JP2009071075A - Electronic component mounting portion, lead frame and electronic device with lead frame, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic component mounting portion and a lead frame such that a die pad portion does not deform in a die bonding process and a wire bonding process against pressure applied when a thin film chip is mounted on a die pad of a lead frame and bonding pressure of a wire, and the lead frame and a mold resin do not shift from each other in a molding process; an electronic device with lead frame; and manufacturing methods thereof. <P>SOLUTION: The electronic component mounting portion for mounting an electronic component has a support projection portion for supporting the electronic component mounting portion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electronic component mounting section and a lead frame for mounting an electronic device such as a sensor for performing fluid identification, a semiconductor device, and the like, an electronic device including the lead frame, and a method for manufacturing the same.

  Conventionally, for example, hydrocarbon liquids such as gasoline, naphtha, kerosene, light oil, and heavy oil, alcohol liquids such as ethanol and methanol, urea aqueous solution liquids, gases, and granular fluids have been used. Patent Documents 1 to 3 are thermal sensors used in fluid identification devices that perform fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid level identification, and the like for a fluid to be identified. And the like.

  As shown in FIG. 21 or FIG. 22, these thermal sensors 100 include a sensor main body 104 constituted by a mold resin 102, and the sensor main body 104 includes a substantially elliptical flange portion 106 and the flange portion. A back surface protruding portion 108 protruding from the back surface of the 106 and a detection portion 110 protruding from the surface of the flange portion 106 are provided.

  The detection unit 110 includes a pair of rectangular plate-shaped fluid identification detection units 112 and a fluid temperature detection unit 114 that are spaced apart from each other by a predetermined distance. The fluid identification detection unit 112 and the fluid temperature detection unit 114 basically have the same structure, and include a heating element and a temperature sensing element. The fluid temperature detection unit 114 does not act on the heating element. Only the temperature sensitive body is allowed to act on.

  Moreover, in these detection parts 112 and 114, the metal die pad part 118 which functions as a heat transfer member arrange | positioned in the sensor main body 104 so that a part may be exposed to the opening part 116 which the mold resin 102 lacked. It has. A thin film chip 122 is mounted on the mounting surface of the die pad 118 opposite to the opening 116.

  Further, in the sensor body 104, the inner pads 124 are arranged so as to face the die pad portions 118 and spaced apart from the die pad portion 118 by a certain distance, and are spaced apart from each other by a certain distance. . An external connection terminal portion 126 extends from these inner leads 124 in the direction of the rear surface protruding portion 108, and an outer lead 128 is formed at the tip of the external connection terminal portion 126.

The electrode of the thin film chip 122 and the electrode 124a of the inner lead 124 are electrically connected by a bonding wire 130 made of Au.
Such a thermal sensor 100 heats a heating element by energization, heats the temperature sensing element by this heating, and thermally affects the heat transfer from the heating element to the temperature sensing element by the identified fluid, Based on the electrical output corresponding to the electrical resistance of the temperature sensing element, the fluid identification as described above is performed for the fluid to be identified.

By the way, such a thermal sensor 100 is manufactured through a manufacturing process as shown in FIG.
That is, the die pad portion 118, the inner lead 124, the external connection terminal portion 126, and the outer lead 128 are integrated using copper, carbon steel, aluminum alloy, aluminum, or the like as a lead frame (not shown) in the manufacturing process. Is formed.

  Then, on the lead frame integrally formed in this way, first, in the frame plating process of step S101, for example, precious metal Pd plating, Au plating, solder Ni plating, Sn plating, Sn, etc. -Pb plating, Sn-Bi plating, Ag plating, Ag-Cu plating, In plating, etc. are performed. In this case, the type of plating is not particularly limited as long as it is a plating metal used for soldering with a noble metal.

  In the frame plating process in step S101, the entire lead frame is plated, and then in the die bonding process in step S102, the thin film chip 122 is attached (bonded) to the die pad portion 118 via the bonding material 101 such as an adhesive. ing.

  Next, in the wire bonding step of step S103, the electrode of the thin film chip 122 and the electrode 124a of the inner lead 124 are electrically connected by a bonding wire 130 made of Au.

  In this state, the lead frame is placed in the mold, and in the molding process of step S104, for example, an epoxy resin is injected, thereby forming the sensor body 104 in which a predetermined portion of the lead frame is covered with the mold resin 102. .

  After that, after the lead frame is separated into a predetermined size in the diver cutting process in step S105, the mold resin deburring process in step S106 is immersed in an acid or alkali solution to thereby remove excess mold resin 102 of the sensor body 104. Remove the resin part.

  Next, in the exterior plating (terminal part plating) step of step S107, in order to improve solderability when soldering an external lead wire or the like to the outer lead 128 at the distal end portion of the external connection terminal part 126, for example, Precious metal Pd plating, Au plating, solder Ni plating, Sn plating, Sn-Pb plating, Sn-Bi plating, Ag plating, Ag-Cu plating, In plating, etc. are performed. In this case, the type of plating is not particularly limited as long as it is a plating metal used for soldering with a noble metal.

Then, in the marking process of step S108, after marking the identifiable part for product operation management, in the mold separating process of step S109, the unnecessary part of the lead frame is cut and removed from the thermal sensor 100, After adjusting the shape of the outer lead 128, the thermal sensor 100, which is a finished product, is obtained.
JP-A-11-153561 JP 2006-29956 A JP 2005-337969 A

  However, in such a conventional thermal sensor, when a thin film chip is mounted on the die pad portion of the lead frame in the die bonding process, the die pad portion may be deformed by the pressure at the time of mounting depending on the shape of the die pad portion. there were.

Further, in the wire bonding process, the die pad part may be deformed by the bonding pressure.
Further, in the molding process, there is a case where the lead frame and the mold resin are displaced due to thermal shrinkage of the mold resin, and the positioning is not surely performed. As described above, when a deviation occurs between the lead frame and the mold resin, the quality of the sensor is deteriorated, and accurate fluid identification cannot be performed.

