阅读说明：本技术 一种多路车用大功率二极管低频噪声测试系统 (High-power diode low-frequency noise test system for multi-way vehicle ) 是由 李金春 冯晶 郜峰利 于思瑶 邱海云 王伟 谢辉 田茂会 于 2020-08-19 设计创作，主要内容包括：本发明公开一种多路车用大功率二极管低频噪声测试系统。包括屏蔽箱(1),与屏蔽箱连接的程控多路选择器(7),用于控制程控多路选择器的计算机(13)；程控多路选择器与置于屏蔽箱内的取样电阻(10)、电压源(14)以及待检测的二极管形成闭合回路,取样电阻两端分别连接有设于屏蔽箱上的SMA接口一(8)和SMA接口二(9)SMA接口一和SMA接口二分别连接低频放大器(11)的两端,低频放大器通过频谱分析仪(12)连接到计算机。本发明能够有效提高筛选准确率,并且能筛选出具有细微缺陷的产品；在低频小电流模式下检测噪声,对产品没有造成损伤；批量检测,筛选周期短,成本低。(The invention discloses a high-power diode low-frequency noise test system for a multi-channel vehicle. Comprises a shielding box (1), a program-controlled multiplexer (7) connected with the shielding box, and a computer (13) for controlling the program-controlled multiplexer; the program-controlled multiplexer, a sampling resistor (10) arranged in a shielding box, a voltage source (14) and a diode to be detected form a closed loop, two ends of the sampling resistor are respectively connected with a first SMA interface (8) and a second SMA interface (9) which are arranged on the shielding box, the first SMA interface and the second SMA interface are respectively connected with two ends of a low-frequency amplifier (11), and the low-frequency amplifier is connected to a computer through a spectrum analyzer (12). The invention can effectively improve the screening accuracy and screen out products with fine defects; noise is detected in a low-frequency low-current mode, and no damage is caused to a product; batch detection, short screening period and low cost.)

1. A high-power diode low-frequency noise test system for a multi-channel vehicle is characterized in that,

comprises a shielding box (1), a program-controlled multiplexer (7) connected with the shielding box (1), and a computer (13) for controlling the program-controlled multiplexer (7);

the program-controlled multiplexer (7), a sampling resistor (10) arranged in the shielding box (1), a voltage source (14) and a diode to be detected form a closed loop, two ends of the sampling resistor (10) are respectively connected with a first SMA interface (8) and a second SMA interface (9) arranged on the shielding box (1), the first SMA interface (8) and the second SMA interface (9) are respectively connected with two ends of a low-frequency amplifier (11), and the low-frequency amplifier (11) is connected to a computer (13) through a spectrum analyzer (12).

2. The system for testing the low-frequency noise of the high-power diodes for the multi-channel vehicle as claimed in claim 1,

shielding case (1) inside packing has insulating layer (2), inside 8X 16 slots (3) that are equipped with of insulating layer (2), every slot (3) inner wall are equipped with metal casing (4) altogether, and every metal casing (4) bottom all is equipped with good conductor spring (5) be equipped with metal gasket (6) that match each other on the upper cover inboard of good conductor spring (5) upper end and shielding case (1), every metal gasket (6) on the upper cover inboard of shielding case (1) are connected to programme-controlled multiplexer (7) respectively.

3. The system for testing the low-frequency noise of the high-power diodes for the multi-channel vehicle as claimed in claim 1 or 2,

the shielding box (1) is composed of double shielding layers, and an electromagnetic wave absorbing material is filled in the middle of the double shielding layers.

Technical Field

The invention relates to the technical field of semiconductor device detection, in particular to a high-power diode low-frequency noise test system for a multi-channel vehicle.

Background art the demand of diodes in the market is very large at present, diode detection technology and equipment with higher speed and higher accuracy are needed in industrial production, a vehicle high-power diode belongs to a semiconductor device, reliability detection of the semiconductor device is always a difficult problem in the semiconductor industry, and a stress screening method is a commonly used method at present.

Stress screening includes both electrical stress screening and thermal stress screening. The electric stress screening applies intermittent large current to the diode, and generates heat through the self power consumption of the diode so as to change the temperature and generate the thermal stress. Thermal stress screening is accomplished by applying heat to the outside of the diode, which is transferred to the inside of the diode to create internal stresses. Therefore, both electrical stress screening and thermal stress screening are essentially thermal stress screening, with the heat sources being different.

The most common stress screening method in the industry is the temperature cycling method, which is implemented by placing a diode into a high-low temperature cycling test chamber, which can be cycled between high and low temperatures automatically. The high temperature is usually set to 150 ℃, the low temperature is set to-40 ℃, the high temperature and the low temperature are respectively exposed for 0.5-1 hour, and then the temperature is rapidly changed to another temperature.

The disadvantages of stress screening are:

1) defective products cannot be completely screened out; the defects of the chip are large and small, products with large defects can be screened out through stress screening, but the electrical performance of products with small defects is not deteriorated to the extent that the products can be tested out after the products are subjected to stress screening, so that the products flow to the market and have early failure;

2) damage to good products without defects may occur; stress screening is essentially destructive, damage to good products cannot be avoided, and if damage does not deteriorate electrical performance to a measurable degree, early failure can be caused by market flow;

3) the screening period is long and the cost is high; high and low temperature cycles usually take tens to hundreds of hours, are long, consume large amounts of electricity, and are therefore costly.

Therefore, it is necessary to design a reliable nondestructive testing system for high-power diodes used in vehicles.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the multi-channel vehicle high-power diode low-frequency noise test system which can effectively improve the screening accuracy, screen out products with fine defects, does not damage the products, realizes batch detection, and has short screening period and low cost.

