A low-capacitance transient voltage suppression diode array product structure

Abstract

The utility model provides a kind of low-capacitance transient voltage suppression diode array product structure, including lead frame body and chip assembly;Lead frame body is equipped with column unit, each unit contains frame unit, and frame unit is made of four groups of base island component 8 small base island array structure;First small base island is equipped with rectifier diode chip, second small base island is equipped with low-capacitance unidirectional TVS chip, both electrically connected, and base island leads out sixteen pins;The beneficial effects of the utility model are that: multiple signal lines can be protected synchronously, signal symmetrical transmission is guaranteed, and transmission quality is improved;Each channel parameter is consistent, to ensure reliable protection, prevent single path failure;Adapt to a variety of high-speed interfaces, with bidirectional protection, simplify circuit design;Compared with discrete device, reduce cost, simplify assembly process, improve production efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of diode device processing, and specifically relates to a low-capacitance transient voltage suppression diode array product structure. Background Technology

[0002] With the rapid development of electronic technology, modern electronic systems have increasingly higher requirements for circuit protection. Transient voltage suppressor diodes (TVS), as key components for electronic circuit protection, are experiencing significant market demand growth. However, traditional single, independent TVS diodes can no longer meet the requirements of modern electronic systems for efficient and compact protection of multi-signal lines. In multi-signal line scenarios, using multiple discrete TVS diodes is not only costly but also involves complex manufacturing processes. The significant parameter differences between the discrete devices make it difficult to achieve synchronization and symmetry between signals, hindering multi-channel bidirectional collaborative protection of the lines.

[0003] Chinese Patent Publication No. CN102709333B discloses a low-capacitance glass-encapsulated silicon transient voltage suppressor diode. The low-capacitance glass-encapsulated silicon transient voltage suppressor diode includes a housing and leads extending from both ends of the housing. It also includes a transient voltage suppressor diode die, a rectifier diode die, several aluminum foil layers, and two molybdenum electrodes disposed within the housing. The transient voltage suppressor diode die and the rectifier diode die are connected in series. Several aluminum foil layers are respectively disposed on two sides of the transient voltage suppressor diode die and the rectifier diode die. The transient voltage suppressor diode die and the rectifier diode die are also respectively connected to a molybdenum electrode, and the two molybdenum electrodes are respectively connected to a lead. However, the low-capacitance glass-encapsulated silicon transient voltage suppressor diode of this invention has certain drawbacks: its glass encapsulation is not good in terms of flexibility and impact resistance, and it is easily damaged by vibration and impact in complex mechanical environments, resulting in limited reliability and service life; in addition, the single diode structure has low integration, which makes it difficult to meet the requirements of modern electronic equipment for simultaneous protection of multiple signal lines and high integration, and its application scenarios are relatively limited. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a product structure for a low-capacitance transient voltage suppression diode array.

[0005] This utility model is achieved through the following technical solution.

[0006] This utility model provides a low-capacitance transient voltage suppression diode array product structure, which includes a lead frame body and a chip assembly.

[0007] The lead frame body is provided with column units arranged in an array along its length direction, and each column unit contains multiple frame units;

[0008] The frame unit includes four sets of base island components. Each set of base island components includes a first small base island and a second small base island. The four sets of base island components are arranged in an array along the length of the lead frame body, and the first small base island and the second small base island in each set of base island components are arranged opposite each other along the width of the lead frame body. The first small base island and the second small base island in the four sets of base island components are arranged alternately and at intervals along the length of the lead frame body to form an array structure of 8 small base islands.

[0009] The chip assembly includes a rectifier diode chip fixedly disposed on the first small base island and a low-capacitance unidirectional TVS chip fixedly disposed on the second small base island.

[0010] The rectifier diode chip is electrically connected to the low-capacitance unidirectional TVS chip.

[0011] Each of the first and second small base islands has two independent pins, and the four groups of base island components form a total of sixteen pins.

