JP2007083401A - Manufacturing method for wiring substrate, and liquid delivering head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a wiring structure of a wiring substrate brought into ILB connection to a liquid delivering substrate. <P>SOLUTION: A wiring substrate material B is manufactured which has: an opening 11 to mount the liquid delivering substrate not illustrated, a contact part 12 for inputting an electrical signal; a wiring lead 14 arranged in the opening 11; and a wiring sharing part 15. Electrolytic plating of the contact part 12 and the wiring lead 14 is carried out while an internal wiring cable 13 extended to a substrate end edge is made a wiring cable for plating, whereby a plating layer of Au and Ni for protection is formed. Every wiring lead 14 is rendered conductive by the wiring sharing part 15, and therefore, one internal wiring cable 13 to be the wiring cable for plating is enough. After plating processing, the wiring sharing part 15 is removed by blanking or the like. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a wiring board and a liquid discharge head used in a liquid discharge head that performs a recording operation by discharging a liquid such as ink.

  The present invention relates to a liquid ejection head mounted on a general printing apparatus, a copying machine, a facsimile having a communication system, a word processor having a printing unit, or a multifunction recording apparatus in which these apparatuses are combined. Can be applied to.

  A recording apparatus such as an ink jet printer has the characteristics that high-speed recording and recording on various recording media are possible and noise during recording hardly occurs. Therefore, it is widely adopted as a device that bears a recording mechanism such as a printer, a word processor, a facsimile machine, and a copying machine.

  In addition, in the liquid ejection method such as ink, a recording liquid is ejected in parallel to the substrate on which the electrothermal conversion elements are arranged (edge shooter), or perpendicular to the substrate on which the electrothermal conversion elements are arranged. There is a method (side shooter) for discharging the recording liquid.

  FIG. 6 shows a configuration of an ink jet recording head which is a side shooter type general liquid discharge head disclosed in Patent Document 1 and the like. 7A and 7B illustrate a cross-sectional structure of the ink jet recording head. FIG. 7A is an enlarged cross-sectional view showing a CC cross section of FIG. 6A, and FIG. It is an expanded sectional view which shows the DD cross section of).

  The ink jet recording head includes a liquid discharge substrate 101, a wiring substrate 110, and a support member 120. As shown in FIG. 7, the liquid discharge substrate 101 has an ink supply port 104 in the shape of an elongated hole at the center of a heater board 102 made of a silicon substrate, and a plurality of heating resistors are formed on the heater board 102. 107 are arranged on both sides of the ink supply port 104 at substantially equal intervals. Ink is supplied from an ink supply port 104 of the heater board 102. Wiring (not shown) for supplying power to the heating resistor 107 is routed outside the heater board 102 and connected to external extraction electrode pads installed at both ends on the heater board 102. . An orifice plate 105 having a plurality of discharge ports 106 is attached on the heater board 102, and bumps 103 serving as electrodes are formed on the electrode pads.

  For the wiring substrate 110, for example, a flexible wiring substrate is used. In this method, a copper foil is bonded to the base film 110a with an adhesive 110b and patterned to form internal wiring 113, wiring leads 114 that serve as electrode terminals for electrically connecting the bumps 103 of the liquid discharge substrate 101, and contact portions 112. It is a thing. On top of that, there is a cover film 110d bonded via an adhesive 110c.

  The support member 120 is bonded by an adhesive 121 so that the ink supply port 104 of the liquid discharge substrate 101 and the ink supply port 122 of the support member 120 communicate with each other. In addition, the wiring substrate 110 can be connected to the electrode portion of the liquid discharge substrate 101 almost horizontally, and the wiring substrate 110 is bonded and fixed by the adhesive 123.