In order to achieve the purpose, the high-power diode low-frequency noise test system for the multi-channel vehicle comprises a shielding box 1, a program-controlled multiplexer 7 connected with the shielding box 1, and a computer 13 for controlling the program-controlled multiplexer 7;

the program-controlled multiplexer 7, a sampling resistor 10, a voltage source 14 and a diode to be detected which are arranged in the shielding box 1 form a closed loop, two ends of the sampling resistor 10 are respectively connected with a first SMA interface 8 and a second SMA interface 9 which are arranged on the shielding box 1, the first SMA interface 8 and the second SMA interface 9 are respectively connected with two ends of a low-frequency amplifier 11, and the low-frequency amplifier 11 is connected to a computer 13 through a spectrum analyzer 12.

Further, the shielding box 1 is internally filled with an insulating layer 2, 8 × 16 slots 3 are arranged inside the insulating layer 2, a metal groove 4 which is grounded is arranged on the inner wall of each slot 3, a good conductor spring 5 is arranged at the bottom of each metal groove 4, metal gaskets 6 which are matched with each other are arranged at the upper end of each good conductor spring 5 and on the inner side of the upper cover of the shielding box 1, and each metal gasket 6 on the inner side of the upper cover of the shielding box 1 is connected to the program-controlled multiplexer 7 respectively.

Further, the shielding box 1 is composed of double shielding layers, and the electromagnetic wave absorbing material is filled in the middle of the double shielding layers.

Compared with the prior art, the high-power diode low-frequency noise test system for the multi-channel vehicle has the following beneficial effects:

1) the screening accuracy is effectively improved, and products with fine defects can be screened;

2) noise is detected in a low-frequency low-current mode, and no damage is caused to a product;

3) batch detection, short screening period and low cost.

Drawings

FIG. 1 is a schematic view of the overall structure of the shielding box of the present invention;

FIG. 2 is a sectional view showing the overall structure of the shield case according to the present invention;

FIG. 3 is a schematic view of the lower housing of the shielding box of the present invention;

FIG. 4 is a schematic diagram of the circuit configuration of the system of the present invention;

in the figure: 1. the device comprises a shielding box, 2, an insulating layer, 3, a slot, 4, a metal groove, 5, a good conductor spring, 6, a metal gasket, 7, a program-controlled multiplexer, 8, SMA interfaces I and I, 9, SMA interfaces II and II, 10, a sampling resistor, 11, a low-frequency amplifier, 12, a spectrum analyzer, 13, a computer, 14 and a voltage source.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

As shown in fig. 1, the high-power diode low-frequency noise test system for the multi-channel vehicle comprises a shielding box 1, a program-controlled multiplexer 7 connected with the shielding box 1, and a computer 13 for controlling the program-controlled multiplexer 7;

the program-controlled multiplexer 7, a sampling resistor 10, a voltage source 14 and a diode to be detected which are arranged in the shielding box 1 form a closed loop, two ends of the sampling resistor 10 are respectively connected with a first SMA interface 8 and a second SMA interface 9 which are arranged on the shielding box 1, the first SMA interface 8 and the second SMA interface 9 are respectively connected with two ends of a low-frequency amplifier 11, and the low-frequency amplifier 11 is connected to a computer 13 through a spectrum analyzer 12. The multiplexer 7 is controlled by the computer 13 to realize the alternate conduction of the vehicle high-power diodes in the slots 3. Whether the diodes are normal or not is judged by comparing the noise generated by the spectrum analyzer 12 with the noise calculated by the dedicated software in the computer 13 with the noise distribution curve of a large number of normal diodes calculated in advance. The voltage at two ends of the sampling resistor 10 is stabilized by adjusting the output voltage of the voltage source 14, so that the influence of the overlarge voltage fluctuation range after passing through the low-frequency amplifier 11 on the accuracy of measurement is avoided.

Further, shielding box 1 is inside to be filled with insulating layer 2, inside 8 x 16 that is equipped with of insulating layer 2, 128 slots 3 altogether, every 3 inner walls of slot are equipped with metal slot 4 altogether, and every 4 bottoms of metal slot all are equipped with good conductor spring 5 be equipped with 128 metal gasket 6 that match each other on the upper end of good conductor spring 5 and the upper cover inboard of shielding box 1 for when shielding box 1 closed, if put the diode in the slot 3 then form closed circuit. Each metal gasket 6 on the inside of the upper cover of the shielding cage 1 is connected to a program controlled multiplexer 7. The metal slots 4 on the inner wall of each slot 3 are commonly grounded, which can be realized by grounding the negative pole of the voltage source 14.

Further, the shielding box 1 is composed of double shielding layers, and the electromagnetic wave absorbing material is filled in the middle of the double shielding layers. The interference of external electromagnetic wave signals can be effectively prevented, and the accuracy of measurement is improved.

When the multi-channel vehicle high-power diode low-frequency noise test system is used, the shielding box 1 is opened, the diodes to be tested in batches are placed in the corresponding slots 3, the heads of the diodes are in full contact with the metal gaskets 6 on the good conductor springs 5, the shielding box 1 is closed, the tail portions of the diodes are in full contact with the metal gaskets 6 on the box cover to form a closed loop, then the computer 13 controls the program-controlled multiplexer 7 to enable the diodes in the 128 slots 3 to be conducted in turn, voltage signals are obtained at two ends of the sampling resistor 10, after the voltage signals are amplified by the low-frequency amplifier 11, a noise distribution curve is calculated by using professional software in the spectrum analyzer 12 and the computer 13, then the noise distribution curve is compared with the noise distribution curve of the normal diodes to judge whether the diodes are normal or not, and an analysis result is presented to an operator.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.