[0012] The eight small base islands are arranged in a 2×4 matrix within the frame unit, as detailed below:

[0013] Two rows are formed along the width of the lead frame body, each row containing 4 small base islands, namely the first and second small base islands of the four sets of base island components; four columns are formed along the length of the lead frame body, each column containing one first small base island and one second small base island; and along the width of the lead frame body, if the first row from left to right is first small base island, second small base island, first small base island, second small base island, then the second row from left to right is second small base island, first small base island, second small base island, first small base island, that is, the base island types of adjacent rows are arranged alternately.

[0014] The frame unit is encapsulated in a plastic package;

[0015] Of the sixteen pins:

[0016] The pins leading out from the first small island are: pins 3, 4, 7, 8, 11, 12, 15, and 16;

[0017] The pins leading out from the second small island are: pins 1, 2, 5, 6, 9, 10, 13, and 14;

[0018] Pins 1, 2, 3, 4, 5, 6, 7, and 8 extend from one side of the molded body, while pins 9, 10, 11, 12, 13, 14, 15, and 16 extend from the other side of the molded body.

[0019] The electrical connection is a metal wire bonding connection, and the metal wire is a gold wire with a diameter of 50.8 μm.

[0020] The rectifier diode chip is fixed to the first small base island by eutectic bonding.

[0021] The low-capacitance unidirectional TVS chip is fixed to the second small base island by soft solder bonding.

[0022] The lead frame body is provided with an auxiliary cutting channel for separating individual products and an injection molding channel for product encapsulation. The auxiliary cutting channel and the injection molding channel are hollow structures, and the hollow structures extend through the thickness direction of the lead frame body.

[0023] The auxiliary cutting channel is located between adjacent frame units and is used to cut and separate adjacent frame units into independent single products; the injection molding channel is located between adjacent column units and is used for injection molding of encapsulant into adjacent frame units.

[0024] The low-capacitance unidirectional TVS chip has a capacitance value not exceeding 45pF, a breakdown voltage of 13.3V to 16.5V, and a clamping voltage not exceeding 20.5V.

[0025] The reverse breakdown voltage of the rectifier diode chip is not less than 600V, and the forward conduction current is not less than 1A.

[0026] The beneficial effects of this utility model are as follows:

[0027] 1) Synchronous protection of multiple signal lines: Enables multi-channel collaborative protection to ensure synchronous and symmetrical signal transmission; for high-speed differential signals, it avoids signal imbalance caused by differences in protection device parameters, thereby improving signal transmission quality;

[0028] 2) Ensure protection consistency and reliability: The parameters of each channel are highly consistent to overcome the manufacturing deviation problem of discrete components; synchronously respond to interference in multi-line systems to prevent system failure caused by single-channel protection delay;

[0029] 3) Adapts to complex interface requirements: Provides unified protection for various high-speed interfaces, simplifying circuit design; has bidirectional protection capability, eliminating the need for additional directional protection circuit design, saving cost and space;

[0030] 4) Reduced system cost and complexity: Compared with discrete TVS diodes, the production cost is lower; only one device needs to be soldered during assembly, simplifying the production process and improving production efficiency. Attached Figure Description

[0031] Figure 1 This is an overall schematic diagram of the lead frame body structure according to an embodiment of the present utility model;

[0032] Figure 2 This is a schematic diagram of the column unit structure according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the internal structure of the frame unit according to an embodiment of the present utility model;

[0034] Figure 4 is Schematic diagram of the internal circuit of the frame unit in this embodiment of the utility model;

[0035] Figure 5 This is a schematic diagram of the frame unit after plastic sealing according to an embodiment of the present invention;

[0036] In the diagram: 1-lead frame body, 2-frame unit, 3-first small base island, 4-second small base island, 5-rectifier diode chip, 6-low capacitance unidirectional TVS chip, 7-molded body, 8-auxiliary rib cutting channel, 9-injection molding channel, 10-positioning hole, 11-gold wire. Detailed Implementation

[0037] The technical solution of this utility model is further described below, but the scope of protection is not limited to what is described.

