KR20080046109A - Suspension board with circuit and producing method thereof - Google Patents

Abstract

A suspension board with a circuit and a producing method thereof are provided to form an optical waveguide used in an optical assist system with more space than a head slider on a base insulating layer or a cover insulating layer, thereby ensuring freedom in design and improving production efficiency. A suspension board with a circuit(1) comprises a metal supporting board(11), a base insulating layer formed on the metal supporting board, a conductive pattern(13) formed on the base insulating layer, a cover insulating layer formed on the base insulating layer to cover the conductive pattern, and an optical waveguide(19) formed on the base insulating layer or the cover insulating layer.

Description

Circuit part suspension substrate and its manufacturing method {SUSPENSION BOARD WITH CIRCUIT AND PRODUCING METHOD THEREOF}

Correlation with Related Applications

This application claims the priority of Japanese Patent No. 2006-314149 for which it applied on November 21, 2006, and Japanese Patent No. 2007-199996 for which it applied on July 31, 2007, The content of this application is applied here as it is. It shall be mixed in.

Field of invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit part suspension substrate and a method for manufacturing the same, specifically, a circuit part suspension substrate mounted on a hard disk drive or the like employing an optical assist method and a method for manufacturing the same.

Description of the related technology

Recently, as a magnetic recording method for a hard disk or the like, at the time of recording information, the hard disk is heated by light irradiation to reduce the coercive force to the magnetic head. The optical assist method (optical assist magnetic recording method) capable of recording information at a high density in a small recording magnetic field by recording by means of such recording is known.

For example, in the optical assist magnetic recording apparatus employing the optical assist method, the magnetic recording and reproducing element is provided on the side of the head slider by forming a magnetic reproducing element and a magnetic recording element (magnetic head), an optical waveguide and a light source. And it is proposed to support this head slider to a suspension (for example, refer Unexamined-Japanese-Patent No. 2000-195002.).

Summary of the Invention

However, the head slider is formed relatively small so as to meet the demand for miniaturization. Moreover, since the magnetic head is provided, it is difficult to provide other components. Therefore, if the optical waveguide and the light source used in the optical assist method are to be provided in the head slider together with the magnetic head, there are disadvantages in that the layout is restricted, the manufacturing costs are increased, and the manufacturing cost increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a circuit board suspension substrate and a method of manufacturing the same, which can secure the design freedom, improve the manufacturing efficiency, and reduce the manufacturing cost while employing the optical assist method. Is to provide.

The circuit part suspension board | substrate of this invention coat | covers the said conductor pattern on a metal support substrate, the base insulation layer formed on the said metal support substrate, the conductor pattern formed on the said base insulation layer, and the said base insulation layer. The cover insulating layer formed so that it may be provided, and an optical waveguide may be provided.

Moreover, in the circuit part suspension board | substrate of this invention, it is suitable that the said optical waveguide is provided on the said base insulating layer or the said cover insulating layer.

In the circuit part suspension substrate of the present invention, the optical waveguide includes an under cladding layer, a core layer formed on the under cladding layer, and having a higher refractive index than the under cladding layer, and the core layer on the under cladding layer. An over cladding layer having a refractive index lower than that of the core layer, the base insulating layer serving as the under cladding layer, the core layer being formed on the base insulating layer, and the cover insulating layer It is suitable to serve as the above-described over cladding layer.

Moreover, in the circuit part suspension board | substrate of this invention, it is suitable that the light emitting element is further provided and this light emitting element is optically connected with the said optical waveguide.

In addition, in the circuit part suspension board | substrate of this invention, the mounting part for mounting a head slider is provided, The opening part which penetrates the said metal support substrate in the thickness direction is formed in the vicinity of the said mounting part, The said optical waveguide has one end ( It is preferable that the one end is connected to the light emitting element, and the other end thereof is formed to face the opening.

Moreover, in the circuit part suspension board | substrate of this invention, the said optical waveguide is arrange | positioned according to the direction from which the said conductor pattern extends, the said light emitting element is arrange | positioned at the side of the longitudinal direction of the said metal support substrate, and the said mounting part supports the said metal It is suitable to arrange | position on the other side in the longitudinal direction of a board | substrate.

In the circuit part suspension board | substrate of this invention, the optical waveguide used for the optical assist method can be formed with a space margin rather than a head slider. Therefore, design freedom can be secured, manufacturing efficiency can be improved, and manufacturing cost can be reduced.

In addition, a method of manufacturing a circuit part suspension substrate of the present invention includes a base insulating layer formed on a metal support substrate by preparing a metal support substrate, a conductor pattern formed on the base insulating layer, and the base insulating layer on the base insulating layer. Forming a cover insulating layer formed so as to cover the conductor pattern on the substrate; forming an optical waveguide on the base insulating layer or the cover insulating layer; and in the vicinity of a mounting portion for mounting a head slider, the metal Forming an opening that penetrates the support substrate in the thickness direction, and the base insulating layer and / or the cover insulating layer and the optical waveguide intersect a cross section of the optical waveguide from the opening side with a direction in which the optical waveguide extends. It is characterized by including a step of cutting so as to.

In addition, the method of manufacturing a circuit part suspension substrate of the present invention includes a step of preparing a metal support substrate, a step of forming a base insulating layer serving as an under cladding layer on the metal support substrate, and a conductor pattern on the base insulating layer. Forming a core layer having a higher refractive index than the base insulating layer on the base insulating layer, and an over cladding layer to cover the conductor pattern and the core layer on the base insulating layer, A step of forming a cover insulating layer having a lower refractive index than that of the core layer is provided.

In addition, according to the manufacturing method of the circuit part suspension board | substrate of this invention, the optical waveguide used for the optical assist method can be formed on a base insulation layer or a cover insulation layer with a space margin rather than a head slider. Therefore, design freedom can be secured. In addition, since the base insulating layer and / or the cover insulating layer and the optical waveguide are cut at once from the opening side, the light emitted from the optical waveguide can be reliably irradiated toward the desired position, thereby making it easy and quick to manufacture. Therefore, manufacturing efficiency can be improved and manufacturing cost can be reduced.

In addition, in the circuit part suspension substrate and the manufacturing method of the present invention, when the base insulating layer serves as the under cladding layer and the cover insulating layer serves as the over cladding layer, the circuit part suspension substrate can be thinned, the structure can be simplified, and the manufacturing mandate Can be reduced, manufacturing efficiency can be improved, and cost can be reduced.

1 is a plan view showing an embodiment of a circuit portion suspension substrate of the present invention, FIG. 2 is a cross-sectional view taken along an optical waveguide in the circuit portion suspension substrate shown in FIG. 1, and FIG. 3 is a wiring portion of the circuit portion suspension substrate shown in FIG. 1. Sectional drawing of the form in which an optical waveguide is provided on a base insulating layer is shown as sectional drawing along the direction orthogonal to the longitudinal direction (in the following, a width direction). 1 and 2, the base insulating layer 12 and the cover insulating layer 14 are omitted.

1, this circuit part suspension board | substrate 1 mounts the magnetic head 28 (refer FIG. 5) in a hard disk drive, and attaches the magnetic head 28 to the magnetic head 28 and the hard disk ( The external circuit board (for example, to the metal support substrate 11 for supporting while maintaining a small space | interval with the hard disk 26 with respect to the airflow at the time 26 (refer FIG. 5) relatively travels. The conductor pattern 13 for connecting the lead light substrate) 2 and the magnetic head 28 is integrally formed.

