JP6397258B2 - Element substrate, liquid discharge head, and recording apparatus - Google Patents

Description

  The present invention relates to an element substrate, a liquid discharge head, and a recording apparatus, and more particularly to an element substrate on which a plurality of elements and their drive circuits are mounted, a liquid discharge head, and the liquid discharge head as an ink jet recording head. The present invention relates to a recording apparatus that records

  2. Description of the Related Art Conventionally, a drive circuit including a heater (recording element) of a recording head mounted on an ink jet recording apparatus and a driving element made of a semiconductor element such as a transistor for selectively driving the heater, and wiring therefor, are semiconductor processing technology. And are formed on the same substrate. This substrate is called an element substrate.

  FIG. 10 is a diagram showing the relationship between the silicon wafer and the element substrate.

  As shown in FIG. 10, element substrates corresponding to a plurality of recording heads mounted on an ink jet recording apparatus are formed on a single silicon (Si) wafer 200 by using a semiconductor process technology. The element substrate is formed on the Si wafer 200 together with the substrate cutting regions 201 and 202. Four element substrates are cut out from the region A of the Si wafer 200 shown in FIG.

  FIG. 11 is an enlarged view of a part of the Si substrate showing a state in which six element substrates 100 are formed.

  As can be seen from FIG. 11A, a plurality of heaters (recording elements) 101 are formed in two rows at the center of each element substrate 100. On the other hand, a plurality of electrode pads 102 are formed on each of the upper and lower sides of each element substrate 100. The element substrate is electrically connected to the outside of the substrate by these electrodes. In addition, a plurality of electrode pads 103 for inspection are formed separately from the plurality of electrode pads 102 on a part of each of the left and right sides of each element substrate 100. The plurality of electrode pads 103 are used for inspection of various circuit elements when an element substrate is formed on a Si wafer.

  FIG. 11B shows a state in which the head substrate H1000 is formed by bonding the ink discharge port H1101 and the nozzle member H1100 that forms the ink flow path to the element substrate. Next, one head substrate H1000 is formed through a process of cutting and separating the cutting regions 201 and 202 from the Si wafer.

  FIG. 12 is a partially broken perspective view showing the configuration of the head substrate.

  As shown in FIG. 12, the head substrate H1000 is formed by bonding a nozzle member H1100 on the element substrate 100. The plurality of heaters 101 are arranged on both sides of an ink supply port 120 penetrating the main plane of the element substrate 100.

  FIG. 13 is a bottom view of the recording head.

  As shown in FIG. 13, the head substrate H1000 produced through the processes shown in FIGS. 10 to 12 includes an electrode pad 102 and an electrode lead H1201 of a flexible film wiring substrate H1200 that is electrically connected to the outside of the head substrate. Electrically joined. Thereafter, the recording element unit H2000 is formed through a process of covering the periphery of the electrode lead H1201 with the sealing resin H1300. Then, a recording head is created by joining with an ink supply unit (not shown).

  In recent inkjet recording apparatuses, in order to obtain high-quality images at a high speed, it is a mainstream to use an element substrate in which a plurality of heaters are integrated at a high density in a recording head. For this reason, the number of element substrates that can be taken out from a single Si wafer is reduced because the size of the element substrate increases due to an increase in the number of heaters, drive circuits, and electrode pads on the element substrate. This leads to an increase in manufacturing cost.

  In order to reduce the manufacturing cost, Patent Document 1 provides an electrode pad that is not required after the cutting and separating process of the substrate in a cutting region outside the substrate, and enlarging the substrate size by sealing the wiring portion exposed on the cutting surface. The structure which prevents the corrosion of the wiring by the water | moisture content in air | atmosphere is suppressed.

  In addition, Patent Document 2 discloses a configuration in which a sealing resin is filled only around the electrode pads in order to ensure capping reliability when the substrate size is reduced and to further reduce manufacturing costs. Further, in Patent Document 3, electrode pads for inspecting a circuit provided in the electrode pad side in the substrate are arranged in the cutting region, and the metal layer residue remaining on the cross section of the substrate after the cutting and separating step is disclosed. The structure which prevents the corrosion by is disclosed.

Japanese Patent Laid-Open No. 9-252034 JP 2009-000904 A JP 2006-224527 A

  In the conventional head substrate as disclosed in Patent Documents 1 to 3, the size of the head substrate is reduced and the density of electrode pads and wirings inside the substrate is increased. Therefore, the head substrate after being cut and separated from the Si wafer Wirings (wiring end face portions) remaining in the cross section are also arranged with high density. In an ink jet recording apparatus equipped with a recording head using such a head substrate, when recording is performed over a long period of time, the wiring end surface portion is completely sealed with the sealing resin. There is a problem that the circuit is short-circuited.