[0038] refer to Figures 1 to 5

[0039] Example 1

[0040] This invention provides a low-capacitance transient voltage suppression diode array product structure, which achieves multi-channel collaborative protection for high-speed signals by optimizing the base island layout and chip connection method. Figure 1 As shown, the structure includes a lead frame body 1 and a chip assembly. The lead frame body 1 has 14 column units arranged in an array along its length direction. Each column unit contains 5 frame units 2, forming a total of 70 frame units to improve the batch production yield.

[0041] The lead frame body 1 is made of copper and has a silver layer with a thickness of 1.8μm to 5.0μm plated on its surface, forming a highly conductive and corrosion-resistant basic structure.

[0042] The lead frame body 1 has positioning holes 10 on its upper side and upper side for bonding equipment, wire bonding equipment and clamping claw insertion holes. The positioning holes 10 are used to move the lead frame body 1.

[0043] like Figure 2 He Ru Figure 3As shown, each frame unit 2 includes four sets of base island components, and each set of base island components includes a first small base island 3 and a second small base island 4. The four sets of base island components are arranged in an array along the length of the lead frame body 1, and the first small base island 3 and the second small base island 4 in each set of base island components are arranged opposite each other along the width of the lead frame body 1. The first small base island 3 and the second small base island 4 in the four sets of base island components are arranged alternately and at intervals along the length of the lead frame body 1, thereby forming an array structure with 8 small base islands.

[0044] The eight small base islands are arranged in a 2×4 matrix within frame unit 2, as detailed below:

[0045] Two rows are formed along the width direction of the lead frame body 1, each row containing 4 small base islands, namely the first small base island 3 and the second small base island 4 of the four sets of base island components; four columns are formed along the length direction of the lead frame body 1, each column containing one first small base island 3 and one second small base island 4; and along the width direction of the lead frame body 1, if the first row from left to right is the first small base island 3, the second small base island 4, the first small base island 3, and the second small base island 4, then the second row from left to right is the second small base island 4, the first small base island 3, the second small base island 4, and the first small base island 3, that is, the base island types of adjacent rows are arranged alternately.

[0046] The lead frame body 1 is also provided with an auxiliary rib cutting channel 8 and an injection molding runner 9. The auxiliary rib cutting channel 8 is located between adjacent frame units 2. It is a hollow structure that runs through the thickness direction of the lead frame body. In subsequent processing, the adjacent frame units can be cut and separated by the auxiliary rib cutting channel 8 through the cutting operation to form an independent single product. The injection molding runner 9 is located between adjacent column units. It is also a hollow through structure. Its function is to inject the molding compound into the adjacent frame units 2.

[0047] The chip assembly includes a rectifier diode chip 5 fixed on the first small base island 3, and a low-capacitance unidirectional TVS chip 6 fixed on the second small base island 4.

[0048] The rectifier diode chip 5 is securely fixed to the first small base island 3 using eutectic bonding. This rectifier diode chip 5 has specific performance parameters: its reverse breakdown voltage is not less than 600V, and its forward conduction current is not less than 1A, enabling stable rectification in the circuit. The low-capacitance unidirectional TVS chip 6 is fixed to the second small base island 4 using soft solder bonding. This chip has a capacitance not exceeding 45pF, a breakdown voltage between 13.3V and 16.5V, and a clamping voltage not exceeding 20.5V, effectively suppressing transient overvoltages in the circuit.

[0049] like Figure 3 and 4As shown, the rectifier diode chip 5 and the low-capacitance unidirectional TVS chip 6 are electrically connected by a metal wire bonding connection.

[0050] Gold wire 11 with a diameter of 50.8μm was selected as the bonding metal wire to ensure stable and reliable electrical signal transmission between the two.

[0051] The anode of the rectifier diode chip 5 is connected to the anode of the low-capacitance unidirectional TVS chip 6 via a gold wire.

[0052] The arrangement of eight small base islands allows the rectifier diode chip 5, fixed on the first small base island 3, and the low-capacitance unidirectional TVS chip 6, fixed on the second small base island 4, to be connected via wire bonding. The rectifier diode chip has a reverse breakdown voltage of no less than 600V and a forward conduction current of no less than 1A, ensuring stable rectification. The TVS chip has a capacitance of no more than 45pF, a breakdown voltage of 13.3V-16.5V, and a clamping voltage of no more than 20.5V, effectively suppressing transient overvoltages. Together, they provide comprehensive circuit protection, ensuring high-speed signal transmission while accurately clamping under overvoltage conditions. Furthermore, the specific diameter gold wire ensures a stable and reliable connection, enhancing overall electrical performance and reliability.