The circuit part suspension board | substrate 1 is formed in the flat strip shape extended in the longitudinal direction, and is arrange | positioned at the wiring part 3 arrange | positioned at the one side (henceforth a rear side) in the longitudinal direction, and the length of the wiring part 3 The gimbal part 4 arrange | positioned at the other side of a direction (henceforth a ship side) is provided integrally.

The wiring portion 3 is formed in a substantially rectangular shape in plan view extending in the longitudinal direction.

The gimbal part 4 is formed continuously in the front-end | tip of the wiring part 3, and is formed in substantially rectangular shape in planar view which expands with respect to the wiring part 3 in both width direction outer sides. Further, the gimbal portion 4 is formed with a substantially U-shaped slit portion 5 which opens toward the ship side in plan view. Moreover, the gimbal part 4 is the outrigger arrange | positioned at the both sides of the hot water part 6 clamped by the slit part 5 in the width direction, the outer side of the slit part 5, and the front end of the hot water part 6. The unit 8 is integrally provided.

The hot water portion 6 is formed in a substantially rectangular shape in plan view, and has a mounting portion 9 and a terminal forming portion 10.

The mounting portion 9 is an area for mounting the head slider 27 and is disposed at the rear side of the hot water portion 6 and is formed in a substantially rectangular shape in plan view.

The terminal formation part 10 is an area | region in which the magnetic head side connection terminal part 17 mentioned later is formed, and is arrange | positioned at the line side of the mounting part 9. In addition, the terminal formation part 10 is provided with the opening part 7 of substantially rectangular planar view.

The opening part 7 is formed in substantially rectangular shape in planar view so that the metal support substrate 11 may penetrate in the thickness direction, and is formed in the width direction center in the terminal formation part 10 as the vicinity of the mounting part 9. It is.

The conductor pattern 13 has signal wirings for connecting the external connection terminal portion 16, the magnetic head side connection terminal portion 17, and the external connection terminal portion 16 and the magnetic head side connection terminal portion 17 ( 15) integrally and continuously.

Each signal wiring 15 is provided in plurality (four) along the longitudinal direction of the circuit part suspension board | substrate 1, and is arrange | positioned in parallel at intervals mutually in the width direction.

The plurality of signal wirings 15 are formed of the first wiring 15a, the second wiring 15b, the third wiring 15c, and the fourth wiring 15d, and the first wiring 15a and the first wiring 15d are formed. The 2nd wiring 15b, the 3rd wiring 15c, and the 4th wiring 15d are arrange | positioned in order from one side of the width direction to the other side of the width direction.

More specifically, the first wiring 15a, the second wiring 15b, the third wiring 15c and the fourth wiring 15d are formed to extend in parallel with each other in the wiring portion 3. . In the gimbal part 4, the 1st wiring 15a and the 2nd wiring 15b are arrange | positioned so that the outrigger part 8 of the width direction one side may be arrange | positioned, and the 3rd wiring 15c and the 4th wiring ( 15d) is disposed along the outrigger portion 8 on the other side in the width direction. After the 1st wiring 15a, the 2nd wiring 15b, the 3rd wiring 15c, and the 4th wiring 15d reach | attained the outrigger part 8 of the front end side, it extends inward in the width direction, and is further It is returned to the side and arrange | positioned so that it may reach the front-end | tip part of the magnetic head side connection terminal part 17. As shown in FIG.

On the other hand, the 1st wiring 15a and the 2nd wiring 15b are arrange | positioned so that the light-emitting element 20 mentioned later in the wiring part 3 may bypass the width direction inside.

The outer connection terminal portions 16 are arranged at the rear ends of the wiring portions 3, and a plurality (four) are provided so that the rear ends of the wirings 15 are respectively connected. The outer connection terminal portions 16 are arranged at intervals in the width direction. Moreover, the outer side connection terminal part 16 respond | corresponds to the 1st wiring 15a, the 2nd wiring 15b, the 3rd wiring 15c, and the 4th wiring 15d connected to the outer side connecting terminal part 16. Moreover, as shown in FIG. The first external connection terminal portion 16a, the second external connection terminal portion 16b, the third external connection terminal portion 16c and the fourth external connection terminal portion 16d are in the width direction from one side in the width direction. It is arranged sequentially toward the other side. The outer side connecting terminal portion 16 is connected to a terminal portion (not shown) of the external circuit board 2 indicated by broken lines.

The magnetic head side connecting terminal portion 17 is disposed at the gimbal portion 4, and more specifically, is disposed at the rear end portion of the terminal forming portion 10 of the hot water portion 6. The magnetic head side connecting terminal portion 17 is provided with a plurality (four) so that the tip portions of the respective signal wires 15 are connected to each other.

More specifically, the magnetic head side connection terminal portions 17 are arranged at intervals from each other in the width direction so as to follow the trailing edge of the terminal forming portion 10 (the leading edge of the mounting portion 9). In addition, the magnetic head-side connection terminal portion 17 corresponds to the first wiring 15a, the second wiring 15b, the third wiring 15c, and the fourth wiring 15d to be connected to this. The head side connection terminal part 17a, the 2nd magnetic head side connection terminal part 17b, the 3rd magnetic head side connection terminal part 17c, and the 4th magnetic head side connection terminal part 17d are different from the width direction one side from the width direction one side. It is arrange | positioned toward the side one by one.

A terminal portion (not shown) of the magnetic head 28 is connected to the magnetic head side connecting terminal portion 17.

As shown in FIG. 3, the circuit part suspension substrate 1 includes a metal support substrate 11, a base insulating layer 12 formed on the metal support substrate 11, and a base insulating layer 12. And a cover insulating layer 14 formed on the base insulating layer 12 so as to cover the conductor pattern 13.

The metal support substrate 11 is formed corresponding to the external shape of the circuit part suspension substrate 1, as shown to FIG. 1 and FIG.

The base insulating layer 12 has a conductor pattern 13 and an optical waveguide 19 (described later) in the wiring section 3 and the gimbal section 4 so that the peripheral edge of the metal support substrate 11 is exposed. It is formed to correspond to the position to be formed. More specifically, the base insulating layer 12 is formed in a flat band state in which the longitudinal direction and the width direction are slightly shorter than the metal support substrate 11.

The conductor pattern 13 is arrange | positioned over the wiring part 3 and the gimbal part 4, and integrates the outer side connection terminal part 16, the magnetic head side connection terminal part 17, and the signal wiring 15 integrally. It is formed as a wiring circuit pattern provided continuously.

The cover insulation layer 14 is arrange | positioned over the wiring part 3 and the gimbal part 4, and is arrange | positioned so that it may correspond to the position in which the signal wiring 15 is formed. The cover insulation layer 14 is formed so that the outer side connection terminal part 16 and the magnetic head side connection terminal part 17 may be exposed and cover the signal wiring 15. In addition, the cover insulating layer 14 is arrange | positioned so that the area | region in which the optical waveguide 19 mentioned later is formed on the base insulating layer 12 is ensured.

And this circuit part suspension board | substrate 1 is equipped with the optical assist part 18 used for the optical assist method as shown in FIG.

The optical assist portion 18 includes an optical waveguide 19 and a light emitting element 20.

The optical waveguide 19 is disposed over the wiring portion 3 and the gimbal portion 4, and is disposed along the direction in which the conductor pattern 13 extends.

