resistor

Abstract

A resistor includes a die pad and a circuit body disposed on the die pad. The circuit body has an insulating substrate, a first circuit element and a second circuit element disposed on the insulating substrate, and an insulating portion disposed between the first circuit element and the second circuit element to insulate the first circuit element from the second circuit element. The die pad and the circuit body are covered with an insulating resin.

Description

Technical Field

[0001] This invention relates to a resistor. Background Technology

[0002] JP2023-042044A discloses a semiconductor device having a resistor, which can extend the output voltage range with a simple structure.

[0003] As mentioned above, in semiconductor devices where multiple chips are formed on a single die pad for miniaturization, especially under operating conditions where high voltages are applied, short-circuit countermeasures between the multiple chips are necessary. Summary of the Invention

[0004] Therefore, the object of the present invention is to improve the insulation between circuit elements in a resistor comprising multiple circuit elements and sealed with resin, while achieving miniaturization.

[0005] According to a certain aspect of the present invention, a resistor is provided, comprising: a die pad and a circuit body disposed on the die pad, the circuit body having: an insulating substrate, a first circuit element and a second circuit element disposed on the insulating substrate, and an insulating portion disposed between the first circuit element and the second circuit element and insulating the first circuit element from the second circuit element, wherein the die pad and the circuit body are covered by an insulating resin.

[0006] According to one aspect of the present invention, in a resistor comprising multiple circuit elements and sealed with resin, since an insulating portion is provided between the first circuit element and the second circuit element, it is possible to improve the insulation between the circuit elements while achieving miniaturization. Attached Figure Description

[0007] Figure 1 This is a top view of the resistor as seen from the top surface side, illustrating the structure of the resistor involved in this embodiment.

[0008] Figure 2 It is along Figure 1 A cross-sectional view of the resistor in line II-II.

[0009] Figure 3 This is a circuit diagram illustrating a typical voltage divider circuit.

[0010] Figure 4 This is a top view taken from the top surface of the resistor, illustrating the structure of the resistor involved in the first modified example.

[0011] Figure 5This is a top view taken from the top surface of the resistor, illustrating the structure of the resistor involved in the second variation. Detailed Implementation

[0012] [Implementation Method]

[0013] <Resistors>

[0014] The structure of the resistor according to this embodiment will be described with reference to the accompanying drawings. In this specification, the same or equivalent elements are labeled with the same reference numerals in all the drawings.

[0015] The resistor, for example, is a thin-film chip resistor, which is connected to the circuit board of a power module that performs high-voltage and high-current signal processing. In this embodiment, the resistor functions as a voltage divider circuit that divides a high voltage of several hundred volts or more applied to the circuit board into a low voltage of a few volts for detection.

[0016] Figure 1 This is a top view taken from the upper surface of resistor 1, illustrating the structure of resistor 1 according to this embodiment. For ease of understanding, the insulating resin (molding resin) covering the upper surface of resistor 1 is not shown. Figure 1 As shown in the image. Figure 2 It is along Figure 1 A cross-sectional view of resistor 1 on line II-II.

[0017] Resistor 1 is a resistor that includes a die pad 11 and a circuit body 20 disposed on the die pad 11, and the die pad 11 and the circuit body 20 are covered by an insulating resin 30.

[0018] Resistor 1 has lead terminals 12 (multiple lead terminals 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h). Die pads 11 and lead terminals 12 constitute lead frame 10. In this embodiment, when the lead terminals are not distinguished, letters are omitted as in the case of lead terminal 12.

[0019] The die pads 11 and lead terminals 12 constituting the lead frame 10 are formed from thin sheets of metal materials such as copper, copper alloys, and iron-nickel alloys, which have excellent mechanical strength, electrical conductivity, thermal conductivity, and corrosion resistance. The die pads 11 and lead terminals 12 are obtained by processing these metal films through processes such as punching (stamping) and etching.

[0020] The lead terminal 12 has: an inner lead portion 121, which is electrically connected to the electrode connection portion (hereinafter referred to as pad portion P) formed in the first circuit element 22 and the second circuit element 23 of the circuit body 20; and an outer lead portion 122, which is connected to an external wiring (not shown).

