thereof. In FIG. 9, 101 is a diaphragm, 102 is a fixed substrate, 103 is a first electrode, 104 is a second electrode, 105 is a spacer layer, and 106 is a spacer.

In Patent Document 1, a spacer layer 105 and a spacer 106 are separated on at least one peripheral edge of the fixed substrate 102 and the diaphragm 101, so that the distance between the fixed substrate 102 and the diaphragm 101 does not change during manufacture. It is described that the spacer layer 105 can be formed while being held in place, so that the thickness of the spacer layer 105 can be made substantially constant, and the capacitance variation of the capacitive pressure sensor can be reduced.
JP-A-8-240500

  However, as the electronic component package is rapidly becoming smaller and thinner, and the structure is complicated, it is difficult to accurately control the gap between the two electrodes with the conventional manufacturing method described in Patent Document 1. It is becoming.

  First, the thickness of the two substrates and the gap between the two substrates are becoming smaller for the purpose of reducing the thickness of the electronic component package. However, the thinner the substrate, the greater the warpage that occurs when processing the substrate and forming the circuit. In addition, the substrate tends to be deformed when a load is applied such as during bonding. Furthermore, the influence of the warpage and deformation of the substrate on the gap increases as the design value of the gap decreases.

  Further, even when the structure of the movable part is reduced in size and complicated, the two substrates are easily deformed, and the control of the gap has become difficult.

  Furthermore, the downsizing, thinning, and complexity of the electronic component package have caused problems such as difficulty in handling in the manufacturing process in addition to the gap control.

  The present invention is directed to solving the above-described problems of the prior art, and the gap between two substrates to be bonded can be accurately adjusted in response to downsizing, thinning, and complicated structure of electronic component packages. It is an object of the present invention to provide a controlled electronic component package and a bonding method for forming the same.

In order to achieve the above object, an electronic component package according to claim 1 according to the present invention is configured such that the surfaces of the first substrate and the second substrate are arranged to face each other and around the first and second substrates. In an electronic component package in which at least a part is bonded by a bonding member, the electronic component package is arranged around the first substrate, and becomes lower along the side of the first substrate toward the center of the side of the first substrate. A plurality of spacers having different heights are opposed to a joining member in which the joining member is disposed between the plurality of spacers and the height of the joining member is higher than the average height of the spacers on both sides of the joining member. The first substrate and the second substrate are bonded by a bonding member so that the distance between the arranged substrates is smaller in the center than the periphery of the substrate, and the spacer is placed on the plane of the first substrate on the first substrate. are arranged in a direction perpendicular to each side, the Japanese To.

Further, the invention described in claim 2, in the electronic component package according to claim 1, the second substrate, characterized that you have a hole is formed.

According to a third aspect of the present invention, in the electronic component package of the first or second aspect , the hardness of the joining member is lower than the hardness of the spacer .

  According to the configuration and the bonding method of the electronic part package, the distance between the first and second substrates arranged to face each other as the electronic component package can be controlled and bonded with high accuracy.

  According to the present invention, there is an effect that the distance (gap) between two substrates can be accurately controlled and bonded in response to the downsizing, thinning, and complicated structure of the electronic component package.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
1 is a cross-sectional view of an electronic component package according to Embodiment 1 of the present invention. As shown in FIG. 1, the first substrate 1 on which the electrodes are formed and the second substrate 2 on which the functional elements of the acceleration sensor are formed have a plurality of heights that are increased so as to approach the sides of the substrate. The spacers 3 and the spacers 3 and between the spacers 3 and between the spacers 3 and the sides of the substrate are bonded oppositely by the bonding member 4 whose height is increased so as to approach the sides of the substrate. The A gap 5 controlled with high accuracy is formed between the first substrate 1 and the second substrate 2 by the bonding by the spacer 3 and the bonding member 4. Further, the second substrate 2 is bonded to the first substrate 1 in a warped state by the gap 5.

  FIG. 2A is a plan view of the first substrate in Embodiment 1 of the present invention, and FIG. 2B is a cross-sectional view. As shown in FIGS. 2A and 2B, a plurality of spacers 3 having different heights are formed on the first substrate 1 in two rows parallel to each side of the substrate. The joining member 4 is formed so as to be higher than the spacer 3 between the spacer 3 and the side of the substrate.

  The material of the first substrate 1 is often silicon, glass, etc., but any other material may be used. The size of the first substrate 1 is increasing in the order of several mm square and thickness of about 100 μm to 200 μm as the electronic component package becomes smaller and thinner.

