JP2016129184A - Method for melting fuse element of liquid discharge head and device for melting fuse element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for melting fuse elements of a liquid discharge head which can reduce instability in melting the fuse elements of the liquid discharge head.SOLUTION: A method for melting fuse elements of a liquid discharge head 202 comprising a plurality of fuse elements 311 which can be melted by flowing currents thereto performs: a measuring step of measuring voltages which are applied to one fuse element 311 of the plurality of fuse elements 311 when the currents are flown to the one fuse element 311; a determining step of determining a target resistance for adjusting the currents flown into the fuse elements 311 to a target value on the basis of the voltages obtained in the measuring step; and a selecting step of selecting a current adjustment resistance 405 having a resistance value closest to a resistance value of the target resistance, as the current adjustment resistance 405 to be used in melting the fuse elements 311 different from the one fuse element 311, from a plurality of the current adjustment resistances 405 for adjusting the flown currents.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuse element blowing method and a fuse element blowing apparatus for a liquid discharge head including a fuse element that can be blown by passing an electric current.

A liquid discharge head provided with an energy generating element that generates energy for discharging a liquid such as ink generally has a substrate on which a discharge portion is formed. An energy generating element, a driver circuit that drives the energy generating element, and a data input unit that supplies ejection data to the driver circuit are formed on the surface of the substrate. As the energy generating element, an electrothermal conversion element or a piezoelectric element is used.
In recent years, it has been proposed to mount a ROM (Read Only Memory) on a substrate in order to allow the liquid ejection head to hold data such as its own ID (Identity) code and drive characteristics of the energy generating element in a readable manner. ing.
Patent Documents 1 and 2 describe a configuration in which a ROM including a fuse element is formed together with an energy generating element on a substrate of a liquid discharge head. In such a configuration, when the energy generating element is formed on the substrate, the fuse element serving as the ROM can be formed simultaneously. Then, by selectively fusing the fuse element, the liquid discharge head can hold binary data corresponding to the presence or absence of fusing. Such a liquid discharge head does not require a ROM chip to be prepared separately from the substrate, can simplify the structure that can hold various data in a readable manner, can improve productivity, and can be reduced in size and weight. be able to.

  A liquid discharge head is generally manufactured by a process similar to that of a semiconductor device. That is, the liquid discharge head is manufactured through a process of forming an energy generating element and wiring on the substrate, a process of forming a discharge unit on the substrate, mounting a driver circuit on the substrate, and assembling other components. The Further, the assembled liquid discharge head is subjected to a writing step of writing data such as the ID code of the liquid discharge head and the drive characteristics of the energy generating element into a ROM composed of fuse elements. In the write process, the fuse element is blown by selectively passing a current through the fuse element.

Japanese Patent Application Laid-Open No. H10-228561 describes a technique for adjusting the current change over time when the fuse element is blown by flowing current through the fuse element via a resistance element provided outside the substrate.
When the time change of the current at the time of blowing the fuse element is gentle, the temperature rise of the fuse element continues slowly, and the layers around the fuse element are melted to create a space. Thereafter, the melted fuse material scatters in the space, and the fuse element is in an electrically open state.
In addition, when the time change of the current at the time of fuse element blowing is severe, the temperature of the fuse element increases rapidly, and the fuse element is melted before the layers around the fuse element are sufficiently melted. In this case, the space where the melted fuse material scatters is narrow, and the melted fuse material may adhere to the fuse element again, and the fuse element may become conductive again.

US Pat. No. 5,504,507 US Pat. No. 5,363,134 Japanese Patent No. 4799298

Since the liquid exists on the substrate of the liquid discharge head, when the liquid enters the part after the fuse element is blown, the part or the electrode may corrode and the reliability may be impaired. Therefore, the fuse element formed on the substrate of the liquid discharge head needs to have a structure that is surely blown and does not allow liquid to enter.
Therefore, as shown in FIG. 7, a fuse element 110, an interlayer insulating film 104, a fuse electrode 105, a protective film (insulating film) 106, and the like are appropriately stacked on the surface of the substrate 101 so as to form a predetermined shape. . Then, a discharge member 107 using an organic resin is formed on the surface of the protective film 106.
As shown in FIG. 7, the fuse element 110 is located in the lower part of the laminated structure. For this reason, depending on the current waveform flowing through the fuse element 110, the layers around the fuse element 110 may not be sufficiently melted, and the melted fuse material may not be sufficiently scattered. If the melted fuse material does not scatter sufficiently, the fuse element 110 may be conducted again by the melted fuse material.
In the fuse fusing method described in Patent Document 3, the resistance element provided outside the substrate (for example, a ROM writing device) is fixed. For this reason, when this fixed resistance element is used, the current waveform for fusing the fuse element varies to some extent due to the difference in electrical characteristics and fusing characteristics of the fuse element for each liquid ejection head. Therefore, depending on the combination of the ROM writing device and the liquid discharge head, there is a possibility that a situation where the fusing of the fuse element is not stable may occur. For example, if the peak of the current waveform that blows the fuse element is too high, the blown fuse element may become conductive again.

