JP2014063905A - Semiconductor device manufacturing method and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing method which can easily manufacture a semiconductor device capable of easily controlling a thickness of a support member, and stably reducing a stress due to thermal strain, and improving output characteristics.SOLUTION: A manufacturing method of a semiconductor device in which a semiconductor element is mounted on a substrate via a support member comprises: a process of forming at least three recesses independent from each other on the substrate 10 in a region for mounting a semiconductor element 20; a process of coating a liquid first resin composed of a material different from that of the substrate on the recesses; a process of filling the recesses by hardening the first resin and forming in respective recesses, at least three first support members 12 which are independent from each other and each has a dome-like shape raised from a substrate surface; a process of coating a liquid second resin so as to cover all of the first support members arranged in respective recesses; a process of mounting a semiconductor element on the second resin; and a process of hardening the second resin to form a second support member 13.

Description

  The present invention relates to a semiconductor element such as a pressure sensor, and controls the thickness of a support member to stably reduce the stress applied to the semiconductor element and improve its output characteristics.

In a semiconductor element, particularly a semiconductor element such as a pressure sensor or a temperature sensor that obtains an output value from a change in resistance value of a diffused resistor, distortion caused by a difference in thermal expansion coefficient between the element itself and the substrate affects the output characteristics of the element Effect. Specifically, since the resistance value of the diffused resistor formed in the semiconductor element changes due to the piezoresistance effect, the output characteristics of the semiconductor element deteriorate.
In Patent Document 1, a first resin layer (adhesive cured layer) is formed using a known thick film printing method, and after heat curing, a second resin layer (adhesive cured layer) is further formed to form a semiconductor element. A method of forming a resin layer for stress relaxation formed under the semiconductor element by bonding and controlling the thickness is described. The resin layer formed under the semiconductor element plays a role as a stress relaxation layer, and the thickness of the resin layer is important.

  Patent Document 2 discloses that when a resin having a low elastic modulus (for example, 1 MPa or less) is used, the chip is tilted as shown in FIG. 2 in Patent Document 2 and wire bondability is reduced. As a countermeasure, a method of forming a spacer made of resist, glass or the like has been introduced.

  In Patent Document 1, the first resin layer is formed using a well-known thick film printing method. However, in order to form a thick resin film uniformly on a flat surface, the viscosity and thixotropy of the resin are used. Therefore, it is necessary to carefully adjust the printing conditions and the like, and it is difficult to stably obtain the same film thickness. In addition, it can be said that the structural and process problems are that shape changes are likely to occur, for example, the resin may flow due to a change with time after printing, or may be thermally sag when thermally cured.

  Moreover, in patent document 1, although the 1st resin layer is formed in one place, if the 1st resin layer is formed in one place, when the 2nd resin layer is applied, the first resin layer is formed in one place. The second resin layer is largely spread outside the resin layer, and defects such as spreading of the wet spread resin to the bonding pad on the substrate side on which the semiconductor element is mounted are likely to occur. When the resin spreads wet to the bonding pad, the surface of the bonding pad is contaminated, and problems such as the inability to wire bond occur. Furthermore, if the first resin layer is in one place, the mounted chip is liable to be tilted and fixed, and the chip is tilted in the same manner as the problem shown in FIG. In addition, a decrease in wire bondability becomes a problem.

  In Patent Document 2, the wire bondability is improved by forming a spacer. However, when a high elastic modulus material such as a resist or glass is used as the spacer, a difference in thermal expansion coefficient between the element itself and the substrate is caused. The effect of relieving stress due to the generated thermal strain is reduced, and as a result, the characteristics of the device (sensor, etc.) are deteriorated.

Japanese Patent No. 2800463 JP 2012-73233 A

The present invention has been devised in view of such a conventional situation, a semiconductor capable of easily controlling the thickness of a support member, stably reducing stress due to thermal strain, and improving output characteristics. It is a first object of the present invention to provide a method of manufacturing a semiconductor device that can easily manufacture the device.
A second object of the present invention is to provide a semiconductor device in which the stress due to thermal strain is stably reduced and the output characteristics are improved by controlling the thickness of the support member.

