JP2020116773A - Liquid discharge head and manufacturing method thereof - Google Patents

Abstract

To suppress the occurrence of cracks in a substrate and secure a sealing function.SOLUTION: A liquid discharge head 100 comprises: a discharge port forming member 116 provided with a discharge port 104 from which liquid is discharged; a substrate 117 having an energy generating element 112 and a liquid supply port 105 disposed in a plane opposite to the discharge port forming member 116 and having a long axis 105b; a support member 111 supporting the substrate 117 and forming a groove 109 extending along a circumference of the substrate 117 between the support member 111 and the substrate 117; an electric connection part 120 straddling the groove 109 and transmitting electric signals and electric power to the energy generating element 112; and a sealing material 110 containing a filler 109, filling the groove 109, and covering the electric connection part 120. The sealing material 110 has a first part 110a extending parallel to the long axis 105b. The first part 110a has a high-content area 121 that faces an end 105a of the supply port 105 in a direction perpendicular to the long axis 105b and that has a filler content higher than other areas.SELECTED DRAWING: Figure 3

Description

The present invention relates to a liquid ejection head that ejects a liquid and a method for manufacturing the same, and more particularly to the configuration of a sealing material.

The liquid ejection head generally has an element substrate and a support member that supports the element substrate. The element substrate has a discharge port forming member and a substrate. The ejection port forming member includes an ejection port through which a liquid such as ink is ejected, and the substrate includes an energy generating element that generates energy for ejecting the liquid, and a supply path that supplies the liquid. A groove extending along the peripheral edge of the substrate is formed between the substrate and the supporting member, and an electric connection portion for transmitting an electric signal and electric power to the energy generating element is provided so as to straddle the groove. The groove is filled with a sealant and the electrical connection is covered with a sealant.
Since the encapsulant expands and contracts due to temperature changes, when the encapsulant is cured at high temperature and returned to room temperature, or when the environmental temperature changes, the substrate receives force from the encapsulant and deforms. There is something to do. In particular, in a substrate provided with an elongated supply port, cracks may occur near the end of the supply port. Patent Document 1 discloses a liquid ejection head using a sealing material containing a filler. By including a filler in the sealing material, the coefficient of linear expansion of the sealing material can be reduced and thermal deformation of the sealing material can be suppressed.

JP, 2005-132102, A

Mori T., Tanaka K. (1973): “Average stress in matrix and average energy of materials with misfitting inclusions”, Acta Metallurgica, Vol. 21, pp. 571-574.

In order to suppress the deformation of the substrate, it is preferable that the sealing material contains a large amount of filler. On the other hand, at the time of manufacturing the liquid ejection head, the uncured encapsulant is required to have sufficient fluidity so as to fill the groove and cover the electrical connection portion. However, since the viscosity of the encapsulating material and the fluidity of the encapsulating material tend to decrease due to the inclusion of the encapsulating material in the filler, a sufficient sealing function may not be obtained. An object of the present invention is to provide a liquid ejection head that can easily prevent the occurrence of cracks and ensure a sealing function.

The liquid ejection head of the present invention includes an ejection port forming member having an ejection port for ejecting a liquid, an energy generating element for generating energy for ejecting the liquid from the ejection port, and a surface facing the ejection port forming member. A substrate having a liquid supply port arranged and having a long axis, a support member that supports the substrate and forms a groove extending along the peripheral edge of the substrate between the substrate and the groove, straddles the groove, and forms an energy generating element. It has an electric connection part for transmitting an electric signal and electric power, and a sealing material containing a filler and filling the groove to cover the electric connection part. The encapsulant has a first portion extending parallel to the long axis, and the first portion faces the end of the supply port in a direction orthogonal to the long axis and has a higher filler content than other regions. Has a rate area.

According to the present invention, it is possible to provide a liquid ejection head that can easily prevent a substrate from cracking and ensure a sealing function.