More specifically, the optical waveguide 19 is arranged in the wiring portion 3 at intervals on one side in the width direction, that is, on the first wiring 15a and the outermost side in the width direction, and the first wiring 15a. It is installed to extend in parallel with). In addition, the optical waveguide 19 has one side and the front end side in the outrigger portion 8 and the opposite side of the second wiring 15b to the first wiring 15a in the terminal forming portion 10. It is arrange | positioned at intervals and is provided so that it may extend in parallel with the 1st wiring 15a. That is, the optical waveguide 19 extends in parallel with the first wiring 15a, and returns to the rear side from the outrigger portion 8 on the front end side, and then extends along the width direction center of the gimbal portion 4, It is arrange | positioned so that it may reach the opening part 7.

The optical waveguide 19 is optically connected to the light emitting element 20. More specifically, the optical waveguide 19 is formed such that the rear end thereof is connected to the light emitting element 20 and the front end thereof faces the opening 7.

The light emitting element 20 is a light source for injecting light into the optical waveguide 19, for example, a light source that converts electrical energy into light energy and emits light of high energy. The light emitting element 20 is arranged on the rear end side of the metal support substrate 11, and more specifically, on the rear end side of the wiring portion 3, a gap is formed between the outer connection terminal portion 16 and the front end side. It arrange | positions, and is arrange | positioned at intervals in the signal wiring 15 (1st wiring 15a) and the width direction one side. This light emitting element 20 is formed on the base insulating layer 12.

In addition, a supply wiring 30 for supplying electric energy to the light emitting element 20 is connected to the light emitting element 20, and the supply wiring 30 is not illustrated in the external circuit board 2. The supply terminal part 31 for connecting with a terminal part is connected. On the other hand, the supply wiring 30 extends along the signal wiring 15 (the first wiring 15a) on the rear end side of the light emitting element 20, and the supply terminal portion 31 is the external connection terminal portion 16. ) (First outer side connecting terminal portion 16a) and one side in the width direction are arranged at intervals. In addition, the supply wiring 30 is covered with the cover insulating layer 14, and the supply terminal part 31 is exposed from the cover insulating layer 14.

In this optical assist portion 18, in the light emitting element 20, electrical energy supplied from the external circuit board 2 through the supply terminal portion 31 and the supply wiring 30 is converted into light energy, and the light It is emitted to this optical waveguide 19. The emitted light passes through the optical waveguide 19, is reflected in the cross section 21 described later, and is irradiated to the hard disk 26.

In addition, as shown in FIG. 5, the optical waveguide 19 is formed so that the end surface 21 of the front end part may cross | intersect the longitudinal direction of the optical waveguide 19 by predetermined angle (tilt angle) (alpha), for example. As a result, the optical waveguide 19 is formed such that its end face 21 is a mirror surface having an inclination angle α, so that the light incident on the optical waveguide 19 has an optical path at a predetermined angle by the end face 21. The converted and irradiated light is irradiated while scattering toward the desired position. Such inclination angle α is not particularly limited, and is, for example, 35 to 55 mm, preferably 40 to 50 mm, and more specifically 45 mm.

And as shown in FIG. 3, in this circuit part suspension board | substrate 1, the optical waveguide 19 is provided on the base insulating layer 12. As shown in FIG.

The optical waveguide 19 is formed to cover the under cladding layer 22, the core layer 23 formed on the under cladding layer 22, and the core layer 23 on the under cladding layer 22. An over cladding layer 24 is provided.

On the other hand, the optical waveguide 19 is formed on the base insulating layer 12 also in the line half half facing the opening 7. That is, the base insulating layer 12 faces the opening 7 so as to correspond to the optical waveguide 19 so as to be at substantially the same position in plan view.

The over cladding layer 24 is formed so that the width direction both outer edges may become the same position in planar view with the width direction both outer edges of the under cladding layer 22.

4 is a cross-sectional view showing a manufacturing process of the circuit part suspension substrate shown in FIG. 3, wherein a left side view is a sectional view along a width direction in a wiring portion corresponding to FIG. 3, and a right side view is a longitudinal direction in a terminal formation portion. The following enlarged cross-sectional view is shown.

Next, the manufacturing method of this circuit part suspension board | substrate 1 is demonstrated with reference to FIG.

First, in this method, as shown to Fig.4 (a), the metal support substrate 11 is prepared.

The metal support board | substrate 11 is formed with metal materials, such as stainless steel, 42 alloy, aluminum, copper- beryllium, and phosphor bronze. The thickness of the metal support substrate 11 is 15-30 micrometers, for example, Preferably it is 20-25 micrometers.

Next, in this method, as shown in FIG. 4 (b), the base insulating layer 12, the conductor pattern 13, and the cover insulating layer 14 are sequentially stacked on the metal support substrate 11.

In order to sequentially laminate the base insulating layer 12, the conductor pattern 13, and the cover insulating layer 14, the base insulating layer 12 is first formed on the metal support substrate 11.

The base insulating layer 12 is, for example, a polyimide resin, a polyamideimide resin, an acrylic resin, a polyether nitrile resin, a polyether sulfone resin, a polyethylene terephthalate resin, a polyethylene naphthalate resin, a polyvinyl chloride resin, or the like. It is formed with insulating materials, such as resin. Preferably, it is formed of polyimide resin.

In order to form the base insulating layer 12, for example, a photosensitive varnish of the above insulating material is applied to the upper surface of the metal support substrate 11, dried, exposed through a photomask, and then developed. Cured accordingly.

The thickness of the base insulating layer 12 formed by this is 1-35 micrometers, Preferably, it is 8-15 micrometers.

Next, the conductor pattern 13 is formed in the pattern mentioned above.

As the conductor material for forming the conductor pattern 13, for example, a conductor material such as copper, nickel, gold, solder, or an alloy thereof is used.

In order to form the conductor pattern 13, well-known patterning methods, such as an additive method and a subtractive method, are used, for example. Preferably, the additive method is used.

In the conductor pattern 13 formed by this, thickness is 3-50 micrometers, for example, Preferably it is 5-20 micrometers. In addition, the width of each signal wire 15 is, for example, 10 to 200 μm, preferably 20 to 100 μm, and the interval between each signal wire 15 is, for example, 10 to 1000 μm, preferably 20 to 100. [Mu] m. In addition, the widths of the respective external connection terminal portions 16 and the magnetic head side connection terminal portions 17 are, for example, 20 to 1000 µm, preferably 30 to 800 µm, and are spaced between the respective external connection terminal portions 16. And the interval between the respective magnetic head side connection terminal portions 17 is, for example, 20 to 1000 µm, and preferably 30 to 800 µm.

In order to form the cover insulating layer 14 in the above-described pattern, for example, the varnish of the above-described insulating material on the surface of the metal support substrate 11 including the conductor pattern 13 and the base insulating layer 12. Is applied, dried, exposed through a photomask, and cured as necessary after development.

The thickness of the cover insulation layer 14 formed by this is 1-40 micrometers, for example, Preferably it is 1-7 micrometers.

Thereby, the base insulating layer 12, the conductor pattern 13, and the cover insulating layer 14 can be laminated on the metal support substrate 11 one by one.

On the other hand, at the same time as the formation of the conductor pattern 13, the supply wiring 30 and the supply terminal portion 31 are simultaneously formed by the above method.

Subsequently, in this method, as shown in FIG. 4C, the optical waveguide 19 is formed on the base insulating layer 12.

In order to form the optical waveguide 19, the under cladding layer 22, the core layer 23, and the overcladding layer 24 are sequentially stacked on the base insulating layer 12.