A method for manufacturing a semiconductor device according to claim 1 of the present invention is a method for manufacturing a semiconductor device in which a semiconductor element is mounted on a substrate via a support member, and the semiconductor element is mounted on the substrate. A step of forming at least three mutually independent recesses in a region to be formed, a step of applying a liquid first resin made of a material different from the substrate to the recesses, and curing the first resin. A step of forming at least three independent first support members for each of the recesses in a shape that rises in a substantially dome shape from the substrate surface, and so as to cover all the first support members provided for each of the recesses, Applying a liquid second resin on the substrate; mounting a semiconductor element on the second resin; and curing the second resin to form a second support member. The features.
The method for manufacturing a semiconductor device according to claim 2 of the present invention is characterized in that the substrate, the first resin, and the second resin are made of materials having different Young's moduli.
According to a third aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to the first or second aspect, wherein the dispensing method is used in the step of applying the first resin.
According to a fourth aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to any one of the first to third aspects, wherein the first resin and the second resin are silicone resins.
According to a fifth aspect of the present invention, there is provided a semiconductor device manufacturing method according to any one of the first to fourth aspects, wherein the substrate is a ceramic substrate.
A method of manufacturing a semiconductor device according to a sixth aspect of the present invention is the method for manufacturing a semiconductor device according to any one of the first to fifth aspects, wherein the semiconductor element is a pressure sensor or a temperature sensor in which a diffusion resistance is formed. It is characterized by.
A semiconductor device according to a seventh aspect of the present invention is manufactured by the method according to any one of the first to sixth aspects.

In the present invention, the support member is formed by applying a liquid first resin to the concave portion formed on the substrate, and forming at least three independent first support members having a dome-like shape from the surface of the substrate. . And the thickness of a support member can be easily controlled by apply | coating liquid 2nd resin so that all said 1st support members may be covered. Accordingly, it is possible to provide a method for manufacturing a semiconductor device, in which stress due to strain can be stably reduced, and a semiconductor device with improved output characteristics can be easily manufactured. Moreover, in this invention, since the liquid 1st resin is apply | coated in the recessed part formed in the board | substrate, the wetting spread of 1st resin is suppressed and wire bonding can be performed favorably.
In the present invention, the support member is formed so as to cover all of the first support member and at least three independent first support members having a shape bulging from the surface of the substrate. The thickness of the support member can be easily controlled. Accordingly, it is possible to provide a semiconductor device in which stress due to strain is stably reduced and output characteristics are improved.

It is a figure which shows the manufacturing method of a semiconductor device in order of a process, (a) is sectional drawing, (b) is a top view. It is a figure which shows the next process of FIG. 1, (a) is sectional drawing, (b) is a top view. It is a figure which shows the next process of FIG. 2, (a) is sectional drawing, (b) is a top view. It is a figure which shows the next process of FIG. 3, (a) is sectional drawing, (b) is a top view. It is a figure which shows the next process of FIG. 4, (a) is sectional drawing, (b) is a top view.

  Hereinafter, an embodiment of a semiconductor device according to the present invention will be described with reference to the drawings.

1 to 5 are views showing a method of manufacturing a semiconductor device according to the present invention in the order of steps, where (a) is a plan view and (b) is a cross-sectional view.
The method for manufacturing a semiconductor device of the present invention is a method for manufacturing a semiconductor device in which a semiconductor element 20 is mounted on a substrate 10 via a support member.
In the method for manufacturing a semiconductor device according to the present invention, in the substrate 10, the step of forming at least three mutually independent recesses 11 in the region α in which the semiconductor element 20 is mounted, The liquid first resin 12a made of a different material was applied to the recess 11 and the first resin 12a was cured to fill the recess 11 and rise from the surface of the substrate 10 into a substantially dome shape. Forming at least three independent first support members 12 in the shape of each of the recesses 11 and forming a liquid on the substrate 10 so as to cover all of the first support members 12 provided for each of the recesses 11. A step of applying the second resin 13a, a step of mounting the semiconductor element 20 on the second resin 13a, and the second support member 1 by curing the second resin 13a. And forming a.
Hereinafter, it demonstrates in order of a process.

(1) First, a package substrate 10 as shown in FIG. 1 is produced.
As a material of the package substrate 10, a ceramic substrate such as alumina is assumed in this embodiment. As the substrate material, other resins such as epoxy and polyimide can be used. In this embodiment, the ceramic substrate is a laminated substrate having a three-layer structure in which the substrates 10a, 10b, and 10c are laminated, and is manufactured by stacking and firing the three layers.

  At least a bonding pad 2 for connecting the functional component and the package substrate 10 and an external connection electrode 3 used when the package substrate 10 is mounted are formed on the package substrate 10. Although not shown, the bonding pad 2 and the external connection electrode 3 are connected at any part of the package substrate 10. Further, the bonding pad and the external connection electrode may be integrated. As the bonding pad and the external connection electrode, for example, a laminate in which metal materials such as Ni, Cr, Cu, Ti, Pt, and Au are combined can be used. The bonding pad and the external connection electrode are formed by a printing method, an electric field or an electroless plating method.

(2) In the substrate 10, at least three recesses 11 that are independent of each other are formed in the region α on which the semiconductor element 20 is mounted.
As shown in FIG. 1, at least three recesses 11 are formed in the region α where the semiconductor element 20 will be mounted later in the uppermost layer 10c having a three-layer structure. In the example shown in FIG. 1, four recesses 11 are formed. These recesses 11 are independent of each other.

