CN202424153U

CN202424153U - Low capacitance surge protector having ESD protective function

Info

Publication number: CN202424153U
Application number: CN201120302672XU
Authority: CN
Inventors: 张小平
Original assignee: JIANGSU SENCHIP MICROELECTRONICS CO Ltd
Current assignee: Suzhou Juda senchip Microelectronics Co. Ltd.
Priority date: 2011-08-16
Filing date: 2011-08-16
Publication date: 2012-09-05
Anticipated expiration: 2021-08-16

Abstract

Disclosed is a low capacitance surge protector having an ESD protective function, which is characterized by comprising a plurality of cells connected in parallel. The cell is composed of a TVS pipe, a diode, and a solid discharge pipe, wherein the cathode of the TVS pipe is connected with the anode of the solid discharge pipe and is also connected with the cathode of the diode as the cathode of the cell; the anode of the TVS pipe is connected with the gate pole of the discharge pipe; and the cathode of the discharge pipe is connected with the anode of the diode as the anode terminal of the cell to lead out. The low capacitance surge protector structurally realizes the integration of the ESD and surge protection, realizes the objective that the protective voltage can be adjusted alongside the TVS pipe puncture by utilizing the TVS triggering of the discharge door pole after puncturing, and effectively realizes low capacitance and low clamping of the whole device, thereby being widely applicable to the protection of the view screen, ADSL, and other communication lines.

Description

Low electric capacity Surge Protector with esd protection function

Technical field

The utility model relates to overvoltage protector of semiconductor spare field, is specifically related to a kind ofly collect the protection of esd protection and surge and be the Surge Protector of one.

Background technology

Along with of the raising of interface surge protection to the requirement of protection device capacitor; The low big surge protection of electric capacity becomes communication interface protection trend; And on terminal interface is used; Protection has inherent requirement to product to ESD (static discharge), and this just requires protection scheme need possess ESD and surge protection function, and electric capacity can not be too big.The traditional protection mode is to form the two-stage protection through solid discharging tube (Thyristor) and decoupling resistor and TVS pipe; Trigger the discharge tube action through the clamp voltage of TVS pipe and the dividing potential drop of decoupling resistor; Thereby having caused the inconvenience of some application, mainly is that element matching and PCB space hold area are bigger.Low capacitor discharge tubular construction mainly falls appearance through increasing N+ adjustment layer mode on highly resistant material, but because N+ adjustment layer is generally deep structure, in case accomplish, device electric breakdown strength VBO will be difficult to make change again.Because discharge tube structure is 4 layers of PNPN structure, response speed is low with respect to the TVS pipe in addition, therefore can not well accomplish the protection of ESD.

To the some defectives in the existing device of surge protector application, many entity and individual have proposed some new improvement projects.The utility model patent of one " low capacitance overvoltage protection module " by name has been proposed on July 22nd, 2009 like Jiangsu Dongguang Microelectronics Co., Ltd.; And the mandate (patent No. is 200920233468.X) that patents on April 21st, 2010, it discloses a kind of low capacitance overvoltage protection module, its main technical schemes be 3 negative poles of solid discharge chip one end serial connection mutually and diodes; 3 anodal phases of other end serial connection diode also; And diode of solid discharge chip one end links with a diode of the other end and forms at least three outputs, thereby makes protection module protect structure to become the three-terminal protection structure by two ends, can be used in the three-terminal protection circuit; And the low capacitance characteristic that has kept former two end structures; Can be because of not reducing interelectrode capacitance, and cause the decline of electrical property, defencive function weakens.This technical scheme is to the improvement of communication with anti-surge protective device; Its advantage is with respect to two end structures and three solid discharge chip portfolio structures, can reduce cost more than 60% and more than 40%; And can realize small sizeization, enlarge the semiconductor anti-surge device scope of application.But its esd protection effect is unsatisfactory.

In addition; Shanghai Changyuan Wayon Circuit Protection Co., Ltd. on March 16th, 2011 proposed one " unidirectional low electric capacity device of surge protector " by name application for a patent for invention (number of patent application is 201110062647.3) its a kind of unidirectional low electric capacity device of surge protector disclosed; Comprise PIN pipe and the 2nd PIN pipe; The one TVS pipe and the 2nd TVS pipe and GTO pipe, wherein the anode of PIN pipe is as the first exit S1; The negative electrode of the one PIN pipe links to each other with the anode of the 2nd PIN pipe, and links to each other with the anode of GTO pipe; The negative electrode of the 2nd PIN pipe links to each other with the negative electrode of TVS pipe with the 2nd TVS pipe; The anode of the 2nd TVS pipe links to each other with the gate pole of GTO pipe; The negative electrode of GTO pipe links to each other with the anode of TVS pipe, as the second exit S2.Advantage is: utilize the low capacitance characteristic of PIN pipe and the big current drain ability of GTO to realize unidirectional low electric capacity Surge Protector; The protection of employing two-stage; Overcome the requirement that traditional multi-stage protection can not satisfy the low electric capacity of high-speed data, low residual voltage; Realized breakover voltage control and the control of residual voltage lower limit according to the TVS pipe that inserts, the puncture voltage through regulating the TVS pipe effectively control device breakover voltage and transfer after residual voltage.This type of technological shortcoming is that still the esd protection function is not ideal enough, and being difficult to reach protection voltage can puncture the ideal effect of adjusting protection with the TVS pipe.