[0053] like Figure 3 ,like Figure 4 and like Figure 5 As shown, each of the first small base islands 3 and the second small base island 4 has two independent pins, forming a total of sixteen pins across the four base island assemblies. The specific pin distribution is as follows: pins 3, 4, 7, 8, 11, 12, 15, and 16 are from the first small base island 3; pins 1, 2, 5, 6, 9, 10, 13, and 14 are from the second small base island 4. Pins 1, 2, 3, 4, 5, 6, 7, and 8 extend from one side of the molding compound 7, while pins 9, 10, 11, 12, 13, 14, 15, and 16 extend from the other side of the molding compound 7. The frame unit 2 is ultimately encapsulated in an epoxy molding compound 7, thereby protecting the internal chip components and pin structure and improving product stability and reliability.

[0054] Example 2

[0055] The structure of this utility model of a plastic-encapsulated SOP-16 packaged low-capacitance transient voltage suppression diode array product uses four low-capacitance unidirectional TVS chips 6 with a size of 1.5mm×1.5mm×0.25mm and four rectifier diode chips 5 with a size of 0.75mm×0.75mm×0.25mm.

[0056] Among them, the reverse breakdown voltage of rectifier diode chip 5 is not less than 600V, and the forward conduction current is not less than 1A. The capacitance value of low-capacitance unidirectional TVS chip 6 is not more than 45pF, the breakdown voltage is in the range of 13.3V to 16.5V, and the clamping voltage is not more than 20.5V.

[0057] In the four base island modules, each module consists of a rectifier diode chip and a low-capacitance unidirectional TVS chip forming one protection channel, resulting in a total of four protection channels across the four base island modules. Relevant electrical parameters were tested on these four protection channels. The specific test content and results are shown in Table 1 below. All test results meet the electrical performance requirements.

[0058] Table 1

[0059]

[0060] In the table: V (BR) This represents the breakdown voltage of a low-capacitance unidirectional TVS chip, tested under condition I. (BR) =1mA, meaning the voltage at which the device breaks down when the current flowing through it reaches 1mA; the specified range is 13.3V-16.5V; I R This indicates the reverse leakage current; the test condition is at V. (BR) At 12V, the minimum current of the device under reverse bias must not exceed 2μA, as specified in the standard. C This indicates the clamping voltage of a low-capacitance unidirectional TVS chip, tested under pulse current I. P =20.1A, meaning the voltage across the device when subjected to a 20.1A pulse current, the specified value does not exceed 20.5V; C represents the capacitance value of the low-capacitance unidirectional TVS chip, and the test condition is V R =0V, f=1MHz, meaning the capacitance value of the device measured at 0V and 1MHz is specified to be no more than 45pF; I (BR) This represents the breakdown test current, used to test the breakdown voltage V of a low-capacitance unidirectional TVS chip. (BR) The value is 1mA, which determines the breakdown voltage V. (BR) Test current conditions at time; I P This represents the pulse current, specifically the clamping voltage Vc used to test low-capacitance unidirectional TVS chips, with a value of 20.1A; V R This represents the voltage applied when testing the capacitor, with a value of 0V, and f represents the frequency.

[0061] The beneficial effects of this utility model are: it can protect multiple signal lines simultaneously, ensure symmetrical signal transmission, and improve transmission quality; the parameters of each channel are consistent, ensuring reliable protection and preventing single-path failure; it is compatible with a variety of high-speed interfaces, has bidirectional protection, and simplifies circuit design; compared with discrete components, it reduces costs, simplifies the assembly process, and improves production efficiency.

