JP6177018B2 - Semiconductor device, measuring instrument, and manufacturing method of semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device, a measuring instrument, and a method for manufacturing a semiconductor device.

  In recent years, in measuring devices such as a power meter that measures an integrated power amount, a demand for measuring the integrated power amount for each time zone is increasing. Along with this, there has been proposed a semiconductor device in which an oscillator is incorporated in a measuring instrument. As such a semiconductor device, a device in which an integrated circuit and an oscillator are mounted on a lead frame and these are sealed with a mold resin (sealing member) is known (for example, Patent Document 1).

  However, if a strain acts on the mold resin due to a residual stress generated in the molding resin sealing process or a temperature change after sealing, the frequency of the oscillator may fluctuate.

JP 2007-234994 A

  In view of the above facts, an object of the present invention is to provide a semiconductor device that can suppress fluctuations in the frequency of an oscillator.

The semiconductor device according to claim 1, wherein a lead frame having a plurality of inner leads formed around a die pad, an oscillator mounted on a first surface of the die pad, and the first surface of the die pad Are mounted on different second surfaces and are electrically connected to the oscillator, a first sealing member for sealing the oscillator, and sealed with the first sealing member. And a second sealing member that seals the integrated circuit, the center of the thickness of the inner lead from the first surface in the height direction of the second sealing member Is longer than the distance from the second surface in the height direction of the second sealing member to the center of the thickness of the inner lead.

  Since the present invention has the above configuration, fluctuations in the frequency of the oscillator can be suppressed.

It is a perspective view of the integrating watt-hour meter provided with the semiconductor device concerning a 1st embodiment. It is the partially broken view which looked at the semiconductor device concerning a 1st embodiment from the back. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 2 is an exploded perspective view showing the resonator according to the first embodiment. 1 is a block diagram for explaining an LSI of a semiconductor device according to a first embodiment. (A)-(e) is explanatory drawing which shows the procedure which arrange | positions an oscillator and LSI on a lead frame and performs wire bonding in the manufacturing method which manufactures the semiconductor device of 1st Embodiment. FIG. 6 is an explanatory diagram illustrating a procedure for sealing an oscillator with a first sealing resin in the manufacturing method for manufacturing the semiconductor device according to the first embodiment. (A)-(d) is explanatory drawing which shows the procedure which seals a lead frame, an oscillator, and LSI with 2nd sealing resin in the manufacturing method which manufactures the semiconductor device which concerns on 1st Embodiment. It is a flowchart which shows the flow of the 1st frequency correction process which concerns on 1st Embodiment. It is a flowchart which shows the flow of the 2nd frequency correction process which concerns on 1st Embodiment. It is a figure which shows the relationship between the temperature and frequency deviation in the semiconductor device which concerns on 1st Embodiment. It is a block diagram for demonstrating LSI of the semiconductor device which concerns on 2nd Embodiment. (A) is a figure which shows an example of the clock value of the oscillator of the semiconductor device which concerns on 2nd Embodiment, (b) is an example of the clock value of the reference signal oscillator of the semiconductor device which concerns on 2nd Embodiment. FIG. It is a flowchart which shows the flow of the 1st frequency correction process which concerns on 2nd Embodiment. It is a flowchart which shows the flow of the frequency error derivation process concerning 2nd Embodiment. It is a timing chart in the frequency error derivation processing concerning a 2nd embodiment, (a) is a figure showing the time of a count start, and (b) is a figure showing the time of a count stop. It is a flowchart which shows the flow of the 2nd frequency correction process which concerns on 2nd Embodiment. It is a block diagram for demonstrating another example of LSI of the semiconductor device which concerns on 2nd Embodiment. It is a block diagram for demonstrating another example of LSI of the semiconductor device which concerns on 2nd Embodiment. It is the partially broken figure which looked at the semiconductor device concerning a 3rd embodiment from the back. It is a 21-21 line sectional view of Drawing 20. It is the partially broken figure which looked at the semiconductor device concerning a 4th embodiment from the back. It is a top view which shows the lead frame of the semiconductor device which concerns on 4th Embodiment.

(First embodiment)
Hereinafter, a semiconductor device according to the present invention will be described in detail with reference to the accompanying drawings.

<Configuration>

  As shown in FIG. 1, the integrated watt-hour meter 10 including the semiconductor device 24 according to the first embodiment is attached to the upper surface of a fixed plate 102 fixed to an outer wall 100 such as a house. And a transparent cover 14 that covers the main body 12, and a connection portion 16 provided at the lower part of the main body 12.

  A power supply side wiring 18 and a load side wiring 20 are connected from below the connecting portion 16 to supply current to the integrated watt-hour meter 10. The main body 12 is a rectangular box in a plan view, and the main body 12 includes a semiconductor device 24 to be described later and a measurement for measuring an integrated power amount according to a signal output from the semiconductor device 24. An electric energy measuring circuit 22 as means is mounted on a substrate (not shown). In FIG. 1, for convenience of explanation, the sizes of the electric energy measuring circuit 22 and the semiconductor device 24 are exaggerated.

  A horizontally long liquid crystal display 15 is provided in front of the main body 12. The liquid crystal display 15 displays the amount of power used per unit time measured by the power amount measuring circuit 22, the amount of accumulated power used for each time zone, and the like. Note that the integrated watt-hour meter 10 according to the present embodiment is an electronic watt-hour meter using the power amount measurement circuit 22 as a measuring unit, but is not limited thereto, and for example, the amount of power is obtained by rotating a disk. An inductive watt-hour meter to be measured may be used.

  Next, a detailed configuration of the semiconductor device 24 according to the present embodiment will be described. In the following description, the horizontal direction in the plan view of the semiconductor device 24 shown in FIG. 2 is the arrow X direction, the vertical direction is the arrow Y direction, and the height direction in the cross-sectional view of the semiconductor device 24 shown in FIG. This will be described as a direction. As shown in FIGS. 2 and 3, the outer shape of the semiconductor device 24 is a rectangular shape in plan view, and a lead frame 26 serving as a skeleton, an oscillator 28 mounted on the surface of the lead frame 26, An LSI 30 as an integrated circuit mounted on the back surface of the lead frame 26, a first sealing resin (first sealing member) 31 for sealing the oscillator 28, and a first sealing resin for sealing the oscillator 28 and the LSI 30. 2 sealing resin 32 (second sealing member).

  The lead frame 26 is a plate material formed by punching a flat plate made of a metal such as an alloy of copper (Cu) or iron (Fe) and nickel (Ni) with a press machine, and a die pad 26A provided in the center portion; A suspension lead 26B extending diagonally outward from the die pad 26A and a plurality of leads (terminals) 38 provided between adjacent suspension leads 26B are configured.

  The die pad 26A has a rectangular shape in plan view, and a step portion 27 is provided on the die pad 26A. The step portion 27 extends in the vertical direction of the die pad 26A, and is inclined upward from left to right as shown in FIG. For this reason, the die pad 26A is divided into a first mounting surface 26C located above and a second mounting surface 26D located below, with the stepped portion 27 as a boundary. In addition, it is good also as the planar die pad 26A, without providing the level | step-difference part 27. FIG.