The method for forming the recess 11 is not particularly limited. For example, specifically, the uppermost recess 11 is formed by punching or the like before firing the laminated substrate, and then fired. The method of doing can be mentioned.
In the present embodiment, the thickness of each of the substrates 10a, 10b, and 10c is about 100 μm, and the total of the three layers is about 300 μm. However, the number of layers and the thickness may be arbitrarily selected. Although the dimension of the recessed part 11 is designed arbitrarily according to how much the height of the raised part of the first support member 12 is desired, in this embodiment, it is about 200 μm to 400 μm, for example.

Moreover, although the shape of the recessed part 11 has shown the square-shaped thing in FIG. 1, it is not limited to this, A circular shape may be sufficient and it is satisfactory even if it is another shape. However, the recesses 11 need to be formed independently. Further, each of the recesses 11 needs to have the same shape (depth and width).
Furthermore, as for the number of the concave portions 11, the concave portions 11 are formed at four places in the present embodiment, but the effect of the present invention can be obtained if at least three points are formed. Moreover, five or more places may be sufficient and each recessed part 11 should just be formed independently.

(3) A liquid first resin 12 a made of a material different from that of the substrate 10 is applied to the recess 11.
Next, as shown in FIG. 2, the first resin 12 a is applied to the recesses 11 formed at four locations on the substrate 10. A method for applying the first resin 12a is not particularly limited, but for example, a dispensing method is preferably used.

A material having a Young's modulus different from that of the substrate 10 is used for the first resin 12a. As the first resin 12a, a silicone resin having a high stress relaxation property and a small Young's modulus is most suitable.
The Young's modulus of the first resin 12a is preferably about 5 MPa to 20 MPa considering both the stress relaxation effect and the wire bondability. If the Young's modulus is too small, wire bonding becomes difficult. Conversely, if the Young's modulus is too high, the stress relaxation effect becomes small. In the present embodiment, a thermosetting silicone resin is used as the first resin 12a.

  When dispensing the first resin 12a, it is preferable to adjust and pour in an amount of resin that is sufficiently larger than the volume of the recess 11 and does not flow out of the recess 11. Furthermore, the application amount of the first resin 12a to be dispense-applied for each recess 11 is preferably the same. Thereby, the resin shape which rose from the edge of the recessed part 11 in the shape of a dome can be obtained. This is due to the effect of the surface tension of the liquid resin, the shape is easily maintained by the surface tension, and it is possible to suppress problems such as changes over time and thermal sag.

(4) By curing the first resin 12a, at least three independent first support members 12 are formed for each of the recesses 11 so as to fill the recesses 11 and rise from the surface of the substrate 10 into a substantially dome shape.
The first resin 12a is cured by applying predetermined heat (for example, 150 ° C. for 1 hr) to the first resin 12a applied in this way. As a result, at least three independent first support members 12 that fill the inside of the concave portion 11 and rise from the surface of the substrate 10 in a substantially dome shape are formed for each concave portion 11. Since the first support member 12 formed for each recess 11 has the same size of the recess 11 and the same amount of resin applied to the recess 11, the size (high) of the first support member 12 after curing is high. The sheath diameter is formed in a uniform state.

  The raised height of the first support member 12 is preferably in the range of about 10 μm to 50 μm from the surface of the uppermost layer of the substrate 10.

(5) The second phase fat is applied on the substrate 10 so as to cover all the first support members 12 provided for each recess 11.
Next, as shown in FIG. 3, a liquid second resin 13 a is further applied on the thermally cured first support member 12. As the coating method of the second resin 13a, the dispensing method is suitable similarly to the first resin 12a, but a transfer method using a transfer pin may be used.

A material having a Young's modulus different from that of the substrate 10 is used for the second resin 13a. As for the second resin 13a, similarly to the first resin 12a, a silicone resin having a high stress relaxation property and a small Young's modulus is most suitable.
The Young's modulus of the second resin 13a is preferably about 5 MPa to 20 MPa considering both the stress relaxation effect and the wire bondability. If the Young's modulus is too small, wire bonding becomes difficult. Conversely, if the Young's modulus is too high, the stress relaxation effect is reduced. Note that the same material may be used for the first resin 12a and the second resin 13a.

(6) The semiconductor element 20 is mounted on the second resin 13a. Then, the second support member 13 is formed by curing the second resin 13a.
Furthermore, as shown in FIG. 4, the semiconductor element 20 is bonded onto the second resin 13a. Thereby, the semiconductor element 20 is bonded and fixed on the second support member 13. Since the first support member 12 is formed with the same height, the semiconductor element 20 fixed on the second support member 13 is fixed in a horizontal state with respect to the substrate 10.
The semiconductor element 20 is not particularly limited, and may be any semiconductor element that has a diffusion resistance such as a pressure sensor or a temperature sensor and obtains an output value from the amount of change in the diffusion resistance value. An effect can be obtained. For example, in a pressure sensor package where a pressure sensor and a signal processing IC having a temperature sensor for correcting the temperature characteristics of the pressure sensor are installed on the same substrate, the present invention is applied to both the pressure sensor and the signal processing IC. The invention may be applied.