  An object of the present invention is to provide a fuse element fusing method and a fuse element fusing apparatus for a liquid discharge head that can reduce instability of fusing of the fuse element of the liquid discharge head.

In order to achieve the above-described object, a fuse element fusing method for a liquid discharge head according to the present invention is a method for fusing a fuse element for a liquid discharge head including a plurality of fuse elements that can be blown by passing an electric current. A measurement process for measuring a voltage applied to the one fuse element when a current flows through one fuse element of the fuse elements, and a current flowing through the fuse element based on the voltage obtained by the measurement process. A determination step of determining a target resistance to be adjusted to a target value; and a current adjustment resistor having a resistance value closest to the resistance value of the target resistance among a plurality of current adjustment resistors for adjusting the current. And a selection step of selecting a current adjustment resistor used for fusing the fuse element different from the fuse element.
The voltage applied to one fuse element included in the liquid discharge head varies according to variations in characteristics of the fuse element for each liquid discharge head. For this reason, the target resistance determined based on this voltage also corresponds to the variation in the characteristics of the fuse elements for each liquid ejection head. Therefore, among the plurality of current adjustment resistors, a current adjustment resistor having a resistance value closest to the resistance value of the target resistor is also selected according to variations in characteristics of the fuse elements for each liquid ejection head. Therefore, by using the selected current adjustment resistor for fusing the fuse element, it is possible to adjust the current flowing through the fuse element even if the characteristics of the fuse element for each liquid ejection head vary. Therefore, it is possible to reduce instability of fusing of the fuse element of the liquid discharge head.

  According to the present invention, it is possible to reduce instability of fusing of the fuse element of the liquid discharge head.

1 is a block diagram showing a fuse element fusing device 201. FIG. 5 is a perspective view showing an example of a substrate 301. FIG. It is explanatory drawing of the fuse element fusing apparatus 201. FIG. It is a flowchart for demonstrating the fuse element fusing method. It is the figure which showed an example of the waveform of the voltage Vm. It is a figure which shows the calculation formula which calculates | requires the target resistance value R, and the characteristic of a head. It is sectional drawing of the board | substrate of the fuse element part in a liquid discharge head.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
First, a configuration example of a fuse element fusing device to which the present invention is applicable will be described.
FIG. 1 is a block diagram showing a fuse element fusing device 201 and a liquid discharge head 202.
The liquid discharge head 202 is provided with a plurality of fuse elements that function as a ROM. The fuse element fusing device 201 stores binary data corresponding to the presence or absence of fusing in the liquid ejection head 202 by selectively fusing the fuse elements of the liquid ejection head 202. The fuse element fusing device 201 also functions as a ROM writing device.
The fuse element fusing device 201 is provided with a mechanism (not shown) for fixing the liquid discharge head 202 and a connection connector (not shown) for connecting to the electrodes of the liquid discharge head 202. The fuse element blowing device 201 includes a control unit 203, a voltage detection circuit 204, a data input circuit 205, and a data read circuit 206.
The data input circuit 205 is connected to a recording logic circuit (not shown) of the liquid ejection head 202 via a connection connector, and supplies recording data to the recording logic circuit.
The voltage detection circuit 204 detects the voltage waveform of the recording data supplied from the data input circuit 205.
The data reading circuit 206 is connected to a fuse logic circuit (not shown) of the liquid ejection head 202 via a connection connector, and reads recording data stored in the fuse element from the fuse logic circuit.
The control unit 203 controls the voltage detection circuit 204, the data input circuit 205, and the data read circuit 206.
For example, the control unit 203 supplies the recording data of the liquid ejection head 202 to the data input circuit 205. The control unit 203 drives the voltage detection circuit 204 at a timing of detecting a voltage waveform when recording data is supplied by the data input circuit 205. Further, the control unit 203 acquires recording data read from the liquid ejection head 202 by the data reading circuit 206.