  In view of such a current situation, the present invention provides an electronic device in which a die pad portion is not deformed by a pressure when a thin film chip is mounted on a die pad of a lead frame or a bonding pressure of a wire in a die bonding process or a wire bonding process. It is an object of the present invention to provide a component mounting portion, a lead frame, an electronic device including the lead frame, and a manufacturing method thereof.

  It is another object of the present invention to provide an electronic component mounting portion and a lead frame that do not cause a deviation between the lead frame and the mold resin in the molding process, an electronic device including the lead frame, and a method for manufacturing the same. .

The present invention was invented in order to achieve the problems and objects in the prior art as described above,
The electronic component mounting part of the present invention is
An electronic component mounting unit for mounting an electronic component,
The electronic component mounting portion has a support projecting portion for supporting the electronic component mounting portion.

The lead frame of the present invention is
A lead frame including an outer lead portion, an inner lead portion, and an electronic component mounting portion for mounting an electronic component,
The electronic component mounting portion has a support projecting portion for supporting the electronic component mounting portion.

In addition, the manufacturing method of the electronic component mounting portion of the present invention,
An electronic component mounting part manufacturing method for mounting an electronic component,
A support projecting portion for supporting the electronic component mounting portion is formed on the electronic component mounting portion.

In addition, the manufacturing method of the lead frame of the present invention includes:
A method of manufacturing a lead frame comprising an outer lead portion, an inner lead portion, and an electronic component mounting portion for mounting an electronic component,
The electronic component mounting portion includes a step of forming a support projecting portion for supporting the electronic component mounting portion.

  By providing the support protrusions in this way, the die pad part can be supported by holding the support protrusions in the die bonding process, so that the thin film chip is securely mounted at a desired position on the die pad part. (Bonding).

  Furthermore, in the wire bonding process, the die pad portion is supported by holding the support projecting portion, so that the thin film chip electrode and the inner lead tip are surely formed without causing a gap between the lead frame and the mold resin. It can connect with the electrode part of a part with a bonding wire.

  In the molding process, the support projecting portion serves as an anchor when the mold resin is injection-molded, and the deviation between the lead frame and the mold resin due to heat shrinkage can be suppressed.

The present invention also provides:
The support projecting portion is for fixing the position of the electronic component mounting portion.
If the support projecting portion is provided in this way, the die pad portion can be supported and fixed in position during the die bonding step and the wire bonding step. Therefore, the thin film chip can be mounted at a desired position, and the bonding wire can be reliably connected to the desired position.

The present invention also provides:
The length of the support projecting portion is in the range of 0.5 mm to 10 mm.
Thus, if the length of a support protrusion part is set, a die pad can be reliably fixed in the case of a die-bonding process and a wire bonding process.

The present invention also provides:
The support protrusion is provided with a hole.
If holes are provided in the support projecting portions in this way, the resin will flow into the holes in the support projecting portions during the molding process, so the resin in the holes will serve as anchors after the resin is cured. Further, the deviation between the lead frame and the mold resin due to heat shrinkage can be further suppressed.

The present invention also provides:
The lead frame includes an electronic component mounting portion for mounting an electronic component.

With this configuration, an electronic component such as a thin film chip or IC can be mounted on the electronic component mounting portion, and can be used as a sensor, a semiconductor device, or the like.
The present invention also provides:
The inner lead portion and the electronic component mounted on the electronic component mounting portion are electrically connected.

  With this configuration, an electronic component such as a thin film chip or IC is mounted on the electronic component mounting portion, and the inner lead portion and the electronic component mounted on the electronic component mounting portion are electrically connected by wire bonding or the like. Can be used as a sensor, a semiconductor device, or the like.

The present invention also provides:
The inner lead portion and the electronic component mounted on the electronic component mounting portion are hermetically sealed or resin sealed.

  By configuring in this way, the inner lead portion and the electronic component mounted on the electronic component mounting portion are covered with, for example, ceramic or metal, and the inside is hermetically sealed with an inert gas, or resin is formed by resin molding. Since it is sealed (resin molded), the fluid to be detected does not enter and electronic components such as thin film chips do not function, and inner leads, bonding wires, etc. corrode and the quality of the sensor does not deteriorate. Therefore, accurate fluid identification can be performed.

The electronic device of the present invention is
A lead frame according to any one of the above is provided.
The electronic device of the present invention is
It is a sensor for performing fluid identification.

The electronic device of the present invention is
The fluid identification is at least one of fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid leakage identification, and fluid level identification.

  By configuring in this way, fluid physics can be applied to hydrocarbon liquids such as gasoline, naphtha, kerosene, light oil, and heavy oil, alcohol liquids such as ethanol and methanol, urea aqueous solution liquids, gases, and particulates. For example, fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid level identification, and the like can be performed on the identification target fluid by utilizing the physical property, for example, the thermal property of the fluid.

  According to the present invention, in the die bonding step and the wire bonding step, the electronic component mounting portion and the lead in which the die pad portion is not deformed by the pressure when the thin film chip is mounted on the die pad of the lead frame or the bonding pressure of the wire. An electronic device including a frame and a lead frame, and a manufacturing method thereof can be provided.

Further, it is possible to provide an electronic component mounting portion and a lead frame that do not cause a deviation between the lead frame and the mold resin in the molding step, an electronic device including the lead frame, and a method for manufacturing the same. For this reason, for example, accurate fluid identification can be performed.
In addition, hydrocarbon fluids such as gasoline, naphtha, kerosene, light oil, and heavy oil, alcohol-based fluids such as ethanol and methanol, urea aqueous solution fluids, gases, and granular fluids are utilized by utilizing the thermal properties of the fluid. For the fluid to be identified, fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid level identification, etc. can be performed.

