JPH0781171A - Recording apparatus - Google Patents

Abstract

PURPOSE:To enable the anticorrosion of a magnetic head to be enhanced by providing magnetic detecting elements and the like including linear magnetic resistance element patterns comprising a plurality of ferromagnetic substance thin films formed side by side at a given pitch on the surface of a substrate. CONSTITUTION:A magnetic head 8 is fixed by a silicon adhesive on the base plate 100 consisting of aluminum, and on the base plate 100, a flexible printing board 9 is secured via a reinforcing plate consisting of aluminum spaced away from the magnetic head 8 at a predetermined distance. The MR element of the magnetic head 8 is composed of linear MR element patterns consisting of a plurality of ferromagnetic substance thin film formed side by side at a predetermined pitch corresponding to pitch of the magnet of a magnetic scale 7 along the longitudinal direction of the magnetic scale 7. Thus, even in the case where a magnetic wire magnetized at a minutely very small pitch is used as the magnetic scale 7, positional detection can be positively conducted in the carriage 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus, and more particularly to a so-called serial type recording apparatus which moves a carriage having a recording head to perform recording and detects the position of the carriage by a magnetic linear encoder. The present invention relates to a recording device.

[0002]

2. Description of the Related Art A magnetic linear encoder is provided with a linear magnetic scale portion which is magnetized in opposite polarities alternately at a predetermined pitch along the length direction, and is movably provided along the magnetic scale portion. The magnetic head is a magnetic head that detects the magnetic field of the scale portion, and the magnetic head is composed of a magnetoresistive effect element (hereinafter abbreviated as MR element). A configuration has been proposed in which this magnetic linear encoder is used to detect the position of a carriage in a serial type recording apparatus.

In this case, since ink, human sweat, etc. adhere to the magnetic head of the magnetic linear encoder in the recording apparatus, a long-term energization test of the magnetic head causes electrochemical corrosion, resulting in a ferromagnetic material such as permalloy. The line or band-shaped pattern of the MR element made of the thin film of 2 becomes thin, causing a disconnection. In order to prevent this, it is necessary to shield the MR element from ink, sweat fluid, water and the like. For this reason, the structure shown in FIG. 11 is adopted in the magnetic head of the magnetic linear encoder of the conventional recording apparatus.

In FIG. 11, reference numeral 60 is a magnetic scale portion, and 61 is a magnetic head element portion which is a main portion of the magnetic head. The magnetic head element portion 61 has a structure in which an MR element 63 composed of a thin film is formed on a glass substrate 62, and a protective glass plate 65 is adhered onto it by an adhesive 64. The magnetic head element portion 61 is arranged so as to face the magnetic scale portion 60 via the gap g, and the surface on which the MR element 63 is formed is orthogonal to the longitudinal direction of the magnetic scale portion 60 (left-right direction in the drawing). It

According to such a structure, the MR element 63 is covered with the adhesive 64 and the protective glass plate 65, and only the end face is exposed to the atmosphere, which is extremely small, and the corrosion resistance of the MR element can be improved. .

[0006]

However, as shown in FIG.
In such a structure, the MR element 63 has a relationship with the orientation of the deposition surface of the MR element 63 with respect to the magnetic scale portion 60.
Since there is only one line or strip-shaped pattern of the ferromagnetic thin film for detecting the magnetic field, the high output cannot be obtained. In particular, when using a magnetic linear encoder in a printer that performs color recording with a high-density dot system,
Due to the demands for space saving, high-speed response, and high accuracy, the magnetic scale part is made of Fe-Cr-Co and has a diameter of 1
It has been proposed to use a magnet wire as thin as about mm, which is magnetized at a very small pitch of, for example, 50 μm when the pitch of magnetization of the N pole and the S pole is 100 μm or less corresponding to the dot density. In this case, the magnetic head having the structure of FIG. 11 has a problem that the output is extremely low and the required height cannot be obtained.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to attach a magnetic scale part of a magnetic linear encoder, which is thin like the above-mentioned magnet wire, in a serial type recording apparatus for detecting the position of a carriage by using a magnetic linear encoder. Even if the magnetic pitch is very small, it is possible to obtain an output signal of a required height from the magnetic head of the encoder so that the carriage position can be reliably detected and to improve the corrosion resistance of the magnetic head. .