FIG. 3 is a perspective view of the liquid ejection head according to the first embodiment of the present invention. FIG. 3 is a plan view of an element substrate of the liquid ejection head shown in FIG. 1. 3A and 3B are a plan view and a cross-sectional view of the liquid ejection head shown in FIG. 1. It is a graph which shows the relationship between a filler content rate and Young's modulus of a sealing material. It is a graph which shows the relationship between the center position of a high content rate area|region, and the maximum principal stress in the edge part of a supply path. 6A and 6B are a plan view and a cross-sectional view of a liquid ejection head according to a second embodiment of the present invention. 9A and 9B are a plan view and a cross-sectional view of a liquid ejection head according to a third embodiment of the present invention. 9A and 9B are a plan view and a cross-sectional view of a liquid ejection head according to a fourth embodiment of the present invention. 9A and 9B are a plan view and a cross-sectional view of a liquid ejection head according to a fifth embodiment of the present invention. It is a top view and a sectional view of a modification of a 5th embodiment.

Hereinafter, some embodiments and examples of the present invention will be described with reference to the drawings. Although these embodiments and examples are intended for inkjet recording heads that eject ink, the present invention can be widely applied to liquid ejection heads that eject liquid other than ink.

(First embodiment)
First, the first embodiment will be described. FIG. 1A is a perspective view of a liquid ejection head according to a first embodiment of the present invention, and FIG. 1B is an exploded perspective view thereof. 2A is a plan view showing a surface of the liquid discharge head on the ejection port side of the element substrate of FIG. 1, and FIG. 2B is a plan view showing the back surface side thereof. 3A is a plan view of the liquid ejection head shown in FIG. 1, FIG. 3B is a sectional view taken along the line AA of FIG. 3A, and FIG. 3C is FIG. 3A. It is sectional drawing which followed the BB line. Note that the discharge port forming member 116 is not shown in FIG. 3A for convenience. As shown in FIG. 1, the liquid ejection head 100 includes an element substrate 101, an electric wiring member 102, a support member 111, and a housing 103. The housing 103 has an ink containing portion. Although the ink storage unit is integrated with the housing 103, it may be detachable from the housing 103. The element substrate 101 includes a substrate 117 and a discharge port forming member 116 that is supported by the substrate 117 and has a discharge port 104.

The substrate 117 has a plurality of energy generating elements 112 that generate energy for ink to be ejected from the ejection ports 104, and a plurality of electrode pads 107 connected to the electric wiring member 102. The energy generating element 112 and the electrode pad 107 are electrically connected by internal wiring (not shown) of the substrate 117. In the present embodiment, the energy generation element 112 is an electrothermal conversion element, but a piezoelectric element may be used. The substrate 117 has a rectangular shape having a long side 117a parallel to the arrangement direction of the energy generating elements 112 and the ejection ports 104, and a short side 117b intersecting with this (orthogonal in the present embodiment). The substrate 117 may have a parallelogram shape other than a rectangle. On the substrate 117, an ink supply path 105 that penetrates the substrate 117 in the thickness direction is formed. The supply path 105 is a long groove-shaped through hole formed inside the electrode pad 107. The supply path 105 is formed in a truncated pyramid shape by anisotropic etching or the like, but may be formed in a rectangular parallelepiped shape. The supply path 105 has the ink supply port 105 on the surface of the substrate 117 facing the ejection port forming member 116. The supply port 105 is an elongated opening having a major axis 105b parallel to the arrangement direction of the energy generating element 112 and the ejection port 104. The ejection port forming member 116 is formed with a plurality of ejection ports 104 corresponding to the plurality of energy generating elements 112. The ejection port 104 communicates with the supply port 105 by a pressure chamber 108 provided between the substrate 117 and the ejection port forming member 116.

The support member 111 is fixed to the housing 103, and supports the element substrate 101 (substrate 117) on the support surface 111a. The support member 111 has an ink supply flow passage 106 that connects the ink storage portion to the supply passage 105 of the substrate 117. The support member 111 is formed by resin molding using a material in which a resin (modified polyphenylene ether) is mixed with 35% by mass of glass filler in order to improve rigidity. The support surface 111a of the support member 111 is a recess 113 in which the element substrate 101 is arranged. As a result, the groove 109 extending along the peripheral edge of the substrate 117 is formed between the support member 111 and the substrate 117. The groove 109 is formed between the side wall of the recess 113 of the support member 111 and the side wall of the substrate 117, and circulates along the long side 117a and the short side 117b of the substrate 117. The substrate 117 is bonded to the support member 111 by aligning and pressing the support surface 111a of the support member 111 coated with the adhesive. The electric wiring member 102 is adhered to the edge of the support member 111 with an adhesive different from the adhesive for adhering the element substrate 101.