Next, the configuration of the liquid discharge head 202 will be described below.
A substrate 301 as shown in FIG. 2 is incorporated in the liquid discharge head 202.
On the substrate 301, a fuse part 310, an electrode pad 320, an energy generating element 330, and wiring (not shown) are formed.
The energy generating element 330 generates discharge energy for discharging a liquid such as ink. As the energy generating element 330, an electrothermal conversion element (for example, a heater element) or a piezoelectric element is used. The energy generating element 330 discharges droplets from a discharge port (not shown) by generating discharge energy.
The electrode pad 320 is a pad for electrically connecting a wiring formed on the substrate 301 to an external terminal. The electrode pad 320 is supplied with a drive signal for the energy generating element 330.
The fuse portion 310 includes a plurality of fuse elements 311 that can be blown by flowing current. The fuse element fusing device 201 can store various recording data in the fuse portion 310 by selectively fusing each fuse element 311.
The supply port 340 is formed on a center line extending in the longitudinal direction of the substrate 301. The energy generating element 330 is disposed along the supply port 340.
A flow path and a discharge port for discharging liquid are formed on the upper portion of the substrate 301 configured as described above by a resin layer, and liquid is supplied from a liquid tank (not shown) to the supply port 340 at the lower portion of the substrate 301. To connect the supply section. Thereby, the liquid discharge head 202 is formed. Note that due to individual differences in the liquid discharge heads 202, there may be differences in the electrical characteristics and fusing characteristics of the fuse elements between the liquid discharge heads 202.

Since the liquid discharge head 202 includes the fuse element 311, for example, various recording data can be stored in the fuse element 311 at the time before the liquid discharge head 202 is shipped. The recording data is, for example, an ID code of the liquid ejection head 202, an electrical characteristic value of the liquid ejection head 202, and the like.
For example, when the liquid discharge head 202 is mounted on the recording apparatus and used, the recording apparatus reads the recording data stored in the fuse element 311 and uses the conditions according to the electrical characteristics of the liquid discharge head 202. The liquid discharge head 202 can be driven.

FIG. 3 is an explanatory diagram of the fuse element fusing device 201 connected to the fuse element 311.
A drive element 402 for melting the fuse element 311 and reading information from the fuse element 311 is connected to the fuse element 311. In the present embodiment, drive elements 402 are individually connected to the plurality of fuse elements 311, and these drive elements 402 are selectively driven by a fuse selection circuit 403.
The fuse selection circuit 403 includes a signal line, a decoder that generates a time division selection signal, a latch circuit for signals including other signals, a shift register, an input pad (not shown) that receives a signal from the outside of the substrate 301, and the like. Including.
On the common wiring 501 side of the plurality of fuse elements 311, a plurality of resistance elements 405 having different resistance values that are selectively connected to the power source Vin by the resistance selection circuit 404 are provided. The resistance element 405 is an example of a current adjustment resistor for adjusting the current flowing through the fuse element 311.
An A / D converter 406 for reading a voltage is provided in the wiring portion 407 connecting the plurality of fuse elements 311 and the plurality of resistance elements 405. The A / D converter 406 is an example of the voltage detection circuit 204 and the data read circuit 206 shown in FIG. The A / D converter 406 is also an example of a measurement unit. The A / D converter 406 measures the voltage Vm of the wiring unit 407 at an arbitrary timing. Note that a circuit including the resistance selection circuit 404 and the resistance element 405 is an example of the data input circuit 205.

