JP2002286521A - Method for manufacturing flow measuring instrument - Google Patents
Method for manufacturing flow measuring instrumentInfo
- Publication number
- JP2002286521A JP2002286521A JP2001087809A JP2001087809A JP2002286521A JP 2002286521 A JP2002286521 A JP 2002286521A JP 2001087809 A JP2001087809 A JP 2001087809A JP 2001087809 A JP2001087809 A JP 2001087809A JP 2002286521 A JP2002286521 A JP 2002286521A
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- resistor
- film
- heat treatment
- diaphragm
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、流量測定装置の製
造方法に関する。The present invention relates to a method for manufacturing a flow measuring device.
【０００２】[0002]
【従来の技術】特開平６−１２０５２５号公報には、ヒ
ートワイヤの熱に対する抵抗値の特性の経時的な安定化
を図ることを目的とし、半導体基板上に絶縁膜を介して
金属抵抗層を形成し、次に金属抵抗層をパターンエッチ
ングしてヒートワイヤを形成し、さらにヒートワイヤの
下方部分における半導体基板をエッチングにより除去し
てヒートワイヤブリッジを形成し、その後、センサ動作
時よりも高い温度によって熱処理を施すことを特徴とす
る流量測定装置の製造方法が提案されている。2. Description of the Related Art Japanese Unexamined Patent Publication No. Hei 6-120525 discloses an object of stabilizing the resistance of a heat wire to heat over time by forming a metal resistance layer on a semiconductor substrate via an insulating film. And then heat etching by pattern etching of the metal resistive layer to form a heat wire, further removing the semiconductor substrate by etching the lower portion of the heat wire to form a heat wire bridge, and then at a higher temperature than during sensor operation. There has been proposed a method of manufacturing a flow rate measuring device, wherein a heat treatment is performed by the method.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、上記従
来技術によると、金属抵抗層の両側の電極部は、通常、
金属抵抗層のリード部の上に電極パッドを形成して構成
されるが、上記熱処理を施した際に、金属抵抗層のリー
ド部と電極パッドとの間で相互拡散が起こり、ワイヤボ
ンディングの密着強度が弱くなるという問題があった。However, according to the above prior art, the electrode portions on both sides of the metal resistance layer are usually
An electrode pad is formed on the lead portion of the metal resistive layer. However, when the above heat treatment is performed, mutual diffusion occurs between the lead portion of the metal resistive layer and the electrode pad, and adhesion of wire bonding occurs. There was a problem that the strength was weakened.
【０００４】本発明は、上記従来技術の問題点を解決
し、金属抵抗層に対して熱処理を施しても電極パッドと
金属抵抗層のリード部との間で相互拡散を起さず、ワイ
ヤボンディングの際の密着強度を保持することができる
流量測定装置の製造方法を提供することを目的とする。The present invention solves the above-mentioned problems of the prior art, and does not cause interdiffusion between an electrode pad and a lead portion of a metal resistance layer even when a heat treatment is performed on the metal resistance layer. An object of the present invention is to provide a method for manufacturing a flow measuring device capable of maintaining the adhesion strength at the time of the above.
【０００５】[0005]
【課題を解決するための手段】本発明による流量測定装
置の製造方法は、下記一連の工程〜からなることを
特徴とする。A method of manufacturing a flow measuring device according to the present invention comprises the following series of steps.
【０００６】半導体基板上に下部絶縁膜を形成する 前記下部絶縁膜上に導電膜を形成する 前記導電膜から複数の感温抵抗体と前記感温抵抗体の
各リード部とを形成するためのエッチングを行う 前記感温抵抗体及び前記リード部の上に上部絶縁膜を
形成する 前記上部絶縁膜の電極パッドを形成すべき部位をエッ
チングする 前記各リード部上に前記電極パッドを形成する 前記半導体基板に空洞部を形成して前記感温抵抗体の
一部又は全部を要素とするダイアフラムを形成する 前記電極パッドを除く領域に対し熱処理を行う ここで、前記熱処理を行う領域は前記ダイアフラム上に
ある前記感温抵抗体に対して行う。Forming a lower insulating film on the semiconductor substrate, forming a conductive film on the lower insulating film, forming a plurality of temperature-sensitive resistors and respective leads of the temperature-sensitive resistor from the conductive film; Forming an upper insulating film on the temperature-sensitive resistor and the lead portion, etching a portion of the upper insulating film where an electrode pad is to be formed, forming the electrode pad on each of the lead portions, A cavity is formed in the substrate to form a diaphragm that includes part or all of the temperature-sensitive resistor. A heat treatment is performed on a region excluding the electrode pad. Here, the region where the heat treatment is performed is on the diaphragm. This is performed for a certain temperature-sensitive resistor.
【０００７】また、前記電極パッドを遮温材で覆い前記
ダイアフラムに光線を照射して前記感温抵抗体に対して
前記熱処理を行う。In addition, the electrode pad is covered with a heat insulating material, and the heat treatment is performed on the temperature-sensitive resistor by irradiating the diaphragm with a light beam.