  The present invention has been made in view of the above-described conventional example, and without causing an increase in size or addition of a manufacturing process, a highly reliable element substrate that does not short-circuit even after long-term use, a liquid discharge head, and its It is an object to provide a recording apparatus using the head as a recording head.

  In order to achieve the above object, the element substrate of the present invention has the following configuration.

That is, a rectangular element substrate formed by a semiconductor manufacturing process on a silicon wafer, and obtained by cutting the silicon wafer after the formation, for the inspection of a circuit mounted on the element substrate, A plurality of wirings connected to a plurality of inspection electrode pads provided outside the element substrate and applied with the same voltage as applied to the plurality of inspection electrode pads, and for operating the circuit A plurality of pads for applying a voltage to the plurality of pads, and when the element substrate is cut from the silicon wafer, a plurality of cutting points at which the plurality of wirings are cut are at the end portions of the element substrate, provided so that the distance between the cutting points the adjacent higher potential is large between the voltage applied to the cutting point adjacent to the voltage applied to the plurality of cutting points is large, the Some number of cutting points are provided on the side where the plurality of pads are provided in the element substrate is provided on the side of the remaining plurality of cutting points of the plurality of pads of the device substrate is not provided It is characterized by that.

  According to another aspect of the present invention, the element substrate having the above-described configuration, a plurality of heaters, a liquid supply path supplied from the outside, and a plurality of discharge ports that discharge liquids corresponding to the plurality of heaters, respectively. A liquid ejection head characterized by comprising:

  According to another aspect of the present invention, there is provided a recording apparatus that uses the above-described liquid discharge head as a recording head and performs recording by discharging ink from the recording head onto a recording medium according to an ink jet method.

  Therefore, according to the present invention, if the potential difference between the cutting points of the plurality of wirings connected to the external electrode pads used for the circuit inspection and the voltage applied to the adjacent cutting points is large, the distance between the adjacent cutting points is set. Arrange them to be larger. Therefore, it is possible to prevent a short circuit between cutting points due to a potential difference between voltages applied to the respective wirings as the member deteriorates due to long-time use of the element substrate.

  For this reason, since a special structure and manufacturing process are not required, there is an advantage that the size of the element substrate is not increased and the manufacturing process is not complicated.

1 is an external perspective view showing an outline of a configuration of an ink jet recording apparatus that is a typical embodiment of the present invention. It is a block diagram which shows the control structure of the inkjet recording device shown in FIG. FIG. 3 is an enlarged view of a part of a Si substrate showing a state in which six element substrates 100 are formed by a semiconductor manufacturing process according to a first embodiment of the present invention, and a partially broken perspective view showing a configuration of a head substrate. It is an enlarged plan view of the lower right end of the element substrate before cutting and separating. 2 is a diagram showing a drive circuit and a logic circuit formed on an element substrate 100. FIG. 6 is an enlarged view of a partial region of an element substrate used in the recording head of Comparative Example 1. FIG. 6 is an enlarged view of a partial region of an element substrate used in a recording head of Comparative Example 2. FIG. 10 is an enlarged plan view of a lower right end of an element substrate before cutting and separation according to Embodiment 2. FIG. It is an enlarged plan view of the lower right end of the element substrate before cutting and separation according to the third embodiment. It is a figure which shows the relationship between a silicon wafer and an element substrate. It is an enlarged view of a part of the Si substrate showing a state in which six element substrates are formed. It is a partially broken perspective view which shows the structure of a head substrate. FIG. 6 is a bottom view of the recording head.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In this specification, “recording” (hereinafter also referred to as “printing”) is not only for forming significant information such as characters and figures, but also for images on a wide range of recording media, regardless of significance. A case where a pattern, a pattern, or the like is formed or a medium is processed is also expressed. It does not matter whether it has been made obvious so that humans can perceive it visually.

  “Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall.

  The term “ink” should be broadly interpreted in the same way as the definition of “recording”. When applied to a recording medium, the “ink” forms an image, a pattern, a pattern, or the like, or processes the recording medium. It represents a liquid that can be subjected to the treatment. Examples of the ink treatment include solidification or insolubilization of the colorant in the ink applied to the recording medium.

  Furthermore, unless otherwise specified, the “recording element” collectively refers to an ejection port or a liquid path communicating with the ejection port and an element that generates energy used for ink ejection.

  Furthermore, the “recording element (or nozzle)” collectively refers to an ejection port or a liquid path communicating with the ejection port and an element that generates energy used for ink ejection unless otherwise specified.

  The recording head substrate (head substrate) used below does not indicate a simple substrate made of a silicon semiconductor but indicates a configuration in which each element, wiring, and the like are provided.