In order to sequentially stack the under cladding layer 22, the core layer 23, and the over cladding layer 24, the under cladding layer 22 is first formed on the base insulating layer 12.

Examples of the material for forming the under cladding layer 22 include a polyimide resin, a polyamide resin, a silicone resin, an epoxy resin (such as an alicyclic epoxy resin), an acrylic resin, or a fluorene derivative resin, and a fluorene derivative resin. Mixed resins of alicyclic epoxy resins and mixed resins of these resins and alicyclic ether compounds (for example, oxetane compounds and the like) are used. These resin, Preferably, it mix | blends a photosensitive agent and is used as photosensitive resin. Preferably, the mixed resin of photosensitive fluorene derivative resin (photosensitive fluorene type epoxy resin) and alicyclic epoxy resin is used as a raw material. In addition, as a photosensitizer, a well-known onium salt etc. are used, for example, More specifically, 4, 4-bis [di ((beta) hydroxyethoxy) phenylsulfinio] phenyl sulfide-bis-hexafluoro antimonate, etc. are mentioned. Used.

In order to form the under cladding layer 22 in the above-described pattern, for example, a varnish (resin solution) of the above-mentioned resin is prepared by using a known diluent, and the varnish is applied to the surface of the base insulating layer 12. It is dried and hardened as needed. In addition, when photosensitive resin is used, after application and drying of a varnish, it exposes through a photomask, dissolves an unexposed part with a well-known organic solvent, etc., and develops and hardens it as needed after that.

The refractive index of the under cladding layer 22 formed in this way is 1.45-1.55, for example. The thickness of the under cladding layer 22 is, for example, 1 to 50 µm, preferably 5 to 20 µm, and the width is, for example, 20 to 200 µm, preferably 30 to 100 µm.

Next, the core layer 23 is formed on the under cladding layer 22.

As the material for forming the core layer 23, a resin material having a higher refractive index than the resin material of the under cladding layer 22 is used. As such a resin material, the above resin is used, for example, Preferably, the mixed resin of the photosensitive fluorene derivative resin (as a raw material photosensitive fluorene type epoxy resin) and an oxetane compound is used.

In order to form the core layer 23 in the above-described pattern, for example, a varnish (resin solution) of the above-mentioned resin is prepared by using a known diluent, and the varnish is subjected to base insulation including the under cladding layer 22. After apply | coating to the surface of the layer 12, it dries and hardens as needed. In addition, when photosensitive resin is used, after application | coating and drying of a varnish, it exposes through a photomask, dissolves an unexposed part with a well-known organic solvent, etc., develops, and hardens as needed after that.

The refractive index of the core layer 23 formed in this way is set higher than the refractive index of the under cladding layer 22, for example, 1.55-1.65. The thickness of the core layer 23 is, for example, 1 to 30 µm, preferably 2 to 20 µm, and the width is, for example, 1 to 30 µm, preferably 2 to 20 µm.

Next, the over cladding layer 24 is formed on the under cladding layer 22 so as to cover the core layer 23.

As the material for forming the over clad layer 24, the same resin material as the under clad layer 22 is used.

In order to form the over cladding layer 24 in the above-described pattern, for example, a varnish (resin solution) of the above-mentioned resin is prepared by using a known diluent, and the varnish is prepared using the core layer 23 and the under cladding layer ( After application | coating to the surface of the base insulating layer 12 containing 22), it dries and hardens as needed. In addition, when photosensitive resin is used, after application and drying of a varnish, it exposes through a photomask, dissolves an unexposed part with a well-known organic solvent, etc., and develops and hardens it as needed after that.

The refractive index of the over cladding layer 24 formed in this way is set lower than the refractive index of the core layer 23, and is set like the refractive index of the under cladding layer 22, for example. In addition, the thickness at the surface of the core layer 23 of the over cladding layer 24 is, for example, 1 to 50 µm, preferably 5 to 20 µm, and the width is, for example, 20 to 200 µm, preferably 30 to 100 μm.

In this way, the optical waveguide 19 provided with these can be formed by sequentially laminating the under cladding layer 22, the core layer 23, and the overcladding layer 24 on the base insulating layer 12.

Next, in this method, as shown in FIG.4 (d), the opening part 7 is formed in the metal support substrate 11 in the terminal formation part 10. FIG.

In order to form the opening 7, it is formed by, for example, drilling such as a drill, for example, etching such as dry etching or wet etching. Preferably, it forms by etching.

In the width direction, the opening part 7 is arrange | positioned in the center so that the opening part 7 may overlap with the front end part of the optical waveguide 19 more specifically, in the longitudinal direction, The tip end portion of the optical waveguide 19 is formed so as to be disposed at the half side of the line.

The opening 7 formed in this way is 50-500 micrometers in width, Preferably it is 100-200 micrometers, and length (length direction length) is 50-500 micrometers, for example, Preferably it is 100-200 micrometers. .

Subsequently, in this method, as shown in FIG. 4 (e), the tip end portions of the base insulating layer 12 and the optical waveguide 19 are subjected to laser processing from the opening 7 side to the tip end portions of the optical waveguide 19. The cross section 21 is cut to cross the longitudinal direction.

In the laser processing, as shown by the broken line in FIG. 4E, the base insulating layer is formed from the opening 7 side (the lower side in the thickness direction) so that the laser beam passing through the opening 7 crosses the longitudinal direction at a predetermined angle. The base insulating layer 12 and the optical waveguide 19 are cut at once by irradiating the 12 and the optical waveguide 19.

Thereby, the base insulating layer 12 and the optical waveguide 19 are cut from the opening 7 side by laser processing so that the end surface 21 of the tip end portion of the optical waveguide 19 intersects the longitudinal direction. Can be.

Thereafter, the light emitting element 20 is connected to the rear end of the optical waveguide 19 at the rear end side of the wiring portion 3 so as to be electrically connected to the front end of the supply wiring 30. Install on). Thereby, the circuit part suspension board | substrate 1 is obtained.

And in the circuit part suspension board | substrate 1 obtained in this way, in the wiring part 3, as for the wiring part 3, the external side connection terminal part 16 and the supply terminal part 31 are external. It is connected with the terminal part which is not shown in figure of the circuit board 2. As shown in FIG. In addition, an IC 32 for controlling the magnetic head 28 (see FIG. 5) and the light emitting element 20 is mounted on the external circuit board 2, and the IC 32 is an IC wiring 33. Is connected electrically to the terminal portion to which the external connection terminal portion 16 and the supply terminal portion 31 are connected.

In addition, as shown in FIGS. 1 and 5, the head slider 27 is mounted on the mounting portion 9 of the gimbal portion 4 on the circuit portion suspension substrate 1. A magnetic head 28 is mounted on the head slider 27. The mounting of the head slider 27 causes the terminal portion (not shown) of the magnetic head 28 to be electrically connected to the magnetic head side connecting terminal portion 17. Is connected. In addition, by mounting the above-described head slider 27, the magnetic head 28 is disposed in the vicinity of the end face 21 of the tip end portion of the optical waveguide 19 so as to face the opening 7.

In the hard disk drive in which the magnetic head 28, the head slider 27, the circuit part suspension board 1, and the external circuit board 2 are mounted, the optical assist method can be adopted.