【０００８】あるいは、前記電極パッドを介して前記ダ
イアフラム上にある前記感温抵抗体の一部又は全部に通
電して前記熱処理を行う。Alternatively, the heat treatment is performed by passing a current through a part or the entirety of the temperature-sensitive resistor on the diaphragm through the electrode pad.
【０００９】あるいは、前記ダイアフラム上にある前記
感温抵抗体を加熱する加熱抵抗体を前記ダイアフラム上
に形成し前記加熱抵抗体に通電して前記熱処理を行う。[0009] Alternatively, a heating resistor for heating the temperature-sensitive resistor on the diaphragm is formed on the diaphragm, and the heating resistor is energized to perform the heat treatment.
【００１０】前記熱処理の温度は３００℃以上とする。The temperature of the heat treatment is 300 ° C. or higher.
【００１１】[0011]
【発明の実施の形態】図１は、本発明の第１実施形態に
係る製造方法によって製造される流量測定装置であって
内燃機関の吸気流量を測定するための吸気流量測定装置
の平面図、図２は、図１図示Ａ−Ａ線による断面図、図
３は、図１図示Ｂ部の拡大図、図４は、図２図示Ｃ部の
拡大図をそれぞれ示す。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view of an intake flow rate measuring apparatus for measuring an intake flow rate of an internal combustion engine, which is a flow rate measuring apparatus manufactured by a manufacturing method according to a first embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. 1, FIG. 3 is an enlarged view of a portion B in FIG. 1, and FIG. 4 is an enlarged view of a portion C in FIG.
【００１２】図１〜図４において、吸気流量測定装置１
は半導体基板２（例えばＳｉ基板）を有する。半導体基
板２には、後述する発熱抵抗体５と流量検出用抵抗体６
の下方位置に空洞部２ａが形成されている。半導体基板
２の上面全体に２層（例えばＳi3Ｎ4 膜とＳi Ｏ2 膜）
からなる下部絶縁膜３が形成されている。下部絶縁膜３
の２層は、圧縮応力膜と引張り応力膜との組み合わせか
らなり、これにより下部絶縁膜３に生じる応力の緩和を
図っている。下部絶縁膜３の上面に導電膜４（例えばＰ
ｔ膜、ポリシリコン膜、Ｎi Ｃr 膜、Ｔa Ｎ膜、Ｗ膜又
はＳi Ｃ膜）が形成されている。導電膜４は、抵抗体
５、６、７、８とリード部９、１０、１１、１２、１
３、１４とによって構成されている。抵抗体５〜８は、
例えば発熱抵抗体５、流量検出用抵抗体６、流体温度検
出用抵抗体としての第１吸気温検出用抵抗体７及び同じ
く流体温度検出用抵抗体としての第２吸気温検出用抵抗
体８からなる。また、リード部９〜１４は、例えば発熱
抵抗体５のリード部９、流量検出用抵抗体６のリード部
１０、第１吸気温検出用抵抗体７のリード部１１、第２
吸気温検出用抵抗体８のリード部１２、発熱抵抗体５と
第１吸気温検出用抵抗体７との共通リード部１３及び流
量検出用抵抗体６と第２吸気温検出用抵抗体８との共通
リード部１４からなる。導電膜４の上面には、各リード
部９〜１４の端部を除いて下部絶縁膜３と同様な２層構
造の上部絶縁膜１５が形成されており、各リード部９〜
１４の端部の上面に、図示しない接続配線と接合可能な
電極パッド１６、１７、１８、１９、２０、２１（例え
ばＡl からなる電極パッド）が形成されている。抵抗体
５〜８及びリード部９〜１４は、半導体基板２の中央部
に配置してあり、また、下部絶縁膜３と上部絶縁膜１５
は、抵抗体５〜８及びリード部９〜１４を中心として上
下方向に対称に配置してある。このため、温度変化に対
して反り変動が発生しにくくなり熱ストレスに対して強
い構造になるとともに、半導体基板２にダイアフラム２
２（空洞部２ａの真上部分）の構造体を形成可能にな
る。なお、下部絶縁膜３及び上部絶縁膜１５は、絶縁性
を有しかつ導電膜４の保護膜として機能できるものであ
ればよいため、上記構成以外に、Ｔi Ｏ2膜、Ａl2Ｏ3
膜、Ｔa2Ｏ5 膜、Ｍg Ｏ膜などの単一膜又は多層膜であ
ってもよい。In FIG. 1 to FIG.
Has a semiconductor substrate 2 (for example, a Si substrate). The semiconductor substrate 2 includes a heating resistor 5 and a flow rate detecting resistor 6 described later.
A cavity 2a is formed at a position below the space. Two layers (for example, a Si 3 N 4 film and a SiO 2 film) on the entire upper surface of the semiconductor substrate 2
A lower insulating film 3 is formed. Lower insulating film 3
These two layers are composed of a combination of a compressive stress film and a tensile stress film, thereby relaxing the stress generated in the lower insulating film 3. On the upper surface of the lower insulating film 3, a conductive film 4 (for example, P
t film, polysilicon film, NiCr film, TaN film, W film or SiC film). The conductive film 4 includes the resistors 5, 6, 7, 8 and the leads 9, 10, 11, 12, 1.
