CN205580375U - A tunnel junction magnetism resistance gear sensor chip for declining tooth pitch detects - Google Patents

Abstract

The utility model discloses a magnetism resistance gear sensor chip that little tooth pitch detected. This new design will respond the region and arrange chip one side border position in, reduce the gear greatly to responding the detection interval between the region to improve output signal intensity, be favorable to little tooth pitch to detect, simultaneously, this is novel to contain many bar responses passageway in single response regional, utilizes single design drawing can produce the various space width's of adaptation gear sensor chip. In addition, this sensor chip design center part adopts the regional ultrahigh resolution of realization of big response, uses in the aspect of being favorable to the magnetic grid chi very much. Sensor response direction is unanimous with responding the access alignment direction, can effectively avoid carrying on the back magnetic field by force and get into saturated state with sensor chip. In addition, this magnetism resistance gear sensor still has small -size, low -power consumption, big impedance, high SNR and to air gap's high adaptability.

Description

A kind of tunneling junction magnetoresistive gear sensor chip detected for micro-tooth pitch

Technical field

This utility model relates to magnetic resistance gear sensor field, particularly relates to a kind of high sensitivity magneto-resistor gear sensor chip being suitable for multiple space width detected for micro-tooth pitch.

Background technology

Owing at magnetic rotary encoder, magnetic railings ruler read head, automobile four-wheel drives, and the demand of the multiple industrial circle such as bent axle and ABS system, the exploitation of high class gear sensor receives extensive concern.Traditional Hall and magnetic anisotropy gear sensor, owing to its intrinsic size is relatively big, resolution, the limitation that sensitivity is on the low side, it is difficult to meet market at aspects such as gear speed, direction, tooth position determine for integrated, the demand of high-performance sensors.Meanwhile, in legacy chip designs, response region is positioned at chip central part, size limitation due to package casing, it is difficult to shorten the detection spacing between same the surveyed gear surface of response region, thus is substantially reduced chip signal output in actual applications, it is difficult to detection micron order space width.Additionally due to the response region of current gear sensor chip exists corresponding relation with space width, to different size gear and space width, being required for redesigning manufacture sensor, design production cost is caused to raise.

Utility model content

The chip detection spacing existed for current gear sensor industry is big, output signal is weak, it is difficult to detect small space width, and the problem that a sensor design version only can be suitably used for single space width environment, this utility model uses one can improve output signal, and adapt to different space width with the tunnel knot magnetic resistance (TMR) the gear sensor chip as sensitive material, the size utilizing TMR to bring with solution tradition magnetic resistance sensor chip design for sensitive material is bigger, the problems such as output signal is weak, and sensitivity is on the low side.Utilize distinctive near side (ns) edge-multiple response channel chip to design so that chip can measure the as little as 50 extra small space widths of μm simultaneously, and realize one single chip and adapt to and detect different space width situation.

Basis is the most novel provides a kind of tunneling junction magnetoresistive gear sensor chip detected for micro-tooth pitch, including: silicon substrate, the one or more response regions being positioned on silicon substrate, the response region of chip is placed in chip homonymy edge placement, each response region comprises the response channel that at least two is rectangular-shaped and arranged in parallel along the long limit of rectangle, each response channel is formed by least two feeler arm splits, every feeler arm is in series by least two comb structures, every comb structure is by least two magneto-resistor and the upper electrode that is covered in described magneto-resistor two ends, bottom electrode is connected in series, single described magneto-resistor is oval column structure, described magneto-resistor major axis is parallel with the long limit of described response channel.

Preferably, every described feeler arm also includes the contact electrode being positioned at two ends, and for a plurality of comb structure being connected in series between described contact electrode, described response region surface covers insulating passivation layer beyond contact electrode position.

Preferably, the material of described upper electrode is gold, and described bottom electrode is the multiple structure that tantalum is alternately constituted with ruthenium.

Preferably, the sensitive direction of described sensor chip is perpendicular to the long limit of described response channel, the double crossing over biased direction of described sensor chip is perpendicular to the sensitive direction of described sensor chip, and the pinning of described sensor chip is oriented parallel to the sensitive direction of described sensor chip.

Preferably, multiple response regions of described sensor chip connect along sensitive direction.

Preferably, described sensor chip is the full bridge structure being made up of a plurality of response channel.

Preferably, described sensor chip is the bridge construction of enjoying a double blessing being made up of a plurality of response channel, and in bridge construction of enjoying a double blessing, two full-bridge spacing are half tooth pitch.

Basis is the most novel additionally provides a kind of magnetic resistance gear sensor, and described magnetic resistance gear sensor includes above-mentioned magnetic resistance gear sensor chip.