[0008]

In order to solve the above-mentioned problems, according to the present invention, there is provided a recording apparatus for carrying out recording by moving a carriage carrying a recording head, and means for detecting the position of the carriage. As a linear magnetic scale part fixed in parallel to the moving path of the carriage and magnetized in a reverse polarity at predetermined pitches alternately along the length direction, and a magnetic field of the magnetic scale part fixed to the carriage. In a recording apparatus provided with a magnetic linear encoder including a magnetic head for detecting a magnetic field and a magnetic head for detecting a magnetic field at a base portion, a base plate and a magnetic scale held on the base plate. A substrate having an insulating layer on at least the surface thereof, arranged parallel to the magnetic scale part, and a magnetic scale part on the surface of the substrate along the length of the magnetic scale part. A magnetic detection element having a linear magnetoresistive effect element pattern made of ferromagnetic thin films formed in parallel at a pitch corresponding to the magnetization pitch, and on the surface of the substrate so as to cover the magnetic detection element. A protective film made of an insulator formed on the electrode, an electrode part connected to the magnetic detection element, an island part having conductivity provided on the electrode part, and the base plate on the base plate. A configuration is adopted that includes a transmission unit that is held at a predetermined distance from the magnetic detection element and that transmits a detection signal from the magnetic detection element, and an electrical conductor that electrically connects the island portion and the transmission unit. did.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of the main part relating to the position detection of the carriage in the recording apparatus of the embodiment.

In FIG. 1, a carriage 1 indicated by an alternate long and short dash line is provided with a recording head 2 of an ink jet system or the like, is slidably provided on a guide bar 3, and a guide shaft having a spiral groove formed on an outer peripheral surface thereof. It is guided to reciprocate by 4. That is, the carriage 1 has an engagement portion (not shown) that engages with the spiral groove of the guide shaft 4, and when the guide shaft 4 is rotationally driven by a carriage drive motor (not shown),
The engaging portion moves along the spiral groove of the guide shaft 4, and the carriage 1 moves.

The carriage 1 reciprocates along the platen 5 as shown by the double-headed arrow, and the recording head 2 is driven during this movement, with respect to the recording sheet 6 wound on the outer peripheral surface of the platen 5. Ink droplets are ejected to record dots D at a predetermined pitch P. Then, images or characters are recorded in a dot matrix pattern.

On the other hand, a magnetic scale unit 7 and a magnetic head 8 which constitute a magnetic linear encoder for detecting the position of the carriage 1 and generating a synchronizing signal are provided.

The magnetic scale portion 7 is composed of a magnet wire having a diameter of about 1 mm, and the N pole and the S pole are alternately magnetized in opposite polarities along the length direction at a pitch corresponding to the pitch P of the dots D. Has been done. For the sake of convenience, the pitch P of the dots D, that is, the pitch of the magnetization is shown to be much larger than it actually is, and the actual pitch is 100 μm or less. The magnetic scale portion 7 is stretched in parallel with the guide shaft 4, that is, in parallel with the moving path of the carriage 1, and is fixed to a main body frame of a recording device (not shown).

The magnetic head 8 is an MR head that detects the magnetic field of the scale portion 7 by an MR element, and is slidable with respect to the scale portion 7 and fixed in the carriage 1. An output signal of the magnetic head 8 according to the magnetic field of the scale portion 7 is guided to a control circuit board 11 of the recording apparatus via a flexible printed board 9 and a flexible cable 10, and the control circuit outputs the output signal of the magnetic head 8 to the carriage 1. The position is designed to be detected.

Next, details of the structure of the magnetic head 8 will be described with reference to FIGS.
This will be described with reference to FIG.

In FIG. 2, as a constituent member of the magnetic head 8, reference numeral 12 is a slider, which is formed in a hollow cylindrical shape, and through which the magnetic scale portion 7 is inserted, and slide bearing portions 12a formed at both ends thereof. The magnetic scale unit 7 is slidably provided and fixed to the carriage 1.

An MR element substrate 13 made of an insulating glass is fixed to the inside of the slider 12, and the MR element substrate 13 is arranged so as to face the magnetic scale portion 7 in parallel via a gap g. The portion of the magnetic scale portion 7 on the side facing the substrate 13 is magnetized as a magnetized portion 7a.