3 and 14. The resistors 5 to 8
For example, the heating resistor 5, the flow rate detection resistor 6, the first intake temperature detection resistor 7 as a fluid temperature detection resistor, and the second intake temperature detection resistor 8 also as a fluid temperature detection resistor Become. The leads 9 to 14 include, for example, the lead 9 of the heating resistor 5, the lead 10 of the flow detection resistor 6, the lead 11 of the first intake air temperature detection resistor 7, and the second
The lead portion 12 of the intake air temperature detecting resistor 8, the common lead portion 13 of the heating resistor 5 and the first intake air temperature detecting resistor 7, the flow rate detecting resistor 6, the second intake air temperature detecting resistor 8, Of the common lead portion 14. An upper insulating film 15 having the same two-layer structure as the lower insulating film 3 is formed on the upper surface of the conductive film 4 except for the ends of the leads 9 to 14.
Electrode pads 16, 17, 18, 19, 20, 21 (for example, electrode pads made of Al) are formed on the upper surface of the end portion of the substrate 14, which can be connected to a connection wiring (not shown). The resistors 5 to 8 and the leads 9 to 14 are arranged at the center of the semiconductor substrate 2, and the lower insulating film 3 and the upper insulating film 15
Are arranged symmetrically in the vertical direction about the resistors 5 to 8 and the leads 9 to 14. For this reason, the warp fluctuation hardly occurs due to the temperature change, and the structure becomes strong against the thermal stress.
2 (directly above the cavity 2a). The lower insulating layer 3 and the upper insulating film 15, because as long as it can function as a protective film of a and the conductive film 4 of insulating, in addition to the above configuration, Ti O 2 film, Al 2 O 3
It may be a single film or a multilayer film such as a film, a Ta 2 O 5 film, and a MgO film.
【００１３】発熱抵抗体５、流量検出用抵抗体６、第１
吸気温検出用抵抗体７及び第２吸気温検出用抵抗体８
は、吸気の流れの順方向に対して、上流側から、第１吸
気温検出用抵抗体７、第２吸気温検出用抵抗体８、流量
検出用抵抗体６及び発熱抵抗体５の順に配置されてい
る。発熱抵抗体５は、後述するブリッジ回路５２によ
り、第１吸気温検出用抵抗体７が検出する吸気温度より
も常に一定温度だけ高い基準温度に設定される。第１、
第２吸気温検出用抵抗体７、８は、吸気温度の検出にあ
たって発熱抵抗体５の発熱による抵抗値変化が生じない
よう発熱抵抗体５から比較的離れた位置に形成されてい
る。また、流量検出用抵抗体６は、発熱抵抗体５の発熱
によって作り出される温度環境下に置いて吸気流量及び
吸気流れ方向を検出可能なように吸気流れ順方向におい
て発熱抵抗体５の上流側近傍に形成されている。流量検
出用抵抗体６は、吸気流れ方向が順方向の場合は、その
検出温度が発熱抵抗体５の基準温度よりも低くなる。こ
れは、発熱抵抗体５の吸気流れ方向の長さが比較的長い
ため、発熱抵抗体５の吸気流れ上流部は吸気流れによっ
て冷却され基準温度よりも低い温度となり、また、流量
検出用抵抗体６の検出温度は、発熱抵抗体５の吸気流れ
上流部の温度と略等しいためである。一方、吸気流れ方
向が逆方向の場合は、発熱抵抗体５の吸気流れ下流部の
温度が基準温度よりも高くなるため、流量検出用抵抗体
６の検出温度は発熱抵抗体５の基準温度よりも高くな
る。したがって、検出温度を基準温度又は吸気温度と比
較することによって吸気流れ方向を検出することができ
る。また、吸気流れ方向に関わらず吸気流量が大きい程
検出温度と基準温度又は吸気温度との温度差が大きくな
ることから、検出温度によって吸気流量を検出すること
ができる。Heating resistor 5, flow rate detecting resistor 6, first resistor
Intake temperature detection resistor 7 and second intake temperature detection resistor 8
Is arranged in the order of the first intake temperature detecting resistor 7, the second intake temperature detecting resistor 8, the flow rate detecting resistor 6, and the heating resistor 5 from the upstream side in the forward direction of the intake flow. Have been. The heating resistor 5 is set to a reference temperature that is always higher by a certain temperature than the intake air temperature detected by the first intake air temperature detecting resistor 7 by a bridge circuit 52 described later. First,
The second intake air temperature detecting resistors 7 and 8 are formed at positions relatively distant from the heat generating resistor 5 so that a change in resistance value due to heat generation of the heat generating resistor 5 does not occur when detecting the intake air temperature. Further, the flow rate detecting resistor 6 is located near the upstream side of the heating resistor 5 in the forward direction of the intake flow so that the intake flow rate and the direction of the intake flow can be detected under a temperature environment created by the heat generated by the heating resistor 5. Is formed. When the flow direction of the intake air flows in the forward direction, the detected temperature of the flow rate detection resistor 6 becomes lower than the reference temperature of the heating resistor 5. Since the length of the heating resistor 5 in the intake flow direction is relatively long, the upstream portion of the heating resistor 5 in the intake flow is cooled by the intake flow to a temperature lower than the reference temperature. This is because the detected temperature 6 is substantially equal to the temperature of the heating resistor 5 upstream of the intake air flow. On the other hand, when the direction of the intake air flow is opposite, the temperature of the downstream side of the intake flow of the heating resistor 5 becomes higher than the reference temperature, so that the detection temperature of the flow rate detection resistor 6 is higher than the reference temperature of the heating resistor 5. Will also be higher. Therefore, the intake air flow direction can be detected by comparing the detected temperature with the reference temperature or the intake air temperature. Also, regardless of the direction of intake air flow, the larger the intake air flow rate, the greater the temperature difference between the detected temperature and the reference temperature or intake air temperature, so that the intake air flow rate can be detected based on the detected temperature.