Next, the fuse element fusing method will be described in detail.
FIG. 4 is a flowchart for explaining the fuse element blowing method.
First, the resistance selection circuit 404 selects the resistance element Rx that comes to the center when the plurality of resistance elements 405 are arranged in descending order of resistance value, and selects the resistance element Rx as the power source Vin (for example, the driving voltage of the energy generating element 330). 24V) and the wiring portion 407. The resistance element Rx is, for example, a reference resistance element that allows a target current value to flow through the fuse element 311 200 nsec after the voltage Vm of the wiring portion 407 falls, in design. The resistance element Rx may not be a reference resistance element.
Next, the fuse selection circuit 403 drives the drive element 402 connected to an arbitrary fuse element 311 among the plurality of fuse elements 311.
In the case of this example, the fuse selection circuit 403 drives a drive element 402 connected to a spare fuse element 311 that does not store recording data stored in the liquid ejection head 202 among the plurality of fuse elements 311. The spare fuse element 311 is an example of one of the plurality of fuse elements 311. Here, the plurality of fuse elements 311 have the same or substantially the same electrical characteristics. For example, the plurality of fuse elements 311 are fuse elements having the same specifications.
When the drive element 402 is driven, a current flows through the spare fuse element 311 connected to the drive element 402 via the resistance element Rx, so that the spare fuse element 311 is melted.
At this time, the A / D converter 406 samples and measures the voltage Vm of the wiring portion 407 at the timing of driving the drive element 402 (step S401). In this case, the voltage Vm represents a voltage applied to the spare fuse element 311 through which a current flows through the resistance element Rx.
Here, the step in which the A / D converter 406 samples and measures the voltage Vm of the wiring portion 407 is the voltage of the one fuse element when a current flows through one fuse element of the plurality of fuse elements. It is an example of the measurement process which measures.
In the case of this example, the A / D converter 406 samples 80 times at 10 nsec intervals from the start of driving of the drive element 402. Note that the sampling interval and the number of samplings can be changed as appropriate. FIG. 5 is a diagram illustrating an example of a voltage waveform indicated by the voltage Vm sampled by the A / D converter 406. The voltage waveform shown in FIG. 5 also means a fuse blown voltage waveform.
Next, the control unit 203 determines a target resistance value R from the voltage waveform of the wiring unit 407 acquired by the A / D converter 406 (step S402). The target resistance value R is a resistance value of a resistor that adjusts the current flowing through the fuse element 311 to the target current value (hereinafter referred to as “target resistance”). The target resistance value R can also be referred to as an “optimum resistance value”. The target current value is an example of a target value. The control unit 203 is an example of a determination unit.
Here, the step of determining the target resistance value R of the target resistance is an example of a determination step of determining a target resistance for adjusting the current flowing through the fuse element to the target value based on the voltage obtained by the measurement step.
The control unit 203 determines the target resistance based on the difference between the value of the current flowing through the spare fuse element 311 specified based on the measured voltage Vm and the target current value.
In the case of this example, the control unit 203 reads the voltage Vm after 200 nsec from the time when the voltage waveform of the wiring unit 407 falls, and obtains the target resistance value R by the calculation formula shown in FIG. The constant a in the calculation formula shown in FIG. 6A is obtained from the slope of the typical characteristic for each liquid discharge head type shown in FIG. 200 nsec is an example of a predetermined time. The predetermined time is not limited to 200 nsec and can be changed as appropriate.
In the calculation formula shown in FIG. 6A, “(Vin−Vm) / Rx” indicates the value of the current flowing through the spare fuse element 311 in the measurement process. For this reason, the calculation formula shown in FIG. 6A is based on the difference between the current value flowing in the measurement process specified based on the voltage Vm obtained in the measurement process and the target current value It. It also means determining the target resistance. Further, the calculation formula shown in FIG. 6A means a formula for calculating a resistance value (target resistance value R) of a target resistance for adjusting the current flowing through the spare fuse element 311 to the target value. In this case, the spare fuse element 311 functions as a representative of the plurality of fuse elements 311.
Subsequently, the control unit 203 uses a resistance element 405 having a resistance value closest to the target resistance value R among the plurality of resistance elements 405 as a current adjustment resistor used for fusing a fuse element 311 different from the spare fuse element 311. The resistance selection circuit 404 is selected.
In this example, the control unit 203 selects a fuse selection signal indicating that a resistance element 405 having a resistance value closest to the target resistance value R is selected as a current adjustment resistor used for fusing a fuse element 311 different from the spare fuse element 311. , Output to the resistance selection circuit 404. The resistance selection circuit 404 selects a resistance element 405 having a resistance value closest to the target resistance value R as a current adjustment resistor used for fusing the fuse element 311 different from the spare fuse element 311 in accordance with the fuse selection signal (step S403). ). The resistance selection circuit 404 is an example of a selection unit.
Here, the step of selecting the resistance element 405 uses a current adjustment resistor having a resistance value closest to the resistance value of the target resistance among a plurality of current adjustment resistors for fusing a fuse element different from the one fuse element. It is an example of the selection process selected as a current adjustment resistor.
When there are a plurality of resistance elements 405 having a resistance value closest to the target resistance value R, for example, a resistance element having a small resistance value is selected among them.
Further, for example, the resistance element 405 having a resistance value closest to the target resistance value R may be selected from the resistance elements 405 having a resistance value smaller than the target resistance value R.
The resistance selection circuit 404 connects the selected resistance element 405 between the power source Vin and the wiring portion 407.
Next, the control unit 203 selectively drives the driving element 402 connected to the fuse element 311 corresponding to the recording data by the fuse selection circuit 403 based on the recording data stored in the liquid ejection head 202 to cause the fuse element 311 to be driven. Fusing is performed (step S404). The fuse element 311 to be melted at this time is a fuse element 311 different from the spare fuse element 311.