[0021] In this embodiment, the circuit body 20 has an insulating substrate 21, a first circuit element 22 and a second circuit element 23, and an insulating portion 24 disposed between the first circuit element 22 and the second circuit element 23.

[0022] In this embodiment, the insulating substrate 21 has a first insulating substrate 211 and a second insulating substrate 212, which are separated from each other.

[0023] The first insulating substrate 211 and the second insulating substrate 212 are formed of insulating material. In this embodiment, as an example, the insulating substrate 21 is an alumina (Al2O3) substrate. In addition to an alumina substrate, the insulating substrate 21 can also be a thermal oxide film obtained by modifying the surface of a silicon substrate into an oxide film, a silicon oxide film formed by CVD, or a silicon nitride film.

[0024] Furthermore, in this embodiment, a first circuit element 22 is formed on a first insulating substrate 211, and a second circuit element 23 is formed on a second insulating substrate 212. The first circuit element 22 and the second circuit element 23 are thin-film circuit patterns formed by using a material capable of forming circuit patterns, through film deposition by sputtering, plasma CVD, or the like, and then by photolithography or the like.

[0025] Examples of metallic materials capable of forming thin-film circuit patterns include copper, chromium (Cr), chromium (Cr)-based metallic materials, nickel-chromium (Ni-Cr), nickel-chromium (Ni-Cr)-based metallic materials, and metal oxide materials. The metallic material can be appropriately selected based on the application of resistor 1, from materials that provide high-precision resistance tolerance and temperature characteristics, materials with high voltage and surge resistance, and materials with good TCR (temperature coefficient of resistance) characteristics.

[0026] In this embodiment, as an example of a material capable of forming circuit patterns, a chromium (Cr) alloy or a nickel-chromium (Ni-Cr) alloy is preferably used.

[0027] After the circuit patterns of the first circuit element 22 and the second circuit element 23 are formed, the pad portion P is formed by film deposition using a conductive material. In this embodiment, as an example, the pad portion P is formed by sputtering an Al alloy.

[0028] The first circuit element 22 is formed on the first insulating substrate 211 in a predetermined circuit pattern shape. In this embodiment, the first circuit element 22 has a first resistor 221 and a second resistor 222 as a circuit pattern shape.

[0029] The first resistor 221 is configured with a zigzag shape having a predetermined linewidth, zigzag amplitude, and zigzag number, which corresponds to the resistance value R1. Furthermore, the second resistor 222 is configured with a zigzag shape having a predetermined linewidth, zigzag amplitude, and zigzag number, which corresponds to the resistance value R2.

[0030] The second circuit element 23 is formed on the second insulating substrate 212 in a predetermined circuit pattern shape. In this embodiment, the second circuit element 23 has a third resistor 231 and a fourth resistor 232 as a circuit pattern.

[0031] The third resistor 231 is configured to have a zigzag shape with a predetermined linewidth, zigzag amplitude, and zigzag number, which is the same as the resistance value R3. Furthermore, the fourth resistor 232 is configured to have a zigzag shape with a predetermined linewidth, zigzag amplitude, and zigzag number, which is the same as the resistance value R4.

[0032] In this embodiment, the circuit pattern shape of the first circuit element 22 formed on the first insulating substrate 211 is the same as the circuit pattern shape of the second circuit element 23 formed on the second insulating substrate 212. The resistor 1 has a first circuit element 22 and a second circuit element 23 having the same circuit pattern shape arranged side-by-side.

[0033] Figure 3 This is a circuit diagram illustrating a typical voltage divider circuit.

[0034] Figure 3 The voltage divider circuit shown amplifies the potential difference between the input voltage Vin- input to the inverting input terminal and the input voltage Vin+ input to the non-inverting input terminal, and outputs the amplified potential difference as the output voltage Vout. It is designed to satisfy the following condition: R2 / R1=R4 / R3.

[0035] Furthermore, the voltage divider circuit is designed to satisfy R1>R2 when the output potential difference is smaller than the input potential difference. In this case, a voltage reduction circuit is formed where the output voltage Vout is less than the input potential difference.

[0036] In this embodiment, the resistance values ​​R1 of the first resistor 221 and R2 of the second resistor 222 formed in the first circuit element 22, and the resistance values ​​R3 of the third resistor 231 and R4 of the fourth resistor 232 formed in the second circuit element 23 are configured to satisfy the following condition: R2 / R1=R4 / R3, where R1>R2.