Hereinafter, embodiments (examples) of the present invention will be described in more detail with reference to the drawings.
1 is a top view of a multi-piece lead frame of the present invention, FIG. 2 is a partially enlarged top view of the lead frame of FIG. 1, and FIG. 3 is a manufacturing process of a thermal sensor using the lead frame of FIG. FIG. 4 is a partially enlarged top view of the lead frame in FIG. 1 for explaining the manufacturing process of the thermal sensor using the lead frame in FIG. 1, and FIG. 5 uses the lead frame in FIG. 6 is a longitudinal sectional view of the thermal sensor of FIG. 5, FIG. 7 is a longitudinal sectional view of the thermal sensor of FIG. 6, taken along line AA, and FIG. 8 is a molding process. FIG. 9 is a schematic diagram for explaining the results of FIG.

1 to 3, reference numeral 1 denotes a lead frame body having a lead frame as a whole.
The lead frame body 1 in FIG. 1 is a so-called multi-cavity type, and shows an embodiment applied to manufacture a thermal sensor.

  That is, the lead frame body 1 includes a plurality of lead frames 2 arranged in parallel, and the lead frame 2 includes an outer frame body 4 having a substantially rectangular flat plate shape, and the outer frame body 4 is disposed in a mold. In total, four positioning holes 3 are formed for positioning.

  In addition, two sets of four outer leads 8 spaced apart from each other by a predetermined distance are extended from the lower frame 6 of the outer frame 4. External connection terminal portions 10 are formed above these outer leads 8, and in the external connection terminal portions 10, horizontal support portions 16 that extend left and right to the left frame body 12 and the right frame body 14 of the outer frame body 4. It is supported. Note that two left central support portions 18 and a right central support portion 20 are extended from the central portion of the lower frame body 6 and are connected to the horizontal support portion 16, respectively.

  Further, an inner lead 22 extending so as to incline toward the center is formed above the external connection terminal portion 10 so as to be spaced apart from each other by a predetermined distance. An inner lead tip 24 is disposed.

  Further, the left suspension lead 26 and the right suspension lead 28 are spaced apart from the inner lead 22 by a predetermined distance from the left frame 12 and the right frame 14 of the outer frame 4 so as to correspond to the shape of the inner lead 22, respectively. It is extended. On the other hand, a left central suspension lead 30 and a right central suspension lead 32 extend from the left central support portion 18 and the right central support portion 20, respectively.

  The left suspension lead 26 and the left central suspension lead 30 extend upward from the inner lead distal end portion 24 of the inner lead 22, and are spaced apart from each other by a predetermined interval so as to face the inner lead distal end portion 24. A substantially rectangular die pad portion 34 constituting the arranged electronic component mounting portion is formed.

  Similarly, the right suspension lead 28 and the right center suspension lead 32 extend upward from the inner lead distal end portion 24 of the inner lead 22, and are spaced apart from each other at a certain interval so as to face the inner lead distal end portion 24. A substantially rectangular die pad portion 34 that constitutes the electronic component mounting portion arranged in the above manner is formed.

  As will be described later, a support projecting portion 36 for supporting the die pad portion 34 is projected from the upper tip portion of these die pad portions 34 in the die bonding process in step S5 and the wire bonding process in step S6. The support projecting portion 36 also has an anchor effect at the time of injection molding of the mold resin and a support effect in the mold in the molding step of Step S7.

  Further, the support projecting portion 36 may be provided with a through-hole 37. In the case where such a hole 37 is provided, in the molding process of step S7, the mold resin is placed in the hole 37. By flowing into and solidifying the resin, the resin in the hole 37 serves as an anchor, and the displacement between the lead frame 2 and the mold resin due to heat shrinkage can be further suppressed.

A method of manufacturing a thermal sensor using the lead frame 2 configured as described above will be described below.
First, as shown in the process schematic diagram of FIG. 3, in the resist printing / exposure process in step S1, a resist is printed so as to have a predetermined pattern, exposed, and then blacked out in FIG. The inner lead tip 24, the outer lead 8, and the external connection terminal portion 10 of the inner lead 22 shown are exposed.

  Next, in the Ni plating (partial) step of step S2, Ni plating as base plating is applied to the inner lead tip 24, the outer lead 8, and the external connection terminal 10 of the inner lead 22 which are exposed portions. Then, in the peeling process in step S3, the resist is removed with an alkaline solution.

  Thereafter, in the Au plating (partial) process of step S4, the inner lead 22 of the inner lead 22, the outer lead 8, and the external connection terminal portion 10 are plated with Au on the upper surface of the Ni plating as the base plating to form a frame. To manufacture.

  Next, in the die bonding step of step S5, as shown in FIG. 4, the thin film chip 40 is mounted (bonded) to the die pad portion 34 via the bonding material 38 such as an adhesive. At this time, the thin film chip 40 is mounted in a state in which the support projecting portion 36 extended to the upper tip portion of the die pad portion 34 of the lead frame 2 is supported, whereby the die pad portion 34 is subjected to the pressure at the time of mounting. It does not deform.

In addition, in order to support the die pad part 34 reliably, it is preferable that the length of the support protrusion part 36 exists in the range of 0.5 mm-10 mm.
In the wire bonding step of step S6, an electrode (not shown) of the thin film chip 40 and the electrode portion 24a of the inner lead tip 24 are electrically connected by a bonding wire 42 made of Au. Even in this case, since the wire bonding is performed in a state where the support projecting portion 36 of the die pad portion 34 is supported, the die pad portion 34 is not deformed by the bonding pressure.

  Then, in this state, the lead frame 2 is placed in the mold, and in the molding process of step S7, for example, an epoxy resin is injected, so that a predetermined portion of the lead frame 2 is shown in FIG. A sensor body 54 constituted by the mold resin 44 is formed.