In this hard disk drive, for example, the hard disk 26 relatively travels with respect to the end face 21 and the magnetic head 28 of the tip portion of the optical waveguide 19. Then, the light emitted from the light emitting element 20 passes through the optical waveguide 19, and in the end face 21, the optical path is converted or scattered upward, and the hard disk 26 facing the upper end face of the end face 21. ) Is irradiated to the surface. The surface of the hard disk 26 is heated by irradiation of light from the end face 21 of the optical waveguide 19, and in this state, the hard disk 26 is irradiated by the magnetic field from the magnetic head 28. The information is recorded. Then, since the coercive force of the hard disk 26 is reduced, information can be recorded in this hard disk 26 at high density by irradiation of a small magnetic field.

And in this circuit part suspension board | substrate 1, the optical waveguide 19 used for the optical assist method can be formed with a space margin rather than the head slider 27 formed smaller than the circuit part suspension board | substrate 1. have.

In particular, since the optical waveguide 19 is provided on the base insulating layer 12 having more space than the head slider 27, design freedom can be secured and manufacturing efficiency can be improved. In addition, the manufacturing cost can be reduced.

Moreover, since this circuit part suspension board | substrate 1 is equipped with the light emitting element 20, and the light emitting element 20 is optically connected with the optical waveguide 19, on the base insulating layer 12, the light emitting element 20 and the optical waveguide 19 can be provided together. Therefore, optical connection reliability can be improved and the optical assist method can be reliably implemented.

Moreover, since this circuit part suspension board | substrate 1 is equipped with the mounting part 9, the head slider 27 can be mounted reliably. Moreover, in this circuit part suspension board | substrate 1, the opening part 7 is formed in the vicinity of the mounting part 9, and since the front-end | tip part of the optical waveguide 19 is formed so that the opening part 7 may face, for laser processing, As a result, the end face 21 of the tip portion of the optical waveguide 19 can be reliably cut.

That is, in the manufacturing method of this circuit part suspension board | substrate 1, the end surface 21 of the front-end | tip part of the optical waveguide 19 is laser-processed from the opening part 7 side to the base insulation layer 12 and the optical waveguide 19. As shown in FIG. ) So that it crosses the longitudinal direction. Then, since the base insulating layer 12 and the optical waveguide 19 can be cut at once in the opening 7, the end face 21 can be reliably formed as a smooth mirror surface. Therefore, in the circuit part suspension board | substrate 1, while making it possible to reliably irradiate the light radiate | emitted from the optical waveguide 19 to a desired position, ie, the surface of the hard disk 26, this circuit part suspension board | substrate 1 is simple and It can be manufactured quickly. Therefore, manufacturing efficiency can be improved and manufacturing cost can be reduced.

In this circuit part suspension substrate 1, the light emitting element 20 is arranged on the rear end side of the circuit part suspension substrate 1, that is, the rear end side of the wiring part 3, and the mounting part 9 is the circuit part suspension substrate 1. ) Is arranged at the tip end side, that is, the hot water part 6 of the gimbal part 4. Therefore, the freedom in designing the layout of the light emitting element 19 and the head slider 27 can be secured.

FIG. 6 is a cross-sectional view taken along the width direction in the wiring portion of the circuit portion suspension substrate shown in FIG. 1, which is a cross-sectional view of an optical waveguide provided on the cover insulating layer, and FIG. 7 is a portion of the circuit portion suspension substrate shown in FIG. 6. As a sectional drawing which shows a manufacturing process, a left side figure is sectional drawing along the width direction in the wiring part corresponding to FIG. 6, and a right side figure is an enlarged sectional view along the longitudinal direction in a terminal formation part. In addition, about the member corresponding to said each part, the same referential mark is attached | subjected in FIG. 6 and FIG. 7, and the detailed description is abbreviate | omitted.

In the above description, the optical waveguide 19 is provided on the base insulating layer 12, but it is also possible to provide the optical waveguide 19 on the cover insulating layer 14, for example.

In FIG. 6, in this circuit part suspension board | substrate 1, the cover insulation layer 14 is formed so that the periphery edge may become substantially the same position in planar view with the periphery edge of the base insulation layer 12. In FIG.

The optical waveguide 19 is formed on the signal wiring 15 (more specifically, the first wiring 15a) in the outrigger portion 8 of the wiring portion 3 and the gimbal portion 4. . In addition, the core layer 23 of the optical waveguide 19 is formed so as to overlap the first wiring 15a in the planar view in the wiring section 3 and the outrigger section 8 of the gimbal section 4. have.

In addition, the optical waveguide 19 is formed on the cover insulation layer 14 in the terminal forming portion 10 of the gimbal portion 4, and the first wiring 15a of the terminal forming portion 10 is formed. It is arrange | positioned so that it may shift on the other side in the width direction, More specifically, it is arrange | positioned so that it may extend in parallel with the 1st wiring 15a at intervals with the 1st wiring 15a. That is, the optical waveguide 19 extends along the center of the terminal forming portion 10 in the terminal forming portion 10 and is disposed to reach the opening 7.

The light emitting element 20 is formed on the cover insulating layer 14.

In order to manufacture this circuit part suspension board | substrate 1, as shown in FIG.7 (a), the metal support board | substrate 11 is prepared first, and as shown in FIG.7 (b), then the metal support board | substrate 11 is shown. The base insulating layer 12, the conductor pattern 13, and the cover insulating layer 14 are sequentially laminated on the substrate. Subsequently, as shown in FIG. 7C, the optical waveguide 19 is formed on the cover insulating layer 14. Subsequently, as shown in FIG. 7D, the opening 7 is formed in the metal support substrate 11 in the terminal forming portion 10, and as shown in FIG. 7E, the base insulating layer. (12) The cover insulating layer 14 and the optical waveguide 19 are cut so that the end surface 21 of the tip end portion of the optical waveguide 19 crosses the longitudinal direction by laser processing from the opening 7 side. Thereby, the circuit part suspension board | substrate 1 can be manufactured.

Thus, by forming the optical waveguide 19 on the cover insulating layer 14, even when the base insulating layer 12 can not afford space, the freedom of design of the optical waveguide 19 can be secured, The manufacturing efficiency can be improved and the manufacturing cost can be reduced.

In the above description, the optical waveguide 19 is provided on one side in the width direction of the first wiring 15a. However, the arrangement is not limited and, for example, is not shown, but the width of the fourth wiring 15d is shown. Direction can be installed on the other side. In addition, the opposite side of the first wiring 15a to the second wiring 15b (that is, the opposite side of the fourth wiring 15d to the third wiring 15c), the first wiring 15a and the second wiring It is also possible to provide the optical waveguide 19 between the wirings 15b and between the third wirings 15c and the fourth wirings 15d. Preferably, from the viewpoint of the space and from the viewpoint of disposing the tip of the optical waveguide 19 at the center of the gimbal portion 4 in the width direction, the optical waveguide 19 is one side in the width direction of the first wiring 15a. Or the other side in the width direction of the fourth wiring 15d.

In addition, although the optical waveguide 19 is provided in the circuit part suspension board | substrate 1 in the above-mentioned description, the number is not specifically limited, For example, depending on the use and the purpose of the circuit part suspension board | substrate 1, a plurality is provided. It is also possible to provide two optical waveguides 19.

In addition, in the above description, although the under cladding layer 22 and the over cladding layer 24 are provided in the optical waveguide 19, the under cladding layer 22 and / or the over cladding layer 24 are provided, for example. The optical waveguide 19 can also be formed without providing.

