JPS6144703A - Abrasion-resistant layer and electronic part - Google Patents

Abstract

PURPOSE:An abrasion-resistant layer, obtained by decomposing a mixed gas containing a boron compound, phosphorus compound and silicon compound with a plasma, and forming a deposit layer consisting of B, P and Si, having improved heat resistance, etc., and suitable for thermal heads of thermosensitive printers, etc. CONSTITUTION:A boron compound, e.g. BH3 or BCl3, is mixed with a phosphorus compound, e.g. PH3, or PCl3, and a silicon compound, e.g. SiH4 or halogenated silicon, at <=5 atomic ratio of the phosphorus to the boron and <=20 atomic ratio of the silicon to the boron to prepare a mixed gas, which is, together with a carrier gas, e.g. hydrogen, introduced into a reactor, and decomposed with a plasma by the high-frequency or microwave method to form a deposit layer, consisting of phosphorus and silicon, and having about 0.1-10mum film thickness on a substrate and give the aimed abrasion-resistant layer.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION Technical Field The present invention relates to a wear-resistant layer and an electronic component having a wear-resistant layer. More specifically, it has high hardness, excellent abrasion resistance, and excellent heat resistance, and can be used as a protective layer for various devices, such as the wear-resistant layer of thermal heads for thermal printers used in facsimiles, etc., to extend the life of the device. The present invention relates to an elongated wear-resistant layer and an electronic component such as a thermal head having this wear-resistant layer.

BACKGROUND OF THE INVENTION Conventionally, a thermal head for a thermal printer used as one of the output methods of a facsimile 2 computer terminal device, printing device, recorder, etc. has been constructed as shown in FIG. 1, for example.

That is, on the base 2, there is a glaze layer 3 for heat storage,
A heat generating resistor layer 4 is formed, and a pair of lead layers 51 and 53 are ohmically connected to the heat generating resistor layer 4.

Further, as the uppermost layer, a wear-resistant layer 6 is disposed in order to prevent wear and damage of the heating resistor layer 4 and the lead layers 51, 53 due to sliding contact with the thermal paper.

Then, the heating resistor layer 4 is connected via the lead layers 51 and 53.
By energizing, the heating resistor layer 4 in the area between the lead layers 51 and 53 generates heat, and this heat is applied to the thermal paper that is in relative sliding contact with this through the abrasion resistant layer 6. A recording is made.

In such a thermal head, the wear-resistant layer 6 has high hardness, excellent wear resistance, and excellent heat resistance.
As a result, even if the head is subjected to sliding contact with thermal paper and repeated heat generation over a long period of time, its function is maintained, for example, the resistance value of the heating resistor layer does not deteriorate, and the life of the head is maintained. is required.

Therefore, in view of these points, the present inventors have previously proposed that a B-P-3i thin film is preferable as a wear-resistant layer for thermal heads, etc. (Japanese Patent Application No. 55-21950, etc.) ).

The thin film according to the above proposal is formed by the CVD method,
It has excellent wear resistance and heat resistance.

However, this thin film still does not have sufficient abrasion resistance and heat resistance under the extremely harsh conditions of use in thermal heads, and repeatedly generates heat over a long period of time under load when running in contact with thermal paper. For example, this causes a deterioration in the resistance value of the heat generating resistor layer, which ultimately leads to the end of the life of the head, and further improvements in the characteristics of the wear-resistant layer are desired.

When forming a heat-resistant protective layer on a substrate using the conventional CVD method, it is buried at a high temperature of 80°C to 900°C, so cracks may appear as it is used due to thermal stress at high temperatures. This is because resistance value deterioration occurs.

Note that if sputtering is used, the substrate heating temperature can be increased to 50°C.
Although the temperature can be lowered to 0° C. or lower, the layer will have a structure containing many cavities, and the mechanical strength and abrasion resistance of the layer will be significantly reduced.

II. Purpose of the Invention The purpose of the present invention is to form a wear-resistant layer by plasma decomposition (glow discharge decomposition) of a mixed gas containing B, P, and Si, so that the film quality is homogeneous and the film has good wear resistance and heat resistance. The object of the present invention is to provide a wear-resistant layer which can be formed into a good thin film and further improve the head life when used as a protective layer for electronic parts such as those for thermal heads.