【００１４】図５は、吸気流量測定装置１の等価回路図
を示す。FIG. 5 shows an equivalent circuit diagram of the intake air flow measuring device 1.
【００１５】図５において、バッテリ端子＋Ｂとグラン
ドＧＮＤとの間に、トランジスタ５１とブリッジ回路５
２が直列に接続されている。ブリッジ回路５２は、発熱
抵抗体５、第１吸気温検出用抵抗体７及び抵抗５３、５
４、５５によって構成され、ブリッジ回路５２の検出端
５２ａ、５２ｂは、トランジスタ５１のスイッチング動
作を制御する比較器５６に接続されている。一定の吸気
温度下においては、発熱抵抗体５が基準温度より低くな
ると、その抵抗値の減少により検出端５２ａ、５２ｂ間
に電位差が生じ比較器５６の出力によりトランジスタ５
１が導通し、発熱抵抗体５に電流が流れて発熱抵抗体５
の温度が上昇する。そして、発熱抵抗体５の温度が基準
温度に達すると、その抵抗値の上昇、比較器５６の出力
によりトランジスタ５１は遮断し、発熱抵抗体５への通
電が停止し発熱抵抗体５の温度が低下する。このような
動作の繰り返しにより、発熱抵抗体５は発熱、冷却を繰
り返し発熱抵抗体５は吸気温度よりも一定温度高い基準
温度に保たれる。In FIG. 5, a transistor 51 and a bridge circuit 5 are connected between a battery terminal + B and a ground GND.
2 are connected in series. The bridge circuit 52 includes a heating resistor 5, a first intake air temperature detection resistor 7, and resistors 53 and 5.
The detection terminals 52 a and 52 b of the bridge circuit 52 are connected to a comparator 56 that controls the switching operation of the transistor 51. At a constant intake air temperature, when the temperature of the heating resistor 5 becomes lower than the reference temperature, a decrease in the resistance value causes a potential difference between the detection ends 52a and 52b, and the output of the comparator 56 causes the transistor 5 to output.
1 conducts, a current flows through the heating resistor 5 and the heating resistor 5
Temperature rises. When the temperature of the heating resistor 5 reaches the reference temperature, the transistor 51 is shut off by the rise of the resistance value and the output of the comparator 56, the power supply to the heating resistor 5 is stopped, and the temperature of the heating resistor 5 decreases. descend. By repeating such an operation, the heating resistor 5 repeats heat generation and cooling, and the heating resistor 5 is maintained at the reference temperature that is higher by a certain temperature than the intake air temperature.
【００１６】また、直流定電圧端子ＶccとグランドＧＮ
Ｄとの間に、分圧回路５７が接続されている。分圧回路
５７は、流量検出用抵抗体６、第２吸気温検出用抵抗体
８及び抵抗５８によって構成され、分圧回路５７の出力
端５７ａは増幅器５９の入力端に接続されている。増幅
器５９の他方の入力端には基準電圧Ｖr が入力されてお
り、増幅器５９は、分圧回路５７の出力電位と基準電圧
Ｖr との電位差を増幅して出力する。分圧回路５７の出
力電圧は、吸気温度の変動に対して第２吸気温検出用抵
抗体８の抵抗値及び流量検出用抵抗体６の抵抗値が各々
比例的に変化するため吸気温度が変動しても変化しない
が、吸気流れ方向及び吸気流量の変動によって変化す
る。このため、増幅器５９の出力によって、吸気流れ方
向及び吸気流量を検出することができる。Further, a DC constant voltage terminal Vcc and a ground GN
A voltage dividing circuit 57 is connected between the voltage dividing circuit 57 and D. The voltage dividing circuit 57 includes the flow rate detecting resistor 6, the second intake air temperature detecting resistor 8, and the resistor 58, and the output terminal 57 a of the voltage dividing circuit 57 is connected to the input terminal of the amplifier 59. The reference voltage Vr is input to the other input terminal of the amplifier 59, and the amplifier 59 amplifies and outputs the potential difference between the output potential of the voltage dividing circuit 57 and the reference voltage Vr. The output voltage of the voltage dividing circuit 57 varies in the intake air temperature because the resistance value of the second intake air temperature detection resistor 8 and the resistance value of the flow rate detection resistor 6 each change proportionally to the fluctuation of the intake air temperature. It does not change even if it changes, but it changes due to fluctuations in the intake flow direction and the intake flow rate. Therefore, the flow of the intake air and the flow of the intake air can be detected from the output of the amplifier 59.