More specifically, when the refractive index of the cover insulating layer 14 is lower than the refractive index of the core layer 23, the under insulating layer 14 is replaced by the under cladding layer 22 without providing the under cladding layer 22. It can be used as.

In addition, when the refractive index of the base insulating layer 12 is lower than the refractive index of the core layer 23, the base insulating layer 12 may be used as the under cladding layer 22 without providing the under cladding layer 22. Can be. In that case, when the refractive index of the cover insulating layer 14 is lower than the refractive index of the core layer 23, the cover insulating layer 14 and the over cladding layer 24 may be formed integrally as one layer. Can be.

That is, without providing the over cladding layer 24 and the under cladding layer 22, the cover insulating layer 14 is also used as the over cladding layer 24, and the base insulating layer 12 is used as the under cladding layer ( 22) can be used as.

In order to manufacture such a circuit part suspension board | substrate 1, the metal support substrate 11 is prepared first, as shown to FIG. 8 (a).

Subsequently, as shown in FIG. 8B, the base insulating layer 12 also serving as the under cladding layer 22 is formed on the metal support substrate 11. In order to form the base insulating layer 12 which also serves as the under cladding layer 22, the resin similar to the resin material which forms the base insulating layer 12 mentioned above, or the resin material which forms the under cladding layer 22, for example is similar. A varnish (resin solution) of the material is prepared, the varnish is applied to the upper surface of the metal support substrate 11, dried, exposed and developed through a photomask as necessary, and cured as necessary.

The refractive index of the base insulating layer 12 is 1.45-1.70, for example. In addition, the thickness of the base insulating layer 12 is 1-35 micrometers, Preferably, it is 5-15 micrometers.

Thereafter, as shown in FIG. 8C, the conductor pattern 13 is formed on the base insulating layer 12. In order to form the conductor pattern 13, a well-known patterning method, such as an additive method and a subtractive method, is used as mentioned above, for example. Preferably, the additive method is used. On the other hand, the conductor pattern 13 is formed in the same pattern as the conductor pattern 13 shown in FIG. 1 from the above conductor materials.

On the other hand, simultaneously with the formation of the conductor pattern 13, the supply wiring 30 and the supply terminal portion 31 are simultaneously formed by the above-described method.

Subsequently, as shown in FIG. 8 (d), the core layer 23 is formed on the base insulating layer 12.

In order to form the core layer 23, the varnish (resin solution) of the resin material which forms the said core layer 23 is prepared, the varnish is apply | coated to the upper surface of the base insulation layer 12, and it is dried. Then, it exposes and develops through a photomask as needed, and hardens as needed.

The refractive index of the core layer 23 is set higher than the refractive indices of the base insulating layer 12 and the cover insulating layer 14, for example, 1.55-1.65. The thickness of the core layer 23 is, for example, 1 to 30 µm, preferably 2 to 20 µm, and the width is, for example, 1 to 30 µm, preferably 2 to 20 µm. In addition, the core layer 23 is arrange | positioned in the same pattern as the core layer 23 shown in FIG.

Subsequently, as shown in FIG. 8E, the over cladding layer 24 covers the conductor pattern 13 (including the supply wiring 30) and the core layer 23 on the base insulating layer 12. The cover insulating layer 14 which functions also as () is formed. In order to form the cover insulating layer 14 which also serves as the over cladding layer 24, for example, a resin material such as the resin material forming the cover insulating layer 14 or the resin material forming the over cladding layer 24 is formed. A varnish (resin solution) is prepared, and the varnish is applied to the upper surface of the base insulating layer 12 including the conductor pattern 13 and the core layer 23, dried, and then, if necessary, through a photomask. It exposes and develops and hardens as needed. Thereby, the cover insulation layer 14 exposes the external connection terminal part 16, the magnetic head side connection terminal part 17, and the supply terminal part 31, and the signal wiring 15, the core layer 23, and the like. It is formed to cover the supply terminal portion 31.

The refractive index of the cover insulating layer 14 is 1.45-1.70, for example. In addition, the thickness (thickness on the surface of the core layer) of the cover insulation layer 14 is 1-40 micrometers, Preferably it is 1-12 micrometers.

As shown in Fig. 8 (f), the opening 7 is formed in the metal support substrate 11 in the terminal forming portion 10 by the above method, and then Fig. 8 (g). As shown in the figure, the end portions 21 of the tip portions of the base insulation layer 12, the core layer 23, and the cover insulation layer 14 are laser-processed from the opening 7 side so that the end faces 21 of the tip portions thereof are in the longitudinal direction. Cut to cross. Thereby, the circuit part suspension board | substrate 1 can be manufactured.

In the circuit part suspension substrate 1 manufactured in this way, the base insulating layer 12 doubles as the under cladding layer 22, the cover insulating layer 14 doubles as the over cladding layer 24, and the conductor pattern 13. And the core layer 23 are covered by the cover insulating layer 14 on the upper surface of the base insulating layer 12.

Therefore, the circuit part suspension substrate 1 can be reduced in thickness, structure can be simplified, and manufacturing man-hours can be reduced, manufacturing efficiency can be improved, and cost can be reduced.

In the above description, the over cladding layer 24 or the cover insulating layer 14 is provided so as to cover the core layer 23, but without the over cladding layer 24 or the cover insulating layer 14. The core layer 23 can also be exposed, that is, exposed to air to form a so-called air clad. Preferably, from the viewpoint of preventing damage due to external factors of the core layer 23, the over cladding layer 24 or the cover insulating layer 14 is provided.

In addition, instead of the under cladding layer 22 and the over cladding layer 24, it is also possible to provide the light reflection layer which consists of metal foil layers.

In addition, although the opening part 7 was formed in the width direction center in the gimbal part 4 in the above-mentioned description, the arrangement is not limited to this, For example, it can also be provided in the width direction one end part or the width direction other end part. have. Preferably, the opening part 7 is formed in the width direction center in the gimbal part 4 so that the width direction center part of the head slider 27 and the front end part of the optical waveguide 19 may oppose in the longitudinal direction. do.

Example

Although an Example is shown to the following and this invention is demonstrated to it further more concretely, this invention is not limited to an Example at all.

Example 1 (Optical waveguide is provided on the base insulating layer)

A metal support substrate made of stainless steel having a thickness of 20 μm was prepared (see Fig. 4 (a)).

Subsequently, the base insulating layer which consists of polyimide resin was formed in said pattern on the metal support substrate. The thickness of this base insulating layer was 10 micrometers.

Subsequently, the additive pattern and supply wiring and supply terminal part which consist of copper were formed simultaneously by the additive method. Their thickness was 10 micrometers.

Next, the cover insulation layer which consists of polyimide resin was formed in said pattern on the base insulation layer. The thickness of this cover insulating layer was 5 micrometers. Thereby, the base insulating layer, the conductor pattern, and the cover insulating layer were sequentially laminated on the metal support substrate (see FIG. 4 (b)).

Next, an optical waveguide was formed on the base insulating layer. In order to form an optical waveguide, the under cladding layer was formed first.