Summary of the invention

The technical problem that the utility model will solve is to overcome the shortcoming that can not have esd protection and surge protection function and protection voltage adjustment inconvenience simultaneously concurrently that exists in the existing Surge Protector use; A kind of low electric capacity Surge Protector with esd protection function is provided; This protector not only has esd protection and anti-surge function simultaneously, and its protection voltage can be adjusted with the puncture of TVS pipe.

The utility model solves the problems of the technologies described above the technical scheme of being taked: a kind of low electric capacity Surge Protector with esd protection function; Be formed in parallel by a plurality of cellulars; Said cellular by a TVS manage, a diode and a solid discharging tube constitute; Wherein the negative electrode of TVS pipe links to each other with the anode of solid discharging tube; And link to each other as the negative electrode of cellular with the negative electrode of diode, the anode of TVS pipe then links to each other with the gate pole of discharge tube, and the negative electrode of discharge tube links to each other with the anode of diode and draws as the cellular anode tap.

As the improvement of the utility model, said TVS pipe expands district and P+ by N type substrate, N+ successively from bottom to top and expands the district and constitute, wherein the negative electrode N+ of TVS pipe expand the district be positioned at cellular central authorities, the doping content scope is 7e15/cm ^-3～2e18/cm ^-3, P+ expands the anode that the district is used to make the TVS pipe.

Another improvement as the utility model; Said solid discharging tube expands district, N type substrate, P+ base and N+ emitter region by back side P+ successively from bottom to top and constitutes; Wherein said back side P+ expands the district for the junction depth scope is the dark knot expansion district of 20～40 μ m, as the anode of solid discharging tube, is produced on the back side of N type substrate; Be positioned at the N+ emitter region under, structure ringwise; Said P+ base is that large tracts of land distributes, be produced on back side P+ expand the district directly over, as the short base of solid discharging tube; On the P+ base, make the N+ emitter region, and reserving the negative electrode short circuit hole that has same potential on the negative electrode short circuit hole to let gate pole trigger the time around equidistant place, anodes centre position of TVS pipe.

As the further improvement of the utility model, it is structurally overlapping with the P+ base of solid discharging tube that the anode P+ of said TVS pipe expands the district; The anode of said TVS pipe is provided with electric current is stopped through the oxide layer that negative electrode short circuit orifice flow goes out.

The beneficial effect of the utility model is:

Through the TVS pipe is integrated with discharge tube; The function that has realized esd protection and surge protection is integrated; Utilize TVS pipe to puncture the triggering of back on the device architecture, realized that protection voltage can puncture with the TVS pipe adjust, realized the low electric capacity and the low clamper of entire device effectively the discharge tube gate pole.

Description of drawings

Low electric capacity device of surge protector unit born of the same parents' circuit structure that Fig. 1 proposes for the utility model with esd protection function;

The low electric capacity device of surge protector circuit structure that Fig. 2 proposes for the utility model with esd protection function;

The low electric capacity device of surge protector electrical characteristics figure that Fig. 3 proposes for the utility model with esd protection function;

The low electric capacity device of surge protector structure that Fig. 4 proposes for the utility model with esd protection function;

Fig. 5 is the plan structure of the low electric capacity device of surge protector with esd protection function of the utility model proposition.

Embodiment

Below in conjunction with accompanying drawing and embodiment the principle and the advantage of the utility model are done further to set forth.

A kind of low electric capacity Surge Protector with esd protection function; As depicted in figs. 1 and 2; Compose in parallel by a plurality of cellulars; The basic structure of cellular is made up of TVS pipe T1, a diode D1 and a solid discharging tube G1, and wherein the TVS negative electrode of managing T1 links to each other with the anode of discharge tube G1, and links to each other with the negative electrode of diode D1 and to constitute the anode of cellular; The anode of TVS pipe T1 and the gate pole of discharge tube G1 link to each other; The negative electrode of discharge tube G1 links to each other with the anode of diode D1 and constitutes the negative electrode of cellular.The negative electrode of cellular is linked to each other with negative electrode, and anode links to each other with anode and constitutes the cellular array, forms the low electric capacity device of surge protector structure with esd protection function.