An MR element is provided on the surface of the substrate 13. This is shown in FIG. FIG. 3 shows A of FIG.
The magnified state of the magnetic scale 7 and the MR
The layout of element patterns and the like are schematically shown. As shown in FIG. 3, on the surface of the substrate 13, an MR element pattern 14 which is a linear pattern made of a thin film of a ferromagnetic material such as permalloy that constitutes an MR element is formed along the magnetic scale along the length direction of the magnetic scale portion. Magnetization pitch of part 7 (between N poles,
To a plurality of poles (here, seven poles) are arranged side by side at a pitch corresponding to the pitch between the S poles.

Further, a protective film 15 made of an insulator is formed on the substrate 13 so as to cover the entire MR element pattern 14.

Here, the film thickness of the MR element pattern 14 is 50.
The thickness is about 0 angstrom, and the gap g can be suppressed to about 20 μm ± 5 μm due to its magnetic characteristics, and therefore the thickness of the protective film 15 can be suppressed to about 10 μm ± 3 μm.

By the way, FIG. 3 merely schematically shows the cross-section of the MR element portion. In reality, the number of MR element patterns 14 is larger, and the protective film 15 is preferably a two-layer film. To be done. An example of the structure of the actual magnetic head 8 is shown in FIG. FIG. 4 is a plan view of the surface of the MR element portion of the magnetic head 8 as seen through the protective film.

In FIG. 4, seven MR element patterns 1
Four sets are provided by connecting 4 like a zigzag, and the thin film patterns of the electrodes 16a and 16b are connected to both ends of each set. That is, in this case, 28
The MR element is composed of the MR element pattern 14 of the book.

As the protective film, a SiN _x film (X = 0.05 at% or more) 15a is formed directly on the MR element pattern 14, and an epoxy film 1 made of a UV epoxy resin is formed thereon.
5b is formed into a two-layer protective film. Here, the process of selecting the protective film in this way will be described below.

As described above, the thickness of the protective film 15 is 10 μm.
It is necessary to keep m ± 3 μm. On the other hand, in general, as a simple method, it is possible to control the film thickness by screen printing, spin coating, or the like using a UV epoxy resin. In this case, in order to suppress corrosion as much as possible, C
A UV epoxy with l ⁻¹ ion of 50 ppm or less is used.
Further, if the temperature of the MR element pattern 14 made of permalloy is raised to 150 ° C. or higher, the MR characteristics are deteriorated. Therefore, a room temperature curing type UV epoxy is used so as to form the protective film 15 at 150 ° C. or lower.

An MR head was manufactured by forming a protective film under such conditions, and an accelerated environment test was conducted. The condition is that the MR head is immersed in saline water and the regular current is 1.2 mA.
Conducted a power test. As a result, the MR element was broken in 1 hr. On the other hand, the MR head of the conventional example shown in FIG. 14 was OK even after energizing for 100 hours.

The cause of this is considered to be that the boiling water absorption of the UV epoxy resin is 0.4 wt% at 1 hr, and the water and ions in the saline solution pass through the epoxy molecules by absorbing water. The UV epoxy resin has a considerably low boiling water absorption rate among organic resins, but it seems to be still difficult at this level. In that respect, the boiling point of the inorganic film is about 0.

Further, in the case of UV epoxy resin, the adhesive strength to the glass surface of the substrate is not so good, and there is a possibility that the interface is delicately peeled off. When a cross-cut test based on JIS was conducted this time, there was no peeling on the permalloy surface, but peeling of the epoxy resin on the glass surface was observed. In particular, this phenomenon is -20 before the accelerated environmental test.
After 20 times of ℃ and + 70 ℃ heat shock,
It was also found that the breakage of the MR element became faster when the energization test was performed. The weak adhesive strength at the interface is considered to be due to the compatibility between the glass and the epoxy resin or the difference in the coefficient of linear expansion.

On the other hand, in the case of an inorganic protective film,
The adhesive strength with glass can be changed by (1) material, (2) film forming method, and (3) film forming means, and the adhesive strength can be increased more than that of the epoxy film.

As an inorganic insulating material having good adhesion to a glass substrate, there is a Si inorganic insulating material. It is considered that this is because it has a good compatibility with SiO ₂ which is the main component of glass and forms a Si—Si bond. However, this time, we sputtered a protective film with exactly the same components as the glass substrate, but the film quality was poor, and alkaline ions such as Pb ⁺ and Na ⁺ in the glass components were generated in the environment promotion test, and the disconnection of the MR element was accelerated. I broke the wire in about 10 hours.

