JP2009071079A - Electronic component laminate, lead frame having the laminate, electronic device having the lead frame, manufacturing method of electronic component laminate, manufacturing method of lead frame, and manufacturing method of electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an electronic component laminate capable of alleviating stress from a die-bond resin, to provide a manufacturing method of a lead frame capable of stably alleviating stress from the die-bond resin, and to provide a manufacturing method of an electronic device. <P>SOLUTION: In the electronic component laminate comprising an electronic component packaging section and an electronic component, the electronic component packaging section is joined to the electronic component by an adhesive layer, and the thickness of the adhesive layer ranges from 3 to 25 μm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to, for example, a sensor for performing fluid identification, an electronic component laminate used in an electronic device such as a semiconductor device, a lead frame including the laminate, an electronic device including the lead frame, and an electronic component. The present invention relates to a laminate manufacturing method, a lead frame manufacturing method, and an electronic device manufacturing method.

  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, granular materials, etc., use the thermal properties of the fluid. Patent Document 1 discloses a thermal sensor used in a fluid identification device that performs identification such as fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid level identification, etc. (Japanese Patent Laid-Open No. 11-153561), Japanese Patent Laid-Open No. 2006-29956, Japanese Patent Laid-Open No. 2005-337969, etc. have already been proposed.

  As shown in FIGS. 24 to 25, these thermal sensors 100 include a sensor main body 104 formed of 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 106 and a detecting portion 110 protruding from the surface of the flange portion 106 are provided.

  The detection unit 110 includes a pair of fluid identification detection units 112 and a fluid temperature detection unit 114 having two rectangular flat plates 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 includes a heating element. Only the temperature sensor is allowed to act without acting.

  As shown in FIGS. 24 to 25, in these detection units 112 and 114, the heat transfer member arranged in the sensor main body 104 so that a part thereof is exposed to the opening 116 from which the mold resin 102 is missing. A metal die pad portion 118 functioning as A thin film chip 122 is mounted on the mounting surface of the die pad 118 opposite to the opening 116. The thin film chip 122 is bonded to the die pad portion 118 through an adhesive layer made of epoxy or the like.

  Further, in the sensor body 104, the die pads 118 are arranged at regular intervals so as to face the die pads 118, and a plurality of inner leads 124 are arranged at regular intervals. Yes. 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 distal end portion 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.
In the thermal sensor 100 configured as described above, the heating element is heated by energization, the temperature sensing element is heated by this heating, and the heat transfer from the heating element to the temperature sensing element is thermally performed by the identified fluid. It is configured to perform the fluid identification as described above for the fluid to be identified based on the electrical output that affects and corresponds to the electrical resistance of the temperature sensing element.
JP-A-11-153561 JP 2006-29956 A JP 2005-337969 A

By the way, such a conventional thermal sensor 100 is manufactured as follows.
That is, the die pad portion 118, the inner lead 124, the external connection terminal portion 126, and the outer lead 128 are integrally formed using Cu or the like as a lead frame.

Then, for example, Ni plating or Ag plating is applied to the entire surface of the lead frame in which these are integrally formed.
After these plating processes are performed on the entire surface of the lead frame, a thin film chip 122 is attached (bonded) to the die pad portion 118 via an adhesive 101 made of epoxy or the like.

  Here, as the adhesive 101, an epoxy resin filled with an alumina filler is preferably used. The epoxy resin filled with the alumina filler has advantages of high thermal conductivity, excellent insulation, and excellent impact resistance.

Next, 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 or the like.
In this state, the lead frame is placed in the mold and a predetermined resin is injected to form a sensor body 104 in which the mold resin 102 is loaded and integrated in a predetermined portion of the lead frame.

  Thereafter, the lead frame is separated into a predetermined size and then immersed in a solution such as acid or alkali, so that a so-called “burr” that is an excess portion of the mold resin 102 of the sensor body 104 is removed.

  Next, in order to improve the 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 portion 126, for example, Sn plating, Au plating, and Sn-Pb are used together. Crystal alloy plating is applied.