Another object of the present invention is to provide a highly durable electronic component having this improved wear-resistant layer.

That is, the first invention is a wear-resistant layer characterized by comprising boron, phosphorus, and silicon deposited by plasma decomposition of a mixed gas containing a boron compound, a phosphorus compound, and a silicon compound.

Moreover, the second invention is characterized by comprising boron, phosphorus, silicon, and 1 at% or less hydrogen and/or halogen deposited by plasma decomposition of a mixed gas containing a boron compound, a phosphorus compound, and a silicon compound. It is a wear layer.

And the third invention is boron, phosphorus and silicon buried by plasma decomposition of a mixed gas containing a boron compound, a phosphorus compound and a silicon compound, or boron, phosphorus,
The present invention is an electronic component characterized by having a wear-resistant layer made of silicon and 1 at % or less of hydrogen and/or halogen.

■Specific structure of the invention Hereinafter, a specific configuration of the present invention will be explained in detail.

The wear-resistant layer of the present invention contains B, P and Si.

In this case, the Si content in the wear-resistant layer is B 1 in atomic ratio.
However, it is 20 or less, especially 0.01 to 5.

When S i /B exceeds 20, conductivity occurs and the film becomes unsuitable as an insulating film.

Furthermore, when S i /B is less than o or oi, the mechanical strength of the film decreases, resulting in insufficient wear resistance. In addition, cracks may occur or peeling may occur due to internal strain.

In addition, P/B is 5 or less in atomic ratio, especially 0.001-1
It is.

When P/B exceeds 5, the mechanical strength decreases, and the strength decreases with use.

Moreover, when P/B is less than o or ooi, the mechanical strength of the film decreases, resulting in insufficient wear resistance. In addition, cracks may occur or peeling may occur due to internal strain.

In addition to such B, P, and Si, the wear-resistant layer may contain H and/or halogen depending on the source used.

However, the amount of H or halogen is 1 at% or less.
This is because if it exceeds 1 at%, the resistance will decrease.

In addition, as mentioned above, the wear-resistant layer of the present invention includes B, P, and S.
It has t as an essential component, and contains H or a halogen if necessary, but may contain other elements in an amount of approximately 1% by weight or less based on the total weight, depending on the case.

Examples of such elements include Ge and Sn.

Examples include Pb, AIL, Zr, and Nb.

The wear-resistant layer having such a composition takes an amorphous or polycrystalline form.

In this way, when a thin film layer consisting of the three essential components B, P, and St and having the above composition ratio is formed by glow discharge decomposition under the conditions described below, a hard film with homogeneous mechanical strength and high wear resistance can be obtained. A coating can be obtained.

The film thickness may be determined as appropriate depending on the application, but usually,
0.1=lOILm, especially 0.5-10 JLm.

In order to form the layer made of P and Si, a glow discharge decomposition (plasma decomposition) method is used.

Plasma decomposition may be performed by a radio frequency method or a microwave method.

When following the high frequency method, 1~30MHz, 100W~
It is sufficient to input power of about several kilowatts.

Also, when following the microwave method, I GHz ~ 1
It is sufficient to input power of about 0 GHz and Zoo to 500 W.

The raw material gas used is boron hydride, for example, BH
3, B2 H8, etc., boron halides, e.g. BCl3
．． Phosphorus hydrides, such as PH3, phosphorus halides, such as PCJ13. A silane-based gas such as SiH4, silicon halide, etc. may be used.

Hydrogen, argon, helium, or the like, particularly hydrogen, may be used as the carrier, and the raw material gas may be introduced into the reaction system in a predetermined quantitative ratio.

In order to obtain the optimum hydrogen content for the wear-resistant layer, the optimum types and flow rates of the raw material gas and carrier gas may be determined experimentally.

Note that the operating pressure may be approximately 0.01 to 5 Torr, and the substrate temperature may be approximately 150 to 500°C.

Particularly preferably, at a substrate temperature of 350 to 450°C, the formed thin film has homogeneous film quality, high hardness, and good wear resistance.