Here, since the first support member 12 is provided independently at each of the four corners of the semiconductor element 20, a passage connecting the area immediately below the semiconductor element 20 and the outside of the semiconductor element 20 is formed, whereby the second resin 13 a is formed. Is in a state where it can flow across each side of the semiconductor element 20.
When the second resin 13a is applied to such a structure and the semiconductor element 20 is mounted on the second resin 13a, the second support 13 at the four corners is used as a spacer, and the second gap 13 is formed in a slight gap created by the semiconductor element 20 and the substrate 10. Since the resin 13a flows (a kind of capillary phenomenon), the resin thickness can be further stabilized, and a problem that the second resin 13a protrudes outside the semiconductor element 20 can be suppressed.

The first support member 12 formed in each recess 11 is formed in a dome shape. In order to stabilize the height of the semiconductor element 20 mounted on the first support member 12 without inclination, at least three points are required. The first support member 12 needs to be formed with respect to the recess 11.
In this state, predetermined heat (for example, 150 ° C., 1 hr) is further applied to cure the second resin 13b, thereby bonding the semiconductor element 20 and the substrate 10 together.

(7) Next, wire bonding is performed as shown in FIG.
The Al pad 21 of the semiconductor element 20 and the bonding pad 2 of the package substrate 10 are electrically connected by wire bonding using the Au wire 4.
At this time, if the second resin 13a spreads to the bonding pad 2 on the package substrate 10 side, there is a problem in that a poor bonding of the wire occurs. Since the dripping at the time of applying is suppressed, wire bonding can be performed satisfactorily and defects are reduced.
The semiconductor device 1 is manufactured as described above.

  Although not shown, the semiconductor element 20 may be protected by attaching a protective substrate so as to cover the semiconductor element 20. Further, not only the semiconductor element 20 but also a signal processing IC may be arranged in the same package. Further, a signal processing circuit may be formed inside the semiconductor element 20.

  As described above, in the present invention, the support member has a shape in which the first resin 12a is applied to the concave portion 11 formed in the substrate 10, fills the concave portion 11, and rises from the surface of the substrate 10 in a substantially dome shape. At least three independent first support members 12 are formed. And the thickness of a support member can be easily controlled by apply | coating 2nd resin 13a so that all said 1st support members 12 may be covered. As a result, it is possible to easily manufacture a semiconductor device in which stress due to thermal strain is stably reduced and output characteristics are improved. Moreover, in this invention, since resin is apply | coated in the recessed part 11 formed in the board | substrate 10, there is no dripping of resin, and wire bonding can be performed favorably.

  The method for manufacturing a semiconductor device and the semiconductor device of the present invention have been described above. However, the present invention is not limited to this, and can be appropriately changed without departing from the spirit of the invention.

  The present invention is widely applicable to semiconductor device manufacturing methods and semiconductor devices.

  DESCRIPTION OF SYMBOLS 10 board | substrate, 11 recessed part, 12a 1st resin, 12 1st support member, 13a 2nd resin, 13 2nd support member, 20 semiconductor element.

Claims (7)

A method of manufacturing a semiconductor device in which a semiconductor element is mounted on a substrate via a support member,
Forming, in the substrate, at least three recesses independent of each other in a region where the semiconductor element is mounted;
Applying a liquid first resin made of a material different from that of the substrate to the recess;
Forming the at least three independent first support members for each of the recesses in a shape that fills the recesses and rises in a substantially dome shape from the substrate surface by curing the first resin;
Applying a liquid second resin on the substrate so as to cover all of the first support member provided for each of the recesses;
Mounting a semiconductor element on the second resin;
A step of curing the second resin to form a second support member.   The method of manufacturing a semiconductor device according to claim 1, wherein the substrate, the first resin, and the second resin are made of materials having different Young's moduli.   3. The method of manufacturing a semiconductor device according to claim 1, wherein a dispensing method is used in the step of applying the first resin.   The method for manufacturing a semiconductor device according to claim 1, wherein the first resin and the second resin are silicone resins.   The method of manufacturing a semiconductor device according to claim 1, wherein the substrate is a ceramic substrate.   The method of manufacturing a semiconductor device according to claim 1, wherein the semiconductor element is a pressure sensor or a temperature sensor in which a diffusion resistance is formed.   A semiconductor device manufactured by the method according to claim 1.

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