On the other hand, the film of SiN _x (X = 0.05 at% or more) is formed by reactive sputtering or ion plating.
A film having good adhesion is obtained at 50 ° C or lower. For SiN _x ,
The film is amorphous, and when the N content is 0.05 at% or more, the electric resistance changes from 10 ² Ω to 10 ¹⁶ Ω or more.
Further, the hardness is Knoop hardness of H _K 2000 or more by adding N ₂ = 0.05 at% or more, preferably N ₂
Is 10 at% or more and H _{K is} 3000 or more. The Si film itself has H _K = 1000 or less.

As with SiN _x , a SiO _Y (Y = 0.05 at% or more) film can also be formed as a film with good adhesion at 150 ° C. or lower by reactive sputtering or ion plating. SiO _{Y is} also amorphous and contains O _{2 at} least 0.05 at%.
By adding, it becomes an insulator and the hardness is also improved.
However, SiO ₂ has a lower Knoop hardness than SiN, and H _K
= 2000 is the limit. Hardness of the protective film means M
When the R element is assembled and it comes into contact with jigs and tools, M
It is necessary because damage to the protective film to the extent that the R element is exposed to air causes fatal corrosion.

SiO _Y is a Si-based alkoxide or Si (O
It is also possible to form a film by a method in which H) ₄ or the like is spin-coated and dried at 150 ° C. or lower. SiO _{Y is} also SiN _x
Also becomes a dense film as a film quality. This is because there are no grain boundaries.

Also, the observation of the disconnection situation in the case of the organic protective film and the inorganic protective film is different, and in the case of the organic system, a thick protective film is possible (however, if the thickness is 30 μm or more, the magnetic Since it is in contact with the scale, it must be 25 μm or less.)
The device film does not electrolyze. However, after about 1 hour, the permalloy film of the MR element pattern immediately below the outermost periphery of the protective film reacts to generate bubbles, and after 10 minutes, the reaction spreads over the entire surface. In the case of an epoxy UV resin film, this reaction is such that even if one MR element pattern film is separated from the adjacent pattern film by the glass of the substrate, the film of the adjacent element pattern is moved from the next one like migration. It has been corroded to the next. This is once the saline solution Cl
^{When -1} or Na ⁺ ions react with the permalloy film, it is considered that the ions penetrating into the epoxy and the poor adhesion of the interface cause the electrolyte solution of Cl ^-1 ions to spread over the glass part and spread corrosion over the entire surface. .

On the other hand, in the case of an inorganic protective film having a high degree of adhesion such as SiN _x , corrosion is caused by (1) corrosion from pinholes due to dust, (2) corrosion from above the film due to poor film quality, and (3)
Corrosion due to peeling between the MR element substrate and the film due to large film stress can be mentioned. Here, the corrosion of (2) and (3) can be dealt with by controlling the Ar gas pressure and the N ₂ gas pressure during the sputtering of film formation. These have been previously studied for reactive sputtering. But (1)
It is very difficult to eliminate the cause of corrosion of. This is because it is necessary to eliminate zero dust particles of 1 μm or more within an area of 5 mm × 5 mm.

When the SiN _x protective film has pinholes, the thin film portion of the MR element pattern 14 immediately below the pinholes of the SiN _x film 15a is corroded as shown in FIG.
When the reaction is observed under a microscope, the reaction just below the pinhole on the surface of the permalloy film is always generated immediately after immersion in the saline solution and application of electricity, and the reaction gas spouts. It seems that there are pinholes on the glass surface, but the reaction gas does not come out because there is no substance to react.

Further, the reaction on the surface of the permalloy thin film of the MR element pattern spreads to the surroundings in a round state, but the reaction proceeds to the adjacent pattern over the glass portion of the substrate as in the case where the protective film is an epoxy resin. There is no such thing. This is considered to be due to the high degree of adhesion between the glass and SiN _x , and stops at the edge of the pattern. Further, as in the case of the epoxy resin, when the reaction starts, it does not spread over the entire surface at once, but it reacts immediately from the pinhole portion after immersion, gradually spreads over the permalloy film over time, and finally breaks.

Therefore, in the case of a protective film containing only a SiN _x film,
Those that exceed 100 hours or more in immersion current in a saline solution are determined by the probability of pinhole generation. Class 1
Those produced in a clean room of about 10,000 are OK only about 10%.