  Further, the term “on the substrate” means not only the element substrate but also the surface of the element substrate and the inside of the element substrate near the surface. In addition, the term “built-in” as used in the present invention is not a term indicating that each individual element is simply arranged separately on the surface of the substrate, but each element is manufactured in a semiconductor circuit. It shows that it is integrally formed and manufactured on an element plate by a process or the like.

<Outline of recording apparatus (FIGS. 1-2)>
FIG. 1 is an external perspective view showing an outline of the configuration of a recording apparatus that performs recording using an ink jet recording head (hereinafter referred to as a recording head) that is a typical embodiment of the present invention.

  As shown in FIG. 1, an ink jet recording apparatus (hereinafter referred to as a recording apparatus) 1 has an ink jet recording head (hereinafter referred to as a recording head) 3 that performs recording by discharging ink in accordance with an ink jet method. Recording is performed by reciprocating in the direction. A recording medium P such as recording paper is fed through the paper feeding mechanism 5 and conveyed to a recording position, and recording is performed by discharging ink from the recording head 3 to the recording medium P at the recording position.

  In addition to mounting the recording head 3 on the carriage 2 of the recording apparatus 1, an ink tank 6 for storing ink to be supplied to the recording head 3 is mounted. The ink tank 6 is detachable from the carriage 2.

  The recording apparatus 1 shown in FIG. 1 is capable of color recording. For this reason, the carriage 2 contains four inks containing magenta (M), cyan (C), yellow (Y), and black (K) inks, respectively. An ink cartridge is installed. These four ink cartridges are detachable independently.

  The recording head 3 of this embodiment employs an ink jet system that ejects ink using thermal energy. For this reason, an electrothermal converter is provided. The electrothermal transducer is provided corresponding to each of the ejection ports, and ink is ejected from the corresponding ejection port by applying a pulse voltage to the corresponding electrothermal transducer in accordance with the recording signal. The recording apparatus is not limited to the serial type recording apparatus described above, but a so-called full line type in which recording heads (line heads) in which ejection openings are arranged in the width direction of the recording medium are arranged in the conveyance direction of the recording medium. It can also be applied to other recording devices.

  FIG. 2 is a block diagram showing a control configuration of the recording apparatus shown in FIG.

  As shown in FIG. 2, the controller 600 includes an MPU 601, a ROM 602, a special purpose integrated circuit (ASIC) 603, a RAM 604, a system bus 605, an A / D converter 606, and the like. Here, the ROM 602 stores a program corresponding to a control sequence to be described later, a required table, and other fixed data. The ASIC 603 generates control signals for controlling the carriage motor M1, the transport motor M2, and the recording head 3. The RAM 604 is used as a development area for image data, a work area for program execution, and the like. A system bus 605 connects the MPU 601, the ASIC 603, and the RAM 604 to each other to exchange data. The A / D converter 606 inputs analog signals from the sensor group described below, performs A / D conversion, and supplies a digital signal to the MPU 601.

  In FIG. 2, reference numeral 610 denotes a host device corresponding to the host or MFP shown in FIG. Image data, commands, status, and the like are transmitted and received by packet communication between the host device 610 and the recording device 1 via an interface (I / F) 611. This packet communication will be described later. Note that a USB interface may be further provided as the interface 611 separately from the network interface so that bit data and raster data transferred serially from the host can be received.

  Reference numeral 620 denotes a switch group, which includes a power switch 621, a print switch 622, a recovery switch 623, and the like.

  Reference numeral 630 denotes a sensor group for detecting the apparatus state, and includes a position sensor 631, a temperature sensor 632, and the like. In this embodiment, in addition to this, a photo sensor for detecting the remaining amount of ink is provided. Details of this photosensor will be described later.

  Further, 640 is a carriage motor driver that drives a carriage motor M1 for reciprocating scanning of the carriage 2 in the direction of arrow A, and 642 is a conveyance motor driver that drives a conveyance motor M2 for conveying the recording medium P.

  The ASIC 603 transfers data for driving a recording element (ejection heater) to the recording head while directly accessing the storage area of the RAM 604 during recording scanning by the recording head 3. In addition, this recording apparatus is provided with a display unit composed of an LCD or LED as a user interface.

  Next, an example of a head substrate constituting a liquid discharge head used as a recording head in the recording apparatus having the above configuration will be described.

  FIG. 3 is an enlarged view of a part of the Si substrate showing a state where six element substrates 100 are formed by the semiconductor manufacturing process according to the first embodiment, and a partially broken perspective view showing the configuration of the head substrate according to the first embodiment. . In addition, the same reference number is attached | subjected to the same component already demonstrated in Fig.11 (a) and FIG. 12, and the description is abbreviate | omitted.