  Since a support projecting portion 36 is provided at the upper end portion of the die pad portion 34, the support projecting portion 36 serves as an anchor when the mold resin is injection-molded. 2 and mold resin are suppressed.

  Further, since the resin also flows into the hole 37 formed in the support projecting portion 36, the resin in the hole 37 solidifies, so that the resin in the hole 37 serves as an anchor and is caused by heat shrinkage. Deviation between the lead frame 2 and the mold resin is further suppressed.

Thereafter, in the diver cutting process of step S8, the lead frame 2 is separated into a predetermined size.
Then, in the marking process in step S9, marking is performed on an identifiable portion for product operation management, for example, the side surface portion of the flange portion 56, and then in the mold separating process in step S10, unnecessary portions of the lead frame 2 are thermally treated. After cutting and removing from the sensor 50 and adjusting the shape of the outer lead 8, the thermal sensor 50, which is the finished product shown in FIGS. 5 to 7, is obtained.

  As shown in FIGS. 5 to 8, the thermal sensor 50 thus obtained includes a sensor main body 54 formed of a mold resin 44, and the sensor main body 54 has a substantially elliptical flange. A back surface projecting portion 58 projecting from the back surface of the flange portion 56, and a detecting portion 60 projecting from the surface of the flange portion 56.

  The detection unit 60 includes a pair of rectangular plate-shaped fluid identification detection units 62 and a fluid temperature detection unit 64 that are spaced apart from each other by a predetermined distance. The fluid identification detection unit 62 and the fluid temperature detection unit 64 have basically the same structure, and include a heating element and a temperature sensing element. The fluid temperature detection unit 64 includes a heating element. Only the temperature sensor is allowed to act without acting.

  The detection units 62 and 64 include a metal die pad portion 34 that functions as a heat transfer member disposed in the sensor body 54 sealed with the mold resin 44. A thin film chip 40 is mounted on the mounting surface of the die pad portion 34 via a bonding material 38.

  Further, in the sensor main body 54, a plurality of inner leads 22 are disposed so as to be opposed to the die pad portions 34 by being spaced apart from the die pad portions 34 by a certain distance and being spaced apart from each other by a certain distance. Yes. The external connection terminal portion 10 extends from these inner leads 22 in the direction of the rear surface protruding portion 58, and the outer lead 8 is formed at the tip portion of the external connection terminal portion 10.

The electrode 40a of the thin film chip 40 and the electrode portion 24a of the inner lead tip 24 are electrically connected by a bonding wire 42 made of Au.
The thermal sensor 50 configured as described above is configured to perform fluid identification based on a method as disclosed in Patent Document 3.

  9 is an exploded perspective view showing an embodiment in which the thermal sensor 50 according to the present invention is applied to a fluid identification device, FIG. 10 is a partially omitted sectional view of FIG. 9, and FIG. 11 is a fluid identification device according to the present invention. It is a figure which shows the attachment state to the tank.

  As shown in FIGS. 9 to 11, a tank opening 68 is provided in the upper part of the tank 66, and a fluid identification device 70 according to the present invention is attached to the tank opening 68.

  The tank 66 is provided with an inlet pipe 72 through which fluid is injected and an outlet pipe 74 through which fluid is taken out. The outlet pipe 74 is connected to the tank 66 at a height position close to the bottom of the tank 66, and is connected to a fluid use device (not shown) via the pump 76.

  The fluid identification device 70 includes a fluid identification sensor unit 78 and a support unit 80. A fluid identification sensor part 78 is attached to one end (lower end) of the support part 80, and an attachment for attaching to the tank opening 68 at the other end (upper part) of the support part 80. A portion 82 is provided.

The fluid identification sensor unit 78 includes a fluid identification detection unit 62 including a heating element and a temperature sensing body, and a fluid temperature detection unit 64 that measures the temperature of the fluid.
In the fluid identification device 70 configured as described above, the heating element is heated by energization based on the method disclosed in Patent Document 3, and the temperature sensing body is heated by this heating, and the heating element is changed to the temperature sensing body. The fluid to be identified is thermally affected by the fluid to be identified, and the fluid identification as described above is performed for the fluid to be identified based on the electrical output corresponding to the electrical resistance of the temperature sensing element. Has been.

Hereinafter, liquid type identification will be described as an example of fluid identification. In the present embodiment, the portion surrounded by the alternate long and short dash line in FIG.
In FIG. 12, the switch 86 is described as simply opening and closing, but when the custom IC 84 is built, a plurality of voltage application paths capable of applying different voltages are formed to control the heater. Any one of the voltage application paths may be selected.

  In this way, the selection range in the characteristics of the heating element 62a4 of the fluid identification detection unit 62 is greatly expanded. In other words, it is possible to apply an optimum voltage for identification according to the characteristics of the heating element 62a4. In addition, since a plurality of voltages different from each other can be applied during heater control, the types of fluids to be identified can be expanded.

  In FIG. 12, the resistors 88 and 90 are described as having a constant resistance value. However, when the resistors 88 and 90 are built in the custom IC 84, each of the resistors 88 and 90 is formed to have a variable resistance value. In addition, the resistance values of the resistors 88 and 90 may be appropriately changed for identification.

  Similarly, the characteristics of the differential amplifier 92 and the liquid temperature detection amplifier 94 may be adjusted when being built in the custom IC 84, and the amplifier characteristics may be changed as appropriate for identification.

  In this way, it is easy to set the characteristics of the liquid type detection circuit to an optimum one, and individual variations in manufacturing of the fluid identification detection unit 62 and the fluid temperature detection unit 64 and individual manufactures of the custom IC 84 are achieved. Variations in identification characteristics that occur based on variations can be reduced, and manufacturing yield is improved.