Then, unnecessary portions of the lead frame are cut and removed from the sensor 100, and the shape of the outer lead 128 is adjusted, whereby the sensor 100 as a finished product is obtained.
By the way, in the electronic component mounting part in such a thermal sensor 100, conventionally, after the die pad part 118 is plated, as described above, an adhesive containing an alumina filler made of, for example, an epoxy system is formed on the upper layer as described above. The material 101 was applied, and the thin film chip 122 was bonded through the adhesive material 101.

  However, when such an adhesive material 101 is applied to the surface of the die pad portion 118, the thin film chip 122 always receives stress from the adhesive material 101. Therefore, if there is a difference in the thickness of the applied adhesive material 101, the stress received from the adhesive material 101 varies, and if the stress is too large, the thin film chip 122 peels off. Has occurred, affecting the reliability of the sensor.

In view of such circumstances, the present invention can relieve stress from an adhesive (die bond resin) for joining an electronic component such as a thin film chip to a die pad part, and as a result, a process such as peeling of the thin film chip. It aims at providing the electronic component laminated body which can improve the defect rate in the inside. Another object of the present invention is to provide a lead frame that can relieve stress from an adhesive for joining an electronic component such as a thin film chip to a die pad part, and an electronic device including the lead frame. Yes.

  The present invention also provides a method for manufacturing an electronic component laminate that can relieve stress from an adhesive, a method for manufacturing a lead frame that can relieve stress from an adhesive, and a method for manufacturing an electronic device. The purpose is to provide.

The present invention was invented in order to achieve the problems and objects in the prior art as described above,
Electronic component laminate according to the present invention,
An electronic component laminate comprising an electronic component mounting part and an electronic component,
The electronic component mounting part and the electronic component are joined by an adhesive layer,
The adhesive layer has a thickness in the range of 3 μm to 25 μm.

According to the electronic component laminate having such a configuration, the electronic component can be reliably fixed to the electronic component mounting portion without being peeled off.
Here, it is preferable that the application surface on which the adhesive layer is applied is limited to the upper surface of the die pad portion on which the electronic component is placed.

With such a configuration, it is easy to set the coating thickness of the adhesive layer to a predetermined thickness.
A lead frame according to the present invention is characterized by comprising the electronic component laminate.

With such a lead frame, the electronic component can be reliably fixed to the electronic component mounting portion without peeling off.
Here, the lead frame preferably includes an outer lead portion and an inner lead portion.

The lead frame according to the present invention is
The inner lead portion and the electronic component mounted on the electronic component mounting portion are electrically connected.

In the lead frame according to the present invention, it is preferable that the inner lead portion and the electronic component mounted on the electronic component mounting portion are hermetically sealed or resin-sealed.
Furthermore, the electronic device according to the present invention preferably includes any one of the lead frames described above.

Moreover, the electronic device according to the present invention is preferably applicable to a sensor for performing fluid identification.
Furthermore, in the electronic device according to the present invention, 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. It may be.

According to such an electronic device, for example, hydrocarbon liquid such as gasoline, naphtha, kerosene, light oil, heavy oil, alcohol liquid such as ethanol and methanol, urea aqueous solution,
For fluids such as gas and granular materials, using the thermal properties of the fluid, fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow identification, fluid level identification, etc. Identification can be made.

An electronic component laminate manufacturing method according to the present invention is an electronic component laminate manufacturing method comprising an electronic component mounting portion and an electronic component,
The thickness of the adhesive layer that joins the electronic component mounting part and the electronic component is in the range of 3 μm to 25 μm.

A lead frame manufacturing method according to the present invention is characterized by using an electronic component laminate manufactured by the above-described electronic component laminate manufacturing method.
The lead frame manufacturing method according to the present invention includes an outer lead portion and an inner lead portion.

In addition, the manufacturing method of the lead frame according to the present invention includes:
It is preferable that the inner lead portion and the electronic component mounted on the electronic component mounting portion are electrically connected.

  Furthermore, in the lead frame manufacturing method according to the present invention, it is preferable that the inner lead portion and the electronic component mounted on the electronic component mounting portion are hermetically sealed or resin-sealed.

An electronic device manufacturing method according to the present invention includes a lead frame manufactured by any one of the above-described lead frame manufacturing methods.
Furthermore, the electronic device manufacturing method according to the present invention is preferably applicable to a sensor for performing fluid identification.