According to the present embodiment, the target resistance value R is determined based on the voltage waveform when the spare fuse element 311 is blown. Then, the resistance element 405 having a resistance value closest to the target resistance value R is selected from the plurality of resistance elements 405 as a resistance used for adjusting the current at the time of fusing.
The voltage of the spare fuse element 311 varies according to variations in characteristics of the fuse element 311 for each liquid ejection head 202. Therefore, the target resistance value R and the resistance element 405 having the closest resistance value to the target resistance value R are set according to variations in characteristics of the fuse elements 311 for each liquid ejection head 202.
For this reason, the resistance used for adjusting the current flowing through the fuse element at the time of fusing can be selected according to the characteristics of the fuse element provided in the liquid discharge head. Therefore, even if there is a difference in the electrical characteristics and fusing characteristics of the fuse elements for each liquid discharge head, it is possible to stabilize the current flowing through the fuse elements and reduce the instability of the fusing elements of the liquid discharge head. It becomes possible to do. Therefore, it is possible to increase the reliability of the recording data recorded on the fuse element.
Note that a current different from the target current value may flow through the fuse element used for voltage measurement. In this embodiment, a spare fuse element 311 that does not store recording data is used for voltage measurement. For this reason, it becomes possible to avoid the influence on recording data storage due to the flow of a current different from the target current value.
In the present embodiment, the target resistance is determined based on the difference between the value of the current flowing through the spare fuse element 311 in the measurement process and the target current value. Therefore, it is possible to determine a target resistance that eliminates the difference.
In the present embodiment, the voltage Vm after 200 nsec which is a predetermined time from the falling timing of the waveform of the voltage Vm is measured, and the target resistance is determined based on the measurement result. The fall of the waveform of the voltage Vm means that the current flowing through the spare fuse element 311 starts to increase. Therefore, the voltage Vm after a predetermined time from the falling timing of the waveform of the voltage Vm corresponds to the value of the current after a predetermined time after the current flowing through the spare fuse element 311 starts to increase. Therefore, it is possible to determine a target resistance that adjusts the value of the current after a predetermined time after the current flowing through the spare fuse element 311 starts to increase to the target current value.

(Embodiment 2)
Next, a second embodiment of the present invention will be described.
Also in this embodiment, the configuration of the fuse element blowing apparatus to which the fuse element blowing method is applied is the same as that of the first embodiment.
In the present embodiment, the possibility that a situation in which the blown fuse is conducted again when the peak of the current waveform for blowing the fuse element is excessively high can be reduced.

First, the resistance value Rfn of each of the plurality of fuse elements 311 shown in FIG. 3 is measured. Even if the plurality of fuse elements 311 have, for example, the same specifications in design, there may be a difference in characteristics between the fuse elements 311 due to manufacturing relations. For this reason, the case where the resistance values Rfn of the fuse elements 311 are different can be considered.
In this example, the resistance selection circuit 404 selects the resistance element Rx from the plurality of resistance elements 405, and the resistance element Rx is connected to the power source Vin set to 3.3 V, for example, the drive voltage of the fuse selection circuit 403. Connected between the sections 407.
Next, the fuse selection circuit 403 selectively drives each drive element 402 connected to each of the plurality of fuse elements 311 one by one. At that time, the A / D converter 406 samples the voltage Vm at the timing of driving each of the drive elements 402.
The control unit 203 obtains the resistance value Rfn of each of the plurality of fuse elements 311 from the sampled voltage Vm by the following formula: Rfn = Vm · Rx / (Vin−Vm).
Next, the control unit 203 sets the voltage of the power source Vin to a voltage that melts the fuse element 311 (for example, 24 V of the driving voltage of the energy generating element 330).
Next, the fuse selection circuit 403 drives the drive element 402 connected to the fuse element 311 having the lowest resistance value among the fuse elements 311 in accordance with an instruction from the control unit 203. The fuse element 311 having the lowest resistance value among the fuse elements 311 is an example of one fuse element.
When the driving element 402 is driven, a current flows through the resistance element Rx to the fuse element 311 connected to the driving element 402, and the fuse element 311 is melted.
At that time, the A / D converter 406 samples and measures the voltage Vm of the wiring portion 407 at the timing of driving the driving element 402. In the case of this example as well, the voltage waveform as shown in FIG. 5 is acquired by sampling 80 times at 10 nsec intervals from the start of driving of the drive element 402 as in the first embodiment. Also in the present embodiment, the sampling interval and the number of samplings can be changed as appropriate.
Next, the control unit 203 determines the target resistance value R from the voltage waveform of the wiring unit 407 acquired by the A / D converter 406.
In the case of this example, the control unit 203 reads the voltage Vm after 200 nsec from the time when the voltage waveform of the wiring unit 407 falls, and obtains the target resistance value R by the calculation formula shown in FIG. The constant a in the calculation formula shown in FIG. 6A is obtained from the slope of the typical characteristic for each liquid discharge head type shown in FIG.
Subsequently, the control unit 203 uses a resistance element 405 having a resistance value closest to the target resistance value R as a current adjustment resistor used for adjusting a current at the time of fusing. The selection circuit 404 makes the selection.
The resistance selection circuit 404 connects the selected resistance element 405 between the power source Vin and the wiring portion 407.
Next, the control unit 203 selectively drives the drive element 402 connected to the fuse element 311 corresponding to the print data by the fuse selection circuit 403 based on the print data stored in the liquid ejection head 202, The fuse element 311 is blown.