Hereinafter, the liquid type identification operation in the present embodiment will be described.
When the urea aqueous solution US is accommodated as the liquid to be identified in the tank 66, the urea aqueous solution US is also filled in the liquid to be measured introduction path 96 formed by the cover member 98 that covers the fluid identification sensor unit 78. The urea aqueous solution US in the tank 66 including the liquid to be measured introduction path 96 does not substantially flow.

  A single pulse voltage having a predetermined height (for example, 10V) with respect to the heating element 62a4 by closing the switch 86 for a predetermined time (for example, 8 seconds) by a heater control signal output from the microcomputer 91 to the switch 86. P is applied to cause the heating element to generate heat. At this time, the output voltage (sensor output) Q of the differential amplifier 92 gradually increases during the voltage application to the heating element 62a4 and gradually decreases after the voltage application to the heating element 62a4 is completed, as shown in FIG. To do.

  In the microcomputer 91, as shown in FIG. 13, the sensor output is sampled a predetermined number of times (for example, 256 times) for a predetermined time (for example, 0.1 second) before the voltage application to the heating element 62a4 is started. An operation for obtaining an average value is performed to obtain an average initial voltage value V1. This average initial voltage value V1 corresponds to the initial temperature of the temperature sensing element 62a2.

  Also, a first time which is a relatively short time from the start of voltage application to the heating element (for example, ½ or less of a single pulse application time and 0.5 to 3 seconds; 2 seconds in FIG. 13) The sensor output is sampled a predetermined number of times (for example, 256 times) at the elapse of time (specifically, immediately before the elapse of the first time), and the average value is calculated to obtain the average first voltage value V2.

  This average first voltage value V2 corresponds to the first temperature when the first time elapses from the start of the single pulse application of the temperature sensing element 62a2. Then, a difference V01 (= V2−V1) between the average initial voltage value V1 and the average first voltage value V2 is obtained as the liquid type corresponding first voltage value.

  Further, when a second time (for example, a single pulse application time; 8 seconds in FIG. 13) has elapsed (specifically, the second time has elapsed since the start of voltage application to the heating element). The sensor output is sampled a predetermined number of times (for example, 256 times) immediately before), and an operation for obtaining the average value is performed to obtain the average second voltage value V3.

  This average second voltage value V3 corresponds to the second temperature when the second time has elapsed from the start of the single pulse application of the temperature sensing element 62a2. Then, a difference V02 (= V3−V1) between the average initial voltage value V1 and the average second voltage value V3 is obtained as the liquid type-corresponding second voltage value.

  A part of the heat generated in the heating element 62a4 based on the single pulse voltage application as described above is transmitted to the temperature sensing element 62a2 through the liquid to be measured. There are mainly two forms of this heat transfer that differ depending on the time from the start of pulse application. That is, in the first stage within a relatively short time (for example, 3 seconds, particularly 2 seconds) from the start of pulse application, the heat transfer is mainly dominated by conduction (for this reason, the first voltage value V01 corresponding to the liquid type is mainly liquid. Affected by the thermal conductivity of

  On the other hand, in the second stage after the first stage, heat transfer is mainly dominated by natural convection (for this reason, the liquid type-corresponding second voltage value V02 is mainly influenced by the kinematic viscosity of the liquid). This is because in the second stage, natural convection occurs due to the liquid to be measured heated in the first stage, and the ratio of heat transfer due to this increases.

  As described above, the optimum concentration (weight percent: the same applies hereinafter) of the aqueous urea solution US used in the exhaust gas purification system is 32.5%. Therefore, the allowable range of the urea concentration of the urea aqueous solution US to be accommodated in the tank 66 can be set to 32.5% ± 5%, for example. The width ± 5% of the allowable range can be appropriately changed as desired. That is, in this embodiment, the urea aqueous solution US having a urea concentration in the range of 32.5% ± 5% is defined as the predetermined liquid.

  The liquid type corresponding first voltage value V01 and the liquid type corresponding second voltage value V02 change as the urea concentration of the urea aqueous solution US changes. Therefore, the range (predetermined range) of the liquid type-corresponding first voltage value V01 and the range of the liquid type-corresponding second voltage value V02 (predetermined range) corresponding to the urea aqueous solution US within the range of the urea concentration of 32.5% ± 5%. Exists.

  By the way, even if it is liquid other than urea aqueous solution US, the output in the predetermined range of said liquid type corresponding | compatible 1st voltage value V01 and the predetermined range of liquid type corresponding | compatible 2nd voltage value V02 is obtained depending on the density | concentration. There is a case. That is, even if the liquid type corresponding first voltage value V01 or the liquid type corresponding second voltage value V02 is within the predetermined range, the liquid is not necessarily the predetermined urea aqueous solution US.

  For example, as shown in FIG. 14, the urea concentration is within the range of the first voltage value V01 corresponding to the liquid type obtained with the urea aqueous solution US having the urea concentration within a predetermined range of 32.5% ± 5% (that is, the sensor display concentration value). In the range of 32.5% ± 5%), there is a first voltage value corresponding to the liquid type of the sugar aqueous solution having a sugar concentration in the range of about 25% ± 3%.

  However, the value of the liquid type corresponding second voltage value V02 obtained from the sugar aqueous solution within the sugar concentration range is the range of the liquid type corresponding second voltage value V02 obtained with the urea aqueous solution US within the predetermined urea concentration range. It will be far away.

  That is, as shown in FIG. 15, in the sugar aqueous solution within the sugar concentration range of 15% to 35% including the sugar concentration range of about 25% ± 3%, the liquid type corresponding first voltage value V01 is predetermined. However, the liquid type-corresponding second voltage value V02 is significantly different from the urea aqueous solution US within the predetermined urea concentration range.

  In FIG. 15, both the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 are shown as relative values with 1.000 being a urea aqueous solution having a urea concentration of 30%. As described above, by determining that both the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 are within the respective predetermined ranges, it is determined whether or not the liquid is a predetermined liquid. It can be reliably identified that the aqueous sugar solution is not a predetermined liquid.