In order to form the under clad layer in the above-described pattern, first, an alicyclic ring having 35 parts by weight of bisphenoxyethanol fluorene diglycidyl ether (fluorene derivative, epoxy equivalent 300 g / eq.) And a cyclohexene oxide skeleton 25 parts by weight of a formula epoxy resin (Celoxide 2081, manufactured by Daicel Chemical Co., Ltd.), 4,4-bis [di (βhydroxyethoxy) phenylsulfinio] phenylsulfide-bis-hexafluoro antimonate (photosensitive agent) 2 parts by weight of 50% propion carbonate solution, 40 parts by weight of 3,4-epoxycyclohexenylmethyl-3 ', 4'-epoxycyclohexene carboxylate (diluent, alicyclic epoxy, Celoxide 2021P, manufactured by Daicel Chemical Corporation) Varnish was prepared. Subsequently, this varnish was apply | coated to the surface of a base insulating layer, and it dried by heating at 80 degreeC for 15 minutes. Then, it exposed through the photomask and developed by melt | dissolving the unexposed part with the gamma beaurolactone type organic solvent. Then, the under cladding layer was formed on the base insulating layer by heating and hardening at 100 degreeC for 15 minutes.

The under cladding layer (the under cladding layer after curing) had a refractive index of 1.540 at a wavelength of 830 nm. The under cladding layer had a thickness of 10 μm and a width of 30 μm.

Next, a core layer was formed on the under cladding layer.

In order to form the core layer in the above-described pattern, first, 70 parts by weight of bisphenoxyethanol fluorene diglycidyl ether (fluorene derivative, epoxy equivalent 300 g / eq.), 1,1,1-tris {4 30 parts by weight of-[2- (3-oxetanyl)] butoxyphenyl} ethane (oxetane compound), 4,4-bis [di (βhydroxyethoxy) phenylsulfinio] phenylsulfide-bis-hexa 1 part by weight of a 50% propion carbonate solution of fluoro antimonate (photosensitive agent) and 30 parts by weight of ethyl lactate (diluent) were blended to prepare a varnish. Subsequently, this varnish was apply | coated to the surface of the base insulating layer containing an under cladding layer, and it dried by heating at 80 degreeC for 15 minutes. Then, it exposed through the photomask and developed by melt | dissolving the unexposed part with the gamma beaurolactone type organic solvent. Then, the core layer was formed on the under cladding layer by heating and hardening at 100 degreeC for 15 minutes.

The refractive index at the wavelength of 830 nm of this core layer (core layer after hardening) was 1.594. In addition, the thickness of the core layer was 5 micrometers, and the width was 5 micrometers.

Next, the over cladding layer was formed so that a core layer might be covered on an under cladding layer.

In order to form the over cladding layer in the above-described pattern, first, a varnish similar to the varnish for forming the under cladding layer is prepared, and then the varnish is made of a base insulating layer including a core layer and an under cladding layer. It applied to the surface and dried by heating at 80 degreeC for 15 minutes. Then, it exposed through the photomask and developed by melt | dissolving the unexposed part with the gamma beaurolactone type organic solvent. Then, by heating and hardening at 100 degreeC for 15 minutes, the over cladding layer was formed on the under cladding layer so that the core layer may be coat | covered.

The refractive index at wavelength 830 nm of this over clad layer (over cladding layer after hardening) was 1.540. In addition, the thickness in the surface of the core layer of the over cladding layer was 10 micrometers, and width was 30 micrometers.

As a result, an optical waveguide was formed on the base insulating layer at intervals from the first wiring (see Fig. 4C).

Next, the planar rectangular opening part was formed in the metal support substrate by the terminal formation part by wet etching (refer FIG.4 (d)). The width of this opening was 100 µm and the length was 100 µm.

Subsequently, the base insulating layer and the optical waveguide were cut at once so that the cross section of the tip end portion of the optical waveguide crosses the longitudinal direction by laser processing from the opening side (see FIG. 4E). The inclination angle of the cross section formed by this cutting was 45 kPa.

Thereafter, on the rear end side of the wiring portion of the circuit portion suspension substrate, a light emitting element was provided on the base insulating layer so as to be optically connected to the rear end of the optical waveguide and electrically connected to the front end of the supply wiring (FIGS. 1 and 2). Reference).

Example 2 (the form in which the optical waveguide is installed on the cover insulation layer)

In Example 1, the circuit part suspension board | substrate was manufactured like Example 1 except having provided the optical waveguide in the cover insulation layer and installing the light emitting element on the cover insulation layer (FIG. 1, FIG. 2, and FIG. 7).

In other words, the cover insulation layer was formed such that its peripheral edge is substantially the same position as the peripheral edge of the base insulating layer in plan view (see Fig. 7 (b)).

In the terminal forming portion, the optical waveguide overlaps the first wiring on the cover insulating layer in the outrigger portion of the wiring portion and the gimbal portion, and on the other side in the width direction of the first wiring portion on the cover insulating layer. It formed so that it shifted. Moreover, the light emitting element was provided on the cover insulating layer.

Example 3 (Form where the base insulating layer doubles as the under cladding layer and the cover insulating layer doubles as the over cladding layer)

A metal support substrate made of stainless steel having a thickness of 20 μm was prepared (see Fig. 8 (a)).

Next, the base insulating layer which consists of polyimide resin was formed in the said pattern on the metal support substrate. The refractive index at the wavelength of 830 nm of this base insulating layer was 1.541. In addition, the thickness of the base insulating layer was 6 micrometers (refer FIG. 8 (b)).

Subsequently, the conductive pattern, supply wiring, and supply terminal part which consist of copper were formed simultaneously on the base insulating layer by the additive method (refer FIG. 8 (c)). Their thickness was 10 micrometers.

Next, a core layer was formed on the base insulating layer.

In order to form the core layer in the above-described pattern, first, 70 parts by weight of bisphenoxyethanol fluorene diglycidyl ether (fluorene derivative, epoxy equivalent 300 g / eq.), 1,3,3-tris {4 30 parts by weight of-[2- (3-oxetanyl)] butoxyphenyl} ethane (oxetane compound), 4,4-bis [di (βhydroxyethoxy) phenylsulfinio] phenylsulfide-bis-hexa 0.5 weight part of 50% propioncarbonate solutions of fluoro antimonate (photosensitive agent), and 28 weight part of ethyl lactate (diluent) were mix | blended and the varnish was prepared. Subsequently, this varnish was apply | coated to the surface of a base insulating layer, and it dried by heating at 80 degreeC for 15 minutes. Then, it exposed through the photomask and developed by melt | dissolving the unexposed part with the gamma beaurolactone type organic solvent. Then, the core layer was formed on the base insulating layer by heating and hardening at 100 degreeC for 15 minutes (refer FIG. 8 (d)).

The refractive index at the wavelength of 830 nm of this core layer (core layer after hardening) was 1.588. In addition, the thickness of the core layer was 5 micrometers, and the width was 5 micrometers.

Subsequently, the cover insulation layer was formed in the said pattern so that a conductor pattern and a core layer might be coat | covered on the base insulation layer.

In order to form the cover insulation layer in the above-described pattern, first, 35 parts by weight of bisphenoxyethanol fluorene diglycidyl ether (fluorene derivative, epoxy equivalent 300 g / eq.), (3,4-epoxycyclohex) 40 parts by weight of methyl 3 ', 4'-epoxycyclohexyl-carboxylate, 25 parts by weight of an alicyclic epoxy resin (Celoxide 2081, manufactured by Daicel Chemical Co., Ltd.) having a cyclohexene oxide skeleton, 4,4-bis [die 1 part by weight of a 50% propioncarbonate solution of (β-hydroxyethoxy) phenylsulfinio] phenylsulfide-bis-hexafluoro antimonate (photosensitive agent) was blended to prepare a varnish. Subsequently, this varnish was apply | coated to the surface of the base insulating layer containing a conductor pattern and a core layer, and it dried by heating at 80 degreeC for 15 minutes. Then, it exposed through the photomask and developed by melt | dissolving the unexposed part with the gamma beaurolactone type organic solvent. Thereafter, by heating and curing at 100 ° C. for 15 minutes, the cover insulation is exposed to cover the signal wiring, the core layer, and the supply terminal portion by exposing the external connection terminal portion, the magnetic head side connection terminal portion, and the supply terminal portion on the base insulating layer. A layer was formed (see FIG. 8 (e)).