  As a method of connecting the wiring of the wiring board 110 to the electrode portion of the liquid discharging substrate 101, generally, the bump 103 of the liquid discharging substrate 101 and the wiring lead 114 of the wiring board 110 are metal-bonded by ultrasonic waves and heat. There is. This is called inner lead bonding. The bonding portion between the bump 103 of the liquid discharge substrate 101 and the wiring lead 114 of the wiring substrate 110 includes a sealing adhesive 130 a on the wiring lead 114 and a sealing adhesive around the liquid discharge substrate 101. Insulation from the surroundings is achieved by sealing with 130b.

As shown in FIG. 8, the exposed wiring leads 114 and the contact portions 112 as electric signal input portions use a number of internal wirings 113 extending from the wiring leads 114 to the edge of the substrate as plating wirings. Then, electrolytic plating is performed with nickel (Ni) and gold (Au). Thus, the structure which prevents corrosion of copper foil is known.
Japanese Patent Laid-Open No. 2003-21678

  However, the wiring lead 114 and the contact portion 112 exposed on the surface of the wiring substrate 110 have the following problems in the plating process for preventing corrosion due to ink or the like. That is, in order to perform the electrolytic plating with Ni or Au, the internal wirings 113 to be the plating wirings extending to the edge of the substrate are required by the number of the wiring leads 114. For this reason, as shown in FIG. 8, the number of wirings laid inside the wiring board increases, and the cost increase accompanying the increase in the size of the board may become a problem.

  The present invention provides a wiring board manufacturing method capable of reducing the number of wirings for plating for performing electrolytic plating on wiring leads and electrical signal input portions exposed to the outside, and preventing an increase in board size and cost. It is intended to provide.

  The method for manufacturing a wiring board according to the present invention includes an electric signal input portion and a plurality of internal wirings exposed on the surface, a plurality of wiring leads electrically connected to the electrode portions of the element chips in the device holes, And a wiring sharing part for connecting the plurality of wiring leads to each other, and a step of manufacturing a wiring board in which at least one internal wiring is extended to the edge of the board, and extending to the board edge of the wiring board. And a step of plating the electrical signal input portion and the wiring lead using the internal wiring and the wiring sharing portion in the device hole, and a step of removing the wiring sharing portion in the device hole.

  By providing the wiring sharing portion, for example, 1 is provided for the internal wiring (plating wiring) necessary for performing electrolytic plating on the electric signal input portion for inputting the driving power and the electric signal from the apparatus main body and the wiring lead. It can only be a book. Compared to the case where the wiring for plating is required for the number of lead wirings, unnecessary wiring can be eliminated, the board size of the wiring board can be greatly reduced, and the cost can be reduced.

  By using such a wiring board for the liquid discharge head, it is possible to promote the cost reduction of the liquid discharge head.

  The best mode for carrying out the present invention will be described with reference to the drawings.

  As shown in FIG. 1 and FIG. 2, the wiring board material B before plating processing includes an opening 11 that is a device hole, a contact portion 12 that is an electric signal input portion exposed on the back side in the drawing, an internal wiring 13, The wiring lead 14 and the like exposed from the opening 11 are included. The contact portion 12 and the wiring lead 14 are subjected to electrolytic plating with nickel (Ni) or gold (Au) for the purpose of preventing corrosion. The wiring lead 14 in the opening 11 is formed integrally with the wiring sharing portion 15 that conducts them, and therefore, as shown in FIG. 3, the internal wiring that becomes the plating wiring extending to the edge of the substrate is formed. 13 can be only one.

  After the plating process, the wiring sharing portion 15 is removed by punching shown in FIG. 2, laser processing shown in FIG. The wiring board 10 manufactured in this way is bonded to a support member 20 that supports the liquid discharge substrate 1 as shown in FIG. Next, electrical connection is made between the bumps 3 on the heater board 2 of the liquid discharge substrate 1 and the wiring leads 14. In the conventional example, by omitting at least most of the wiring for plating that is required for the number of wiring leads, it is possible to prevent an increase in cost associated with the increase in the size of the wiring substrate 10 and to provide an inexpensive liquid discharge head.