[0037] In other words, the circuit body 20 in resistor 1 constitutes a voltage reduction circuit.

[0038] The insulating part 24 is disposed between the first circuit element 22 and the second circuit element 23, physically isolating the first circuit element 22 and the second circuit element 23, and electrically insulating the first circuit element 22 and the second circuit element 23.

[0039] As the insulating material constituting the insulating part 24, an inorganic material or resin with insulating properties can be used.

[0040] As an insulating inorganic material, glass fiber materials formed by mixing silica, alumina, calcium oxide, magnesium oxide, and boron oxide can be used. In addition, inorganic materials such as aluminum nitride and magnesium oxide, as well as minerals such as mica, can be used.

[0041] As an insulating resin, thermosetting resins such as epoxy resin, silicone resin, polyurethane resin, and phenolic resin can be used. By mixing fillers such as silica filler and curing agents into these thermosetting resins, the coefficient of thermal expansion of the insulating resin is made to be close to the coefficient of thermal expansion of the first circuit element 22, the second circuit element 23, the first insulating substrate 211, and the second insulating substrate 212.

[0042] From the perspective of preventing short circuits between the first circuit element 22 and the second circuit element 23, and from the perspective of ensuring the volume of the insulating portion 24 that can achieve sufficient insulation effect, it is preferable to maximize the spacing between the first circuit element 22 and the second circuit element 23, as well as the first insulating substrate 211 and the second insulating substrate 212 within the area of ​​the die pad 11 of the resistor 1.

[0043] like Figure 1 As shown, the first circuit element 22 and the second circuit element 23 of resistor 1 are connected to the inner lead portion 121 at a predetermined pad portion P by bonding lead W.

[0044] Under high temperature and pressure conditions, gold (Au) can form a highly reliable intermetallic compound with aluminum (Al). Utilizing this property, the pad portion P of the first circuit element 22 and the second circuit element 23 are bonded to the inner lead portion 121 using Au leads via ultrasonic vibration. Copper (Cu) leads can also be used instead of Au leads. In wire bonding, bonding leads with a diameter of 10 μm to 100 μm are typically formed.

[0045] exist Figure 3 In the voltage divider circuit shown, when the voltage is reduced from high to low, the high voltage is applied to the terminals (Vin-, Vin+) on the input side. Therefore, in resistor 1, it is preferable to use a resistor equivalent to... Figure 3 The input terminals for the input voltage Vin- and input voltage Vin+ are located away from the configuration.

[0046] Therefore, in this embodiment, lead terminals 12a and 12d are used as input terminals. This prevents short circuits between the lead terminals 12.

[0047] Furthermore, in this embodiment, lead terminals 12f and 12g are connected to an operational amplifier (not shown). Lead terminals 12b and 12c, although not electrically connected to external wiring, function as joints for bonding with a circuit board (not shown). This improves the mounting strength when mounting resistor 1 to the circuit board.

[0048] Resistor 1 is sealed with insulating resin 30 while the pad portion P of the first circuit element 22 and the inner lead portion 121 are connected by lead bonding.

[0049] As the insulating resin 30, thermosetting resins such as epoxy resin, silicone resin, polyurethane resin, and phenolic resin can be used. By mixing fillers such as silica filler and curing agents into these thermosetting resins, the coefficient of thermal expansion of the insulating resin is set to a value close to the coefficient of thermal expansion of the first circuit element 22, the second circuit element 23, the first insulating substrate 211, and the second insulating substrate 212.

[0050] In this embodiment, from the perspective of affinity, the insulating resin 30 is preferably the same resin as the insulating resin applied to the insulating part 24.

[0051] By sealing the lead frame 10 and the circuit body 20 with insulating resin 30, the lead frame 10 and the circuit body 20 can be protected from damage caused by external impact, dust adhesion, moisture and other effects, thereby maintaining the performance of resistor 1 for a long time.

[0052] The resistor 1, configured as described above, has a connection terminal at the outer lead portion 122 that is soldered to a predetermined position on the wiring (external wiring) of a circuit board (not shown).