  The leads 38 are elongated members extending toward the center of the die pad 26A, and a plurality of leads 38 are formed around the die pad 26A at a predetermined interval. In the present embodiment, 16 leads 38 are formed between adjacent suspension leads 26B. The lead 38 includes an inner lead 38A located on the die pad 26A side and an outer lead 38B located on the outer peripheral end side of the semiconductor device 24. The inner lead 38A is located below the die pad 26A. Thus, it is pushed down by the press and extends parallel to the die pad 26A (see FIG. 3). The tip of the inner lead 38A closest to the die pad 26A is covered with the plating film 40. In the present embodiment, as an example, the plating film 40 is formed of silver (Ag). However, the present invention is not limited to this. For example, the plating film may be formed of a metal such as gold (Au).

  The outer lead 38B is exposed from the second sealing resin 32 and bent downward, and the tip is parallel to the inner lead 38A. That is, it is a gull wing lead. The outer lead 38B is covered with a solder plating film. As a material of the solder plating film, tin (Sn), an alloy of tin (Sn) and lead (Pb), an alloy of tin (Sn) and copper (Cu), or the like is used.

  Here, an oscillator mounting area 42 is provided on the first mounting surface 26C of the die pad 26A, and the oscillator 28 is mounted on the oscillator mounting area 42 via an adhesive (adhesive member) 49. (See FIG. 3). The oscillator 28 is a rectangular electronic component whose longitudinal direction is the vertical direction. In the present embodiment, the frequency is 32 that can be externally attached to a general-purpose semiconductor device 24 mounted on a general electronic device. .768 kHz oscillator 28 is used. Here, the adhesive 49 is applied so as to adhere to the entire surface on the mounting side of the oscillator 28, and is preferably bonded with an adhesive having the same elastic modulus as the first sealing resin 31 to be dictated. Has been.

As shown in FIG. 4, the oscillator 28 includes a vibrating piece 44, a package main body 46 that houses the vibrating piece 44, and a lid 48, and has a rectangular shape in plan view. . The resonator element 44 is a crystal resonator element in which an excitation electrode 44A is formed on the surface of a tuning-fork type crystal element made of artificial quartz. When a current is passed through the excitation electrode 44A, the resonator element 44 oscillates due to the piezoelectric effect. . Here, the vibrating piece 44 is not limited to a tuning fork type, and an AT-cut crystal piece may be used. In addition to quartz, a resonator element formed of lithium tantalate (LiTaO ₃ ) or lithium niobate (LiNbO ₃ ) may be used. Further, a MEMS vibrating piece made of silicon may be used.

  The package body 46 is a box having an open top, and a pedestal 47 to which the vibration piece 44 is fixed is formed at the bottom on one end side in the longitudinal direction. The base of the vibrating piece 44 is fixed to the pedestal 47 so that the vibrating piece 44 can vibrate, and the package body 46 and the lid 48 are joined in a vacuum state, whereby the vibrating piece 44 is hermetically sealed. In addition, external electrodes 34 as terminals electrically connected to the excitation electrode 44 </ b> A of the resonator element 44 are formed at both ends of the lower surface of the package body 46.

  The external electrode 34 is formed to have the same width as the width of the package body 46. As shown in FIG. 2, the size of the external electrode 34 is set to an electrode pad 50 formed on an LSI 30 to be described later, and an oscillator electrode. It is larger than the pad 54. Further, the opening 26C of the die pad 26A is formed larger than the external electrode 34.

  As shown in FIGS. 2 and 3, an LSI 30 as an integrated circuit or a semiconductor chip is mounted on the second mounting surface 26D of the die pad 26A via an adhesive (not shown). The LSI 30 is a rectangular and thin electronic component, and the lower surface of the LSI 30 and the lower surface of the oscillator 28 have substantially the same height.

  A plurality of electrode pads 50 electrically connected to the wiring inside the LSI 30 are provided at the outer peripheral end of the lower surface along each side of the rectangular LSI 30. The electrode pads 50 are made of metal such as aluminum (Al) or copper (Cu), and 16 electrode pads 50 are provided on each side of the LSI 30. The number of electrode pads 50 may be the same on each side, or may be different, for example, by reducing or increasing the number of sides on which an oscillator electrode pad 54 described later is provided. Each electrode pad 50 is connected to the inner lead 38 </ b> A by a bonding wire 52. In the present embodiment, 16 electrode pads 50 are provided on each side of the LSI 30 so as to match the number of leads 38. However, the number of electrode pads 50 is not limited to this, and more than the number of leads 38 is provided. It may be used for other purposes.

  In addition to the electrode pad 50, an oscillator electrode pad 54 is provided on the outer peripheral end of the LSI 30 on the oscillator 28 side. Two oscillator electrode pads 54 are provided in the center of the LSI 30 in the vertical direction, and are located between the electrode pads 50. That is, a region where the oscillator electrode pad 54 is disposed is formed at the center, and the electrode pad 50 is provided on each of the regions from the center to the end of the side where the electrode pad 54 is provided, and on the remaining three sides. An arrangement region is formed. The oscillator electrode pad 54 is connected to the external electrode 34 of the oscillator 28 by a bonding wire 52. The bonding wire is a linear conductive member made of a metal such as gold (Au) or copper (Cu).

  The two oscillator electrode pads 54 provided at the center in the vertical direction of the LSI 30 are provided apart from the electrode pads 50 provided on the same side. In other words, the distance between the oscillator electrode pad 54 and the electrode pad 50 adjacent to the oscillator electrode pad 54 is longer than the distance between the electrode pads 50.

  The distance between the electrode pad for the oscillator 54 and the adjacent electrode pad 50 is made equal to the distance between the electrode pads 50, and the electrode pad 50 adjacent to the oscillator electrode pad 54 is not wire-bonded. The distance between the wire-bonded electrode pad 50 and the oscillator electrode pad 54 may be longer than the distance between the wire-bonded electrode pads 50. In other words, on the electrode pad 50 of the LSI 30, the bonding wire 52 and the electrode that connect the oscillator electrode pad 54 and the external electrode 34 rather than the distance between the bonding wire 52 that connects the electrode pad 50 and the inner lead 38 </ b> A. The distance between the pad 50 and the bonding wire 52 that connects the inner lead 38A is longer.

  Here, the bonding wire 52 connecting the oscillator electrode pad 54 and the external electrode 34 and the bonding wire 52 connecting the electrode pad 50 and the inner lead 38A cross three-dimensionally, and FIG. As shown, the bonding wire 52 connecting the electrode pad 50 and the inner lead 38A is formed so as to straddle the bonding wire 52 connecting the oscillator electrode pad 54 and the external electrode 34. Yes. Thereby, a short circuit of the bonding wire 52 can be prevented.

  The center of the LSI 30 and the center of the rectangular parallelepiped oscillator 28 are arranged in parallel so as to substantially coincide on the X axis. That is, the deviation width from the X axis at the center of the oscillator 28 in the Y axis direction is narrower than the width in the Y axis direction at the center. In such an arrangement state, the oscillator electrode pad 54 provided near the center of any one side of the LSI 30 and the external electrodes 34 arranged at both ends in the longitudinal direction of the oscillator 28 are connected by the bonding wires 52. doing. At the same time, the electrode pads 50 arranged so as to sandwich the oscillator electrode pad 54 and the electrode pads 50 and the inner leads 38A arranged in parallel in the Y-axis direction are connected by a bonding wire 52.