  In addition, the liquid type corresponding second voltage value V02 may overlap with that of the predetermined liquid. However, in this case, since the liquid type-corresponding first voltage value V01 is different from that of the predetermined liquid, it is possible to reliably identify that the liquid is not the predetermined one based on the determination criterion.

In the present invention, the liquid type is identified by utilizing the fact that the relationship between the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 varies depending on the type of solution as described above.
That is, the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 are affected by thermal conductivity and kinematic viscosity, which are different physical properties of the liquid, and these relations depend on the type of solution. Since they are different, the above liquid type identification becomes possible. By narrowing the predetermined range of the urea concentration, the identification accuracy can be further increased.

  In the embodiment of the present invention, the first calibration curve indicating the relationship between the temperature and the liquid type corresponding first voltage value V01 and the temperature and liquid type corresponding second for several urea aqueous solutions (reference urea aqueous solutions) with known urea concentrations. A second calibration curve showing the relationship with the voltage value V02 is obtained in advance, and these calibration curves are stored in the storage means of the microcomputer 91.

Examples of the first and second calibration curves are shown in FIGS. 16 and 17, respectively.
In these examples, calibration curves are created for reference urea aqueous solutions having urea concentrations c1 (for example, 27.5%) and c2 (for example, 37.5%).

  As shown in FIGS. 16 and 17, since the liquid type corresponding first voltage value V01 and the liquid type corresponding second voltage value V02 depend on the temperature, the liquid to be measured is identified using these calibration curves. At this time, the liquid temperature corresponding output value T input from the temperature sensing body 64a2 of the fluid temperature detecting unit 64 via the liquid temperature detecting amplifier 94 is used. An example of the liquid temperature corresponding output value T is shown in FIG. Such a calibration curve is also stored in the storage means of the microcomputer 91.

  When measuring the liquid type-corresponding first voltage value V01, first, a temperature value is obtained from the liquid temperature-corresponding output value T obtained for the liquid to be measured, using the calibration curve of FIG. The obtained temperature value is defined as t. Next, in the first calibration curve of FIG. 16, the liquid type corresponding first voltage values V01 (c1; t) and V01 (c2; c) of each calibration curve corresponding to the temperature value t. t).

Then, cx of the liquid type corresponding first voltage value V01 (cx; t) obtained for the liquid to be measured to be measured is used as the liquid type corresponding first voltage value V01 (c1; t), V01 (c2; c) of each calibration curve. Determine by performing a proportional operation using t). That is, cx is based on V01 (cx; t), V01 (c1; t), V01 (c2; t), and the following formula (1)
cx = c1 +
(C2-c1) [V01 (cx; t) -V01 (c1; t)]
/ [V01 (c2; t) -V01 (c1; t)] (1)
Ask from.

  Similarly, when measuring the liquid type corresponding second voltage value V02, in the second calibration curve of FIG. 17, the liquid type of each calibration curve corresponding to the temperature value t obtained for the liquid to be measured as described above. Corresponding second voltage values V02 (c1; t), V02 (c2; t) are obtained. Then, the cy of the liquid type corresponding second voltage value V02 (cy; t) obtained for the liquid to be measured is set as the liquid type corresponding second voltage value V02 (c1; t), V02 (c2; t) of each calibration curve. Determine by performing the proportional calculation used.

That is, cy is based on V01 (cy; t), V01 (c1; t), V01 (c2; t), and the following formula (2)
cy = c1 +
(C2-c1) [V02 (cy; t) -V02 (c1; t)]
/ [V02 (c2; t) -V02 (c1; t)] (2)
Ask from.

  In addition, by adopting the first and second calibration curves in FIGS. 16 and 17 using the liquid temperature corresponding output value T instead of the temperature, storage of the calibration curve in FIG. 18 and conversion using this Can be omitted.

  As described above, for each of the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02, a predetermined range that varies depending on the temperature can be set. By setting c1 to 27.5% and c2 to 37.5% as described above, the region surrounded by the two calibration curves in each of FIGS. 16 and 17 becomes a predetermined liquid (that is, urea concentration 32). .5% ± 5% urea aqueous solution).

  FIG. 19 is a graph schematically showing that a predetermined liquid identification criterion based on the combination of the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 changes according to the temperature. As the temperature rises to t1, t2, and t3, the areas AR (t1), AR (t2), and AR (t3) that are determined as the predetermined liquid move.

FIG. 20 is a flowchart showing a liquid type identification process in the microcomputer 91.
First, before applying the pulse voltage to the heating element 62a4 by heater control, N = 1 is stored in the microcomputer (S1), and then the sensor output is sampled to obtain the average initial voltage value V1 (S2).

Next, the heater control is executed, and the sensor output is sampled when the first time has elapsed from the start of voltage application to the heating element 62a4 to obtain the average first voltage value V2 (S3).
Furthermore, the calculation of V2-V1 is performed to obtain a liquid type corresponding first voltage value V01 (S4).

  Next, the sensor output is sampled when the second time has elapsed from the start of voltage application to the heating element 62a4 to obtain an average second voltage value V3 (S5). Next, calculation of V3-V1 is performed to obtain a liquid type corresponding second voltage value V02 (S6).

  Furthermore, referring to the temperature value t obtained for the liquid to be measured, the liquid type-corresponding first voltage value V01 is within a predetermined range at the temperature, and the liquid type-corresponding second voltage value V02 is a predetermined value at the temperature. It is determined whether or not the condition of being within the range is satisfied (S7).

  If it is determined in S7 that at least one of the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 is not within the predetermined range (NO), the stored value N is 3. It is determined whether or not there is (S8).

  If it is determined in S8 that N is not 3 [that is, the current measurement routine is not the third time (specifically, the first or second time)] (NO), then the stored value N is set to 1 only. Increase (S9) and return to S2.