In the method for manufacturing an electronic device according to the present invention,
The fluid identification is preferably 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.

According to the electronic component laminate according to the present invention, the lead frame including the laminate, and the electronic device including the lead frame,
Adhesiveness of the adhesive between the electronic component such as a thin film chip and the die pad part is sufficient, and the adhesiveness between the inner lead part and the resin mold is also good. In addition, when used as a sensor, stable performance can be maintained over a long period of time.

  Moreover, according to the method for manufacturing an electronic component laminate according to the present invention, it is possible to manufacture an electronic component laminate that can stably mount an electronic component on an electronic component mounting portion for a long time without peeling. .

In addition, according to the lead frame manufacturing method of the present invention, an electronic component can be stably adhered to a resin mold over a long period of time.
Furthermore, according to the method for manufacturing an electronic device according to the present invention, since the adhesion between the electronic component and the die pad portion is sufficient, when this electronic device is used as a sensor or the like, it exhibits stable performance over a long period of time. Can do.

In addition, by configuring the electronic device in this way, for example, gasoline, naphtha,
For fluids such as kerosene, light oil, heavy oil and other hydrocarbon liquids, ethanol, methanol and other alcoholic liquids, urea aqueous solution liquids, gases, particulates, etc., use the physical properties of the fluid, for example, the thermal properties of the fluid Thus, it is possible to identify the fluid to be identified, such as fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, and fluid level identification.

Hereinafter, embodiments (examples) of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a plan view of a multi-cavity lead frame according to the present invention, FIG. 2 is a partially enlarged plan view of the lead frame of FIG. 1, FIG. 3 is a partially enlarged plan view of the lead frame of FIG. 5 is a perspective view of the thermal sensor using the lead frame of FIG. 5, FIG. 5 is a longitudinal sectional view of the thermal sensor of FIG. 4, FIG. 6 is a longitudinal sectional view of the thermal sensor of FIG. It is the schematic when resin-molding a lead frame.

In FIG. 1, reference numeral 1 indicates a lead frame body having the lead frame of the present invention 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 (six in this embodiment) lead frames 2 arranged in parallel. The lead frame 2 of the lead frame body 1 is provided with an outer frame body 4 having a substantially rectangular flat plate shape. The outer frame body 4 is positioned when placed in a mold, so that positioning holes 3 are formed in a total of four locations. Is formed.

  As shown in FIGS. 2 and 3, 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.

  Furthermore, 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.

A support portion 36 for supporting the die pad portion 34 protrudes from the upper end portion of the die pad portion 34. In addition, this support part 36 has the anchor effect at the time of injection-molding mold resin, and the support effect in a metal mold | die.

  In this embodiment, the inner lead tip 24 of the inner lead 22, the outer lead 8, and the external connection terminal portion 10 are provided with Au, Ag, Pd, Ni, Sn, Cu, Bi, Sn-Bi, Sn-Ag, Sn--. At least one kind of plating metal selected from Ag—Pb is plated.

  In the present embodiment, it is desirable that the lead frame 2 is made of at least one kind of corrosion-resistant metal selected from stainless steel and Fe—Ni alloy. As described above, if the lead frame 2 is made of a corrosion-resistant metal, the lead frame 2 is not corroded by acid or alkali in the plating process, and the mechanical strength of the lead frame is not lowered. Further, with such a corrosion-resistant metal, the die pad portion 34 supported in a so-called cantilever state on the lead frame 2 is not deformed by the resin pressure of the mold resin at the time of injection molding, so the quality as a sensor is high. For example, accurate fluid identification can be performed.

  By configuring in this way, 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, powders, etc. The physical properties of the fluid, for example, the thermal properties of the fluid, are used to identify the fluid to be identified, such as fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid level identification, etc. be able to.

  As shown in FIGS. 4 to 6, the sensor 50 of the present invention includes a sensor main body 54 that is integrated by a mold resin 44, and the sensor main body 54 includes a substantially elliptical flange portion 56, A back surface protruding portion 58 protruding from the back surface of the flange portion 56 and a detecting portion 60 protruding from the surface of the flange portion 56 are provided.