The electric wiring member 102 is a flexible wiring member for transmitting an electric signal and electric power for ejecting ink from the recording apparatus main body (not shown) to the energy generating element 112. An example of a flexible wiring member is a TAB (Tape Automated Bonding) tape. The electric wiring member 102 is formed of electric wiring and a resin film that covers the electric wiring. A contact portion 102a electrically connected to a connector pin (not shown) of the recording apparatus main body is formed at one end of the electric wiring member 102, and an inner lead 102b is formed at the other end. The inner lead 102b is a lead wiring exposed from the end surface of the resin film. The inner lead 102b is connected to the electrode pad 107 by bonding. The electrode pad 107 and the inner lead 102b straddle the groove 109 between the substrate 117 and the support member 111 to form an electric connection portion 120 that transmits an electric signal and electric power to the energy generating element 112. Since the element substrate 101 is installed in the recess 113, the inner leads 102b of the electric wiring member 102 have substantially the same height as the electrode pads 107 of the element substrate 101, and the reliability of the electric connection portion 120 can be improved. In order to make the layout of the liquid ejection head 100 efficient, the electrical connection portion 120 is arranged in a region along the short side 117b of the substrate 117. Although the electrical connection portions 120 are arranged in the regions along the short sides 117b on both sides, they may be arranged only in the regions along the one short side 117b. The electrical connection section 120 may be configured by an electrode pad, a connection terminal of an electric wiring member, and a wire connecting the electrode pad and the connection terminal.

The ink contained in the ink container is introduced into the pressure chamber 108 through the ink supply channel 106 of the support member 111 and the supply channel 105 of the substrate 117. The energy generating element 112 operates at a predetermined timing by an electric signal and electric power sent from the recording apparatus main body via the electric connecting portion 120, and imparts energy for ejecting the ink. As a result, the ink in the pressure chamber 108 is ejected from the ejection port 104.

The groove 109 between the substrate 117 and the support member 111 is filled with the sealing material 110. The encapsulant 110 also covers the electrical connections 120 for protection. The sealing material 110 is filled over the entire circumference of the groove 109. Therefore, the sealing material 110 has a first portion 110a extending parallel to the major axis 105b of the supply port 105 and a second portion 110b intersecting (orthogonal in the present embodiment) the first portion 110a. .. The encapsulant 110 is formed of a thermosetting resin such as an epoxy resin, is filled in the groove 109 and covers the electrical connection portion 120, and is then cured by being heated. The encapsulant 110 is heat-cured and then heat-shrinks when cooled. Due to the thermal contraction of the sealing material 110, cracks may occur on the substrate 117 starting from the end 105a of the supply port 105 in the direction parallel to the major axis 105b. As the coefficient of linear expansion of the encapsulant 110 increases, the thermal contraction of the encapsulant 110 increases, so that the substrate 117 is more likely to crack. Therefore, in order to reduce the linear expansion coefficient of the sealing material 110, the sealing material 110 contains the filler 109. In the following description, the volume content of the filler 109 in the sealing material 110 is referred to as the filler content.

In this embodiment, the filler content of the sealing material 110 is locally increased. The reason is that it is not necessary to increase the filler content in the entire area of the sealing material 110 in order to suppress the occurrence of cracks in the substrate 117. That is, if the filler content of the sealing material 110 is high in the vicinity of the end portion 105a of the supply port 105 where the substrate 117 is easily cracked, the effect of suppressing the cracking of the substrate 117 can be obtained. The region where the filler content of the sealing material 110 is locally increased (hereinafter referred to as the high content region 121) is the supply port of the first portion 110a in the direction orthogonal to the major axis 105b of the supply port 105. It is provided in a region facing the end portion 105a of 105. The high content region 121 is preferably arranged across a straight line L1 extending through the end portion 105a of the supply port 105 and parallel to the second portion 110b.