Compared with prior art, this utility model has the advantages that TMR gear sensor chip of the present utility model has high sensitivity, strong adaptability, excellent performance, the advantage of low cost.Comparing with existing like product, resolution is high, low in energy consumption, it is possible to adaptive different space width gear trains also can measure the detection environment of as little as 50 μm space widths.

Accompanying drawing explanation

As part of the specification, following Figure of description is used for explaining the technical solution of the utility model, for those of ordinary skill in the art, on the premise of not paying creative work, it is possible to pass through the following drawings, it is thus achieved that other accompanying drawings.

Fig. 1 is existing gear sensor chip package and back of the body magnet positions front elevational schematic；

Fig. 2 is existing gear sensor chip package and back of the body magnet positions schematic top view；

Fig. 3 is this utility model gear sensor chip package and back of the body magnet positions front elevational schematic；

Fig. 4 is existing gear sensor detection close-toothed wheel schematic diagram；

Fig. 5 is that existing gear sensor detects big tooth pitch gear schematic diagram；

Fig. 6 is this utility model gear sensor detection close-toothed wheel schematic diagram；

Fig. 7 is that this utility model gear sensor detects big tooth pitch gear schematic diagram；

Fig. 8 is the chip search coverage schematic diagram comprising multiple response channel；

Fig. 9 is the single feeler arm schematic diagram comprising 5 comb structures

Figure 10 is TMR distribution and series connection schematic side view in comb structure；

Figure 11 is TMR distribution and series connection front elevational schematic in comb structure；

Figure 12 is that single response region tests narrow space width, detection channels connection schematic diagram；

Figure 13 is the wide space width of multiple response region test, detection channels connection schematic diagram；

Figure 14 is 90 degree of phase contrast connection circuit of bridge of enjoying a double blessing；

Figure 15 is 90 degree of phase contrast chip connection schematic diagrams of bridge of enjoying a double blessing.

Detailed description of the invention

For making the purpose of this utility model embodiment, technical scheme and advantage clearer, below in conjunction with the accompanying drawing in this utility model embodiment, technical scheme in this utility model embodiment is clearly and completely described, obviously, described embodiment is a part of embodiment of this utility model rather than whole embodiments.

Fig. 1, Fig. 2 are tradition the facing of magnetic resistance gear sensor chip design, schematic top view.As can be seen from the figure being placed in chip central part due to response region, in conjunction with the required intrinsic space of encapsulation, cause gear tip edge big to this detection spacing of chip response region, chip signal output is weak, and sensitivity is low.Fig. 3 is the front elevational schematic of this utility model TMR gear sensor chip design, owing to response region is placed in position, chip-side edge, presses close to package casing, detection spacing is greatly reduced.

Basis is the most novel utilizes microelectronics photoetching technique to make comb teeth shape feeler arm on Silicon Wafer, the comb of two feeler arms is fitting for a rectangular response passage, and the response channel multiple this kind of methods formed is arranged in parallel, as the response region of chip along the long limit of rectangle.Chip detection sensitive direction is response channel orientation, and the double crossing over biased direction of chip is perpendicular to sensitive direction, and the pinning of chip is oriented parallel to sensitive direction.

When Fig. 4, Fig. 5 are tradition magnetic resistance gear sensor measurement large and small different tooth pitch gear, the basic mode of magnetic resistance gear sensor arrangement change.It can be seen that for tackling different space width, in chip, two response region distances need to adjust close to space width half, and to obtain peak signal output, if tooth pitch change, then response region distance needs to redesign.Fig. 6, Fig. 7 are that this utility model TMR gear sensor measures large and small different space width gear schematic diagram.It can be seen that response region position is fixed, being spaced apart the response channel of space width half position by activation, the design utilizes single design can meet the detection needs of various space width, and redesigns production without changing template.Simultaneously because response region presses close to package casing, when detection, sensor levels can be positioned over gear place plane, make one side of sensor press close to gear top, reduce detection spacing, strengthen output signal.

Fig. 8 is the arrangement mode of multiple response channel in sensor designed by this utility model, and each sensor chip is made up of one or more response regions, and each response region comprises a plurality of response channel, and the typical sizes of single search coverage is 1000 μm * 450 μm.The sensitive direction of sensor is perpendicular to the long limit of response channel, and multiple response regions can splice along sensitive direction.Shown in single feeler arm schematic diagram in 9, every feeler arm two ends are contact electrode, and stage casing is in series by a plurality of comb structure, comprises 5 comb structures in figure.By Figure 10, shown in Figure 11 comb structure side view, top view, comb structure by being covered in the upper electrode of TMR, bottom electrode is staggered is connected in series, bottom electrode directly contacts with silicon substrate, upper electrode typical material is gold, bottom electrode is the multiple structure that tantalum and ruthenium replace superposition, response region surface covers insulating passivation layer beyond contact electrode position, wall scroll TMR is oval column structure, each TMR is respectively by upper, under each electrode cover, connected by upper/lower electrode between magneto-resistor, TMR major axis limit long with response channel rectangle is parallel.Generally feeler arm comprises 5 comb structures, and each comb structure comprises 18 tunnel knot magnetic resistance, and the most each feeler arm comprises 90 tunnel knot magnetic resistance.