  The detection unit 60 includes a pair of fluid identification detection units 62 and a fluid temperature detection unit 64 each having a rectangular plate shape and spaced apart from each other. The pair of fluid identification detection unit 62 and fluid temperature detection unit 64 have basically the same structure and are provided with a heating element and a temperature sensing element. Only the temperature sensor is allowed to act without acting.

  As shown in FIGS. 4 to 6, in these detection units 62 and 64, a metal die pad portion 34 that functions as a heat transfer member is provided in the sensor main body 54 sealed with the mold resin 44. Yes. A thin film chip 40 is mounted on the mounting surface of the die pad portion 34 via an adhesive 38.

  As the adhesive material 38, for example, a die bond resin made of an epoxy type filled with an alumina filler is preferably used. The epoxy resin filled with the alumina filler has advantages of high thermal conductivity, excellent insulation, and excellent impact resistance.

The thickness of the adhesive (bonding material) 38 applied to the mounting surface of the die pad portion 34 is preferably in the range of 3 μm to 25 μm. More preferably, it is the range of 3 micrometers-10 micrometers.
If the thickness of the adhesive (bonding material) 38 made of the die bond resin is within such a range, the thin film chip 40 can be securely bonded to the die pad portion 34. Moreover, if it adhere | attaches in the range of such thickness, the stress from the adhesive material 38 which acts on the thin film chip 40 can be restrained small, and the thin film chip 40 does not peel.

As described above, according to the present invention, the adhesiveness can be favorably maintained by setting the thickness of the adhesive 38 made of the die bond resin in the above range.
As a result of repeated experiments, it was found that the flow range of the resin does not protrude from the die pad portion 34 in order to keep the adhesive 38 made of the die bond resin at a constant thickness. That is, if the resin flow range is limited to the die pad portion 34, it is easy to set the resin thickness constant.

FIG. 20 shows an experimental result by simulation that confirms that the adhesion of the thin film chip 40 to the die pad portion 34 is good.
FIG. 20 is a result of examining the stress change of the stress applied to the thin film chip 38 by the adhesive 38 depending on the thickness of the adhesive 38 (die bond layer) applied. It was confirmed that when the lower limit value of the adhesive 38 exceeds 10 μm, the sensor film stress σ decreases in all of the X direction, Y direction, Z direction, and τ direction.

  Furthermore, the process defect rate drastically decreased by changing the thickness of the adhesive 38 from 3 μm to 10 μm. For example, when the thickness of the adhesive 38 is 3 ± 2 μm, the in-process defect rate was 6.6%, but when the thickness was 10 ± 5 μm, it was drastically reduced to 0.1%.

  As described above, it has been obtained from simulation results that the mounting thickness of the thin film chip 40 mounted on the lead frame is changed to relieve the stress applied to the thin film surface from the resin sealing performed later. By reducing the stress in this way, the defect rate in the process was improved. From this simulation result, it was found that the die bond thickness was 3 μm to 25 μm, preferably 3 μm to 10 μm.

  FIGS. 21A and 21B show stress measurement positions in the case where the sensor 50 measures what kind of stress acts on each part by simulation. FIG. 21C shows [1] ] To [9] are tabulated stress confirmation points.

  FIG. 22 shows the stress of each part when the thickness of the die bond adhesive (acrylic resin) 38 in the sensor 50 is 10 μm (0.01 mm), the resin (mold resin) 44 is molded at 175 ° C. and cooled to −10 ° C. The value (Mpa) is shown. FIG. 23 shows the stress value (Mpa) of each part when the thickness of the adhesive 38 is 10 μm (0.01 mm), the resin is molded at 175 ° C. and cooled to −30 ° C. in the sensor 50.

Thus, it was confirmed that the stress is remarkably reduced as compared with the conventional product when the thickness of the adhesive 38 is 10 μm as in the present invention, whether it is −10 ° C. or −30 ° C.
In the sensor main body 54 having such a configuration, the inner leads 22 are arranged so as to face the die pad portions 34 and spaced apart from the die pad portion 34 by a certain distance, and are spaced apart from each other by a certain distance. Has been placed. 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 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 disclosed in Japanese Patent Application Laid-Open No. 2005-337969.

  8 is an exploded perspective view showing an embodiment in which the sensor 50 according to the present invention is applied to a fluid identification device, FIG. 9 is a partially omitted sectional view of FIG. 8, and FIG. It is a figure which shows an attachment state.