  As can be seen from FIGS. 3A to 3B, each element substrate has a rectangular shape, and a plurality of electrode pads 102 are provided on the short side (lower side as the upper side) of each element substrate. It is done. Further, in the direction of the long side (right side and left side), a rectangular region used as the ink supply port 120 when mounted on the recording head is formed.

  FIG. 3A is a plan view of the element substrate formed on the Si wafer. As shown in FIG. 3A, in this embodiment, a plurality of electrode pads are provided in a cutting region 202 in a region further outside the region where the plurality of electrode pads 102 on each of the upper and lower sides of each element substrate 100 are formed. A plurality of electrode pads 103 for inspection are formed in parallel with the array 102.

  FIG. 3B is a partially broken perspective view of the head substrate H1000 formed by cutting and separating the cutting areas 201 and 202 of the Si wear after joining the nozzle member H1100 forming the nozzles and the ink flow paths.

  As shown in FIG. 3B, on the cut surface of the element substrate parallel to the arrangement direction of the plurality of electrode pads 102, wirings that couple the plurality of electrode pads 103 and the circuit inside the element substrate 100 are provided. The cut area 202 is cut and exposed to form cutting points 112a to 112c.

  In order to reduce the size of the element substrate at both ends of the heater rows of the plurality of heaters 101 formed on the element substrate 100, a plurality of square electrode pads 102 having a side length of 140 μm are arranged at a high density of 150 μm pitch. Arranged. The shortest distance from the electrode pad at the end to the right side of the element substrate that is perpendicular to the arrangement direction of the electrode pads 102 is to eliminate as much space as possible from the width of the element substrate in the arrangement direction of the plurality of electrode pads 102. The distance is 35 μm.

  FIG. 4 is an enlarged plan view of the lower right end of the element substrate before cutting and separation.

  As shown in FIG. 4, the wiring that connects the electrode pad 103 and the internal circuit of the element substrate includes a wiring 111 a connected to the power supply circuit of the element substrate 100, a wiring 111 b connected to GND, and heater driving control. Wiring 111c connected to the logic circuit. These wirings have a minimum wiring width of 5 μm and a minimum wiring interval of 5 μm that can be stably manufactured inside the element substrate by using a semiconductor manufacturing process, and a region between the electrode pad 102e at the end and the right side of the element substrate. Are arranged to pass through in parallel.

  In the vicinity of the lower side of the element substrate 100 parallel to the arrangement direction of the electrode pads 102, a part of the wiring 111a and the wiring 111b is arranged in parallel with the lower side of the element substrate 100, and the wiring 111c is parallel to the right side of the element substrate 100. It arrange | positions so that it may become. The wirings 111a, 111b, and 111c are connected to the inspection electrode pads 103a, 103b, and 103c through the cutting points 112a, 112b, and 112c cut in the cutting and separating step, respectively. The wirings 111a, 111b, and 111c are arranged so that the distance D1 between the cutting points 112a and 112b is 40 μm and the distance D0 between the cutting points 112b and 112c is 10 μm.

  Here, when the recording operation of the recording apparatus is executed, the wiring 111a connected to the drive circuit for driving the heater controls the potential of 12V, the wiring 111b connected to GND controls the potential of 0V, and the heater driving is controlled. A potential of 3 V is applied to the wiring 111c connected to the logic circuit. Therefore, potentials of 12V, 0V, and 3V are applied to the cutting points 112a, 112b, and 112c, respectively, 12V (= V1) between the cutting points 112a and 112b, and 3V between the cutting points 112b and 112c. A potential difference of (= V0) is generated.

  As described above, in this embodiment, the larger the potential difference generated between the cutting points during the recording operation, the larger the wiring interval is.

  The wirings 111a, 111b, and 111c patterned on the element substrate 100, the electrode pad 102, and the electrode pad 103 are made of an alloy of Al and Cu, and the surface of the electrode pad 103 is plated with gold.

  Next, a nozzle member H1100 that forms an ink discharge port H1101 and an ink flow path (not shown) is joined, and then the cutting regions 201 and 202 are cut to separate the head substrate H1000. Then, as described in the prior art, the electrode pads 102 on the head substrate H1000 and the electrode leads of the flexible film wiring substrate electrically connected to the outside of the head substrate are electrically joined.

  After this step, an epoxy resin sealing resin is formed in a sealing region including the plurality of electrode pads 102 and the cut surface of the element substrate 100 so that the wirings 111a, 111b, and 111c exposed at the cutting point of the element substrate 100 are not exposed to ink. Apply. In this way, the recording element unit H2000 as shown in FIG. 11 is formed. Thereafter, it is joined to an ink supply unit (not shown) to complete the recording head.

  In this embodiment, the sealing resin is applied so that the distance from the end of the electrode pad 103 to the inner side of the element substrate 100 is 50 μm.