  The spacer 3 is formed by processing the substrate by etching or the like. Alternatively, a method of forming a high hardness material such as Ni by plating or the like can be considered, and this height is often about several μm. The joining member 4 is formed to have a height higher than that of the spacer 3, and a material having a hardness lower than that of the spacer 3 is preferable. For example, Au plating, resin adhesive, and the like. The reason why the height of the bonding member 4 is set higher than the height of the spacer 3 is that when the first substrate 1 and the second substrate 2 are pressure bonded, the bonding member 4 and the second substrate 2 are first brought into contact with each other. This is because the joining member 4 is deformed to provide sufficient joining strength. The cross-sectional shape of the joining member 4 is a rectangular cross-section in FIG. 2, but any shape such as a trapezoid, a triangle, or a circle may be used.

  FIG. 3A is a plan view of the second substrate in Embodiment 1, and FIG. 3B is a cross-sectional view. As shown in FIGS. 3A and 3B, the acceleration sensor generally has a structure in which the weight 7 is supported by the beam 6, and a hole 8 is often formed on the substrate.

  The material of the second substrate 2 often uses silicon, but any material may be used. The size is the same as that of the first substrate 1 described above, and is often several mm square and a thickness of about 100 μm to 200 μm. However, the beam 6 may have a very weak structure, such as a few tens of μm or less. Due to such a structure and thinness, the substrate is often warped as shown in the cross-sectional view of FIG. The amount of warping is as small as submicron to 1 μm, but the influence is very large considering that the gap 5 after joining the two substrates shown in FIG. 1 is several μm.

  Conventionally, when performing thin film formation and hole processing on a substrate, circuit pattern design, thin film formation condition determination, hole processing condition determination, etc. that do not cause warpage as much as possible were performed, but when trying to reduce warpage Whether it becomes convex or convex downward varies depending on the individual substrates. In the present invention, the processing conditions are determined so that the central portion of the surface facing the first substrate 1 is convex, instead of eliminating the warp that occurs in such a processing step. In general, it is difficult to eliminate warping, but it is often easy to warp in a certain direction. As for the shape, in Embodiment 1, the shape as shown in FIG. 3 is taken as an example. However, the substrate having a thin thickness, the structure is not complicated and not rigid, and the film configuration is complicated and easily warps. The effect of the present invention is great regardless of the shape.

  FIG. 4 is a diagram showing a bonding method according to the first embodiment. As shown in FIG. 4, the first substrate 1 and the second substrate 2 are pressed and joined, but when the substrates are not warped, they are as flat and as hard as possible like the substrate holding portion 9. It is desirable to apply pressure. On the other hand, when the substrate is warped, pressure is applied through the elastic body 10 as shown in FIG. Alternatively, pressure is applied with a material having high hardness processed into a shape close to the warped shape of the substrate.

  Further, it is desirable that the height of the spacer 3 of the first substrate 1 is determined so as to be close to the warped shape of the second substrate 2, and the arrangement of the bonding members 4 of the first substrate 1 is as shown in FIG. In the case of such a board | substrate, it is good to arrange | position between the spacer 3 and the spacer 3, and between the spacer 3 and the edge | side of a board | substrate. This is because the force that is elastically restored to the original state is applied to the bonded member 4 that has been pressed, and the shape after the first substrate 1 and the second substrate 2 are bonded is more than the central portion of the substrate. This is because the portion closer to the side works to be deformed in the direction in which the gap 5 becomes larger.

  As a bonding method, heating and pressure welding may be used. Preferably, Au is used as the bonding member 4 and plasma treatment is performed in vacuum, and then pressure bonding is performed at room temperature or low temperature. In this example, both the spacer 3 and the bonding member 4 are arranged on the first substrate 1, and neither the second substrate 2 is arranged, but the spacer 3 is arranged on the first substrate 1, The bonding member 4 may be disposed on the two substrates 2. Further, the joining member 4 may be disposed on both of the two substrates.

(Embodiment 2)
FIG. 5A is a plan view of the first substrate in Embodiment 2 of the present invention, and FIG. 5B is a side view. Similar to FIG. 2A described above, when joining to the second substrate 2, as shown in FIGS. 5A and 5B, the first substrate 1 is provided along the side of the substrate. A spacer 3 whose height is changed so as to become lower as it approaches the central portion may be formed, and the bonding member 4 may be disposed between the spacer 3 and the spacer 3. At this time, the height of the joining member 4 is preferably higher than the average height of the spacers 3 on both sides of each joining member 4. This is because when the two substrates are bonded, the bonding member 4 comes into contact with the second substrate 2 before the spacer 3 and the second substrate 2 come into contact with each other. In addition, various arrangements of the spacer 3 and the joining member 4 are conceivable. However, the height of the spacer 3 is determined so as to be a shape close to the warped shape of the second substrate 2 to be joined. Just place it.