As one method of improving this, SiN _x
There is a method to increase the film thickness of. Generally, it is better to have a thickness of 200 angstroms rather than 100 angstroms, but the bending point at which the number of pinholes greatly decreases is 500 angstroms or more. The thickness gradually decreases as the thickness increases from 500 angstroms to 5 μm, but on the other hand, when the thickness increases to 3 μm or more, the total stress increases and the MR output gradually decreases, and when the thickness exceeds 5 μm, it considerably decreases. Also,
When the thickness is 3 μm or more, it takes a considerable amount of time to form the film, resulting in extremely low productivity.

In view of the above, the protective film 15 is a multilayer film. In this case, there are two possible multi-layer films. One is an insulating inorganic film having a good adhesion and a small number of pinholes, and an organic film that can be applied thickly at low cost. Shall be formed. On the other hand, the film immediately above is an insulating inorganic film with good adhesion and few pinholes, and an inorganic film having a high film forming speed is coated thereon.

The protective film immediately above the thin film of the MR element pattern is optimally a SiN _x film having a thickness of 1 to 2 μm.
The degree is optimal. Moreover, when forming an organic film on it, UV epoxy resin is the most desirable. This is because the Cl ⁻¹ ion concentration is low, the adhesion is high, and it can be cured at room temperature.

From the above circumstances, as the optimum protective film 15, as shown in FIG. 4, the SiN _x film 15a is formed directly on the thin film of the MR element pattern 14, and the UV epoxy is formed thereon. An epoxy film 15b made of resin is formed.

The film forming method will be described below. First, a permalloy film is formed by vapor deposition on a large glass plate that will be cut into a number of MR element substrates 13 later, and the electrodes 16a and 16b and the MR element pattern are formed by etching. Process into 14 shapes. In this case, for example, 150 or more patterns having the same shape as in FIG. 4 are formed on the one large glass plate.

After that, the SiN _x film 15a is sputtered to a thickness of 2 μm by masking only the lower side of the electrodes 16a and 16b in FIG. That is, the SiN _x film 15a covers the entire MR element pattern 14 and the electrodes 16a and 16b and the entire upper half of the MR element substrate 13 in FIG. It is formed to a size that covers the boundaries of the plates.

Next, an epoxy film 15b made of UV epoxy resin is formed by screen printing. Its thickness is 8μ
The film is formed at m ± 3 μm. At that time, the epoxy film 15b is
The size is set so as to cover the entire MR element pattern 14 and the upper portions of the electrodes 16a and 16b from the SiN _x film 15a, but not to cover the cutting edge of the large glass plate before cutting, which is the outer edge of the MR element substrate 13. That is, the epoxy film 15b
Is, Si inside the film formation region of the SiN _x film 15a so that the entire periphery is positioned on the entire periphery inside of the SiN _x film 15a
It is formed smaller than the N _x film 15a. This is because when the large glass plate is cut to the size of the MR element substrate 13 after the formation of each of the above films, the epoxy film 15b covers the boundaries to be cut and is cut off when cut. This is because. Note that the SiN _x film 15a does not peel off well even when cut with a precision cutting blade.

Further, since the epoxy film on the SiN _x film has a higher degree of adhesion than that on the glass substrate and the peeling from the end face of the epoxy film is reduced, the epoxy film 15b is the SiN _x film as described above. It is better to form it smaller than 15a.

After the epoxy film 15b is formed in this manner, the large glass plate is cut into the size of the MR element substrate 13 to complete the element portion of the magnetic head 8.

When the samples thus produced were accelerated and subjected to an environmental test, all 100 out of 100 pieces were electrically energized for 100 hours or longer.

As another embodiment of the protective film 15, S
When metal Cr was deposited on the iN _x film by sputtering to a thickness of 5 μm instead of the epoxy film, 100 of 100 tests were also OK.

The electrodes 16a, 1 exposed in FIG.
The lower part of 6b is soldered with a lower solder, joined with a flexible printed board (FPC), and covered with a thick UV epoxy resin to prevent corrosion. Since this portion has a large distance from the magnetic scale portion 7, the epoxy resin can be thickened.