To form the encapsulant 110, first, the groove 109 is filled with an uncured liquid encapsulant 110 to cover the electrical connection portion 120. However, the encapsulating material 110 having a high filler content has a high viscosity and is inferior in filling property and coatability. The groove 109 between the element substrate 101 and the support member 111 is, for example, less than 1 mm, and in order to apply the sealing material 110 to such a narrow space quickly and reliably, the sealing material is entirely provided in the groove 109. It is preferable that the viscosity of 110 is low. On the other hand, in order to suppress the occurrence of cracks in the substrate 117, a region having a high filler content may be locally provided as described above.

Therefore, in the present embodiment, the magnetic filler 109a is used as the filler 109, the sealing material 110 having a relatively low filler content is filled in the groove 109, and then the magnetic filler 109a is moved to a specific region by magnetic force. Form a high content rate region 121. The filler 109 is composed only of the magnetic filler 109a. According to this embodiment, the uncured encapsulant 110 including the magnetic filler 109a is filled in the groove 109 to form the first portion 110a and the second portion 110b of the encapsulant 110. At this time, since the filler content is substantially uniform over the entire area of the sealing material 110, it is easy to fill the sealing material 110 in details such as the gaps between the grooves 109 and the electrical connection portions 120. Next, in the region of the first portion 110a facing the end portion 105a of the supply port 105 in the direction orthogonal to the major axis 105b of the supply port 105, a high content region 121 having a higher filler content than other regions is provided. The magnetic filler 109a is moved by magnetic force so that it is formed. The magnetic force is applied by the permanent magnet M1 installed on the back surface 111b of the support surface 111a of the support member 111 at least at a position facing the high content region 121. After that, the encapsulating material 110 in which the high content region 121 is formed is heated and cured. This makes it possible to achieve both the filling property of the filler 109 and the suppression of cracking of the substrate 117. The magnetic filler 109a can be formed of ferrite, neodymium, or the like, and the magnetic characteristics and particle size of the magnetic filler 109a can be appropriately selected. FIG. 1 shows the position where the magnet M1 is arranged. In the present embodiment, the magnet M1 is installed only at a position facing the high content region 121 of the back surface 111b of the support surface 111a. The width and magnetic force of the magnet M1 can be appropriately selected. Although the magnet M1 remains installed even when the encapsulating material 110 is heated and hardened, the magnet M1 is supported after the magnetic filler 109a is moved to a desired location and before the encapsulating material 110 is hardened. You may keep away from 111.

(First embodiment)
An epoxy resin having a linear expansion coefficient of 60 ppm and a Young's modulus of 4 GPa was made to contain ferrite particles having a linear expansion coefficient of 10 ppm and a Young's modulus of 100 GPa at a filler content of 30% to prepare an uncured encapsulating material 110. The magnetic properties of the ferrite particles were a residual magnetic flux density of 200 mT, a coercive force of 100 kA/m, and an average particle size of 1 μm. After applying the encapsulant 110, the magnet M1 having a width W of 1 mm was arranged on the back surface 111b of the support surface 111a at a position facing the position where the high content region 121 was formed. The magnets M1 were arranged on the first portions 110a on both sides, respectively. With the magnet M1 held, the sealing material 110 was cured by heating at 100° C. for 1 hour. After the encapsulating material 110 was cured, the encapsulating material 110 was cut along the line BB in FIG. 3A, and the cross section was observed. As shown in FIG. 3C, the filler content was high in the region where the magnet M1 was arranged (high content region 121), and was low in the regions 122 on both sides of which the magnet M1 was not arranged. In the high content region 121, the filler content was about 60%, the linear expansion coefficient of the encapsulating material 110 was 18 ppm, and the Young's modulus was 10 GPa. In the region 122, the filler content of the filler 109 was about 10%, the linear expansion coefficient of the encapsulating material 110 was 50 ppm, and the Young's modulus was 2 GPa.