  Furthermore, since the oscillator electrode pad 54 is provided apart from the electrode pad 50, the bonding wire 52 that connects the electrode pad 50 and the inner lead 38A connects the oscillator electrode pad 54 and the external electrode 34. The portion of the bonding wire 52 that is lower than the oscillator 28 passes through. In other words, it is possible to avoid crossing the vicinity of the apex of the bonding wire 52 that connects the oscillator electrode pad 54 and the external electrode 34, and to efficiently make a three-dimensional intersection.

  Further, the connecting position of the bonding wire 52 on the external electrode 34 of the oscillator 28 is shifted from the center position of the oscillator 28 to the inner lead 38A side in the X-axis direction. By connecting in this way, it can reduce that the bonding wire 52 contacts the edge part of LSI30. On the other hand, in the X-axis direction, the center of the oscillator 28 is shifted from the center of the external electrode 34. By connecting in this way, it is possible to reduce the number of times of intersection between the electrode pad 50 and the bonding wire 52 that connects the inner lead 38A.

  Here, the oscillator 28 is sealed with the first sealing resin 31. The first sealing resin 31 is filled so as not to provide a gap inside, and covers a surface other than the mounting surface mounted on the die pad 26 </ b> A of the oscillator 28. The first sealing resin 31 also covers a part of the bonding wire 52 that connects the oscillator electrode pad 54 and the external electrode 34. Note that the thickness of the first sealing resin 31 is formed so as not to affect the size of the semiconductor device 24. In the present embodiment, the first sealing resin 31 is made of a material having a lower elastic modulus than that of a second sealing resin 32 described later and a low elastic modulus of 100 MPa or less.

  The oscillator 28, the LSI 30, and the lead frame 26 are sealed with a second sealing resin 32, and the outer shape of the semiconductor device 24 is formed. The second sealing resin 32 is filled so as not to provide a gap therein, and the height of the second sealing resin 32 is at least twice the height of the inner lead 38. . In other words, the distance from the surface of the second sealing resin 32 on the oscillator 28 mounting side to the center of the inner lead 38 is the distance from the surface of the second sealing resin 32 on the LSI 30 mounting side to the center of the inner lead 38. Longer than the distance. Further, the distance from the surface on the LSI 30 mounting side of the second sealing resin 32 to the center of the die pad 26 is longer than the distance from the surface on the LSI 30 mounting side of the second sealing resin 32 to the inner lead 38. In the present embodiment, a thermosetting epoxy resin containing a silica-based filler is used as the second sealing resin 32. However, the present invention is not limited to this. For example, a thermoplastic resin is used. Also good. Further, the second sealing resin 32 is a material having a higher elastic modulus than the first sealing resin 31.

  Next, the internal configuration of the LSI 30 will be described. As shown in FIG. 5, the LSI 30 includes an oscillation circuit 51, a frequency dividing circuit 53, a time measuring circuit 56, a temperature sensor 58, a control unit 60, and a register unit 70. The oscillation circuit 51 is connected to the oscillator 28 and causes the oscillator 28 to oscillate. The frequency divider 53 divides the signal output from the oscillator 28 (in this embodiment, a frequency of 32.768 kHz) to obtain a predetermined clock (for example, 1 Hz). The time measuring circuit 56 measures time based on the signal divided by the frequency dividing circuit 53 and transmits the time to the control unit 60. The temperature sensor 58 measures the temperature of the LSI 30 and transmits it to the control unit 60. Note that the temperature of the oscillator 28 that is disposed on the same lead frame in the vicinity of the LSI 30 and is electrically connected to the LSI 30 can be regarded as the same as the temperature of the LSI 30. That is, the temperature sensor 58 can accurately measure the temperature of the oscillator 28 disposed around the LSI 30. Based on the time measured by the time measuring circuit 56, the controller 60 causes the liquid crystal display 15 to display the accumulated power amount per unit time measured by the power amount measuring circuit 22 (see FIG. 1). The register unit 70 includes a plurality of registers for storing various data used when correcting the oscillation frequency of the oscillator 28. The plurality of registers will be described in detail in the description of oscillation frequency correction described later. In addition to this, the LSI 30 incorporates an arithmetic circuit for performing arithmetic operations and an internal power supply.

<Manufacturing procedure>
Hereinafter, a manufacturing procedure of the semiconductor device 24 will be described.
First, as shown in FIG. 6A, the lead frame 26 is mounted on the mounting table 2 of the bonding apparatus 1 so that the inner lead 38A is positioned above and the die pad 26A is positioned below. The mounting table 2 is formed with a step 8 for supporting the second mounting surface 26D of the die pad 26A. The oscillator 28 is encapsulated and transported in a package 29 on the tape with the external electrode 34 facing upward. The lead frame 26 is previously formed with a stepped portion 27 by press working or the like.

  Next, as shown in FIG. 6B, the package 29 is opened, the oscillator 28 is taken out by the picker 4, and the external electrode 34 of the oscillator 28 faces upward as shown in FIG. 6C. The oscillator 28 is disposed on the first mounting surface 26C of the die pad 26A, and is fixed to the first mounting surface 26C with an adhesive 49. When the oscillator 28 is enclosed in the package 29 with the external electrode 34 facing downward, the picker 4 having a rotating mechanism is used, and after the oscillator 28 is taken out by the picker 4, it is rotated. It is preferable to place the oscillator 28 upside down by the mechanism and place the external electrode 34 on the die pad 26 </ b> A after facing the upper side.

  After the oscillator 28 is fixed to the first mounting surface 26C of the die pad 26A, as shown in FIG. 6D, the LSI 30 is connected to the second mounting surface 26D of the die pad 26A, the electrode pad 50, and the electrode pad 54 for the oscillator. And are fixed with an adhesive (not shown) so that they face upward. Since the second mounting surface 26D is formed so as not to overlap the first mounting surface 26C in plan view, the LSI 30 is also fixed so as not to overlap the oscillator 28 in plan view. Further, the LSI 30 and the oscillator 28 are fixed to the same side surface of the die pad 26A.

  After the LSI 30 is fixed, as shown in FIG. 6E, the electrode pad 50 of the LSI 30 and the inner lead 38A of the lead frame 26 are connected by the bonding wire 52, and the oscillator electrode pad 54 of the LSI 30 and the oscillator are connected. 28 external electrodes 34 are connected by bonding wires 52. At this time, the bonding wire 52 connecting the electrode pad 50 of the LSI 30 and the lead 38 is connected so as to straddle the bonding wire 52 connecting the oscillator electrode pad 54 of the LSI 30 and the external electrode 34 of the oscillator 28. .

  Next, as shown in FIG. 7, the first sealing resin 31 is discharged from above the oscillator 28 by the dispenser 500 to seal the oscillator 28. At this time, the thickness of the first sealing resin 31 can be changed by controlling the discharge amount of the first sealing resin 31 to be discharged. After the oscillator 28 is sealed with the first sealing resin 31, the first sealing resin 31 is cured by heating.

Next, a procedure for sealing the semiconductor device 24 with the second sealing resin 32 will be described.
First, as shown in FIG. 8A, the semiconductor device 24 is molded so that the first mounting surface 26C of the lead frame 26 (die pad 26A) is positioned above and the second mounting surface 26D is positioned below. 5 is fixed inside the cavity 6. At this time, the side on which the LSI 30 is mounted is located closer to the injection port 7 of the mold 5 than the side on which the oscillator 28 is mounted, and the portion on which the LSI 30 is mounted is the center in the height direction of the cavity 6. It is preferable to arrange the semiconductor device 24 so as to be located in the vicinity. Further, the semiconductor device 24 is arranged such that the outer lead 38 </ b> B protrudes outside the mold 5.