Further, the film forming rate may be approximately 1 to 20 persons/sec.

The wear-resistant layer thus formed has high wear resistance and heat resistance, and when used as a protective layer for various devices, can significantly improve the life of the device.

In particular, when the abrasion resistant layer of the present invention is used as an abrasion resistant layer for a thermal head, such effects become much more remarkable, and as the head is used, the wear resistant layer under the load during thermal paper contact. Even when heat is generated repeatedly over a very long period of time, the amount of deterioration in the resistance value of the heat generating resistor layer is significantly reduced, and the life of the head is significantly improved.

In such a case, a typical example of constructing a thermal head using the body wear layer of the present invention may be carried out as follows.

That is, the substrate 2 may be made of ceramics such as alumina.

Further, as shown in FIG. 1, the heat storage glaze layer 3 provided on the substrate 2 may be formed from a normal glass material. Note that the glaze layer 3 is similar to the normal case.
It is provided over almost the entire area on the board, and its thickness is 15~
200 Pm, and furthermore, it may be formed from a paste or slurry containing glass by a conventional method such as screen printing or dipping.

On the other hand, a heating resistor layer 4 is arranged on the glaze layer 3 as shown in FIG. The heating resistor layer 4 may be formed by various methods, but from the viewpoint of its characteristics, a polycrystalline silicon thin film is preferable.

In addition, this polycrystalline silicon thin film contains P.

Impurities such as As, B, and Sb may be contained in a range of about 100% by weight or less, and the solenoid (7) resistance is 2.
It may be about X l O-4 to 5 They are separated into a large number and arranged in a predetermined arrangement so as to form a shape, and their thickness is generally 0.1 to 5 m.

A pair of lead layers 51 and 53 are connected to the heating resistor layer 4 having a predetermined shape and a predetermined arrangement so as to face each other with a predetermined gap. The lead layer may be formed as a thin film using various methods using various high-melting point metals, including aluminum, gold, nickel, copper, tantalum, titanium, tungsten, molybdenum, or alloys thereof, as well as tungsten silicide and molybdenum silicide. It is preferable to consist of the following.

In this case, the lead layers 51 and 53 may be located above or below the heat generating resistor layer 4, and the thickness of the lead layer is approximately 0.5 to 21 Lm. do it.

Then, the wear-resistant layer 6 of the present invention is provided as the uppermost layer over almost the entire upper surface of the heat-resistant base as such a laminate.

Above, we have described one typical example of configuring a thermal head, but in addition to this, various intervening layers may be provided in the thermal head, or the portion of the board corresponding to the heat generating portion may be made convex as shown in the figure. Needless to say, various other embodiments are possible.

Further, the wear-resistant layer may have a two-layer structure, and the compositions of the upper layer and the lower layer may be changed.

■ Specific effects of the invention The wear-resistant layer of the present invention is a very homogeneous film, and has excellent wear resistance,
It has extremely high heat resistance.

Therefore, an electronic component, especially a thermal head, having the wear-resistant layer of the present invention can provide a highly durable thermal head whose characteristics do not change over a long period of time.

In addition, these properties can be used not only for thermal heads but also as wear-resistant layers for various devices to improve the lifespan of devices.

For example, by taking advantage of its abrasion resistance, it is useful as an abrasion-resistant layer of a semiconductor photodetection head that is used in sliding contact with a transparent recording paper. .

The present inventor conducted various experiments in order to confirm the effects of the present invention. An example is shown below.

EXPERIMENTAL EXAMPLE A thermal head as shown in FIG. 1 was prepared to confirm the effects of the present invention.

First, as the substrate 2, 98% alumina with a size of 300 mm x 300 II m and a thickness of 2 m II is used, and 80% alumina is
#1. A glaze layer 3 having a thickness of m was formed.

Then, according to chemical vapor deposition, boron was added to 1% using silane and diporane as sources and hydrogen as carrier gas.
Depositing a polycrystalline silicon thin film with a thickness of l#Lm containing % by weight,
A plurality of parallel strip-shaped polycrystalline silicon thin film heating resistor layers 4 each having a width of 1100p were formed by photolithography with gaps of 30p and 30m.