Further, in the embodiment shown in FIG. 4, Si
The N _x film 15a covers the upper half of the MR element substrate 13, that is, the entire MR element pattern 14 and the vicinity of the connection portions of the electrodes 16a and 16b with the MR element pattern 14. This is because the lead electrode portion of the MR element is formed below the MR element substrate 13, and if this portion is also covered, the electrode portion cannot be soldered. However, when the protective film is formed in such a shape,
The permalloy at the boundary of the SiN _x film 15a may be broken due to heat shock or the like. This is SiN
Stress and solder stress or the like of the _x film 15a is, SiN _x film 15
It is considered that the concentration is linearly concentrated on the boundary portion of a.

The above will be described more specifically with reference to FIGS. 5 (a) and 5 (b). FIG. 5A is a plan view showing a state in which the FPC is connected to the electrodes 16a and 16b of the embodiment shown in FIG. 4, and FIG. 5B is a cross-sectional view of a main part.

On the electrodes 16a and 16b, the conductor portion 17a of the FPC 17 for outputting the detection result of the MR element is soldered. This soldering is performed with the electrodes 16a, 16
Lower solder 18 is applied on b, a solder layer 19 is formed on the lower solder 18, and the conductor portion 17a is soldered. The protective film 20 is
It is formed so as to cover one end 21 of the SiN _x film 15a. According to such a configuration, the electrodes 16a, 16
Since the thickness of b is thin (about 500 angstroms, which is the same as the thickness of the MR element pattern 14), the lower solder layer 18 and SiN
_A crack may occur at the boundary 22 with the _x film 15a, and in the worst case, the wire may be broken. The following are possible causes for this.

That is, the FPC 17 is connected to the electrodes 16a, 16
When connecting to b, the solder layers 18 and 19 are melted and cooled. At this time, the contraction stress acts in the direction A in FIG. 5B. Furthermore, since the SiN _x film 15a on the electrodes 16a and 16b is formed by a vapor deposition method or a sputtering method, stress in the B direction in FIG. 5B acts during the contraction process. for that reason,
The stress concentrates on the boundary portion 22. In addition, the electrodes 16a, 16
Since a flux is used when the lower solder layer 18 is formed on the b, chlorine ions and the like contained in the flux chemically react with the electrodes 16a and 16b, which are ferromagnetic thin films, and melt. Further, the above phenomena are combined to cause stress corrosion at the boundary portion 22. When the head 8 is energized and left in high humidity, the moisture becomes an electrolytic solution and electrolyzes the electrodes 16a and 16b. This phenomenon remarkably occurs at the boundary portion 22.

Due to the above reasons, the crack or the wire breakage occurs in a substantially straight line, and the direction of the crack follows the direction of the one end 21 of the SiN _x film 15a shown in FIG. 5A.

In order to avoid such a phenomenon, in the embodiment described below, the electrodes 16a and 16b and the flexible printed board 9 are connected by a conductive wire.

This embodiment will be described in detail below with reference to FIGS. 6, 7 and 8.

FIG. 6 is a plan view showing the main part of this embodiment, and FIG.
Is a sectional view thereof, and FIG. 8 is a plan view showing a part of the protective film of the magnetic head portion as seen through.

The magnetic head 8 is fixed on a base plate 100 made of aluminum with a silicon adhesive.
A flexible printed board 9 is fixed on the base plate 100 at a predetermined distance from the magnetic head 8 via a reinforcing plate 101 made of aluminum. The reinforcing plate 101 is fixed to the base plate 100 with a silicone adhesive, and the flexible printed board 9 is the reinforcing plate 1.
It is fixed to 01 by a method such as thermocompression bonding.

Further, the electrodes 16a and 16b of the magnetic head 8 are
(See FIG. 8) Above the island portion 3 which is an electrical contact portion.
3 is configured by the method described later. As shown in FIGS. 6 and 7, the island portion 33 and the flexible printed board 9 are connected by a conductive wire, for example, a wire 102 made of aluminum so as to establish electrical continuity. The wire 102 may be made of gold, silver, copper, or an alloy thereof. The wire sealant 103 is the wire 1
02 is to be protected from external contact, and a resin having a small amount of chlorine ions, for example, an epoxy resin is used.

On the other hand, in FIG. 8, the SiN _x film 15a is formed.
Is formed with a thickness of 1 to 2 μm by a sputtering method, an ion plating method, an evaporation method, or the like. And SiN _x
The electrodes 16a, 16b not covered with the film 15a need to be bonded with a wire, and therefore the electrodes 16a, 1b
6b has a coefficient of linear expansion similar to that of the permalloy used for the electrodes 16a and 16b, is conductive, and is a metal material that is easy to bond, such as Ni, Al, Ni / Au,
Cu and Ti / Cu are stacked as the island portion 33. Hereinafter, a specific configuration and manufacturing method will be described with reference to FIG.