Figure 12, Figure 13 are the response channel connecting schemes adapting to different space width, and response region generally comprises 4 response channel arranged in parallel, and adjacent response channel typical pitch is 250 μm.When response channel is at a distance of 250 μm, as Figure 12 activates 4 continuous response passages, can survey optimum space width is the twice activating response channel distance recently, i.e. 0.5mm；It is as bigger in space width need to be measured, then by Figure 13 scheme by two response regions along sensitive direction split, activating the response channel that spacing is 2 channel widths and then can surveying optimum space width is the gear for 1mm, multiple response regions can splice according to said method further, adapt to the rotating speed of wider space width gear, turn to and hypodontia detection.

Enjoy a double blessing in bridge construction, two electric bridge spacing are set to space width half, two bridge output signal phase 90 degree can be made.Figure 14, Figure 15 respectively enjoy a double blessing 90 degree of phase contrasts of bridge connection circuit and chip bind mode, utilize the state that phase contrast can rotate forward with prototype gear and reverse.Wherein feeler arm R1-R4 and R3-R2 forms electric bridge 1, and feeler arm R5-R8 and R7-R6 forms electric bridge 2, successively may determine that pinion rotation direction by the output of direct comparison bridge 1 and 2 signal.The output signal frequency utilizing electric bridge 1 or 2 can determine that gear rotational speed, signal intensity may determine that gear position and hypodontia detection.

Based on the embodiment in this utility model, all other embodiments that those of ordinary skill in the art are obtained under not making creative work premise, broadly fall into the scope of this utility model protection.Although this utility model is illustrated with regard to preferred implementation and has been described, it is understood by those skilled in the art that without departing from claim limited range of the present utility model, this utility model can be carried out variations and modifications.

Claims (7)

1. the tunneling junction magnetoresistive gear sensor chip for the detection of micro-tooth pitch, it is characterized in that, described sensor chip includes: silicon substrate, the one or more response regions being positioned on silicon substrate, response region is positioned at position, edge, chip the same side, each response region comprises at least two rectangle and the response channel arranged in parallel along the long limit of rectangle, each response channel is formed by least two feeler arm splits, every feeler arm is in series by least two comb structures, every comb structure is at least two magneto-resistor and the upper electrode being covered in described magneto-resistor two ends, bottom electrode is connected in series, single described magneto-resistor is oval column structure, described magneto-resistor major axis is parallel with the long limit of described response channel.

2., according to a kind of tunneling junction magnetoresistive gear sensor chip detected for micro-tooth pitch described in claim 1, it is characterised in that the material of described upper electrode is gold, described bottom electrode is the multiple structure that tantalum is alternately constituted with ruthenium.

3. according to a kind of tunneling junction magnetoresistive gear sensor chip detected for micro-tooth pitch described in claim 1, it is characterized in that, every described feeler arm also includes the contact electrode being positioned at two ends, for a plurality of comb structure being connected in series between described contact electrode, described response region surface covers insulating passivation layer beyond contact electrode position.

4. according to a kind of tunneling junction magnetoresistive gear sensor chip detected for micro-tooth pitch described in claim 1, it is characterized in that, the sensitive direction of described sensor chip is perpendicular to the long limit of described response channel, the double crossing over biased direction of described sensor chip is perpendicular to the sensitive direction of described sensor chip, and the pinning of described sensor chip is oriented parallel to described sensitive direction.

5. according to a kind of tunneling junction magnetoresistive gear sensor chip detected for micro-tooth pitch described in claim 4, it is characterised in that multiple response regions connect along the sensitive direction of described sensor chip.

6. according to a kind of tunneling junction magnetoresistive gear sensor chip detected for micro-tooth pitch described in claim 1, it is characterised in that described sensor chip is the full bridge structure being made up of a plurality of response channel.

7. according to a kind of tunneling junction magnetoresistive gear sensor chip detected for micro-tooth pitch described in claim 1, it is characterised in that described sensor chip is the bridge construction of enjoying a double blessing being made up of a plurality of response channel, and wherein two full-bridge spacing are half tooth pitch.