[0053] <Method for manufacturing the main circuit component>

[0054] The manufacturing method of the circuit body 20 in the resistor 1 according to this embodiment will be described.

[0055] Cleaning of insulating substrate

[0056] The insulating substrate 21 that constitutes the main body of the circuit 20 is cleaned.

[0057] Metal film coating

[0058] Metal thin films for the first circuit element 22 and the second circuit element 23 are formed. In this embodiment, as an example, a metal thin film constituting the first circuit element 22 and the second circuit element 23 is formed on the surface of the insulating substrate 21 (first insulating substrate 211, second insulating substrate 212) by sputtering using chromium (Cr) alloys or nickel-chromium (Ni-Cr) alloys as metal materials.

[0059] Patterning

[0060] By using photolithography, circuit patterns are formed on the metal thin film after film deposition to function as the first resistor 221, the second resistor 222, the third resistor 231, and the fourth resistor 232, respectively.

[0061] Formation of solder pads

[0062] In this embodiment, a pad portion P is formed at a predetermined position of the formed circuit pattern shape by sputtering an Al alloy.

[0063] Circuit body segmentation

[0064] After the pad portion P is formed, the circuit body 20 is cut out by dividing the slits.

[0065] Through the above processes, the circuit body 20 can be manufactured.

[0066] <Resistor Manufacturing Methods>

[0067] Next, the manufacturing method of the resistor 1 according to this embodiment will be described.

[0068] Core bonding

[0069] The circuit body 20 is bonded to the lead frame 10 using an adhesive. As an example of an adhesive, silver paste adhesive can be used.

[0070] Wire bonding

[0071] The pad portions P of the first circuit element 22 and the second circuit element 23 formed in the circuit body 20 are wire bonded to the lead terminals 12 in the lead frame 10.

[0072] Molding

[0073] The lead frame 10, to which the circuit body 20 is connected by wire bonding, is covered (molded) by insulating resin 30. Alternatively, a protective film may be formed on the resistive elements of the first circuit element 22 and the second circuit element 23 of the circuit body 20 before the molding process.

[0074] Coating formation

[0075] As an example, a Sn plating layer is formed on the outer lead portion 122.

[0076] Plastic molding

[0077] The lead frame 10 is cut off from the lead frame body. In addition, the shape of the outer lead portion 122 is modified by stamping using a metal die (plastic forming).

[0078] Through the above processes, resistor 1 can be manufactured.

[0079] [Effects of the Implementation Method]

[0080] In the resistor 1 according to the first embodiment, the circuit body 20 includes: a die pad 11, a first insulating substrate 211 and a second insulating substrate 212 disposed on the die pad 11, a first circuit element 22 disposed on the first insulating substrate 211, a second circuit element 23 disposed on the second insulating substrate 212, and an insulating portion 24 disposed between the first circuit element 22 and the second circuit element 23 to insulate the first circuit element 22 and the second circuit element 23. The lead frame 10 and the circuit body 20 are covered by insulating resin 30.

[0081] The resistor 1 according to the first embodiment includes a first circuit element 22 and a second circuit element 23 in order to achieve miniaturization, and has an insulating portion 24 that insulates the first circuit element 22 from the second circuit element 23, and is sealed with an insulating resin 30.

[0082] Therefore, compared to a conventional resistor that seals the first circuit element 22 and the second circuit element 23 separately with insulating resin 30, resistor 1 can improve the insulation between the first circuit element 22 and the second circuit element 23 while achieving miniaturization. Thus, a compact resistor capable of reliably preventing short circuits between circuit elements can be realized.

[0083] For example, even when used under high voltage conditions, resistor 1 can maintain insulation between the first circuit element 22 and the second circuit element 23, while the first circuit element 22 and the second circuit element 23 are arranged side by side within a single circuit body 20. Therefore, even under high voltage conditions, resistor 1 can avoid short circuits between circuit elements while meeting miniaturization requirements.

[0084] In resistor 1, insulating substrate 21 includes: a first insulating substrate 211 on which a first circuit element 22 is formed; and a second insulating substrate 212 on which a second circuit element 23 is formed and which is separate from the first insulating substrate 211. That is, the first insulating substrate 211 on which the first circuit element 22 is formed and the second insulating substrate 212 on which the second circuit element 23 is formed are separate from each other.