  As shown in FIG. 3, the internal wiring 13 extending to the edge of the substrate is generally supplied with power to the liquid ejection substrate 1 rather than a signal line or the like that is made as thin as possible by not supplying power to the liquid ejection substrate 1. It is recommended to select a power line that is thick because it is supplied. In this way, stable power can be supplied and plating can be performed.

  Furthermore, ink that is a liquid generally used in an ink jet recording apparatus may contain a urea component from the viewpoint of improving the uniformity. Therefore, when the wiring board is packaged in an integrated form, this urea has ammonia gas decomposed by heat in the ink atmosphere inside the package form, and this urea may dissolve into the condensed moisture and become ammonia water.

Therefore, the internal wiring 13 extending to the substrate edge of the wiring substrate 10 has a wiring length L ₁ from the contact portion 12 to the substrate edge extending to the substrate edge of all other contact portions 12. It is desirable to make the distance longer than the distances L ₂ and L ₃ (see FIG. 1). As a result, it is possible to provide an ink jet recording head that does not impair reliability even if the above-described internal wiring corrosion occurs at the edge of the substrate.

  Note that “print” and “record” are manifested not only to form significant information such as characters and figures, but also to be perceptible by humans, regardless of significance and insignificance. Regardless of whether or not, an image, a pattern, a pattern or the like is widely formed on a print medium. The case of processing a medium is also referred to.

  Here, “print medium” and “medium” include not only paper used in general printing apparatuses but also a wide range of materials such as cloth, plastic film, metal plate, glass, ceramics, wood, leather, etc. Say what is acceptable.

  Further, “ink” should be interpreted widely as in the definition of “print”. That is, it refers to a liquid that can be used for forming an image, a pattern, a pattern, or the like, processing of the print medium, or processing of the ink (for example, solidification or insolubilization of the coloring material in the ink) by being applied on the print medium, All liquids used for recording shall be included.

  1 to 4 show a first embodiment. The wiring board material B shows the wiring board 10 in a state before plating, and has a wiring sharing portion 15 connected to all the wiring leads 14 in the opening 11, and one of the plurality of wiring leads 14. The internal wiring 13 extends to the edge of the substrate as the wiring for plating connected to the substrate.

As shown in FIG. 1 and FIG. 2, after the plating process, the punching and cutting jig T ₁ of the press machine disposed immediately above the wiring sharing portion 15 of the wiring board material B is pressed downward to share the wiring. The wiring board 10 is manufactured by separating the portion 15.

  FIG. 3 shows a wiring structure of the wiring board 10, and an internal wiring 13 formed by patterning of copper foil or the like is connected to the contact portion 12 and the wiring lead 14 protruding into the opening 11. Only one of 13 extends to the edge of the substrate.

  The ink jet recording head, which is a liquid discharge head of the present embodiment, is a recording head that performs recording using an electrothermal transducer that causes film boiling in response to an electrical signal. As shown in FIG. The board 1, the wiring board 10, and the support member 20 are included.

  In the liquid discharge substrate 1, an ink supply port 4 is opened in the shape of an elongated hole in the center of a silicon substrate 2, and a plurality of heating resistors are arranged on both sides of the ink supply port 4 at substantially equal intervals. The substrate 2 on which such a heating resistor is formed is called a heater board. Ink is supplied from an ink supply port 4 of the heater board 2. Wiring (not shown) for supplying power to the heating resistor is routed outside the heater board 2, and is connected to electrode portions installed at both ends on the heater board 2. These wirings are generally protected by a nitride insulating film (SiN) having a thickness of several hundreds to several thousands. Then, an orifice plate 5 having a plurality of discharge ports 6 formed by a photolithography technique is attached on the heater board 2. Further, bumps 3 serving as electrodes are formed on the electrode pads, and the liquid discharge substrate 1 is completed. The bump 3 is, for example, a gold bump of about 5 to 30 μm formed by a stud bump method.