The refractive index at the wavelength of 830 nm of the cover insulating layer was 1.542. In addition, the thickness (thickness in the surface of a core layer) of the cover insulating layer was 100 micrometers.

Next, the planar rectangular opening part was formed in the metal support substrate in the terminal formation part by wet etching (refer FIG. 8 (f)). The width of this opening was 100 µm and the length was 100 µm.

Subsequently, the base insulating layer, the core layer, and the cover insulating layer were cut at once by laser processing from the opening side so that the cross sections of their distal ends intersect the longitudinal direction (see Fig. 8 (g)). The inclination angle of the cross section formed by this cutting was 45 kPa.

Thereafter, a light emitting element was provided on the base insulating layer so as to be optically connected to the rear end of the optical waveguide on the rear end side of the wiring portion of the circuit portion suspension substrate and electrically connected to the front end of the supply wiring.

In addition, although the said description was provided as embodiment of an illustration of this invention, this is only a mere illustration and should not interpret it limitedly. Modifications of the invention which are apparent to those skilled in the art are included in the scope of the later claims.

FIG. 1: shows the top view which shows one Embodiment of the circuit part suspension board | substrate of this invention.

FIG. 2: shows sectional drawing along the optical waveguide in the circuit part suspension board | substrate shown in FIG.

FIG. 3 is a cross-sectional view taken along the width direction of the wiring portion of the circuit portion suspension substrate shown in FIG. 1, showing a cross-sectional view of an optical waveguide provided on the base insulating layer. FIG.

FIG. 4 is a cross-sectional view showing the circuit part suspension substrate manufacturing process shown in FIG. 3, wherein the left side view is a sectional view along the width direction in the wiring portion corresponding to FIG. 3, and the right side view is a longitudinal direction in the terminal formation portion. FIG. Is an enlarged cross-sectional view,

(a) is a step of preparing a metal support substrate,

(b) is a step of sequentially laminating the base insulating layer, the conductor pattern and the cover insulating layer on the metal support substrate,

(c) is a step of forming an optical waveguide on the base insulating layer,

(d) is a step of forming an opening in the metal support substrate in the terminal forming portion,

(e) shows the process of cutting the base insulation layer and the optical waveguide so that the cross section of the front-end | tip part of an optical waveguide may cross a longitudinal direction by laser processing.

FIG. 5 is an explanatory diagram of a state in which a hard disk driver equipped with a head slider, a magnetic head, and a circuit part suspension substrate shown in FIG. 1 employs an optical assist method to record information on a hard disk.

FIG. 6: is sectional drawing along the width direction in the wiring part of the circuit part suspension board shown in FIG. 1, and is sectional drawing of the form in which an optical waveguide is provided on a cover insulating layer.

FIG. 7: is sectional drawing which shows the manufacturing process of the circuit part suspension board shown in FIG. 6, A left side figure is sectional drawing along the width direction in the wiring part corresponding to FIG. 6, A right side figure is along the longitudinal direction in a terminal formation part. Is an enlarged cross-sectional view,

(a) is a step of preparing a metal support substrate,

(b) is a step of sequentially laminating the base insulating layer, the conductor pattern and the cover insulating layer on the metal support substrate,

(c) is a step of forming an optical waveguide on the cover insulating layer,

(d) is a step of forming an opening in the metal support substrate in the terminal forming portion,

(e) shows the process of cutting the base insulation layer, the cover insulation layer, and the optical waveguide so that the cross section of the front-end | tip part of an optical waveguide may cross a longitudinal direction by laser processing.

8 is a cross-sectional view illustrating a process of manufacturing a circuit part suspension substrate, a left side view is a cross-sectional view along a width direction in a wiring portion, and a right side view is an enlarged cross-sectional view along a length direction in a terminal formation portion.

(a) is a step of preparing a metal support substrate,

(b) is a step of forming a base insulating layer serving as an under cladding layer on the metal support substrate,

(c) is a step of forming a conductor pattern on the base insulating layer,

(d) is a step of forming a core layer on the base insulating layer,

(e) is a step of forming a cover insulating layer, which also serves as an over cladding layer, to cover the conductor pattern and the core layer on the base insulating layer,

(f) is a step of forming an opening in the metal support substrate in the terminal forming portion,

(g) shows the process of cutting | disconnecting the front end part of a base insulation layer, a core layer, and a cover insulation layer by laser processing from an opening side so that the cross section of these front end parts may cross a longitudinal direction.

Claims (8)

A metal support substrate, a base insulating layer formed on the metal support substrate, a conductor pattern formed on the base insulating layer, a cover insulating layer formed to cover the conductor pattern on the base insulating layer, and light A circuit part suspension substrate, comprising a waveguide. The method of claim 1, The said optical waveguide is provided on the said base insulating layer or the said cover insulating layer, The circuit part suspension board | substrate characterized by the above-mentioned. The method of claim 1, The optical waveguide is formed on the under cladding layer, the core layer formed on the under cladding layer and having a higher refractive index than the under cladding layer, and the core layer on the under cladding layer to cover the core layer. With a low over cladding layer, The base insulating layer serves as the under cladding layer, the core layer is formed on the base insulating layer, and the cover insulating layer serves as the over cladding layer. The method of claim 1, Equipped with an additional light emitting element, The light emitting element is optically connected with the said optical waveguide, The circuit part suspension board | substrate characterized by the above-mentioned. The method of claim 4, wherein I have a mount to mount a head slider, In the vicinity of the mounting portion, an opening penetrating the metal support substrate in the thickness direction is formed, The said optical waveguide is formed so that one end may be connected with the said light emitting element, and the other end shall be provided in the said opening part. The circuit part suspension substrate. The method of claim 5, wherein The optical waveguide is disposed along the direction in which the conductor pattern extends, The light emitting element is disposed on one side in the longitudinal direction of the metal support substrate, The said mounting part is arrange | positioned at the other side in the longitudinal direction of the said metal support substrate, The circuit part suspension board | substrate characterized by the above-mentioned. A base insulating layer formed on the metal supporting substrate, a conductor pattern formed on the base insulating layer, and a cover insulating layer formed on the base insulating layer to cover the conductor pattern. Forming a process, Forming an optical waveguide on the base insulating layer or the cover insulating layer; Forming an opening through the metal support substrate in the thickness direction in the vicinity of the mounting portion for mounting the head slider; And cutting the base insulating layer and / or the cover insulating layer and the optical waveguide from the opening side so that a cross section of the optical waveguide intersects a direction in which the optical waveguide extends. Method of manufacturing a substrate. Preparing a metal support substrate; Forming a base insulating layer, which serves as an under cladding layer, on the metal support substrate; Forming a conductor pattern on the base insulating layer; Forming a core layer having a higher refractive index than the base insulating layer on the base insulating layer; And a step of forming a cover insulating layer having a refractive index lower than that of said core layer by serving as an over cladding layer on said base insulating layer so as to cover said conductor pattern and said core layer. Manufacturing method.

Images