[0085] When resistors are used for high-voltage applications, if the circuit components contain defects such as tiny dirt, dust, or impurities, the greater the difference in potential applied to each circuit component, the easier it is for electrolytic corrosion to spread from the defective parts.

[0086] In contrast, in resistor 1, since the first insulating substrate 211 and the second insulating substrate 212 are separate, electrolytic corrosion caused by the potential difference applied between the first circuit element 22 formed on the first insulating substrate 211 and the second circuit element 23 formed on the second insulating substrate 212 is less likely to occur. Furthermore, because the insulating substrates are separate, electrolytic corrosion can be prevented from propagating between the first circuit element 22 and the second circuit element 23.

[0087] Furthermore, in resistor 1, by arranging the first insulating substrate 211 on which the first circuit element 22 is formed and the second insulating substrate 212 on which the second circuit element 23 is formed as far apart as possible, heat from the circuit body 20 can be easily dispersed to the entire surface of the insulating resin 30 covering resistor 1, thereby improving heat dissipation.

[0088] In resistor 1, the circuit pattern shape of the first circuit element 22 is the same as that of the second circuit element 23. Therefore, performance inconsistencies in resistor 1 can be suppressed. Furthermore, the manufacturing cost of resistor 1 can be reduced.

[0089] In this embodiment, the first circuit element 22 is formed as a circuit pattern with a first resistor having a resistance value of R1 and a second resistor having a resistance value of R2. Furthermore, the second circuit element 23 is formed as a circuit pattern with a third resistor having a resistance value of R3 and a fourth resistor having a resistance value of R4.

[0090] When the circuit pattern is formed as described above, since the first circuit element 22 and the second circuit element 23 have the same circuit pattern shape, it is possible to suppress the performance inhomogeneity of each resistive element.

[0091] Furthermore, when the resistance values ​​R1 of the first resistor 221, R2 of the second resistor 222, R3 of the third resistor 231, and R4 of the fourth resistor 232 are respectively used to form a voltage divider circuit that satisfies R2 / R1=R4 / R3, a high-precision voltage divider circuit can be constructed because the unevenness of each resistor element can be suppressed.

[0092] The first insulating substrate 211, the second insulating substrate 212, the first circuit element 22, and the second circuit element 23 are all thin-film formed. That is, the circuit body 20 is a thin-film formed circuit. Therefore, the miniaturization of the resistor 1 can be achieved.

[0093] Furthermore, since the circuit body 20 is formed of a thin film, the first circuit element 22 and the second circuit element 23 can be wire-bonded to any one of the plurality of lead terminals 12. Due to the wire bonding, an intermetallic compound is formed between the pad portion P in the first circuit element 22 and the lead terminal 12, thus achieving high connection reliability.

[0094] like Figure 2 As shown, in the resistor 1 according to the embodiment, the surface of the die pad 11 is formed to be lower than the inner lead portion 121 in the lead terminal 12. As a result, the height difference between the inner lead portion 121 and the surface of the first circuit element 22 formed on the first insulating substrate 211 can be reduced.

[0095] Therefore, when wire bonding is performed on the first circuit element 22 and the inner lead portion 121, the trajectory of the capillary used for wire bonding can be reduced. This allows for the formation of the bonding lead W along an ideal trajectory. Consequently, errors in wire bonding can be prevented.

[0096] [Variation Example]

[0097] <First Variation>

[0098] Figure 4 This is a top view taken from the upper surface of resistor 2, which is used to describe resistor 2 as a first modified example. Figure 4 In order to make the description easier to understand, the insulating resin 30 covering the upper surface of resistor 2 is not shown. Furthermore, for resistors having... Figure 1 The resistors shown have the same structure and function as resistor 1, and are labeled with the same numbers with detailed descriptions omitted.

[0099] In the first variation, a first circuit element 22 and a second circuit element 23 are formed on an insulating substrate 200 disposed on a die pad 11.

[0100] In the case of resistor 2 in the first modified example, since both the first circuit element 22 and the second circuit element 23 are disposed in the region of the insulating substrate 200, the dimensions of the first circuit element 22 and the second circuit element 23 in the side-by-side direction can be shortened.