On the other hand, if it is determined in S8 that N is 3 [that is, the current measurement routine is the third time] (YES), it is determined that the fluid to be measured is not a predetermined one (S10).
If it is determined in S7 that both the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 are within the respective predetermined ranges (YES), the fluid to be measured is the predetermined one. It is determined that there is (S11).

  In this embodiment, following S11, the urea concentration of the urea aqueous solution is calculated (S12). This concentration calculation is based on the output of the fluid temperature detector 64, that is, the temperature value t obtained for the liquid to be measured, the liquid type-corresponding first voltage value V01, and the first calibration curve in FIG. ) Can be used.

  The concentration calculation is based on the output of the fluid temperature detection unit 64, that is, the temperature value t obtained for the liquid to be measured, the liquid type-corresponding second voltage value V02, and the second calibration curve in FIG. ) Can also be used.

  As described above, the liquid type can be identified accurately and quickly. This liquid type identification routine can be appropriately executed when the engine of the automobile is started, or periodically, when requested by the driver or automobile (ECU described later), when the automobile key is turned off, etc. Whether the liquid in the urea tank is a urea aqueous solution having a predetermined urea concentration can be monitored in a manner.

  A signal indicating whether or not the liquid type is obtained in this way (whether or not it is a predetermined one, and further, a signal indicating the urea concentration in the case of a predetermined one [urea aqueous solution having a predetermined urea concentration]) is not shown. 12 is output to the output buffer circuit 93 shown in FIG. 12, and from there, through the terminal pins, the power supply circuit board and the waterproof wiring, the combustion of an automobile engine (not shown) as an analog output It is output to a main computer (ECU) that performs control and the like.

  The analog output voltage value corresponding to the liquid temperature is also output to the main computer (ECU) through a similar route. On the other hand, a signal indicating the liquid type can be taken out as a digital output as necessary, and can be input to a device that performs a display, an alarm, and other operations through a similar route.

  Further, based on the liquid temperature corresponding output value T input from the fluid temperature detector 64, a warning is issued when it is detected that the temperature of the urea aqueous solution has dropped to near the temperature (about −13 ° C.). can do.

  Note that the above liquid type identification uses natural convection and uses the principle that the kinematic viscosity of the liquid to be measured such as urea aqueous solution and the sensor output have a correlation. In order to improve the accuracy of such liquid type identification, the fluid identification detection unit 62 and the fluid temperature detection unit 64 and the liquid to be measured around the container main body where heat is transferred between the liquid to be measured are removed as much as possible. From this point, it is preferable to use the cover member 98, particularly the one that forms the measured liquid introduction path in the vertical direction. The cover member 98 also functions as a protective member that prevents foreign matter from contacting.

  In the embodiments described above, a urea aqueous solution having a predetermined urea concentration is used as the predetermined fluid. However, in the present invention, the predetermined liquid may be an aqueous solution or other liquid using a substance other than urea as a solute.

  In the above embodiment, the liquid to be measured is used as the fluid to be identified, but hydrocarbon liquids such as gasoline, naphtha, kerosene, light oil, and heavy oil, alcohol liquids such as ethanol and methanol, urea aqueous solution liquid, gas For fluids such as particles, the physical properties of the fluid, such as the thermal properties of the fluid, are used to identify the fluid type, concentration, fluid presence, fluid temperature, and flow rate. In addition, fluid leakage identification, fluid level identification, ammonia generation amount, and the like can be identified.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to this, and in the above embodiment, as shown in FIG. 6, a sensor body made of a mold resin is formed. However, for example, the inside may be hermetically sealed with an inert gas by covering with ceramic or metal.

  In the above-described embodiment, an embodiment applied to manufacture a thermal sensor is shown. However, in addition to a sensor for performing fluid identification, it can be used for various sensors, electronic devices such as semiconductor devices. Various modifications can be made without departing from the object of the present invention.