  When the semiconductor device 24 is fixed inside the cavity 6, as shown by an arrow a in FIG. 8B, the second sealing resin 32 is injected from the injection port 7 provided along the lower surface of the lead frame 26. To do. The second sealing resin 32 injected from the injection port 7 flows evenly above and below the lead frame 26 (die pad 26A) as shown by the arrow b in FIG.

  Thereafter, as indicated by an arrow c in FIG. 8D, the flow rate of the second sealing resin 32 flowing below the die pad 26A is slower than that of the second sealing resin 32 flowing above the die pad 26A. Thus, since the second sealing resin 32 is preferentially filled downward, the lead frame 26 (die pad 26A) is supported from below by the second sealing resin 32.

  When the inside of the cavity 6 is filled with the second sealing resin 32, the mold 5 is heated to cure the second sealing resin 32 to obtain the semiconductor device 24.

<Action>

  Next, the operation of the semiconductor device 24 and the integrated watt-hour meter 10 according to the present embodiment will be described. In the semiconductor device 24 according to this embodiment, the oscillator 28 and the LSI 30 are sealed and integrated with the second sealing resin 32, and the LSI 30 includes the oscillation circuit 51, the frequency dividing circuit 53, and the time measuring circuit. 56 is built in, the time can be measured only by mounting the semiconductor device 24 on the substrate inside the integrating watt-hour meter 10 shown in FIG. That is, it is not necessary to separately mount the oscillator 28, the frequency dividing circuit 53, and the like on the substrate. This eliminates the need for adjustment of the connection between the oscillator 28 and the semiconductor device 24.

  Further, since the temperature sensor 58 is built in the LSI 30, the temperature around the oscillator 28 can be accurately measured. Thereby, even if the signal (frequency) output from the oscillator 28 fluctuates due to a temperature change, the frequency can be corrected with high accuracy. Therefore, it is possible to make the frequency highly accurate even with an inexpensive oscillator without using an expensive highly accurate oscillator.

  Further, as shown in FIG. 2, the external electrode 34 of the oscillator 28 and the oscillator electrode pad 54 of the LSI 30 are directly connected by a bonding wire 52. Therefore, wiring can be performed at the shortest distance without using the lead frame 26, and wiring resistance can be reduced. Further, since the lengths of the two bonding wires 52 connecting the external electrode 34 and the oscillator electrode pad 54 are uniform, the tension applied to the bonding wire 52 can be equalized, and the bonding wire 52 is broken or bent. Can prevent contact. In addition, since wiring can be performed without going through the lead frame 26, it is less susceptible to noise, and signals can be smoothly transmitted from the oscillator 28 to the LSI 30. Further, although noise is likely to occur between the bonding wires 52 formed in parallel, the bonding wire 52 connecting the oscillator electrode pad 54 and the external electrode 34 is connected to the other bonding wires 52. Thus, the three-dimensional crossing can reduce interference between the bonding wire 52 connecting the oscillator electrode pad 54 and the external electrode 34 and the other bonding wire 52, and in particular, oscillation from the other bonding wire 52. The influence of noise on the child 28 can be reduced. Furthermore, since the external electrode 34 is larger than the oscillator electrode pad 54, wire bonding can be easily performed.

  In addition, since the oscillator 28 is sealed with the first sealing resin 31, the first sealing resin 31 can be used even when strain is applied to the second sealing resin 32 due to a temperature change or the like. Strain does not directly affect the oscillator 28 due to the resin 31. Thereby, when the semiconductor device 24 is mounted on the substrate in the reflow process, it is possible to suppress the frequency of the oscillator 28 from fluctuating due to the influence of heat. Further, even when residual stress is generated in the sealing process of the second sealing resin 32, it is possible to suppress the stress from directly acting on the oscillator 28.

  Furthermore, by making the elastic modulus of the first sealing resin 31 lower than that of the second sealing resin 32, the second sealing resin is elastically deformed and stress is applied to the oscillator 28. It can suppress acting. Here, by setting the elastic modulus of the adhesive 49 used when mounting the oscillator 28 to the die pad 26 </ b> A and the elastic modulus of the first sealing resin 31 to the same elastic modulus, The stress acts evenly and the influence on the oscillator 28 can be minimized. Here, the same elastic modulus is not limited to the case where the first sealing resin 31 and the adhesive 49 have the same composition, but also includes the case where the strain with respect to the input stress is approximately the same.

  In the present embodiment, all the inner leads 38A are connected to the electrode pads 50 of the LSI 30. However, the present invention is not limited to this, and any inner lead 38A is connected to the die pad 26A by the bonding wire 52, and the outer leads 38B. The die pad 26A may be grounded by connecting to a ground. In this case, the die pad 26A can be prevented from being charged. Further, since the LSI 30 and the oscillator 28 are arranged on both sides of the lead frame so as to sandwich the lead frame, noise from the LSI 30 to the oscillator 28 can be shielded by the die pad 26A.

<Correction of oscillation frequency>

  Next, frequency correction processing for correcting an error depending on the temperature of the oscillation frequency of the oscillator 28 in the semiconductor device 24 according to the present embodiment will be described.

  For example, when the temperature of the LSI 30 in the semiconductor device 24 is set to room temperature (here, 25 ° C.) at the time of shipment, the semiconductor device 24 is set to a reference temperature (hereinafter, also referred to as “low temperature”) lower than the room temperature. The temperature is measured by the temperature sensor 58 in each state when the temperature is set to a reference temperature higher than normal temperature (hereinafter also referred to as “high temperature”). Then, for example, after shipping, the semiconductor device 24 uses the temperature obtained by this measurement as trimming data and corrects the frequency error of the oscillator 28 in consideration of a measurement error caused by manufacturing variations of the temperature sensor 58.

  The register unit 70 (see FIG. 5) described above stores a temperature measurement value register 71 that stores data indicating the temperature measured by the temperature sensor 58, and indicates the temperature measured by the temperature sensor 58 when the ambient temperature is low. A low temperature register 72 for storing data, a normal temperature register 73 for storing data indicating the temperature measured by the temperature sensor 58 when the ambient temperature is normal temperature, and a temperature measured by the temperature sensor 58 when the ambient temperature is high And a frequency correction register 75 for storing a correction value of the oscillation frequency of the oscillator 28 derived from the data indicating these temperatures. Each register is connected to the control unit 60 via the data bus 76, and the control unit 60 reads and writes each register via the data bus 76.

  In order to correct the frequency error of the oscillator 28, the semiconductor device 24 measures the temperature by the temperature sensor 58 in each state when the temperature of the semiconductor device 24 is low, normal, and high. Then, a first frequency correction process is performed in which the temperature obtained by the measurement is stored as trimming data in the low temperature register 72, the normal temperature register 73, and the high temperature register 74, respectively.

  For example, at the time of a shipping test, the tester first places the semiconductor device 24 inside a thermostatic chamber in which the temperature in the bath is set to room temperature. Then, the user causes the semiconductor device 24 to execute the first frequency correction process by inputting, for example, a measurement operation signal for starting temperature measurement by the temperature sensor 58 to the semiconductor device 24. At this time, for example, the user connects the device that outputs the measurement operation signal to the lead 38 of the semiconductor device 24 to input the measurement operation signal to the semiconductor device 24. In addition, the measurement operation signal includes information indicating whether the temperature set in the thermostatic chamber is normal temperature, high temperature, or low temperature.