[0101] This reduces the mounting area of ​​the circuit body 20 within the lead frame 10 of resistor 2. Therefore, the miniaturization requirement of resistor 2 can be met.

[0102] <Second Variation>

[0103] Figure 5 This is a top view taken from the upper surface of resistor 3, which is used to illustrate resistor 3 as a second variation. Figure 5 In order to facilitate understanding, the insulating resin 30 covering the upper surface of resistor 3 is not shown. Furthermore, for resistors having... Figure 1 The resistors shown have the same function as resistor 1, are labeled with the same numbers and detailed descriptions are omitted.

[0104] In the resistor 3 involved in the second variation, such as Figure 5 As shown, the first circuit element 22 and the second circuit element 23 are formed in a line symmetrical manner with respect to the imaginary line L that runs through the insulating portion 24 disposed between the first circuit element 22 and the second circuit element 23.

[0105] By making the first circuit element 22 and the second circuit element 23 linearly symmetrical, when connected to the lead terminal 12 by wire bonding, the length of the bonding lead W from the pad portion P of the first circuit element 22 and the second circuit element 23 to the lead terminal 12, which is the connection destination, can be equal.

[0106] Furthermore, compared to resistors 1 arranged side-by-side with the same circuit pattern shape, the length of the bonding lead W can be shortened.

[0107] [Other Implementation Methods]

[0108] The above description illustrates one application example of the present invention, but it is not intended to limit the technical scope of the present invention to the specific structure of the above embodiment.

[0109] The circuit pattern shapes of the first circuit element 22 and the second circuit element 23 shown in resistor 1 in this embodiment, resistor 2 in the first variation, and resistor 3 in the second variation are not limited to... Figure 1 , Figure 4 and Figure 5 The shape shown.

[0110] Furthermore, the circuit formed in the first circuit element 22 and the second circuit element 23 is not limited to a resistor.

[0111] As a method for forming the first circuit element 22 and the second circuit element 23 on the insulating substrate 21, plating, vacuum evaporation, ion plating, sputtering, vapor phase growth, cold spraying, and other methods can be used.

[0112] This application claims priority to Japanese Patent Application No. 2024-8204, filed with the Japan Patent Office on January 23, 2024, the entire contents of which are incorporated herein by reference.

[0113] Explanation of reference numerals in the attached figures

[0114] 1, 2, 3, Resistors; 10, Lead frame; 11, Die pad; 12 (12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h), Lead terminals; 20, Circuit body; 21, Insulating substrate; 22, First circuit element; 23, Second circuit element; 24, Insulating part; 30, Insulating resin; 121, Inner lead part; 122, Outer lead part; 200, Insulating substrate; 211, 212, Insulating substrate; 221, First resistor; 222, Second resistor; 231, Third resistor; 232, Fourth resistor; P, Pad part; R1, R2, R3, R4, Resistance value; L, Imaginary line; W, Bonding lead.

Claims

1. A resistor comprising: die pads; and The circuit body configured on the die pads, The circuit body includes: an insulating substrate, a first circuit element and a second circuit element disposed on the insulating substrate, and an insulating portion disposed between the first circuit element and the second circuit element and insulating the first circuit element from the second circuit element. The die pads and the circuit body are covered with insulating resin.

2. The resistor according to claim 1, wherein, The circuit pattern shape of the first circuit element is the same as that of the second circuit element.

3. The resistor according to claim 1 or 2, wherein, The first circuit element has a first resistive element with a resistance value of R1 and a second resistive element with a resistance value of R2. The second circuit element has a third resistive element with a resistance value of R3 and a fourth resistive element with a resistance value of R4. And the result is: R2 / R1 = R4 / R3.

4. The resistor according to claim 1, wherein, The main body of the circuit is a thin-film formed circuit.

5. The resistor according to claim 4, wherein, The main body of the circuit has multiple lead terminals for connection to external wiring. The first circuit element and the second circuit element are respectively connected to any one of the plurality of lead terminals by wire bonding.

6. The resistor according to claim 1, wherein, The insulating substrate comprises: A first insulating substrate on which the first circuit element is formed; and A second insulating substrate having the second circuit element formed thereon and being separate from the first insulating substrate.

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