【００１７】次に、上記吸気流量測定装置１の製造方法
の一例を図６〜図９に基づいて説明する。Next, an example of a method of manufacturing the above-mentioned intake air flow measuring device 1 will be described with reference to FIGS.
【００１８】まず、図６に示すように、半導体基板２と
してＳi 基板を用い、Ｓi 基板２上に下部絶縁膜３とし
てＳi3Ｎ4 膜とＳi Ｏ2 膜の２層を形成し、次に、下部
絶縁膜３の上に、接着層として５０ÅのＴi 層を用い２
００℃で真空蒸着機により導電膜４としてＰt 膜を２０
００Å堆積させ、次に、Ｐt 膜４から抵抗体５〜８とリ
ード部９〜１４を形成するためのエッチングを行う。そ
の後、図７に示すように、抵抗体５〜８及びリード部９
〜１４の上に上部絶縁膜１５として下部絶縁膜３と同様
なＳi3Ｎ4 膜とＳi Ｏ2 膜の２層を形成し、次に、上部
絶縁膜１５の電極パッド１６〜２１を形成すべき部位つ
まり電極パッド形成部位をエッチングする。上部絶縁膜
１５は、抵抗体５〜８及びリード部９〜１４を中心とし
て下部絶縁膜３と上下方向に対称な位置に配置される。
その後、図８に示すように、電極パッド１６〜２１とし
て７０００ÅのＡl 層を形成し、次に、ＴＭＡＨ溶液を
用い異方性エッチングによりＳi 基板２に空洞部２ａを
形成してダイアフラム２２を形成する。その後、図９に
示すように、電極パッド１６〜２１を遮温材６０で覆い
ダイアフラム２２にレーザ光線を照射して熱処理を行
う。この熱処理により発熱抵抗体５及び流量検出用抵抗
体６の抵抗値の経時変化を抑えることができるととも
に、電極パッド１６〜２１に対して熱処理が行われない
ことから電極パッド１６〜２１とリード部９〜１４との
相互拡散を防止することができる。First, as shown in FIG. 6, a Si substrate is used as the semiconductor substrate 2, and two layers of a Si 3 N 4 film and a SiO 2 film are formed as the lower insulating film 3 on the Si substrate 2, A 50 ° Ti layer as an adhesive layer on the lower insulating film 3;
At 00 ° C., a Pt film was formed as a conductive film 4 by a vacuum evaporation machine to form a 20
Then, etching for forming resistors 5 to 8 and leads 9 to 14 is performed from the Pt film 4. Thereafter, as shown in FIG.
, Two layers of a Si 3 N 4 film and a SiO 2 film similar to the lower insulating film 3 are formed as the upper insulating film 15, and then the electrode pads 16 to 21 of the upper insulating film 15 are formed. A part to be formed, that is, a part for forming an electrode pad is etched. The upper insulating film 15 is disposed at a position vertically symmetric with respect to the lower insulating film 3 with the resistors 5 to 8 and the leads 9 to 14 as centers.
Thereafter, as shown in FIG. 8, an Al layer of 7000 ° is formed as electrode pads 16 to 21, and then a cavity 2a is formed in the Si substrate 2 by anisotropic etching using a TMAH solution to form a diaphragm 22. I do. Thereafter, as shown in FIG. 9, the electrode pads 16 to 21 are covered with a heat insulating material 60, and the diaphragm 22 is irradiated with a laser beam to perform a heat treatment. This heat treatment can suppress the temporal change of the resistance values of the heating resistor 5 and the flow rate detecting resistor 6, and since the heat treatment is not performed on the electrode pads 16 to 21, the electrode pads 16 to 21 and the lead portion Interdiffusion with 9 to 14 can be prevented.
【００１９】上記吸気流量測定装置１によると、図１０
に示すように、ワイヤボンディング強度において電極パ
ッド１６〜２１を含む全体に対して熱処理を行った場合
と比べ膜剥れを防止でき、また、図１１に示すように、
発熱抵抗体５及び流量検出用抵抗体６の抵抗値の経時変
化が少ないことから経時的な出力変化を殆ど生じること
がなく、また、図１２に示すように、熱処理温度を３０
０℃以上に設定した場合に出力変化が殆ど生じない。According to the intake air flow measuring device 1, FIG.
As shown in FIG. 11, film peeling can be prevented in comparison with the case where heat treatment is performed on the entirety including the electrode pads 16 to 21 in wire bonding strength, and as shown in FIG.
Since the resistance values of the heat generating resistor 5 and the flow rate detecting resistor 6 have little change with time, there is almost no change in output over time, and as shown in FIG.