  FIG. 9 is a flowchart showing the flow of the first frequency correction process in the semiconductor device 24 according to the present embodiment. The program that executes the first frequency correction processing is a program that is executed at the timing when the measurement operation signal is input, and is stored in advance in a storage unit that the control unit 60 has. Note that the execution timing is not limited to this.

  In step S101, the control unit 60 determines whether or not a predetermined time (for example, several hours) has elapsed since the measurement operation signal was input. Note that the predetermined time is preferably a time required for the internal temperature of the semiconductor device 24 (the temperature of the LSI 30) to coincide with the temperature of the thermostatic chamber.

  When it is determined in step S101 that the predetermined time has elapsed, in step S103, the control unit 60 acquires a measurement value obtained by the temperature sensor 58. Note that the measurement value obtained by the temperature sensor 58 is stored in the temperature measurement value storage register 71. Moreover, when acquiring a measured value with the temperature sensor 58, it measures every predetermined time (for example, 1 minute) progress, and uses the value which averaged the several measured value obtained by multiple times of measurement as a measured value. You may get it.

  In step S105, the control unit 60 stores the acquired measurement value in the normal temperature register 73 when the temperature set in the thermostatic bath is normal temperature (here, 25 ° C.) and is set in the thermostatic bath. When the temperature is high, the temperature is stored in the high temperature register 74, and when the temperature set in the thermostat is low, the temperature is stored in the low temperature register 72, and the first frequency correction process is terminated. Note that the first frequency correction process may be performed in advance in the wafer state.

  The tester arranges the semiconductor device 24 inside the thermostatic chamber in which the temperature in the bath is set to a high temperature, in addition to the state in which the semiconductor device 24 is arranged in the thermostatic bath in which the temperature in the bath is set to room temperature. In each of the above state and the state in which the semiconductor device 24 is disposed inside the thermostatic chamber in which the temperature in the bath is set to a low temperature, the semiconductor device 24 is caused to perform the processes of steps S101 to S105. Thereby, the measured values by the temperature sensor 58 are stored in the normal temperature register 73, the high temperature register 74, and the low temperature register 72, respectively.

  The semiconductor device 24 according to the present embodiment is shipped after the above-described processing is performed, and a second frequency correction process described later is performed at a predetermined timing after the shipment.

  For example, after shipping, the user causes the semiconductor device 24 to execute a second frequency correction process by inputting, for example, a derivation operation signal for starting the derivation of the frequency correction value to the semiconductor device 24. At this time, the user inputs the derivation operation signal by connecting a device that outputs the derivation operation signal to the lead 38 of the semiconductor device 24, for example. Alternatively, the semiconductor device 24 may execute the second frequency correction process at regular intervals.

  FIG. 10 is a flowchart showing the flow of the second frequency correction process in the semiconductor device 24 according to the present embodiment. The program that executes the second frequency correction processing is a program that is executed at the timing when the derivation operation signal is input after the semiconductor device 24 is shipped, and is stored in advance in a storage unit that the control unit 60 has.

  In step S <b> 201, the control unit 60 acquires measurement values stored in the normal temperature register 73, the high temperature register 74, and the low temperature register 72, respectively.

  In step S <b> 203, the control unit 60 derives a correction value (hereinafter also referred to as “frequency correction value”) of the oscillation frequency of the oscillator 28 using the measurement value acquired in step S <b> 201.

FIG. 11 is a diagram showing a relationship between temperature and frequency deviation in the semiconductor device according to the present embodiment. FIG. 11 shows not a frequency error obtained in an actual temperature environment but a theoretical value obtained by calculation using a quadratic function. The quadratic function is expressed by the following equation (1). In the following formula (1), f is a frequency deviation, a is a secondary temperature coefficient, T is a measured temperature, T ₀ is a vertex temperature, and b is a vertex error. The secondary temperature coefficient a is a constant determined in advance according to the individual difference of the oscillator 28 and is stored in advance in a storage unit included in the control unit 60.

... (1)

  In the first embodiment, the frequency deviation f is unknown, but the known secondary temperature coefficient a, the measured value at room temperature stored in the room temperature register 73, and the measurement at high temperature stored in the high temperature register 74. The vertex error b can be derived from the value and the measured value at the low temperature stored in the low temperature register 72. Then, the control unit 60 sets the value of the vertex error b as the frequency correction value so that the frequency deviation becomes the smallest at the temperature T0 at normal temperature.

  In the derivation of the frequency correction value, for example, in a measurement environment at −10 ° C., when the value measured by the temperature sensor 58 is −8 ° C., correction corresponding to + 2 ° C. is necessary. . The product at the shipping stage reads out three-point measurement values of normal temperature, high temperature and low temperature stored in each register through the data bus 76, and derives the temperature in the actual environment using the read data as trimming data. . If the measured value by the temperature sensor 58 is a value that is not stored in each register, the temperature in the actual environment may be derived using the values of the two adjacent registers.

  In step S <b> 205, the control unit 60 stores data indicating the frequency correction value derived in step S <b> 203 in the frequency correction register 75. In the semiconductor device 24, the frequency dividing circuit 53 generates a clock signal from the signal input from the oscillation circuit using the frequency correction value stored in the frequency correction register 75, and thereby the oscillation frequency of the oscillator 28. Is corrected.

  As described above, according to the semiconductor device 24 according to the first embodiment, at the time of shipment, the measurement value obtained by the temperature sensor 58 under the three-point environmental temperature of the semiconductor device 24 is prepared as trimming data. By deriving the frequency correction value based on the original, it is possible to obtain the frequency correction value based on highly accurate temperature information without depending on the manufacturing variation of the temperature sensor 58 for each individual semiconductor device 24.

  In the conventional packaged semiconductor device, when the semiconductor device is driven, the ambient temperature Ta (° C.), the package surface temperature Tc (° C.), and the chip surface temperature Tj (° C.) of the semiconductor device are different. For example, the chip surface temperature Tj is expressed by the following equation (2), where θja is the package thermal resistance (between junction and atmosphere) and P is the power consumption (maximum or average) of the chip.

... (2)

  However, in the semiconductor device 24 according to this embodiment, since the temperature sensor 58 and the oscillator 28 are sealed together, the ambient temperature of the temperature sensor 58 and the ambient temperature of the oscillator 28 are the same. The temperature of the oscillator 28 can be measured with high accuracy by the temperature sensor 58 included in the LSI 30, and therefore the accuracy of frequency correction is prevented from being lowered due to the temperature difference between the oscillator 28 and the temperature sensor 58.

(Second Embodiment)

  Next, a semiconductor device 24 according to a second embodiment of the present invention will be described. In addition, about the structure same as 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 12, in the semiconductor device 24 according to the second embodiment, a clock signal (hereinafter also referred to as “reference clock signal”) that is used as a reference when correcting the oscillation frequency of the oscillator 28 with respect to the LSI 30A. .) Is connected to a clock generator provided with a reference signal oscillator 80. In addition to the configuration of the LSI 30 of the semiconductor device 24 according to the first embodiment, the LSI 30A of the semiconductor device 24 according to the second embodiment transmits the measurement counter 81, the reference counter 82, and the clock signal from the oscillation circuit 57 to the outside. An output terminal 83 for outputting is further provided.