  FIG. 5 is a diagram showing a drive circuit and a logic circuit formed on the element substrate 100.

  As shown in FIG. 5, a heater drive power supply terminal VH and a drive circuit 140 are connected to a heater (electrothermal conversion element) 101 that generates heat for ejecting ink. The drive circuit 140 includes a drive element (power transistor) 140a for supplying a desired current to the heater 101, and a level converter 140b for applying a gate voltage to the power transistor 140a. The level converter 140b is supplied with the second drive voltage that is stepped down from the power transistor drive power supply terminal VHT via the drive voltage generation circuit 144.

  The logic circuit also includes a shift register 143 that temporarily stores an image data signal that determines whether or not to eject ink from the ink ejection port H1101, and a latch circuit 142 that holds the image data signal for each heater. And an AND circuit 141. The shift register 143 is provided with an input terminal for the transfer clock signal CLK and an input terminal for the image data signal DATA for serially inputting the image data signal. The latch circuit 142 is provided with an input terminal for inputting a signal output from the shift register 143 and inputting a latch signal (LT) for controlling the latch timing. The AND circuit 141 inputs a signal output from the latch circuit 142 and a heat enable signal (HE) that determines the timing of supplying current to the heater 101, and performs an AND operation. The drive signal output from the AND circuit 141 is boosted through the level converter 140b and then input to the gate of the power transistor 140a.

  The heater driving power supply terminal VH, the latch signal LT input terminal, and the transfer clock signal CLK input terminal are arranged on the electrode pad 102.

  The inspection electrode pad 103a is electrically connected to the drive circuit 140 via the inspection wiring 111a. The inspection electrode pad 103b is electrically connected to the GND wiring connected to the GND terminal (GNDH) of the heater 101 via the inspection wiring 111b. The inspection electrode pad 103c is electrically connected to the shift register 143 via the inspection wiring 111c.

  Since these electrode pads for inspection are electrically connected to each circuit element, when the heater 101 is driven, the drive voltage 12V of the power transistor is applied to the electrode pad 103a. The logic voltage 3.3V output from the shift register 143 is applied to the electrode pad 103c.

  Next, in order to confirm the effect of this embodiment, the recording heads as Comparative Examples 1 and 2 and the recording head according to this embodiment are operated for a long time, and their electrical characteristics are evaluated.

  FIG. 6 is an enlarged view of a part of the element substrate used in the recording head of Comparative Example 1.

  6 and 4, the region shown in FIG. 6 is the region shown in FIG. 4, that is, the same region as the region B of the element substrate 100 in FIG. This is a region near the end.

  In Comparative Example 1, the wirings 111a to 111c are uniformly 5 μm wide and are arranged in parallel to the region from the side of the electrode pad 102e at the end to the right side of the element substrate, and the adjacent intervals of the cutting points 112a, 112b, and 112c. Is the same as the wiring interval, D0 = D1 = 5 μm. The other configuration is the same as that described with reference to FIG.

  FIG. 7 is an enlarged view of a partial region of the element substrate used in the recording head of Comparative Example 2.

  As can be seen by comparing FIG. 7 and FIG. 4, the region shown in FIG. 7 is the region shown in FIG. 4, that is, the same region as the region B of the element substrate 100 in FIG. This is a region near the end.

  The comparative example 2 is different from the comparative example 1 in that the distance between the wirings 111a to 111c is slightly increased near the lower side of the element substrate, and the adjacent distance between the cutting points 112a, 112b, and 112c is set to D0 = D1 = 10 μm. Other configurations are the same as those of the first comparative example.

  Table 1 shows a result of performing a long-term recording operation test by mounting a recording head on which an element substrate according to Comparative Examples 1 and 2 and Example 1 is mounted on an ink jet recording apparatus, and evaluating electrical characteristics between cutting points. It is a table | surface which shows.

[Table 1]
-----------------------------------
| Recording head | Between cutting points | Potential difference | Distance | (1) | (2) |
-----------------------------------
|| 112a-112b | V0 = 3V | D0 = 5 μm | ○ | × |
| Comparative Example 1------------------------------
|| 112b-112c | V1 = 12V | D1 = 5 μm | × | × |
-----------------------------------
|| 112a-112b | V0 = 3V | D0 = 10 μm |
| Comparative Example 2------------------------------
|| 112b-112c | V1 = 12V | D1 = 10 μm | ○ | × |
-----------------------------------
|| 112a-112b | V0 = 3V | D0 = 10 μm |
| Example 1------------------------------
|| 112b-112c | V1 = 12V | D0 = 40 μm | ○ | ○ |


-----------------------------------
(1) After 1000 hours of recording operation (2) After 2000 hours of recording operation ○: Normal operation (no short circuit)
X: Short circuit occurrence From the results shown in Table 1, with the recording head of Comparative Example 1, a short (leakage current) occurs between the cutting points 112b-112c (wirings 111b-111c) where a potential difference of 12 V occurs when recording is performed for 1000 hours. It can be seen that it occurs. Further, when recording is performed for 2000 hours, a short circuit also occurs between the cutting points 112a-112b (wirings 111a-111b) where a potential difference of 3V occurs. In the recording head of Comparative Example 2, a short circuit does not occur between the cutting points 112a-112b (wirings 111a-111b) where a potential difference of 3V occurs when recording is performed for 2000 hours, but between the cutting points 112b-112c where a potential difference of 12V occurs. A short circuit occurred.