When the temperature is set to 0 ° C. or higher, almost no output change occurs.
【００２０】なお、図１図示の吸気流量測定装置１の製
造工程において、ダイアフラム２２に対して熱処理を行
う代わりに、電極パッド１６等を介して少なくとも発熱
抵抗体５に通電して熱処理を行うようにしてもよい。In the manufacturing process of the intake air flow measuring device 1 shown in FIG. 1, instead of performing heat treatment on the diaphragm 22, at least heat is applied to the heating resistor 5 via the electrode pad 16 or the like to perform heat treatment. It may be.
【００２１】図１３は、第２実施形態に係る製造方法に
よって製造される吸気流量測定装置の平面図、図１４
は、図１３図示Ｄ部の拡大図を示す。FIG. 13 is a plan view of an intake air flow measuring device manufactured by the manufacturing method according to the second embodiment, and FIG.
Shows an enlarged view of the D part shown in FIG.
【００２２】図１３において、吸気流量測定装置１は、
図１図示の吸気流量測定装置１に、発熱抵抗体５を加熱
するための加熱抵抗体７１、加熱抵抗体７１のリード部
７２、７３及び電極パッド７４、７５を追加したことを
特徴としており、その他の構成は図１図示の吸気流量測
定装置１と同様に構成されている。Referring to FIG. 13, an intake air flow measuring device 1 comprises:
A heating resistor 71 for heating the heating resistor 5, lead portions 72 and 73 of the heating resistor 71, and electrode pads 74 and 75 are added to the intake flow rate measuring device 1 shown in FIG. Other configurations are the same as those of the intake flow rate measuring device 1 shown in FIG.
【００２３】そして、この吸気流量測定装置１の製造方
法においては、上述した第１実施形態の製造方法におい
て導電膜４にエッチングを施して抵抗体５〜８、リード
部９〜１４を形成する際に加熱抵抗体７１及びリード部
７２、７３も同時に形成するようにし、また、上部絶縁
膜１５にエッチングを施す際にリード部７２、７３の電
極パッド形成部位に対してもエッチングを施すように
し、さらに、リード部９〜１４の電極パッド形成部位上
に電極パッド１６〜２１を形成する際に電極パッド７
４、７５も同時に形成するようにする。そして、第１実
施形態ではダイアフラム２２に対する熱処理をレーザ光
線を用いて行っているのに対し、第２実施形態では電極
パッド７４、７５を介して加熱抵抗体７１に電流を流し
その発熱によって発熱抵抗体５を加熱するようにして熱
処理を行う。その他の製造工程については、第１実施形
態と同様である。この製造方法によると、図１図示の吸
気流量測定装置１の製造工程において、ダイアフラム２
２に対して熱処理を行う代わりに、電極パッド１６等を
介して少なくとも発熱抵抗体５に通電して熱処理を行う
ようにした場合と比べ、発熱抵抗体５の劣化を抑えるこ
とができる。なお、流量検出用抵抗体６を加熱するため
の加熱抵抗体を形成し、この加熱抵抗体に通電してその
発熱により流量検出用抵抗体６を加熱して熱処理を行う
ようにしてもよい。In the method of manufacturing the intake flow rate measuring apparatus 1, the conductive film 4 is etched to form the resistors 5 to 8 and the leads 9 to 14 in the manufacturing method of the first embodiment. In addition, the heating resistor 71 and the lead portions 72 and 73 are also formed at the same time, and when the upper insulating film 15 is etched, the etching is also performed on the electrode pad formation portions of the lead portions 72 and 73, Further, when forming the electrode pads 16 to 21 on the electrode pad formation sites of the leads 9 to 14, the electrode pads 7
4 and 75 are also formed at the same time. In the first embodiment, the heat treatment of the diaphragm 22 is performed using a laser beam, whereas in the second embodiment, a current flows through the heating resistor 71 via the electrode pads 74 and 75, and the heat is generated by the heat generated. Heat treatment is performed so as to heat the body 5. Other manufacturing steps are the same as in the first embodiment. According to this manufacturing method, in the manufacturing process of the intake air flow measuring device 1 shown in FIG.
Instead of performing the heat treatment on the heat-generating resistor 2, deterioration of the heat-generating resistor 5 can be suppressed as compared with the case where at least the heat-generating resistor 5 is energized through the electrode pad 16 or the like to perform the heat treatment. Note that a heating resistor for heating the flow detection resistor 6 may be formed, and the heat treatment may be performed by applying a current to the heating resistor and heating the flow detection resistor 6 by the generated heat.