As shown in FIGS. 8 to 10, an opening 68 is provided in the upper portion of the tank 66, and a fluid identification device 70 according to the present invention is attached to the 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 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 unit 78 is attached to one end (lower end) of the support 80, and an attachment for attaching to the tank opening 68 at the other end (upper end) of the support 80. 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 (Japanese Patent Laid-Open No. 2005-337969), and the temperature sensing element is heated by this heating. The heat transfer from the heating element to the temperature sensing element is thermally affected by the fluid to be identified, and based on the electrical output corresponding to the electrical resistance of the temperature sensing body, the fluid to be identified is as described above. It is configured to perform accurate fluid identification.

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. 11, for the sake of simplicity, the switch 86 is described as merely opening and closing, but when the custom IC 84 is built, a plurality of voltage application paths capable of applying different voltages are formed. Alternatively, any voltage application path may be selected during heater control. By doing so, the range of selection of 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 different voltages can be applied during heater control, the types of identification target liquids can be expanded.

  Further, in FIG. 11, for the sake of simplicity, 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, the resistance values of the resistors 88 and 90 are variable. For example, 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 becomes 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 the manufacturing of the custom IC 84 are facilitated. Variations in identification characteristics that occur based on individual variations can be reduced, and manufacturing yield is improved.

Hereinafter, the liquid type identification operation in the present embodiment will be described.
When the liquid to be measured US is stored in the tank 66, the aqueous solution US to be measured 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 liquid to be measured US in the tank 66 including the liquid to be measured introduction path 96 does not substantially flow.

  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, a single pulse having a predetermined height (for example, 10V) with respect to the heating element 62a4. A voltage 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. 12, 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.

  In addition, as shown in FIG. 12, the first time (for example, ½ or less of the application time of a single pulse, which is a relatively short time from the start of voltage application to the heating element is 0.5 ~ 3 seconds; 2 seconds in FIG. 12 (specifically immediately before the passage of the first time), the sensor output is sampled a predetermined number of times (for example, 256 times), and the average value is calculated. An average first voltage value V2 is obtained. 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.

  Also, as shown in FIG. 12, when a second time (for example, a single pulse application time; 8 seconds in FIG. 12), which is a relatively long time from the start of voltage application to the heating element has elapsed (specifically Specifically, the sensor output is sampled a predetermined number of times (for example, 256 times) just before the second time elapses, 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.

  By the way, a part of the heat generated in the heating element 62a4 based on the voltage application of the single pulse 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 urea aqueous solution used in the exhaust gas purification system is 32.5%. Accordingly, the allowable range of the urea concentration of the urea aqueous solution to be accommodated in the urea aqueous solution 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, a urea aqueous solution having a urea concentration in the range of 32.5% ± 5% is determined 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 changes. Accordingly, the range (predetermined range) of the liquid type-corresponding first voltage value V01 and the range (predetermined range) of the liquid type-corresponding second voltage value V02 corresponding to the urea aqueous solution within the urea concentration range of 32.5% ± 5% are obtained. Exists.

By the way, even if it is liquid other than urea aqueous solution, depending on the density | concentration, 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. There is. 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 a predetermined urea aqueous solution. For example, as shown in FIG. 13, the urea concentration is within the range of the first voltage value V01 corresponding to the liquid type obtained with the urea aqueous solution having a predetermined range of 32.5% ± 5% (that is, the sensor display concentration value). Within the range of 32.5% ± 5% in terms of conversion, there is a first voltage value corresponding to the liquid type of the sugar aqueous solution having a sugar concentration 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 far from the range of the liquid type corresponding second voltage value V02 obtained with the urea aqueous solution within the predetermined urea concentration range. It will be. That is, as shown in FIG. 14, 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 within the predetermined urea concentration range.

  In FIG. 14, 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 different physical properties of the liquid, that is, thermal conductivity and kinematic viscosity, and their relationship differs depending on the type of solution. Thus, liquid type identification as described above becomes possible. By narrowing the predetermined range of the urea concentration, the identification accuracy can be further increased.