  On the other hand, the recording head according to the first embodiment does not cause a short circuit even when recording is performed for 2000 hours.

  From the above results, after the element substrate is cut and separated, there is a correlation that the shorter the distance (D0, D1) between the cut points exposed on the cut surface, the greater the potential difference (V0, V1), the more likely the short circuit occurs. I understand that there is.

  The cause of this is that there is moisture permeation to the sealing resin covering the electrode pad and the cutting point, and the metal on the cut surface of the wiring is caused by the potential difference generated between the cutting points covered and protected by the sealing resin. Is eluted as ions and moves through the sealing resin, leading to a short circuit. It is considered that so-called ion migration has occurred. This phenomenon was not assumed in the conventional semiconductor integrated circuit, but occurred due to the operating environment unique to the ink jet recording apparatus in which the element substrate was mounted on the recording head used in contact with ink. Conceivable.

  In addition, the degree of occurrence of this phenomenon varies depending on various conditions such as the type of the conductor surface, the type of coating material, and usage conditions. For this reason, the distance between the cutting points where the short circuit occurs and the boundary value of the potential difference also vary depending on the above conditions.

  However, according to the embodiment described above, the larger the potential difference between the two cutting points at the shortest distance, the larger the distance between the cutting points. Therefore, even if the recording operation is performed for a long time, the member Occurrence of a short circuit due to deterioration of the material can be suppressed. In addition, since this configuration does not require an extra space, it is possible to route the wiring to the electrode pad for inspection without increasing the size of the element substrate. Thereby, even if the number of electrode pads for inspection further increases, a highly reliable element substrate can be formed even when the element substrate is downsized.

  FIG. 8 is an enlarged plan view of the lower right end of the element substrate before cutting and separation according to the second embodiment, and is an enlarged view of the region B in FIG. In FIG. 8, the same components as those described in the first embodiment with reference to FIG. 4 are denoted by the same reference numerals, and the description thereof is omitted.

  The difference from the first embodiment is that an inspection electrode pad 103d, a wiring 111d, and a cutting point 112d connected to a wiring having the same potential as the heater driving power supply terminal (VH) shown in FIG. The cutting point 112d is set on the right side of the element substrate 100. Note that a potential of 24V is applied to the heater driving power supply terminal (VH) during the recording operation, and thereby a potential of 24V is also applied to the electrode pad 103d, the wiring 111d, and the cutting point 112d.

  When the recording apparatus mounted with the recording head mounted with the element substrate performs a recording operation, the wirings 111a, 111b, 111c, and 111d and the cutting points 112a, 112b, 112c, and 112d are respectively 12V, 3V, 0V, and 24V. Is applied. Among them, the wirings 111a to 111c pass between the electrode pad 102e at the end and the right side of the element substrate, and the cutting points 112a to 112c correspond to the magnitude of the potential difference on the lower side of the element substrate as in the first embodiment. The distances D0 = 10 μm and D1 = 30 μm are provided.

  On the other hand, the cutting point 112d is provided such that the distance from the lower right end of the element substrate 100 to the cutting point 112d along the right side is D2 = 200 μm. As can be seen from FIG. 8, the wiring from the electrode pad 103 d to the cutting point 112 d is arranged outside the right side of the element substrate 100, that is, through the cutting region 201 of the silicon wafer 200. Note that the cutting point 112d is covered and protected by the sealing resin in the same manner as the other cutting points 112a to 112c.

  This element substrate was mounted on a recording head in the same manner as in Example 1 and mounted on an ink jet recording apparatus, and a long-time recording operation test was performed, and electrical characteristics between cutting points were evaluated.

  Table 2 is a table showing a result of performing a long-term recording operation test by mounting a recording head mounted with an element substrate according to Example 2 on an ink jet recording apparatus and evaluating electrical characteristics between cutting points.