【００２４】[0024]
【発明の効果】本発明によると、電極パッドを遮温材で
覆いダイアフラムに光線を照射して発熱抵抗体及び流量
検出用抵抗体に対し熱処理を行い、あるいは、電極パッ
ドを介して加熱抵抗体に通電し少なくとも発熱抵抗体に
対し熱処理を行うようにしたため、発熱抵抗体等に対し
て熱処理を施しても電極パッドとリード部との間で相互
拡散が起きなくなり、ワイヤボンディングの際の密着強
度を保持することができる。上記複数の実施形態では、
流量検出用抵抗体６を発熱抵抗体５の片側に配設した場
合について説明したが、発熱抵抗体５の両側に流量検出
用抵抗体６を配設して両流量検出用抵抗体６の抵抗値の
差により吸気流量を検出する場合や、発熱抵抗体５の吸
気流量に対する放熱量の差から吸気流量を検出する場合
など、半導体基板上に感温抵抗体を形成したものであれ
ば同様の効果が得られる。According to the present invention, the electrode pad is covered with a heat insulating material, and the diaphragm is irradiated with light rays to perform heat treatment on the heating resistor and the flow rate detecting resistor, or the heating resistor is connected via the electrode pad. And heat treatment is performed on at least the heating resistor, so that even if heat treatment is performed on the heating resistor and the like, mutual diffusion does not occur between the electrode pad and the lead portion, and the adhesion strength during wire bonding is reduced. Can be held. In the above embodiments,
The case where the flow detection resistor 6 is disposed on one side of the heating resistor 5 has been described. However, the flow detection resistor 6 is disposed on both sides of the heating resistor 5 so that the resistance of the two flow detection resistors 6 can be reduced. The same applies to the case where a temperature-sensitive resistor is formed on a semiconductor substrate, such as a case where an intake flow rate is detected based on a difference in value, or a case where an intake flow rate is detected based on a difference in heat radiation amount with respect to the intake flow rate of the heating resistor 5. The effect is obtained.
【図１】本発明の第１実施形態に係る製造方法によって
製造される流量測定装置であって内燃機関の吸気流量を
測定するための吸気流量測定装置の平面図である。FIG. 1 is a plan view of an intake flow rate measurement device for measuring an intake flow rate of an internal combustion engine, which is a flow measurement device manufactured by a manufacturing method according to a first embodiment of the present invention.
【図２】図１図示Ａ−Ａ線による断面図である。FIG. 2 is a sectional view taken along line AA in FIG.
【図３】図１図示Ｂ部の拡大図である。FIG. 3 is an enlarged view of a portion B shown in FIG. 1;
【図４】図２図示Ｃ部の拡大図である。FIG. 4 is an enlarged view of a portion C shown in FIG. 2;
【図５】流量測定装置の等価回路図である。FIG. 5 is an equivalent circuit diagram of the flow measuring device.
【図６】図７、図８及び図９と共に一連の製造工程を示
す断面図である。FIG. 6 is a sectional view showing a series of manufacturing steps together with FIGS. 7, 8 and 9;
【図７】図６、図８及び図９と共に一連の製造工程を示
す断面図である。FIG. 7 is a sectional view showing a series of manufacturing steps together with FIGS. 6, 8 and 9;
【図８】図６、図７及び図９と共に一連の製造工程を示
す断面図である。FIG. 8 is a sectional view showing a series of manufacturing steps together with FIGS. 6, 7 and 9;
【図９】図６、図７及び図８と共に一連の製造工程を示
す断面図である。FIG. 9 is a sectional view showing a series of manufacturing steps together with FIGS. 6, 7 and 8;
【図１０】ワイヤボンディングにおける本実施形態の効
果を示すグラフである。FIG. 10 is a graph showing the effect of the present embodiment on wire bonding.
【図１１】抵抗の経時変化における本実施形態の効果を
示すグラフである。FIG. 11 is a graph showing the effect of the present embodiment on the change over time in resistance.
【図１２】熱処理温度による本実施形態の効果を示すグ
ラフである。FIG. 12 is a graph showing an effect of the present embodiment depending on a heat treatment temperature.
【図１３】第２実施形態に係る製造方法によって製造さ
れる吸気流量測定装置の平面図である。FIG. 13 is a plan view of an intake air flow measuring device manufactured by a manufacturing method according to a second embodiment.