First, as shown in FIG. 9A, the substrate 30
With MR effect on permalloy (Ni80% wt-Fe2
0% wt) 31 is vapor-deposited. Here, the substrate 30 is preferably a glass material having an insulating property, particularly glass having a small amount of alkali components, or a Si substrate obtained by thermally oxidizing the surface to SiO ₂ . At this time, the permalloy 31 is vapor-deposited while applying a magnetic field with a magnet in a direction in which anisotropy is desired. The magnetic body can be another superlattice material such as Ni-Co. The smaller the thickness of the permalloy 31 is, the larger the magnetoresistance change rate (Δρ / ρ) becomes, but it becomes mechanically and chemically fragile.
00 angstrom. And Permalloy 31
The MR element pattern 14 and the electrodes 16a and 16 shown in FIG.
In order to form b and b, a positive resist is spin-coated on the permalloy 31 by about 5 μm and baked. And
The mask is patterned and exposed to light, and then the resist is peeled off. In this case, a resist stripper or an alkaline stripper is used. Then, the pattern is etched with an acid-based etching solution to obtain a predetermined pattern.

Next, as shown in FIG. 9B, Al50 is laminated on the permalloy 31 by continuous vapor deposition to a thickness of 0.2 to 1 μm. The reason why Al is selected in this embodiment is as follows. In the case of continuous vapor deposition, the permalloy metal and the metal for forming the islands are deposited in the same vapor deposition machine, and the metal of the islands is taken into the permalloy as contamination, which may change the magnetism. is there. In particular, since the magnetoresistive effect is brought out by the effect of magnetic anisotropy, Mo, Mn, Cr, etc., which easily reduce the magnetic anisotropy, are not preferable. In addition, permalloy and Ni that cannot be selectively etched,
This is because Fe and the like are also not preferable.

Next, as shown in FIG. 9C, Al50
Only the portion corresponding to the island portion of is protected by the negative resist 51. In this case, the negative resist is spin-coated for about 5 μm and then baked. Then, it is masked in a predetermined pattern shape, exposed, and developed with a dedicated developer.

Next, as shown in FIG. 9D, the island portion 50 is formed.
Al50 other than a is selectively etched so as to stop at the permalloy 31. An alkaline solution is used as the etching solution.

Next, as shown in FIG. 9E, the resist 51 is peeled off. At this time, a phenol-based stripping solution is used. Since the phenol-based stripping solution slightly corrodes permalloy, the permalloy 31 has an advantage that it has a smaller surface area and is not corroded when used before the step in which the pattern is not formed.

Next, as shown in FIG. 9F, a predetermined pattern is formed on the permalloy 31 using the positive resist 52.

The MR shown in FIG. 4 is added to the permalloy 31.
In order to form the element pattern 14 and the electrodes 16a and 16b, a positive resist is spin-coated on the permalloy 31 by about 5 μm and baked. Then, after the mask is exposed in a pattern shape, the resist is peeled off. In this case, a resist stripper or an alkaline stripper is used.
Then, the pattern is etched with an acid-based etching solution to obtain a predetermined pattern.

Next, as shown in FIG. 9G, SiN _x
The film 53 is formed.

According to these embodiments, two boundary portions with the SiN _x film are provided, such as a boundary portion between the island portion and the SiN _x film on the electrode and a boundary portion between the island portion and the SiN _x film. ,
Moreover, since the stress concentration points are dispersed by forming them at a distance, it is possible to prevent the electrode from cracking or breaking.

Further, when the wire is bonded, the permalloy of the electrode is not directly bonded but is bonded through the island portion, so that there is no possibility that the permalloy is deteriorated.

Further, the permalloy of the electrode is used as the island portion and SiN.
_{Since the X} films penetrate and cover each other, there is no exposed part of permalloy, and water, salt, etc. do not easily enter, so that permalloy is not hydrolyzed or corroded.