Thereafter, a W thin film with a thickness of 1.5 gm is deposited thereon, and a window of 1100 x 230 JL is formed in the center of each of the strip-shaped heating resistor layers 4 by photolithography. In this manner, W lead layers 51 and '53 were formed.

Next, an abrasion resistant layer of the present invention or a comparative one was applied over the entire surface of the 8 types of thermal head underlayer laminates formed in this way to a thickness of 1 pm.

In this case, for head B-G, with B2 H6, PH3 and SiH4 as sources, H
13, 56 at a substrate temperature of 400°C with 2 carriers.
Glow discharge decomposition was performed at MHz, 180 W, and 1 Torr, and at that time, the flow rate ratio of each source was changed to form a wear-resistant layer.

The four types of thin films obtained were subjected to compositional analysis using an X-ray microanalyzer, Auger spectroscopy, and varnish force, and it was confirmed that they had the compositions shown in Table 1 below.

In addition, the head H is B2 H,, PH3 and 5it (
4 as a source, vapor phase growth (cv
n) was performed.

For the eight types of heads A-H obtained in this way, a diode matrix was constructed according to a known method, and a lead layer pair was attached to each heating resistor layer of the head while running a thermal paper in contact with it under normal pressure. via, at intervals of 10m5ec, 0
, 5 m5ec pulse energization was repeated.

In this case, the applied power was set to the amount required for the saturation density of the thermal paper.

Pulse energization under such thermal paper running is 2X101.
The test was carried out once, and the resistance value deterioration (%) of all the heating element layers thereafter was measured, and the results were averaged to obtain the results shown in Table 1.

Table 1 A --Leak BIB-0,2Si plug? 12CIB-
0,01P tt 35D (present invention) IB-0,2Si-0,OIP tt
3F Btt
Leak G IB-100Si-2
0P tt Leak HIB-0,2Si-0
,01P CV D! In this case, in heads D and E to which the present invention is applied, the resistance value deterioration is 5% or less.

On the other hand, head B using a thin film protective layer having a composition other than that of the present invention,
C, F, and G show resistance value deterioration of 10% or more.

Further, the head may be in a leak state.

In the conventional CVD method ()l), leakage still occurs.

That is, it can be seen that the wear-resistant layer of the present invention has a great effect on improving the life of the thermal head.

[Brief explanation of drawings]

FIG. 1 is a partially omitted cross-sectional view showing one typical example of applying a wear-resistant layer to a thermal head. l... Thermal head 2... Base, 3... Glaze layer, 4... Heat generating resistor layer, 51.53... Lead layer, 6...Wear-resistant layer Junnin TDC Co., Ltd. agent Patent attorney Yo Ishii - FIG, 1

Claims (7)

[Claims] (1) A wear-resistant layer comprising boron, phosphorus, and silicon deposited by plasma decomposition of a mixed gas containing a boron compound, phosphorus compound, and silicon compound. (2) The wear-resistant layer according to claim 1, wherein the atomic ratio of phosphorus/boron is 5 or less and the atomic ratio of silicon/boron is 20 or less. (3) A wear-resistant layer comprising boron, phosphorus, silicon, and 1 at % or less hydrogen and/or halogen deposited by plasma decomposition of a mixed gas containing a boron compound, phosphorus compound, and silicon compound. (4) The wear-resistant layer according to claim 3, wherein the atomic ratio of phosphorus/boron is 5 or less and the atomic ratio of silicon/boron is 20 or less. (5) Boron, phosphorus and silicon buried by plasma decomposition of a mixed gas containing boron compounds, phosphorus compounds and silicon compounds, or boron, phosphorus, silicon and 1
An electronic component characterized by having a wear-resistant layer made of hydrogen and/or halogen in an amount of at % or less. (6) Claim 5, wherein the electronic component is a thermal head having a glaze layer on the base, a heating resistor layer and an electrode layer on the glaze layer, and a wear-resistant layer as the top layer. Electronic components listed in . (7) The electronic component according to claim 5 or 6, wherein the atomic ratio of phosphorus/boron is 5 or less and the atomic ratio of silicon/boron is 20 or less.