  As shown in FIGS. 13A and 13B, the reference signal oscillator 80 is an oscillator such as a crystal resonator having an oscillation frequency higher than that of the oscillator 28. In the second embodiment, the oscillation frequency of the oscillator 28 is 32.768 KHz, and the oscillation frequency of the reference signal oscillator 80 is 10 MHz.

  The measurement counter 81 is connected to the oscillation circuit 51, and receives a clock signal (hereinafter also referred to as “measurement clock signal”) from the oscillator 28 from the oscillation circuit 51 based on the control of the control unit 60. It is a counter that counts the number of clocks of the clock signal. The reference counter 82 is connected to a clock generator provided with a reference signal oscillator 80, and receives a clock signal from the reference signal oscillator 80 based on the control of the control unit 60 and calculates the number of clocks of the clock signal. Count. As shown in FIGS. 13A and 13B, the reference counter 82 and the measurement counter 81 count the number of clocks within the same time at substantially the same time while synchronizing with each other. The measurement counter 81 and the reference counter 82 may be operated in synchronization with each other based on the operation signal, or a synchronization counter may be used.

  In the second embodiment, in the register unit 70, data indicating the temperature measured by the temperature sensor 58 is stored in the temperature measurement value register 71, and the ambient temperature is lower than room temperature (25 ° C.) in the low temperature register 72. The temperature measured by the temperature sensor 58 when the reference temperature is set and data indicating the frequency error at that temperature are stored. The room temperature register 73 is measured by the temperature sensor 58 when the ambient temperature is the room temperature (25 ° C.). Data indicating the measured temperature and the frequency error at that temperature are stored, and when the ambient temperature is set to a reference temperature higher than room temperature (25 ° C.) in the high temperature register 74, the temperature measured by the temperature sensor 58 and the temperature Data indicating the frequency error is stored, and the frequency correction register 75 is derived from the data indicating the frequency error described above. That data indicating the frequency correction value is stored.

<Correction of oscillation frequency>

  For example, at the time of a shipping test, a user first places the semiconductor device 24 inside a thermostatic chamber in which the temperature in the bath is set to room temperature (here, 25 ° C.). Then, the user causes the semiconductor device 24 to execute the first frequency correction process by inputting, for example, a measurement operation signal for starting temperature measurement by the temperature sensor 58 to the semiconductor device 24. At this time, for example, the user connects the device that outputs the measurement operation signal to the lead 38 of the semiconductor device 24 to input the measurement operation signal to the semiconductor device 24. The measurement operation signal includes information indicating whether the temperature set in the thermostatic chamber is normal temperature, high temperature, or low temperature.

  FIG. 14 is a flowchart showing the flow of the first frequency correction process in the semiconductor device 24 according to the present embodiment. The program that executes the first frequency correction processing is a program that is executed at the timing when the measurement operation signal is input when the semiconductor device 24 is shipped, and is stored in advance in storage means included in the control unit 60.

  In step S301, the control unit 60 determines whether or not a predetermined time (for example, several hours) has elapsed since the measurement operation signal was input. The predetermined time may be a time required for the internal temperature of the semiconductor device 24 (the temperature of the LSI 30) to coincide with the temperature of the thermostatic chamber.

  When it is determined in step S301 that the predetermined time has elapsed, in step S303, the control unit 60 acquires a measurement value obtained by the temperature sensor 58. Note that the measurement value obtained by the temperature sensor 58 is stored in the temperature measurement value storage register 71. The temperature sensor 58 has been confirmed by testing to have a measurement accuracy equal to or higher than a predetermined reference value, and it is guaranteed that the temperature sensor 58 can perform temperature measurement with high accuracy. Or you may make it correct | amend using the measured value by the temperature sensor 58. FIG.

  In step S305, the control unit 60 performs a frequency error derivation process for deriving an error in the oscillation frequency of the oscillator 28. FIG. 15 is a flowchart showing a flow of frequency error derivation processing according to the present embodiment. FIGS. 16A and 16B are timing charts in the frequency error derivation process according to the present embodiment. FIG. 16A is a diagram illustrating a count start time, and FIG. 16B is a diagram illustrating a count stop time.

  In step S <b> 401, the control unit 60 outputs a correction operation signal to the measurement counter 81. The measurement counter 81 to which the correction operation signal is input starts the operation in step S403, starts counting the clock value of the clock signal by the oscillator 28, and outputs a start signal to the reference counter 82.

  The reference counter 83 that has received the start signal starts counting the clock value of the clock signal by the reference signal oscillator 80 in step S405. That is, as shown in FIG. 16A, when the correction operation signal is turned on, the measurement counter 81 starts counting, and the reference counter 82 also starts counting in synchronization with the measurement counter 81.

  In step S407, the measurement counter 81 determines whether or not the count value of the measurement counter is equal to or greater than a predetermined value (32.768 corresponding to 1 second in the present embodiment). If it is not greater than or equal to the predetermined value in step S407, the measurement counter 81 continues counting.

  If it is determined in step S407 that the value is equal to or larger than the predetermined value, in step S409, the measurement counter 81 stops counting and outputs a stop signal to the reference counter 82.

  The reference counter 82 that has received the stop signal stops counting in step S411. That is, as shown in FIG. 16B, when the correction operation signal is turned off, the measurement counter 81 stops counting, and the reference counter 82 also stops counting in synchronization with the measurement counter 81.

  In step S413, the control unit 60 acquires the count value of the reference counter 82.

  In step S415, the control unit 60 derives an error in the oscillation frequency of the oscillator 28 from the count value of the reference counter 82 acquired in step S413. That is, the control unit 60 can generate the reference signal oscillation that can count the count values (that is, 32,768) obtained in the same time in the measurement clock signal by the oscillator 28 with higher accuracy than the oscillator 28. By comparing with the count value of the reference clock signal by the child 80, the error of the oscillation frequency of the oscillator 28 is derived.

  For example, since the oscillation frequency of the reference signal oscillator 80 is 10 MHz, if the count value of the reference counter 82 is “10000000 (decimal number)”, it can be estimated that the oscillator 28 can accurately measure 1 second. The oscillation frequency error need not be corrected by 0, and the oscillation frequency error (frequency correction value) is 0. On the other hand, for example, if the count value of the reference counter 82 is “10000002 (decimal number)”, it can be estimated that the oscillation frequency of the oscillator 28 is delayed by 0.2 ppm, and the oscillation frequency of the oscillator 28 is determined as an error. Therefore, it is necessary to make correction so as to be faster by 0.2 ppm, and an error of the oscillation frequency (frequency correction value) is set to +0.2 ppm. For example, if the value of the reference counter 82 is “9999999 (decimal number)”, the oscillation frequency of the oscillator 28 is increased by 1.0 ppm. That is, it is necessary to delay by 1.0 ppm, and the oscillation frequency error (frequency correction value) is set to -1.0 ppm.

  In step S417, the control unit 60 stops outputting the correction operation signal to the measurement counter 81, and ends the frequency error derivation processing program. The measurement counter 81 and the reference counter 82 stop operating when the correction operation signal input stops.

  In step S307, the control unit 60 stores the temperature measurement value acquired in step S303 and the frequency error derived in step S415 in the room temperature register 73 when the temperature set in the thermostat is room temperature. When the temperature set in the constant temperature bath is high, the first frequency correction processing program is stored in the high temperature register 74, and when the temperature set in the constant temperature bath is low, the temperature is stored in the low temperature register 72. Exit.