【図１４】図１３図示Ｄ部の拡大図である。FIG. 14 is an enlarged view of a D part shown in FIG. 13;
１ 吸気流量測定装置 ２ 半導体基板 ３ 下部絶縁膜 ４ 導電膜 ５ 発熱抵抗体 ６ 流量検出用抵抗体 ７ 流体温度検出用抵抗体（第１吸気温検出用抵抗
体） ８ 流体温度検出用抵抗体（第２吸気温検出用抵抗
体） ９〜１４ リード部 １５ 上部絶縁膜 １６〜２１ 電極パッド ２２ ダイアフラム ２２ａ 空洞部 ６０ 遮温材 ７１ 加熱抵抗体 ７２、７３ リード部 ７４、７５ 電極パッドREFERENCE SIGNS LIST 1 intake air flow measuring device 2 semiconductor substrate 3 lower insulating film 4 conductive film 5 heating resistor 6 flow detection resistor 7 fluid temperature detection resistor (first intake temperature detection resistor) 8 fluid temperature detection resistor ( 9-14 Lead part 15 Upper insulating film 16-21 Electrode pad 22 Diaphragm 22a Cavity part 60 Heat shield 71 Heating resistor 72, 73 Lead part 74, 75 Electrode pad
フロントページの続き (72)発明者 河野 泰 愛知県刈谷市昭和町１丁目１番地 株式会 社デンソー内 Ｆターム(参考） 2F035 AA02 EA08 EA09 Continued on the front page (72) Inventor Yasushi Kono 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 2F035 AA02 EA08 EA09
Claims (6)
徴とする流量測定装置の製造方法。 半導体基板上に下部絶縁膜を形成する 前記下部絶縁膜上に導電膜を形成する 前記導電膜から複数の感温抵抗体と前記感温抵抗体の
各リード部とを形成するためのエッチングを行う 前記感温抵抗体及び前記リード部の上に上部絶縁膜を
形成する 前記上部絶縁膜の電極パッドを形成すべき部位をエッ
チングする 前記各リード部上に前記電極パッドを形成する 前記半導体基板に空洞部を形成して前記感温抵抗体の
一部又は全部を要素とするダイアフラムを形成する 前記電極パッドを除く領域に対し熱処理を行う1. A method for manufacturing a flow measuring device, comprising the following series of steps. Forming a lower insulating film on a semiconductor substrate forming a conductive film on the lower insulating film performing etching for forming a plurality of temperature-sensitive resistors and respective leads of the temperature-sensitive resistor from the conductive film; Forming an upper insulating film on the temperature-sensitive resistor and the lead portion; etching a portion of the upper insulating film where an electrode pad is to be formed; forming the electrode pad on each of the lead portions; a cavity in the semiconductor substrate. Forming a diaphragm with a part or all of the temperature-sensitive resistor as an element, performing heat treatment on a region excluding the electrode pad
ム上にある前記感温抵抗体に対して行うことを特徴とす
る請求項１記載の流量測定装置の製造方法。2. The method according to claim 1, wherein the region in which the heat treatment is performed is performed on the temperature-sensitive resistor on the diaphragm.
アフラムに光線を照射して前記感温抵抗体に対して前記
熱処理を行うことを特徴とする請求項１又は２記載の流
量測定装置の製造方法。3. The flow rate measuring apparatus according to claim 1, wherein the electrode pad is covered with a heat insulating material, and the heat treatment is performed on the temperature-sensitive resistor by irradiating the diaphragm with a light beam. Production method.
ム上にある前記感温抵抗体の一部又は全部に通電して前
記熱処理を行うことを特徴とする請求項１又は２記載の
流量測定装置の製造方法。4. The flow rate measuring apparatus according to claim 1, wherein the heat treatment is performed by energizing a part or all of the temperature-sensitive resistor on the diaphragm through the electrode pad. Production method.
体を加熱する加熱抵抗体を前記ダイアフラム上に形成し
前記加熱抵抗体に通電して前記熱処理を行うことを特徴
とする請求項１又は２記載の流量測定装置の製造方法。5. A heating resistor for heating the temperature-sensitive resistor on the diaphragm is formed on the diaphragm, and the heat treatment is performed by supplying a current to the heating resistor. A manufacturing method of the flow rate measuring device according to the above.
ことを特徴とする請求項１から５のいずれか一項記載の
流量測定装置の製造方法。6. The method according to claim 1, wherein the temperature of the heat treatment is set to 300 ° C. or higher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001087809A JP2002286521A (en) | 2001-03-26 | 2001-03-26 | Method for manufacturing flow measuring instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001087809A JP2002286521A (en) | 2001-03-26 | 2001-03-26 | Method for manufacturing flow measuring instrument |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002286521A true JP2002286521A (en) | 2002-10-03 |
Family
ID=18943004
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001087809A Withdrawn JP2002286521A (en) | 2001-03-26 | 2001-03-26 | Method for manufacturing flow measuring instrument |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2002286521A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012117446A1 (en) * | 2011-03-02 | 2012-09-07 | 日立オートモティブシステムズ株式会社 | Heat-type flow meter |
-
2001
- 2001-03-26 JP JP2001087809A patent/JP2002286521A/en not_active Withdrawn
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012117446A1 (en) * | 2011-03-02 | 2012-09-07 | 日立オートモティブシステムズ株式会社 | Heat-type flow meter |
| CN103380353A (en) * | 2011-03-02 | 2013-10-30 | 日立汽车系统株式会社 | Heat-type flow meter |
| US20130313675A1 (en) * | 2011-03-02 | 2013-11-28 | Hitachi Automotive Systems ,Ltd. | Thermal Type Flowmeter |
| EP2682720A1 (en) * | 2011-03-02 | 2014-01-08 | Hitachi Automotive Systems, Ltd. | Heat-type flow meter |
| EP2682720A4 (en) * | 2011-03-02 | 2014-08-27 | Hitachi Automotive Systems Ltd | Heat-type flow meter |
| CN103380353B (en) * | 2011-03-02 | 2015-08-05 | 日立汽车系统株式会社 | Thermal flowmeter |
| JP5857032B2 (en) * | 2011-03-02 | 2016-02-10 | 日立オートモティブシステムズ株式会社 | Thermal flow meter |
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