  For example, a flexible wiring substrate is used as the wiring substrate 10, and a copper foil is bonded onto the base film 10 a with an adhesive 10 b, and the copper foil is patterned to form an internal wiring 13 and a wiring lead 14 of the copper foil. Then, except for the wiring leads 14 that electrically connect the bumps 3 of the liquid discharge substrate 1, they are covered with a cover film 10d bonded with an adhesive 10c. The base film 10a and the cover film 10d are, for example, resist films with a thickness of 25 μm.

  For example, the wiring lead 14 and the contact portion 12 are plated with gold on a copper foil having a thickness of 30 μm. The adhesives 10b and 10c have a thickness of 10 μm, for example.

  Since the wiring sharing part 15 connected to all the copper foil wirings of the wiring board 10 is provided, one internal wiring 13 is extended to the edge of the board, and this is used as plating wiring with respect to the wiring lead 14 and the contact part 12. Apply gold plating. Thereafter, the wiring sharing portion 15 that is no longer needed is punched out by a press to form the tip portion 14a of the wiring lead 14 and has a shape having a bend 14b between the tip portion 14a and the root portion of the wiring lead 14. .

  As shown in FIGS. 4A and 4B, the bent shape of the wiring board 10 alleviates the influence of thermal expansion or the like when heat is applied to the wiring board 10 at the time of manufacturing the ink jet recording head. When the wiring board 10 is punched out by a press machine and electrically connected to the liquid discharge substrate 1, a downward sag or an edge 14 c such as a burr is generated at the tip of the wiring lead 14 and interferes with the liquid discharge substrate 1. May cause scratches or other adverse effects. Therefore, as shown in FIGS. 1 and 2, it is desirable that the contact portion 12 be the front side and the wiring sharing portion 15 be punched and cut from the back side of the wiring substrate 10 with a press.

  By doing so, as shown in FIG. 4A, there is no fear that the edge of the leading end portion 14a of the wiring lead 14 after cutting the wiring sharing portion 15 or the edge such as a burr damages the liquid discharge substrate 1. A good electrical connection state can be obtained.

  The support member 20 is bonded by an adhesive 21 so that the ink supply port 4 of the liquid ejection substrate 1 and the ink supply port 22 of the support member 20 communicate with each other. In addition, the wiring substrate 10 can be connected to the electrode portion of the liquid discharge substrate 1 almost horizontally, and the wiring substrate 10 is bonded and fixed by the adhesive 23.

  Then, the bumps 3 of the liquid discharge substrate 1 and the wiring leads 14 of the wiring substrate 10 are metal-bonded (inner lead bonding) using ultrasonic waves and heat, and the electrodes are electrically connected and fixed. Next, a first sealing adhesive (not shown) is sealed on the wiring lead 14 by using the second sealing adhesive around the liquid discharge substrate 1, so that the bonding portion is surrounded from the periphery. Insulate and coat. If a thermosetting adhesive is used for these adhesives, for example, the gap between both electrodes is sufficiently fixed.

  According to this embodiment, the wiring for plating necessary for performing electrolytic plating with nickel (Ni) or gold (Au) on the wiring leads and contact portions exposed on the surface of the wiring board is the wiring board. There is only one internal wiring extending to the edge of the substrate. As a result, it is possible to eliminate useless wiring that has been necessary for the number of wiring leads so far, and to prevent an increase in cost due to an increase in the size of the substrate.

  In this embodiment, the number of wiring for plating extending to the substrate edge of the wiring board is one, but this is wider than other wiring such as a power supply line for supplying power to the liquid discharge substrate. It is desirable to choose. Furthermore, the wiring length from the contact part of the internal wiring that extends to the board edge of the wiring board to the board edge that extends from the distance from the other contact part to the board edge from the viewpoint of preventing adverse effects due to corrosion. It is desirable that the length be too long.