According to the above-described embodiment of the present invention, the MR element of the magnetic head 8 of the magnetic linear encoder has the magnetic scale portion 7 on the surface of the MR element substrate 13 facing the magnetic scale portion 7 in parallel. 11 has a linear MR element pattern 14 formed of a ferromagnetic thin film formed in parallel along the length direction of the magnetic scale portion 7 at a pitch corresponding to the magnetization pitch of the magnetic scale portion 7. A significantly higher output can be obtained as compared with the case where the MR element of 1 has a pattern of only one. Therefore, even if a thin magnet wire magnetized with a very small pitch is used as the magnetic scale portion 7, a sufficiently high output can be obtained from the magnetic head 8 and the position of the carriage 1 can be reliably detected. Can be performed with extremely high accuracy and at high speed, and the space of the recording device can be saved.

The protective film 15 is not limited to the above-mentioned two-layer film, but an inorganic film such as a Cr film may be formed on the SiN _x film as described above, or the pin described above. If you clear problems such as holes and productivity, SiN _x (X =
0.05 at% or more) or SiO _Y (Y = 0.05a
It may be a single-layer film made of only a Si-based inorganic insulating material such as t% or more).

[0075]

As is apparent from the above description, according to the present invention, a sufficiently high detection output can be obtained from the magnetic head even when a magnetic scale portion having a small magnetizing pitch is used. The position can be detected reliably,
The carriage position can be detected very accurately and at high speed, and the space of the recording device can be saved.

Further, the protective film can prevent the corrosion of the magnetoresistive effect element to improve the corrosion resistance of the magnetic head and the reliability of the recording apparatus.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a main part relating to carriage position detection of a recording apparatus according to an embodiment of the present invention.

FIG. 2 is a top view of a magnetic scale unit and a magnetic head that form the magnetic linear encoder of the apparatus.

FIG. 3 is an explanatory view schematically showing a magnetized state of a magnetic scale portion, an arrangement of MR element patterns and the like by enlarging a cross section of a portion A in FIG.

FIG. 4 is a plan view showing a protective film on a surface of an MR element portion of a magnetic head as seen through.

FIG. 5 is a diagram for explaining an example in which an FPC is connected to the MR element section.

FIG. 6 is a main part plan view for explaining an example in which a magnetic head and an FPC are connected.

FIG. 7 is a sectional view of FIG.

FIG. 8 is a plan view showing an MR element portion and an island portion of the magnetic head.

FIG. 9 is a process drawing showing a method for obtaining a magnetic head.

FIG. 10 is a cross-sectional view showing a state where corrosion of a thin film of an MR element pattern occurs due to a pinhole in a protective film.

FIG. 11 is a cross-sectional view showing a structure of a main part of a magnetic head of a magnetic linear encoder of a conventional recording device.

[Explanation of symbols]

1 Carriage 2 Recording Head 3 Guide Bar 4 Guide Axis 5 Platen 6 Recording Sheet 7 Magnetic Scale Section 8 Magnetic Head 12 Slider 13 MR Element Substrate 14 MR Element Pattern 15 Protective Film 15a SiN _X Film 15b Epoxy Film 16a Electrode 16b Electrode 33 Island Part 100 Base plate 101 Reinforcement plate 102 Wire 103 Wire sealant

Claims (3)

[Claims] 1. A recording apparatus for recording by moving a carriage carrying a recording head, wherein the means for detecting the position of the carriage is fixed in parallel with a moving path of the carriage and extends in the length direction. A magnetic head for detecting the magnetic field of the magnetic field, which is composed of a linear magnetic scale part magnetized in opposite polarities alternately at a predetermined pitch, and a magnetic head fixed to the carriage for detecting the magnetic field of the magnetic scale part. In a recording device provided with a magnetic linear encoder, the base plate has an insulating layer on at least the surface arranged in parallel to the magnetic scale portion held by the base plate. A substrate, and a plurality of strong electrodes formed on the surface of the substrate side by side along the length of the magnetic scale portion at a pitch corresponding to the magnetization pitch of the magnetic scale portion. A magnetic detection element having a linear magnetoresistive effect element pattern made of a magnetic thin film, a protective film made of an insulator formed on the surface of the substrate so as to cover the magnetic detection element, and the magnetic detection element. An electrode part connected to the electrode part, an electrically conductive island part provided on the electrode part, and a predetermined distance from the magnetic detection element on the base plate. A recording apparatus comprising: a transmitting unit for transmitting a detection signal; and an electric conductor electrically connecting the island portion and the transmitting unit. 2. The recording apparatus according to claim 1, wherein the electric conductor is formed in a wire shape. 3. The recording apparatus according to claim 1, further comprising a protection portion that protects the electric conductor from external contact.