(Embodiment 3)
FIG. 6A is a plan view of the first substrate in Embodiment 3 of the present invention, and FIG. As in the case of FIG. 2A described above, when bonding to the second substrate 2, a plurality of spacers 3 are formed on the first substrate 1 as shown in FIGS. 6A and 6B. In addition, the upper surface of each spacer 3 is not parallel to the substrate but is formed so that the central portion is lower than both ends, and the joining member 4 is formed so that the height of the spacer 3 is higher than the spacer 3 outside the spacer 3. May be arranged.

  By adopting the configuration of each of the embodiments as described above, the spacer 3 having the same height is arranged on the first substrate 1 so as to face the warped second substrate 2 as in the prior art shown in FIG. When the pressure bonding is performed, the warp of the second substrate 2 is not stable because the warp of the second substrate 2 becomes convex or concave at the center, and the state before the bonding of the second substrate 2 is stably maintained. Will be able to. As a result, the gap 5 between the two substrates is stabilized, and the quality of the electronic component package can be stabilized.

  Conventionally, when one substrate is warped when two substrates are joined, joining is performed in a state where the warped substrate is forcibly flattened by suction or the like. When such joining is performed, warping after joining is often not stable as described above. Even if the warpage is stabilized, there is a possibility that a residual stress is generated in the joint portion, so that the strength of the joint portion may be reduced due to a change with time, a thermal load, or the like.

  On the other hand, in the present invention, since the substrates are bonded while maintaining the warped state, no residual stress is generated in the bonded portion even after bonding, and the reliability is improved.

  Further, as a secondary effect, there is an advantage that the electronic component package can be easily handled because the shape of the second substrate 2 after the bonding becomes convex at the center. That is, as shown in FIG. 8, the transfer arm and stage (not shown) can be provided without providing the cavity 11 provided on the lower surface of the second substrate 2 (opposite the surface facing the first substrate 1). For example, the beam 6 and the weight 7 in FIG. 3 (a) do not come into contact with each other, and breakage and scratches do not occur.

  The electronic component package and the bonding method thereof according to the present invention can be bonded by accurately controlling the gap between two substrates in response to downsizing, thinning, and complicated structures of the electronic component package. In the manufacture of electronic component packages, it can be used when it is necessary to accurately form a gap between substrates having problems such as thinness, warpage, and easy deformation.

Sectional drawing of the electronic component package in Embodiment 1 of this invention (A) of the 1st board | substrate in Embodiment 1 of this invention is a top view, (b) is sectional drawing. (A) of the 2nd board | substrate in this Embodiment 1 is a top view, (b) is sectional drawing. The figure which shows the joining method in this Embodiment 1. (A) of the 1st board | substrate in Embodiment 2 of this invention is a top view, (b) is a side view. (A) of the 1st board | substrate in Embodiment 3 of this invention is a top view, (b) is a side view. The figure which shows the joining method using the conventional 1st board | substrate. Diagram showing conventional joining method (A) is a front view showing a conventional capacitive pressure sensor, and (b) is a sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st board | substrate 2 2nd board | substrate 3 Spacer 4 Joining member 5 Gap 6 Beam 7 Weight 8 Hole 9 Substrate holding part 10 Elastic body 11 Cavity 101 Diaphragm 102 Fixed substrate 103 1st electrode 104 2nd electrode 105 Spacer layer 106 Spacer

Claims (3)

In an electronic component package in which the surfaces of the first substrate and the second substrate are arranged to face each other, and at least a part of the periphery of the first and second substrates is bonded by a bonding member.
A plurality of spacers arranged around the first substrate and having a height changed so as to approach the center of the side of the first substrate along the side of the first substrate;
The bonding member is disposed between the plurality of spacers, and the bonding member is formed such that the height of the bonding member is higher than the average height of the spacers on both sides of the bonding member.
The first substrate and the second substrate are bonded by the bonding member so that the distance between the substrates arranged opposite to each other is smaller in the center than the periphery of the substrate, and the spacer is connected to the first substrate. An electronic component package, wherein the electronic component package is disposed in a direction perpendicular to each side of the first substrate on a plane of the first substrate .   The electronic component package according to claim 1, wherein a hole is formed in the second substrate.   The electronic component package according to claim 1, wherein a hardness of the joining member is lower than a hardness of the spacer.

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