FIG. 1 is a top view of a multiple lead frame of the present invention. FIG. 2 is a partially enlarged top view of the lead frame of FIG. FIG. 3 is a process schematic diagram illustrating the manufacturing process of the thermal sensor using the lead frame of FIG. FIG. 4 is a partially enlarged top view of the lead frame of FIG. 1 for explaining a manufacturing process of a thermal sensor using the lead frame of FIG. FIG. 5 is a perspective view of a thermal sensor using the lead frame of FIG. FIG. 6 is a longitudinal sectional view of the thermal sensor of FIG. FIG. 7 is a longitudinal sectional view taken along line AA of the thermal sensor of FIG. FIG. 8 is a schematic diagram illustrating a molding process. FIG. 9 is an exploded perspective view showing an embodiment in which the sensor according to the present invention is applied to a fluid identification device. 10 is a partially omitted cross-sectional view of FIG. FIG. 11 is a diagram illustrating a state in which the fluid identification device according to the present invention is attached to the tank. FIG. 12 is a configuration diagram of a circuit for identifying a liquid type. FIG. 13 is a diagram showing the relationship between the single pulse voltage P applied to the heating element and the sensor output Q. FIG. 14 shows that the liquid type corresponding first voltage value of the sugar aqueous solution within a certain sugar concentration range exists within the range of the liquid type corresponding first voltage value V01 obtained with the urea aqueous solution having the urea concentration within the predetermined range. FIG. FIG. 15 is a diagram illustrating the liquid type corresponding first voltage value V01 and the liquid type corresponding second voltage value V02 for the urea aqueous solution, the sugar aqueous solution, and water, with relative values assuming that the urea aqueous solution having a urea concentration of 30% is 1.000. It is. FIG. 16 is a diagram illustrating an example of a first calibration curve. FIG. 17 is a diagram illustrating an example of a second calibration curve. FIG. 18 is a diagram illustrating an example of the liquid temperature corresponding output value T. FIG. 19 is a graph schematically showing that a predetermined liquid identification criterion based on the combination of the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 changes according to the temperature. FIG. 20 is a flowchart showing a liquid type identification process. FIG. 21 is a longitudinal sectional view of a conventional thermal sensor. FIG. 22 is a longitudinal sectional view taken along line AA of a conventional thermal sensor. FIG. 23 is a process schematic diagram for explaining a manufacturing process of a thermal sensor using a conventional lead frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lead frame body 2 ... Lead frame 3 ... Positioning hole 4 ... Outer frame body 6 ... Lower frame body 8 ... Outer lead 10 ... External connection terminal part 12. ..Left side frame 14 ... Right side frame 16 ... Horizontal support 18 ... Left center support 20 ... Right center support 22 ... Inner lead 24 ... Inner lead tip 24a .. Electrode part 26 ... Left hanging lead 28 ... Right hanging lead 30 ... Left center hanging lead 32 ... Right center hanging lead 34 ... Die pad part 36 ... Supporting protrusion 37 ... Hole 38 ... Bonding material 40 ... Thin film chip 40a ... Electrode 42 ... Bonding wire 44 ... Mold resin 50 ... Thermal sensor 54 ... Sensor body 56 ... Flange Part 58 .. Projection part 60 on the back surface 60... Detection part 62... Fluid identification detection part 62 a 2 · temperature sensing element 62 a 4 • heating element 64 ... fluid temperature sensing part 64 a 2 · temperature sensing element 66 ... tank 68. -Tank opening 70 ... Fluid identification device 72 ... Inlet piping 74 ... Outlet piping 76 ... Pump 78 ... Fluid identification sensor unit 80 ... Supporting unit 82 ... Mounting unit 86 ..Switch 88... Resistor 90... Resistor 91... Microcomputer 92... Differential amplifier 93 .. Output buffer circuit 94. Path 98 ... Cover member 100 ... Thermal sensor 101 ... Bonding material 102 ... Mold resin 104 ... Sensor body 106 ... Flange part 108 ... Back projection part 110 ... Detector 112 ... Fluid identification detection unit 114 ... fluid temperature detection unit 116 ... opening 118 ... die pad part 122 ... thin film chip 124 ... inner lead 124a ... electrode 126 ... external connection terminal part 128 ..Outer lead 130 ... bonding wire US ... urea aqueous solution

Claims (26)

An electronic component mounting unit for mounting an electronic component,
The electronic component mounting portion has a support projecting portion for supporting the electronic component mounting portion.   The electronic component mounting portion according to claim 1, wherein the support projecting portion is for fixing a position of the electronic component mounting portion.   3. The electronic component mounting portion according to claim 1, wherein a length of the support projecting portion is in a range of 0.5 mm to 10 mm.   The electronic component mounting part according to claim 1, wherein the support projecting part is provided with a hole. A lead frame including an outer lead portion, an inner lead portion, and an electronic component mounting portion for mounting an electronic component,
The lead frame according to claim 1, wherein the electronic component mounting portion includes a support projecting portion for supporting the electronic component mounting portion.   The lead frame according to claim 5, wherein the support projecting portion is for fixing a position of the electronic component mounting portion.   The lead frame according to claim 5 or 6, wherein a length of the support projecting portion is in a range of 0.5 mm to 10 mm.   The lead frame according to any one of claims 5 to 7, wherein the support projecting portion is provided with a hole.   The lead frame according to any one of claims 5 to 8, wherein the inner lead portion and an electronic component mounted on the electronic component mounting portion are electrically connected.   The lead frame according to claim 9, wherein the inner lead portion, the electronic component mounted on the electronic component mounting portion, and the support projecting portion are hermetically sealed or resin sealed. .   An electronic device comprising the lead frame according to claim 5.   The electronic device according to claim 11, wherein the electronic device is a sensor for performing fluid identification.   13. The fluid identification is at least one of fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid leakage identification, and fluid level identification. The electronic device according to. An electronic component mounting part manufacturing method for mounting an electronic component,
A method of manufacturing an electronic component mounting unit, comprising: forming a support projecting portion for supporting the electronic component mounting unit on the electronic component mounting unit.   The method of manufacturing an electronic component mounting portion according to claim 14, wherein the support projecting portion is for fixing the position of the electronic component mounting portion.   The length of the said support protrusion part exists in the range of 0.5 mm-10 mm, The manufacturing method of the electronic component mounting part in any one of Claim 14 to 15 characterized by the above-mentioned.   The method for manufacturing an electronic component mounting part according to claim 14, wherein a hole is provided in the support projecting part. A method of manufacturing a lead frame comprising an outer lead portion, an inner lead portion, and an electronic component mounting portion for mounting an electronic component,
A method of manufacturing a lead frame, comprising the step of forming a support projecting portion for supporting the electronic component mounting portion on the electronic component mounting portion.   The lead frame manufacturing method according to claim 18, wherein the support projecting portion is for fixing the position of the electronic component mounting portion.   20. The method for manufacturing a lead frame according to claim 18, wherein the length of the support projecting portion is in the range of 0.5 mm to 10 mm.   21. The lead frame manufacturing method according to claim 18, wherein a hole is provided in the support projecting portion.   The method for manufacturing a lead frame according to any one of claims 18 to 21, wherein the inner lead portion and an electronic component mounted on the electronic component mounting portion are electrically connected.   The lead frame according to claim 22, wherein the inner lead portion, the electronic component mounted on the electronic component mounting portion, and the support projecting portion are hermetically sealed or resin sealed. Production method.   24. A method for manufacturing an electronic device, comprising: a lead frame manufactured by the method for manufacturing a lead frame according to claim 18.   The method of manufacturing an electronic device according to claim 24, wherein the electronic device is a sensor for performing fluid identification.   The fluid identification is at least one of fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid leakage identification, and fluid level identification. The manufacturing method of the electronic device of description.

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