  That is, 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 the liquid type correspondence for some urea aqueous solutions (reference urea aqueous solution) having a known urea concentration. A second calibration curve indicating the relationship with the second 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. 15 and 16, 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. 15 and 16, 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. In this case, 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 also 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.

  In 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. Assuming that the obtained temperature value is t, next, in the first calibration curve of FIG. 15, the liquid type corresponding first voltage values V01 (c1; t), 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, the liquid type of each calibration curve corresponding to the temperature value t obtained for the liquid to be measured in the second calibration curve of FIG. 16 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. 15 and 16 using the output value T corresponding to the liquid temperature instead of the temperature, the calibration curve in FIG. 17 is stored and converted 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. 15 and 16 becomes a predetermined liquid (that is, urea concentration). 32.5% ± 5% urea aqueous solution).

  FIG. 18 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. 19 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 the 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).
Next, 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).

Next, 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).
On the other hand, 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. Alternatively, the 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 second voltage value V02, and the second calibration curve in FIG. 2).

  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, periodically, when requested by the driver or the automobile (an ECU described later), or when the automobile key is turned off. In a desired manner, it is possible to monitor whether the liquid in the urea tank is a urea aqueous solution having a predetermined urea concentration.

  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. 11 is output to the output buffer circuit 93 shown in FIG. 11, from which the combustion of the automobile engine (not shown) is output as an analog output via the terminal pin, the power circuit board and the waterproof wiring. 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 liquid to be measured around the container body 20A where heat is transferred between the fluid identification detection unit 62 and the fluid temperature detection unit 64 and the liquid to be measured can be as much as possible. It is preferable to prevent the forced flow based on external factors from occurring. From this point, it is preferable to use the cover member 98, in particular, one that forms the liquid to be measured 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. However, as described later, for example, hydrocarbon liquids such as gasoline, naphtha, kerosene, light oil, and heavy oil, alcohols such as ethanol and methanol For fluids such as system liquids, urea aqueous solution liquids, gases, and granular materials, the physical properties of the fluid, for example, the thermal properties of the fluid, are used to identify the fluid type, the concentration, and the presence of fluid. Identification such as identification, fluid temperature identification, flow rate identification, fluid leakage identification, fluid level identification, and ammonia generation amount can be performed.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this. For example, in the above embodiment, as shown in FIG. 4, the sensor body 54 sealed with the mold resin 44 is formed. For example, the inside of the sensor body 54 is sealed with an inert gas by sealing with ceramic or metal. You may make it do.

  Moreover, although the Example applied in order to manufacture a thermal type sensor is shown in the said Example, it can also be used for electronic devices, such as various sensors and a semiconductor device, besides the sensor for performing a fluid identification. Various modifications can be made without departing from the object of the present invention.

  In the preferred embodiment of the above embodiment, the electronic component mounting portion and the electronic component are bonded by an adhesive made of an epoxy resin containing an alumina filler, but an acrylic resin is used instead of the epoxy resin. Also good.

FIG. 1 is a plan view of a multiple lead frame of the present invention. FIG. 2 is a partially enlarged plan view of the lead frame of FIG. FIG. 3 is a partially enlarged plan view of the lead frame of FIG. 4 is a perspective view of a thermal sensor using the lead frame of FIG. FIG. 5 is a longitudinal sectional view of the thermal sensor of FIG. 6 is a longitudinal sectional view taken along line AA of the thermal sensor of FIG. FIG. 7 is a schematic diagram illustrating the molding process. FIG. 8 is an exploded perspective view showing an embodiment in which the sensor according to the present invention is applied to a fluid identification device. 9 is a partially omitted cross-sectional view of FIG. FIG. 10 is a diagram showing a state in which the fluid identification device according to the present invention is attached to the tank. FIG. 11 is a configuration diagram of a circuit for identifying a liquid type. FIG. 12 is a diagram showing the relationship between the single pulse voltage P applied to the heating element and the sensor output Q. FIG. 13 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. 14 shows a relative value in which 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 are 1.000 for a urea aqueous solution having a urea concentration of 30%. FIG. FIG. 15 is a diagram illustrating an example of a first calibration curve. FIG. 16 is a diagram illustrating an example of the second calibration curve. FIG. 17 is a diagram illustrating an example of the liquid temperature corresponding output value T. In FIG. FIG. 18 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. 19 is a flowchart showing a liquid type identification process. FIG. 20 shows the experimental results of the simulation of the present invention, and shows what kind of stress change is caused by the thickness of the adhesive when the electronic component is mounted on the mounting surface via the adhesive. It is a graph. FIG. 21 is a schematic cross-sectional view and a table showing points of stress measurement by simulation of the present invention. FIG. 22 shows an experimental result by simulation of the present invention, and is a table showing stress values at points 1 to 9 when molded at 175 ° C. and measured at −10 ° C. FIG. 23 shows the experimental results of the simulation of the present invention, and is a table showing stress values at points 1 to 9 when molded at 175 ° C. and measured at −30 ° C. FIG. 24 is a longitudinal sectional view of a conventional thermal sensor. FIG. 25 is a longitudinal sectional view taken along line AA of a conventional thermal sensor.