[Table 2]
------------------------------
| Between cutting points | Potential difference | Distance | (1) | (2) |
------------------------------
| 112b−112c | V0 = 3V | D0 = 10 μm | ○ | ○ |
| 112a-112b | V1 = 9V | D1 = 30 μm | ○ | ○ |
| 112c−112d | V2 = 24V | D2 = 200 μm | ○ | ○ |
------------------------------
(1) After 1000 hours of recording operation (2) After 2000 hours of recording operation ○: Normal operation (no short circuit)
From the results shown in Table 2, it can be seen that, according to this example, no short circuit occurred even after 2000 hours of recording.

  Here, the width between the electrode pad 102e at the end and the right side of the element substrate is 30 μm, which is the same as in the first embodiment and the first and second comparative examples. Thus, even when four inspection electrode pads to which different potentials are applied are provided, reliability is ensured without increasing the element substrate by arranging wirings for them as in this embodiment. It becomes possible to do.

  Further, as shown in FIG. 8, the cutting point 112d is provided at a position sandwiching the square electrode pad 102 having a side length of 140 μm with respect to the cutting points 112a, 112b, and 112c. The three cutting points are inevitably greatly separated from each other. Therefore, the electrode pad for inspection is arranged so that the potential difference between the voltage applied to each of the cutting point provided on the right side of the element substrate and the cutting point provided on the lower side of the element substrate at the shortest distance is maximized. It is desirable to do. In the example shown in FIG. 8, since voltages of 0V and 24V are applied to the electrode pads 103c and 103d and the wirings 111c and 111d, respectively, the potential difference is 24V, and the distance between the cutting points 112c and 112d is 200 μm. ing.

  FIG. 9 is an enlarged plan view of the lower right end of the element substrate before cutting and separation according to the third embodiment, and is an enlarged view of a region B in FIG. In FIG. 9, the same components as those described in the first and second embodiments with reference to FIGS. 4 and 8 are denoted by the same reference numerals, and the description thereof is omitted.

  The difference from the second embodiment is that an inspection electrode pad, a wiring, and a cutting point to which potentials of 12 V and 24 V are applied at the time of the recording operation are added one by one due to an increase in heaters and drive voltage generation circuits. It is. That is, a plurality of inspection electrode pads, wirings, and cutting points that have the same potential during operation are mixed. Since no potential difference is generated between two cutting points having the same potential applied during operation, a short circuit due to migration does not occur.

  For this reason, in this embodiment, as shown in FIG. 9, there are two cutting points 112a and 112a ′ (12V applied) having the same potential applied during operation, and cutting points 112d and 112d ′ (24V applied). They are arranged adjacent to each other with a minimum wiring interval of 5 μm.

  This element substrate was mounted on a recording head in the same manner as in Example 1 and mounted on an ink jet recording apparatus, and a long-time recording operation test was performed, and electrical characteristics between cutting points were evaluated.

  Table 3 is a table showing the results of carrying out a long-term recording operation test by mounting the recording head mounted with the element substrate according to Example 3 on the ink jet recording apparatus and evaluating the electrical characteristics between the cutting points.

[Table 3]
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| Between cutting points | Potential difference | Distance | (1) | (2) |
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| 112a−112a ′ | V0 = 0V | D0 = 5 μm | ○ | ○ |
| 112d−112d ′ |||||||
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| 112b−112c | V1 = 3V | D1 = 10 μm | ○ | ○ |
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| 112a−112b | V2 = 9V | D2 = 30 μm | ○ | ○ |
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| 112c−112d | V3 = 24V | D3 = 200 μm | ○ | ○ |
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(1) After 1000 hours of recording operation (2) After 2000 hours of recording operation ○: Normal operation (no short circuit)
From the results shown in Table 3, it can be seen that, according to this example, no short circuit occurred even after 2000 hours of recording.

  As described above, according to this embodiment, when a plurality of inspection electrode pads, wirings, and cutting points that have the same potential during operation are mixed, the cutting points that have the same potential are bundled to be as small as possible. Arrange at the wiring interval. Thereby, the wiring from the electrode pad for inspection can be routed without increasing an extra space for the wiring. Therefore, it is possible to form an element substrate that ensures high reliability even if the number of electrode pads for inspection is further increased and the element substrate is further downsized.

100 element substrate, 101 heater, 102 electrode pad, 102a coating area,
103a, 103a′103b, 103c, 103d, 103d ′ electrode pads,
111a, 111a ′, 111b, 111c, 111d, 111d ′ wiring,
112a, 112a ′, 112b, 112c, 112d, 112d ′ cutting points,
120 ink supply port, 140 drive circuit,
140a Drive element (power transistor),
140b level converter, 141 AND circuit, 142 latch circuit,
143 shift register, 144 drive voltage generation circuit,
200 silicon wafer (Si wafer), 201-202 cutting region,
H1000 head substrate, H2000 recording element unit

Claims (13)