According to the present embodiment, the target resistance value R is determined based on the voltage waveform when the fuse element (the fuse element having the minimum resistance) 311 having the largest current at the time of fuse blowing is blown. Then, the resistance element 405 having a resistance value closest to the target resistance value R is selected from the plurality of resistance elements 405 as a resistance used for adjusting the current at the time of fusing.
The resistance of the fuse element blown using the selected resistance is greater than the resistance of the fuse element whose voltage was measured. For this reason, by using the resistor selected to flow a current close to the target current value through the fuse element having the smallest resistance, the current flowing through the other fuse elements can be made smaller than the current close to the target current value. It becomes possible. Therefore, it becomes possible to store the recording data under the condition that the peak of the current waveform for fusing the fuse element is not too high.

In each said embodiment, the number of the resistive elements 405 should just be two or more. For example, when the number of the resistance elements 405 is 2, the resistance element Rx is one of the two resistance elements 405.
In each embodiment described above, the illustrated configuration is merely an example, and the present invention is not limited to the configuration.

201 Fuse Element Fusing Device 202 Liquid Discharge Head 203 Control Unit (Determining Unit)
311 Fuse element 404 Resistance selection circuit (selection means)
405 Resistance element (current adjustment resistor)
406 A / D converter (measuring means)

Claims (6)

A fuse element fusing method for a liquid discharge head comprising a plurality of fuse elements that can be blown by passing an electric current,
A measuring step of measuring a voltage applied to the one fuse element when a current flows through one of the plurality of fuse elements;
A determination step of determining a target resistance for adjusting a current flowing through the fuse element to a target value based on the voltage obtained by the measurement step;
Among the plurality of current adjustment resistors for adjusting the current, a current adjustment resistor having a resistance value closest to the resistance value of the target resistor is used for fusing the fuse element different from the one fuse element. And a selection step of selecting the resistor as a resistor.   2. The method according to claim 1, wherein the one fuse element is a spare fuse element in which data is not stored.   The method of claim 1, wherein the one fuse element is a fuse element having the lowest resistance value among the plurality of fuse elements.   In the determining step, the target resistance is determined based on a difference between the target value and the value of the current flowing in the measuring step specified based on the voltage obtained in the measuring step. The method for fusing a fuse element of a liquid discharge head according to any one of claims 1 to 3.   5. The liquid ejection head according to claim 1, wherein the determining step determines the target resistance based on the voltage measured after a predetermined time from the time of falling of the voltage. Fuse element fusing method. A fuse element fusing device for fusing a fuse element of a liquid discharge head comprising a plurality of fuse elements that can be fused by passing an electric current,
A plurality of current adjusting resistors for adjusting the current;
Measuring means for measuring a voltage applied to the one fuse element when a current flows through one fuse element of the plurality of fuse elements;
Determining means for determining a target resistance for adjusting a current flowing through the fuse element to a target value based on the voltage measured by the measuring means;
Selection means for selecting a current adjustment resistor having a resistance value closest to the resistance value of the target resistor from among the plurality of current adjustment resistors as a current adjustment resistor used for fusing the fuse element different from the one fuse element. And a fuse element fusing device.

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