  In addition to the state in which the semiconductor device 24 is disposed inside the thermostatic chamber in which the temperature in the bath is set to room temperature, the user places the semiconductor device 24 in the thermostatic bath in which the temperature in the bath is set to a high reference temperature. In the state in which the semiconductor device 24 is disposed, and in the state in which the semiconductor device 24 is disposed in the thermostatic chamber in which the temperature in the bath is set to a low reference temperature, the semiconductor device 24 is caused to perform the processes of steps S301 to S309. As a result, the temperature measurement value by the temperature sensor 58 and the error of the oscillation frequency of the oscillator 28 are stored in the room temperature register 73, the high temperature register 74, and the low temperature register 72, respectively.

  The semiconductor device 24 according to the present embodiment is shipped after the above-described processing is performed, and the oscillation frequency of the oscillator 28 indicates the frequency correction value stored in the frequency correction register 75 at a predetermined timing after shipment. Correction is performed based on the above-described equation (1) using the data. Note that the secondary temperature coefficient a and the apex error b in the second embodiment are determined by the frequency error derived at each temperature. Note that the frequency error may be obtained by linear approximation from the difference between the oscillation frequency error values stored in the higher temperature register and the lower temperature register. Then, when the system is reset, periodically, in response to the input of a predetermined signal via the lead 38, or when the oscillation frequency of the oscillator 28 is corrected using the above equation (1), the second described later. Frequency correction processing is performed.

  The user causes the semiconductor device 24 to execute the second frequency correction process by inputting, for example, a derivation operation signal for starting the derivation of the frequency correction value to the semiconductor device 24. At this time, the user inputs the derived operation signal, for example, by connecting a device that outputs the measurement operation signal to the lead 38 of the semiconductor device 24.

  FIG. 17 is a flowchart showing the flow of the second frequency correction process in the semiconductor device 24 according to the present embodiment. The program that executes the second frequency correction process is a program that is executed at the timing when the measurement operation signal is input, and is stored in advance in storage means included in the control unit 60.

  In step S503, the control unit 60 measures the current environmental temperature with the temperature sensor 58, and acquires the measured value. Note that the measurement value obtained by the temperature sensor 58 is stored in the temperature measurement value storage register 71.

  In step S505, the control unit 60 determines whether or not the temperature acquired in step S503 is different from the temperature measured in the thermostat (for example, the temperature acquired in step S303). If this determination is not necessary, the process may proceed to step S505 without performing the process of step S505 after performing the process of step S503.

  If it is determined in step S505 that the temperatures are not different, the control unit 60 determines that there is no need to change the frequency correction value, and ends the second frequency correction process.

  If it is determined in step S505 that the temperatures are different, the control unit 60 derives a frequency error by performing the same process as in step S305 described above in step S507. In step S507, the control unit 60 derives the secondary temperature coefficient a and the apex error b by substituting the data stored in each register of the register unit 70 into the above-described equation (1).

  In step S <b> 511, the control unit 60 stores the frequency correction value in the frequency correction register 75. At this time, if it is determined in step S505 that the temperatures are not different, a frequency correction value is derived and stored using the temperature and frequency error stored in the low temperature register 72, the normal temperature register 73, and the high temperature register 74. To do. On the other hand, if it is determined in step S505 that the temperatures are different, a frequency correction value is derived and stored using the frequency error derived in step S507.

  In the semiconductor device 24, the frequency divider 53 corrects the signal input from the oscillator based on the frequency correction value stored in the frequency correction register 75, thereby correcting the oscillation frequency of the oscillator 28. Do.

  As described above, according to the semiconductor device 24 according to the second embodiment, by measuring the frequency error at the actual temperature, even if the frequency deviation varies depending on the temperature due to the manufacturing variation of the oscillator 28, the time measurement is always stable. Can be engraved.

  Further, according to the semiconductor device 24 according to the second embodiment, by incorporating a time correction circuit inside the LSI 30A of the semiconductor device 24, time measurement can be performed with high accuracy even when the frequency accuracy of the clock signal supplied from the outside is low. It can be performed.

  In addition, according to the semiconductor device 24 according to the second embodiment, even if the number of terminals is limited by replacing an empty terminal due to the built-in oscillator 28 with another function (for example, serial communication or addition of I2C). High functionality can be realized.

  In the present embodiment, the error of the oscillation frequency of the oscillator 28 is derived using the reference signal oscillator 80, the measurement counter 81, and the reference counter 82, but the method of deriving the error is not limited to this, and the oscillation circuit 51 By comparing the time of a predetermined time (in this embodiment, 1 second (32, 768 CLK)) in the clock signal output from the oscout terminal output from the time with the predetermined time accurately measured by another method The oscillator 28 may measure how long the predetermined time is actually measured.

  In addition, after correcting the oscillation frequency error of the oscillator 28 in the semiconductor device 24 according to the second embodiment, the measurement error of the temperature sensor 58 in the semiconductor device 24 according to the first embodiment is corrected as necessary. You may perform the correction | amendment which considered.

  18 and 19 are block diagrams showing another example of the electrical configuration of the LSI 30A of the semiconductor device 24 according to this embodiment.

  As shown in FIG. 18, the semiconductor device 24 includes an output terminal 84, and an error (frequency correction value) in the oscillation frequency of the oscillator 28 derived by the control unit 60 is output to the outside of the semiconductor device 24. It may be output via. As a result, it is possible to carry out periodic calibration for finding characteristic deterioration of the reference clock generator.

  As shown in FIG. 19, the LSI 30 </ b> A of the semiconductor device 24 may be connected to the measurement counter 81 with a high-accuracy clock generation circuit 85 serving as a calibration reference. In this case, in step S413 described above, the control unit 60 acquires the count value of the measurement counter 81 and the count value of the reference counter 82, and compares the count value of the measurement counter 81 with the count value of the reference counter 82. . For example, if the frequency of the clock signal of the measurement counter 81 is 10 MHz and the frequency of the clock generation circuit 85 connected to the reference counter 82 is 10 MHz, the clock generator having the reference signal oscillator 80 and the clock connected to the reference counter 82 If the generator 85 generates a clock signal having the same frequency, the count value of the measurement counter 81 and the count value of the reference counter 82 become the same value, but the characteristics of the reference signal oscillator 80 change. If so, a difference occurs between the count value of the measurement counter 81 and the count value of the reference counter 82. When there is a difference between the count value of the measurement counter 81 and the count value of the reference counter 82, the control unit 60 determines whether the difference is within a predetermined allowable error range, and determines the determination result. 8 to the output terminal 84. As a result, it is possible to carry out periodic calibration for finding characteristic deterioration of the clock generator provided with the reference signal oscillator 80.

  As shown in FIG. 19, even if the LSI 30A of the semiconductor device 24 includes the clock generation circuit 85, the clock signal output from the oscillation circuit 51 and the clock generation circuit 85 are included in the LSI 30A. A selector 86 that selectively inputs one of the output clock signals and outputs it to the measurement counter 81 may be connected. The semiconductor device 24 shown in FIG. 19 can function in the same manner as the semiconductor device 24 shown in FIG. 18 by connecting the selector 86.

(Third embodiment)

  Next, a semiconductor device 200 according to a third embodiment of the present invention will be described. In addition, about the structure same as 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIGS. 20 and 21, the die pad 202A of the lead frame 202 constituting the semiconductor device 200 according to the present embodiment is formed on a plane and has no stepped portion.