Shown in the electrical characteristics figure of Fig. 3 cellular, when the surge voltage from the forward process surpasses the puncture voltage of TVS pipe T1, TVS pipe T1 conducting; Electric current flows into the gate pole of discharge tube G1 through TVS pipe T1; When the electric current of the gate pole of flowing through reached the trigger condition of discharge tube G1, discharge tube G1 opened, and this moment, discharge tube G1 got into big electric current negative resistance state; TVS pipe T1 turn-offs, and surge current discharges through discharge tube G1.After surge current was released, electric current reduced gradually, and when the electric current that flows through discharge tube G1 was lower than it and keeps electric current, discharge tube G1 got back to blocking state.Diode D1 provide forward characteristic to device, makes device have the characteristic of forward diode.

Like Fig. 4, shown in Figure 5; The P+ base that the P+ of TVS pipe is expanded district and discharge tube separate independent making;, the P+ base of discharge tube G1 carries out the N+ expansion district 22 of TVS pipe and the making that P+ expands district 26 after accomplishing again; The puncture voltage of TVS pipe will not be subject to the structural parameters of discharge tube G1 like this, thereby can realize the more voltage protection of wide region.Primary structure comprises: make ring-shaped P+expansion district 25 at the back side of N type substrate, be used to form the anode of discharge tube G1, this expands the district and expands the district for dark knot, and the junction depth scope is 20～40 μ m.Make large tracts of land P+ in the front of material and expand district 23, constitute the P+ base of discharge tube G1, on the P+ base, make N+ emitter region 24, short circuit hole 41 is reserved in N+ emitter region 24, and short circuit hole 41 equates apart from the spacing that N+ expands district 22.The cathode layer N+ that directly over cellular, makes TVS pipe T1 expands the district, and the doping content scope is 7e15/cm ^-3～2e18/cm ^-3, junction depth 3～15 μ m.Expand at N+ and make P+ in the district and expand the district, the TVS that needs through acquisitions of adjustment P+ junction depth manages the puncture voltage of T1.At last, through the etching mode N+ is expanded directly over the district, the oxide layer 28 between two N+ emitter regions 24 keeps, and other regional oxide layers etch away.Deposit layer of metal 31, the anode exit of formation device.Constitute the cathode end of device again in the back side of material deposit layer of metal 32.

Claims

1. low electric capacity Surge Protector with esd protection function; It is characterized in that being formed in parallel by a plurality of cellulars; Said cellular by a TVS manage, a diode and a solid discharging tube constitute, wherein the negative electrode of TVS pipe links to each other with the anode of solid discharging tube, and links to each other as the negative electrode of cellular with the negative electrode of diode; The anode of TVS pipe then links to each other with the gate pole of discharge tube, and the negative electrode of discharge tube links to each other with the anode of diode and draws as the cellular anode tap.

2. the low electric capacity Surge Protector with esd protection function according to claim 1; It is characterized in that described TVS pipe expands the district by N type substrate, N+ from bottom to top successively and P+ expansion district constitutes; Wherein the negative electrode N+ of TVS pipe expand the district be positioned at cellular central authorities, the doping content scope is 7e15/cm ^-3～2e18/cm ^-3, P+ expands the anode that the district is used to make the TVS pipe.

3. the low electric capacity Surge Protector with esd protection function according to claim 1; It is characterized in that: described solid discharging tube expands district, N type substrate, P+ base and N+ emitter region by back side P+ successively from bottom to top and constitutes; Wherein said back side P+ expands the district for the junction depth scope is the dark knot expansion district of 20～40 μ m, as the anode of solid discharging tube, is produced on the back side of N type substrate; Be positioned at the N+ emitter region under, structure ringwise; Said P+ base is that large tracts of land distributes, be produced on back side P+ expand the district directly over, as the short base of solid discharging tube; On the P+ base, make the N+ emitter region, and reserving the negative electrode short circuit hole that has same potential on the negative electrode short circuit hole to let gate pole trigger the time around equidistant place, anodes centre position of TVS pipe.

4. according to the described low electric capacity Surge Protector with esd protection function of one of claim 1～3, it is characterized in that: it is structurally overlapping with the P+ base of solid discharging tube that the anode P+ of said TVS pipe expands the district.

5. according to the described low electric capacity Surge Protector with esd protection function of one of claim 1～3, it is characterized in that: the anode of said TVS pipe is provided with electric current is stopped through the oxide layer that negative electrode short circuit orifice flow goes out.