A rectangular element substrate formed by a semiconductor manufacturing process on a silicon wafer, and obtained by cutting the silicon wafer after the formation,
For the inspection of the circuit mounted on the element substrate, the same voltage is applied to the plurality of inspection electrode pads provided outside the element substrate and applied to the plurality of inspection electrode pads. A plurality of wires to which is applied ,
A plurality of pads for applying a voltage to operate the circuit ;
When the element substrate is cut from the silicon wafer, a plurality of cutting points at which the plurality of wirings are cut are adjacent to voltages applied to the plurality of cutting points at the end portions of the element substrate. The larger the potential difference between the voltage applied to the cutting point, the larger the distance between the adjacent cutting points ,
A part of the plurality of cutting points is provided on the side of the element substrate on which the plurality of pads are provided;
Element substrate having the remaining plurality of cutting points, characterized in Rukoto provided on the side where the plurality of pads of the device substrate is not provided. The element substrate according to claim 1 , wherein among the plurality of cutting points, the cutting points to which the same voltage is applied are provided adjacent to each other. Wherein the plurality of cutting points, the element substrate according to claim 1 or 2, characterized in that sealed by a resin. Multiple heaters;
A plurality of driving elements for driving the plurality of heaters;
The circuit is
A drive circuit for driving the plurality of drive elements;
Element substrate according to any one of claims 1 to 3, characterized in that it comprises a logic circuit for controlling the driving of the drive circuit. A surface including a first side and a second side adjacent to the first side; a first side surface including the first side and intersecting the surface; and the surface including the second side and the first side A second side surface intersecting the side surface, the surface comprising a circuit including an element and a plurality of pads connected to the circuit and disposed along the first side, and electrically connected to the circuit In an element substrate including the connected first wiring, second wiring, and third wiring,
The end of the first wiring and the end of the second wiring are located on the first side surface, and the end of the third wiring is located on the second side surface,
When the circuit is operated, the potential difference between the end of the first wiring and the end of the second wiring is smaller than the potential difference between the end of the second wiring and the end of the third wiring,
An element substrate, wherein an interval between an end portion of the first wiring and an end portion of the second wiring is smaller than an interval between an end portion of the second wiring and an end portion of the third wiring. A surface including a first side and a second side adjacent to the first side; a first side surface including the first side and intersecting the surface; and the surface including the second side and the first side A second side surface intersecting the side surface, the surface comprising a circuit including an element and a plurality of pads connected to the circuit and disposed along the first side, and electrically connected to the circuit In an element substrate including the connected first wiring, second wiring, and third wiring,
Each of the first wiring, the second wiring, and the third wiring includes a portion sandwiched between the pad closest to the second side surface and the second side surface of the plurality of pads, and the first side surface. And an end located at
When the circuit is operated, the potential difference between the end of the first wiring and the end of the second wiring is larger than the potential difference between the end of the second wiring and the end of the third wiring,
The end portion of the second wiring is adjacent to the end portion of the first wiring and the end portion of the second wiring at an interval smaller than the interval between the end portion of the first wiring and the end portion of the second wiring. And the end of the third wiring are adjacent to each other,
At least one of an end portion of the first wiring, an end portion of the second wiring, and an end portion of the third wiring is sandwiched between the pad closest to the second side surface and the second side surface. An element substrate, wherein the element substrate is provided farther from the second side surface than a portion to be provided. The first wiring, the second wiring, and the third wiring are provided on a silicon wafer before being cut as the element substrate, and a plurality of wirings provided outside the element substrate for the inspection of the circuit. The element substrate according to claim 5, wherein the element substrate is connected to an electrode pad for inspection. The end of the first wiring, the end of the second wiring, and the end of the third wiring are sealed with resin. Element substrate. A plurality of heaters as the element;
A plurality of drive elements for driving the plurality of heaters;
The circuit is
A drive circuit for driving the plurality of drive elements;
The element substrate according to claim 5, further comprising a logic circuit that controls driving of the driving circuit. The logic circuit is:
A shift register for temporarily storing data signals from outside,
A latch circuit for latching a data signal stored in the shift register;
Enter the heat enable signal for determining a timing of supplying a current to the heater from the outside, according to claim 4 or characterized in that it comprises an AND circuit which performs AND operation between the latched data signal by the latch circuit 9. The element substrate according to 9 . The drive circuit is
A level converter that boosts the signal from the AND circuit;
The element substrate according to claim 10 , further comprising a transistor that operates as the driving element driven by a signal from the level converter. The element substrate according to claim 4 or any one of claims 9 to 11 ,
A liquid supply port supplied from the outside;
A liquid discharge head comprising: a plurality of discharge ports for discharging liquid corresponding to each of the plurality of heaters. A recording apparatus that uses the liquid discharge head according to claim 12 as a recording head and performs recording by discharging ink from the recording head onto a recording medium according to an ink jet method.

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