  In addition, two openings 202C are formed in the oscillator mounting region on which the oscillator 28 of the die pad 202A is mounted, with the oscillator mounting beam 206 interposed therebetween. An oscillator 28 is mounted via Here, the oscillator 28 is mounted in a direction in which the external electrode 34 and the opening 202C face each other. The LSI 30 is mounted on the die pad 202A on the back surface of the lead frame 202 via an adhesive. The bonding wire 52 extending from the LSI 30 to the oscillator 28 is connected to the external electrode 34 of the oscillator 28 through the opening 202C.

  The LSI 30 is mounted on the left side of the center portion of the die pad 202A so as not to overlap the opening 202C formed in the die pad 202A. For this reason, the entire surface of the LSI 30 is bonded to the die pad 202A.

  The oscillator 28 is fixed to the first surface of the die pad 202A, the LSI 30 is fixed to the second surface opposite to the first surface, the oscillator electrode pad 54 of the LSI 30, the external electrode 34 of the oscillator 28, and The electrode pad 50 of the LSI 30 and the inner lead 38A are connected by a bonding wire 52.

  Here, as shown in FIG. 21, the first sealing resin 31 is discharged onto the front and back surfaces of the die pad 202 </ b> A to seal the oscillator 28. That is, the first sealing resin 31 is discharged from the dispenser to the oscillator 28 with the side on which the oscillator 28 of the die pad 202A is mounted facing up, and heat treatment is performed once. Subsequently, the semiconductor device 200 is inverted, the external electrode 34 of the oscillator 28 is directed upward, and the first sealing resin 31 is discharged from the dispenser to the oscillator 28. At this time, it is preferable to fill the opening 202C of the die pad 202A with the first sealing resin 31.

  In the semiconductor device 200 according to the present embodiment, a part of the mounting surface of the oscillator 28 is covered with the first sealing resin 31, so that the oscillator 28 and the die pad are compared with the semiconductor device 24 according to the first embodiment. The contact area with 202A is reduced, and a wider range can be sealed with the first sealing resin 31 accordingly. As a result, when thermal stress acts on the second sealing resin 32, the stress can be evenly applied to the oscillator 28 via the first sealing resin 31, and the frequency of the oscillator 28 varies. Can be suppressed. Other operations are the same as in the first embodiment.

(Fourth embodiment)

  Next, a semiconductor device 300 according to a fourth embodiment of the present invention will be described. In addition, about the structure same as 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIG. 22, the lead frame 302 constituting the semiconductor device 300 according to this embodiment has a die pad 302 </ b> A in which a step portion 304 is formed.

  As shown in FIG. 23, the die pad 302A is located at the center of the lead frame 302, and the first mounting surface 302B on the right side in the drawing from the step portion 304 and the second mounting surface on the left side in the drawing from the step portion 304. 302C. Further, as shown in FIG. 23, the first mounting surface 302B is provided with an oscillator mounting region 314 on which the oscillator 28 is mounted, and the second mounting surface 302C has an LSI mounting on which the LSI 30 is mounted. Region 316 is provided.

  Here, in the oscillator mounting region 314, a plurality of openings 318 penetrating the die pad 302A in the thickness direction are formed. In this embodiment, eight openings 318 are arranged in two rows at equal intervals. However, the present invention is not limited to this, and the size of the openings 318 and the number of openings 318 may be changed as appropriate. .

  The oscillator mounting region 314 includes a beam portion 320A extending in the vertical direction in the drawing and a beam portion 320B extending in the horizontal direction in the drawing by the plurality of openings 318. The oscillator 28 is mounted by applying an adhesive to the beam portions 320A and 320B.

  The oscillator 28 mounted on the oscillator mounting region 314 is sealed with a first sealing resin 31 as shown in FIG. Here, the first sealing resin 31 is also discharged onto the surface of the die pad 302 </ b> A opposite to the surface on which the oscillator 28 is mounted, and fills the opening 318.

  In the semiconductor device 300 according to the present embodiment, since the oscillator 28 is mounted on the beam members 320A and 320B, the contact area with the die pad 302A is reduced as compared with the first embodiment, and the stress from the die pad 302A is reduced. It is hard to receive.

  Further, the stress from the die pad 302A acts on the oscillator 28 evenly via the beam portions 320A and 320B, so that stress concentration can be suppressed. Further, the first sealing resin 31 is filled in the plurality of openings 318, and the oscillator 28 is sealed with the first sealing resin 31 except for the beam portions 320A and 320B. Even when a strain acts on the second sealing resin 32 constituting the outer shape of the semiconductor device 300, the strain is reduced by the first sealing resin 31 and the frequency of the oscillator 28 fluctuates. Can be suppressed. Other operations are the same as in the first embodiment. Alternatively, the first sealing resin 31 may be discharged only to the oscillator 28 side without filling the opening 318 with the first sealing resin 31.

  The first to fourth embodiments of the present invention have been described above, but the present invention is not limited to such embodiments, and the first to fourth embodiments may be used in combination. Needless to say, the present invention can be implemented in various forms without departing from the scope of the invention.

10 watt-hour meter (measuring equipment)
22 Electricity measurement circuit (measuring means)
24 Semiconductor Device 26 Lead Frame 28 Oscillator 30 LSI (Integrated Circuit)
31 1st sealing resin (1st sealing member)
32 Second sealing resin (second sealing member)
49 Adhesive 200 Semiconductor Device 202 Lead Frame 300 Semiconductor Device 302 Lead Frame 320 Opening

Claims (8)

A lead frame having a plurality of inner leads formed around the die pad;
An oscillator mounted on the first surface of the die pad;
An integrated circuit mounted on a second surface different from the first surface of the die pad and electrically connected to the oscillator;
A first sealing member for sealing the oscillator;
The oscillator sealed with the first sealing member, and a second sealing member for sealing the integrated circuit,
The distance from the first surface in the height direction of the second sealing member to the center of the thickness of the inner lead is from the second surface in the height direction of the second sealing member. A semiconductor device formed longer than the distance to the center of the thickness of the inner lead.   The semiconductor device according to claim 1, wherein the first sealing member has a lower elastic modulus than the second sealing member. The oscillator is bonded to the first surface via an adhesive member,
The semiconductor device according to claim 1, wherein the adhesive member has the same elastic modulus as that of the first sealing member.   The semiconductor device according to claim 1, wherein at least a part of the first surface is covered with the first sealing member. An opening is formed in an oscillator mounting region where the oscillator of the die pad is mounted,
The semiconductor device according to claim 4, wherein the opening is filled with the first sealing member.   The semiconductor device according to claim 1, wherein the oscillator and the integrated circuit are mounted on the first surface and the second surface of one surface of the die pad. A semiconductor device according to any one of claims 1 to 6;
Measuring means for measuring an integrated amount according to a signal output from the semiconductor device;
Measuring instrument. Mounting an oscillator on a first surface of the die pad in a lead frame having a plurality of inner leads formed around the die pad;
Mounting an integrated circuit on a second surface different from the first surface of the die pad;
Electrically connecting the oscillator and the integrated circuit;
Sealing the oscillator with a first sealing member;
Sealing the oscillator sealed with the first sealing member, and sealing the integrated circuit with a second sealing member,
The distance from the first surface in the height direction of the second sealing member to the center of the thickness of the inner lead is from the second surface in the height direction of the second sealing member. A method of manufacturing a semiconductor device, which is formed longer than the distance to the center of the thickness of the inner lead.