Claims

1. A low-capacitance transient voltage suppression diode array product structure, the array product structure comprising a lead frame body (1) and a chip assembly, characterized in that: The lead frame body (1) is provided with column units arranged in an array along its length direction, and each column unit contains multiple frame units (2); The frame unit (2) includes four sets of base island components. Each set of base island components includes a first small base island (3) and a second small base island (4). The four sets of base island components are arranged in an array along the length direction of the lead frame body (1). The first small base island (3) and the second small base island (4) in each set of base island components are arranged opposite to each other along the width direction of the lead frame body (1). The first small base island (3) and the second small base island (4) in the four sets of base island components are arranged alternately and at intervals along the length direction of the lead frame body (1) to form an array structure of 8 small base islands. The chip assembly includes a rectifier diode chip (5) fixed on the first small base island (3) and a low-capacitance unidirectional TVS chip (6) fixed on the second small base island (4); The rectifier diode chip (5) is electrically connected to the low-capacitance unidirectional TVS chip (6); Each of the first small base island (3) and the second small base island (4) has two independent pins, and the four groups of base island components form a total of sixteen pins.

2. A low capacitance transient voltage suppression diode array product structure as defined in claim 1, wherein, The eight small islands are arranged in a 2×4 matrix within the frame unit (2), as follows: Two rows are formed along the width direction of the lead frame body (1), each row containing 4 small base islands, namely the first small base island (3) and the second small base island (4) of the four sets of base island components; four columns are formed along the length direction of the lead frame body (1), each column containing one first small base island (3) and one second small base island (4); and along the width direction of the lead frame body (1), if the first row from left to right is the first small base island (3), the second small base island (4), the first small base island (3), and the second small base island (4), then the second row from left to right is the second small base island (4), the first small base island (3), the second small base island (4), and the first small base island (3), that is, the base island types of adjacent rows are arranged alternately.

3. The low-capacitance transient voltage suppression diode array product structure as described in claim 1, characterized in that, The frame unit (2) is encapsulated within a plastic encapsulation (7); Of the sixteen pins: The pins leading out from the first small base island (3) are: pins 3, 4, 7, 8, 11, 12, 15, and 16; The pins leading out from the second small island (4) are: pins 1, 2, 5, 6, 9, 10, 13, and 14; Pins 1, 2, 3, 4, 5, 6, 7, and 8 extend from one side of the molded body (7), and pins 9, 10, 11, 12, 13, 14, 15, and 16 extend from the other side of the molded body (7).

4. The low-capacitance transient voltage suppression diode array product structure as described in claim 1, characterized in that: The electrical connection is a metal wire bonding connection, and the metal wire is a gold wire with a diameter of 50.8 μm (11).

5. The low-capacitance transient voltage suppression diode array product structure as described in claim 1, characterized in that: The rectifier diode chip (5) is fixed on the first small base island (3) by eutectic bonding.

6. The low-capacitance transient voltage suppression diode array product structure as described in claim 1, characterized in that: The low-capacitance unidirectional TVS chip (6) is fixed to the second small base island (4) by means of soft solder bonding.

7. The low-capacitance transient voltage suppression diode array product structure as described in claim 1, characterized in that: The lead frame body (1) is provided with an auxiliary cutting channel (8) for separating a single product and an injection molding channel (9) for product encapsulation. Both the auxiliary cutting channel and the injection molding channel are hollow structures, and the hollow structures penetrate through the thickness direction of the lead frame body.

8. The low-capacitance transient voltage suppression diode array product structure as described in claim 7, characterized in that: The auxiliary cutting channel (8) is located between adjacent frame units (2) and is used to cut and separate adjacent frame units into independent single products; the injection molding channel (9) is located between adjacent column units and is used for injection molding of plastic sealant into adjacent frame units (2).

9. The low-capacitance transient voltage suppression diode array product structure according to claim 1, characterized in that: The low-capacitance unidirectional TVS chip has a capacitance value not exceeding 45pF, a breakdown voltage of 13.3V to 16.5V, and a clamping voltage not exceeding 20.5V.

10. The low-capacitance transient voltage suppression diode array product structure according to claim 1, characterized in that: The reverse breakdown voltage of the rectifier diode chip (5) is not less than 600V, and the forward conduction current is not less than 1A.

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