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 frame body 14 Right frame body 16 Horizontal direction support part 18 Left side center support part 20 Right side center support part 22 Inner lead 24 Inner lead tip 24a Electrode portion 26 Left suspension lead 28 Right suspension lead 30 Left center suspension lead 32 Right center suspension lead 34 Die pad portion 36 Support portion 38 Bonding material 40 Thin film chip 42 Bonding wire 44 Mold resin 50 Thermal type Sensor 54 Sensor body 56 Flange portion 58 Back surface protruding portion 60 Detection portion 62 Fluid identification detection portion 64 Fluid temperature detection portion 66 Tank 68 Tank opening portion 70 Fluid identification device 72 Inlet piping 74 Outlet piping 76 Pump 78 Fluid identification sensor portion 80 Support Part 82 mounting part 100 thermal type Nsa 101 adhesive (Daidondo resin)
102 Mold resin 104 Sensor body 106 Flange portion 108 Back surface protruding portion 110 Detection portion 112 Fluid identification detection portion 114 Fluid temperature detection portion 116 Opening portion 118 Die pad portion 120 Mounting surface 122 Thin film chip 124 Inner lead 124a Electrode 126 External connection terminal portion 128 Outer lead 130 Bonding wire

Claims (17)

An electronic component laminate comprising an electronic component mounting part and an electronic component,
The electronic component mounting part and the electronic component are joined by an adhesive layer,
The thickness of the said adhesive material layer is the range of 3 micrometers-25 micrometers, The electronic component laminated body characterized by the above-mentioned.   2. The electronic component laminate according to claim 1, wherein an application surface to which the adhesive layer is applied is limited to an upper surface of a die pad portion on which the electronic component is placed.   A lead frame comprising the electronic component laminate according to claim 1.   The lead frame according to claim 3, wherein the lead frame includes an outer lead portion and an inner lead portion.   The lead frame according to claim 4, wherein the inner lead portion and the electronic component mounted on the electronic component mounting portion are electrically connected.   The lead frame according to claim 4 or 5, wherein the inner lead portion and the electronic component mounted on the electronic component mounting portion are hermetically sealed or resin-sealed.   An electronic device comprising the lead frame according to claim 3.   The electronic device according to claim 7, wherein the electronic device is a sensor for performing fluid identification.   9. 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 laminate manufacturing method comprising an electronic component mounting portion and an electronic component,
The method of manufacturing an electronic component laminate, wherein a thickness of an adhesive layer that joins the electronic component mounting portion and the electronic component is in a range of 3 μm to 25 μm.   A method for manufacturing a lead frame, comprising using the electronic component laminate manufactured by the method for manufacturing an electronic component laminate according to claim 10.   The lead frame manufacturing method according to claim 11, wherein the lead frame includes an outer lead portion and an inner lead portion.   13. The method for manufacturing a lead frame according to claim 12, wherein the inner lead portion and an electronic component mounted on the electronic component mounting portion are electrically connected.   14. The method of manufacturing a lead frame according to claim 12, wherein the inner lead portion and the electronic component mounted on the electronic component mounting portion are hermetically sealed or resin-sealed. 15. A method for manufacturing an electronic device, wherein the lead frame manufactured by the method for manufacturing a lead frame according to claim 11 is used.   The electronic device according to claim 15, 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 electronic device according to.