FIG. 5 shows a method of manufacturing a liquid discharge head according to the second embodiment. In this embodiment, instead of a press machine for punching out the wiring sharing portion 15 of the wiring board material B from above, the laser processing machine T ₂ above the wiring sharing portion 15 and a camera unit S for alignment. Is arranged. The laser beam machine T ₂ above the wiring sharing unit 15 is cut with a laser along the two-dot chain line N in the opening 11 while aligning the wiring board material B with the wiring board material B, and the wiring sharing unit 15 is separated. The state shown in FIG.

  In this embodiment, the tip of the wiring lead 14 that is electrically connected to the liquid discharge substrate is formed by laser processing. Etc. are difficult to remain. Therefore, more reliable electrical connection is possible when the wiring substrate 10 is electrically connected to the liquid ejection substrate.

It is a figure explaining the state before the plating process of the wiring board by Example 1. FIG. It is a figure explaining the cutting process of the wiring share part by Example 1. FIG. The wiring structure of the wiring board by Example 1 is shown, (a) is the top view which shows the whole, (b) is the expansion partial top view which expands and shows the inside of the frame Q of (a). FIG. 3 is a cross-sectional view illustrating a main part of the ink jet recording head according to the first embodiment. 6 is a diagram illustrating a method of manufacturing a wiring board according to Example 2. FIG. An ink jet recording head according to a conventional example is shown, in which (a) is an exploded perspective view showing an exploded main part thereof, and (b) is a perspective view showing an assembled state of (a). FIG. 7 shows a part of the apparatus of FIG. 6, (a) is a cross-sectional view taken along line CC in FIG. 6, and (b) is a cross-sectional view taken along line DD in FIG. 6. . FIGS. 7A and 6B show a wiring structure of the wiring board of FIG. 6, wherein FIG. 7A is a plan view showing the whole and FIG. 6B is an enlarged partial plan view showing the inside of a frame P of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid ejection board | substrate 2 Heater board 3 Bump 4 Ink supply port 5 Orifice plate 6 Ejection port 10 Wiring board 11 Opening 12 Contact part 13 Internal wiring 14 Wiring lead 15 Wiring sharing part 20 Support member

Claims (10)

Electrical signal input part exposed on the surface and a plurality of internal wirings, a plurality of wiring leads electrically connected to the electrode part of the element chip in the device hole, and a wiring for electrically connecting the plurality of wiring leads in the device hole to each other Producing a wiring board having a shared portion and extending at least one internal wiring to the edge of the board;
Plating the electrical signal input portion and the wiring lead using the internal wiring extending to the substrate edge of the wiring substrate and the wiring sharing portion in the device hole;
And a step of removing the wiring sharing portion in the device hole.   2. The method of manufacturing a wiring substrate according to claim 1, wherein the element chip is a liquid discharge substrate that discharges liquid in response to an electric signal.   3. The method for manufacturing a wiring board according to claim 2, wherein the internal wiring extending to the edge of the board is a power line for supplying power to the liquid discharge board.   4. The electric signal input unit connected to the internal wiring extending to the substrate edge is located farther from the substrate edge than other electric signal input units. Wiring board manufacturing method.   5. The method of manufacturing a wiring board according to claim 1, wherein the wiring sharing part is punched out.   6. The method of manufacturing a wiring board according to claim 5, wherein the wiring sharing portion is punched from a surface opposite to the surface having the electric signal input portion.   The method of manufacturing a wiring board according to claim 1, wherein the wiring sharing part is cut by laser processing.   7. The method of manufacturing a wiring board according to claim 1, wherein the wiring lead is bent and deformed simultaneously when the wiring sharing portion is removed.   A wiring board manufactured by the method for manufacturing a wiring board according to claim 1.   9. A liquid discharge head comprising: a wiring board manufactured by the method for manufacturing a wiring board according to claim 2; and a liquid discharge board incorporated in a device hole of the wiring board.

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