In order to evaluate the resistance of the substrate 117 to cracking, the entire liquid discharge head was cooled to -25°C. The greater the temperature difference from the curing temperature, the more the sealing material 110 contracts, and the greater the deformation of the substrate 117. It was confirmed that in the severe evaluation environment of -25° C., the liquid ejection head 100 of the present embodiment suppresses the occurrence of cracks in the substrate 117. For quantitative evaluation, the maximum principal stress at the end portion 105a of the supply port 105 of the substrate 117 was measured. The starting point of the crack is the end portion 105a of the supply port 105, and the higher the maximum principal stress at this portion, the easier the crack occurs. The maximum principal stress was measured by Raman shift by Raman spectroscopy. In the comparative example in which the same sealing material 110 as that in the example was used and the movement of the magnetic filler 109a by the magnet M1 was omitted, the maximum principal stress of the substrate 117 was 100 MPa, whereas in this example, the maximum principal stress was 100 MPa. The stress was 25 MPa and decreased to 1/4. If the maximum principal stress is reduced to about 70% of that of the comparative example, there is a sufficient effect of suppressing the cracking of the substrate 117. In the present embodiment, since it is reduced to 25%, it is confirmed that the substrate 117 has sufficient resistance to cracking.

When the filler content is high, the linear expansion coefficient of the sealing material 110 is low, but the Young's modulus is high. If the Young's modulus of the encapsulating material 110 is large, the stress at the time of contraction is not relaxed even if the strain of the encapsulating material 110 is reduced, so the force pulling the substrate 117 is increased and the substrate 117 is easily cracked. When the filler content is low, the Young's modulus of the encapsulant 110 gradually increases as the filler content increases. However, as the filler content increases, the Young's modulus rapidly increases as the filler content increases. Regarding the increase of Young's modulus, some theories as shown in Non-Patent Document 1 are known, and it is known that the ideal assumption follows the theory called Reuss law. Therefore, in this example, the relationship between the filler content and the Young's modulus of the sealing material 110 was measured. The results are shown in FIG. The Young's modulus increased non-linearly from a filler content of about 60%, and sharply increased above 80%.

Next, a plurality of liquid ejection heads having different filler contents in the high content region 121 were created, and the entire liquid ejection head was cooled to -25°C in the same manner as described above. When the filler content of the high content region 121 exceeds 80%, cracking of the substrate 117 occurred. Therefore, the volume content of the filler 109 is preferably about 80% or less. In this range, the effect of lowering the linear expansion coefficient of the encapsulant 110 is greater, so that the effect of suppressing the occurrence of cracks in the substrate 117 can be obtained. In the above examples, the sealing material 110 having a filler content of 30% was used, the filler content was about 60% in the high content area 121, and the filler content was about 10% in the area 122 adjacent thereto. Based on this, in order to obtain a filler content of about 80% in the high content region 121, a sealing material having a filler content of about 40% should be used. If the filler content is about 40% or less, the viscosity of the encapsulating material 110 is low, and therefore the coating property and filling property of the encapsulating material 110 are not impaired. Therefore, if the filler content of the high content region 121 is about 80%, the coating property and filling property of the sealing material 110 are not impaired. If the filler content is 40% or more, the coefficient of linear expansion of the sealing material 110 can be sufficiently reduced. From the above, the filler content of the high content region 121 is preferably 40% or more and 80% or less.

Next, the position of the high content rate region 121 was changed, and the relationship between the center position of the high content rate region 121 and the maximum principal stress at the end 105a of the supply path 105 was obtained. The filler content was 30%. The results are shown in FIG. The broken line shows a comparative example made in the same manner as the example except that the movement of the magnetic filler 109a by the magnet M1 was omitted. As shown in FIG. 3A, a position where a straight line L1 drawn from the end portion 105a of the supply port 105 at a right angle to the long axis 105b of the supply port 105 intersects the first portion 110a is set to 0 (reference position), and The outside was minus and the inside was plus. The maximum principal stress is small in the vicinity of the reference position, but the maximum principal stress increases as the high content region 121 is moved from the end portion 105a of the supply port 105 to the outside or the inside. The maximum principal stress became minimum at a position about 0.5 mm outside the reference position. In a region where the high content region 121 is apart from the reference position by -0.5 mm to 2 mm, the maximum principal stress is reduced to about 70% of that of the comparative example, and shows the resistance required to suppress the occurrence of cracks. Was confirmed. As a result, the portion having the highest filler content should be between the position 2.0 mm away from the straight line L1 on the center side of the substrate 117 and the position 0.5 mm away from the straight line L1 on the opposite side. Is preferred.

(Second embodiment)
Next, a second embodiment will be described. Here, the difference from the first embodiment will be mainly described. The configuration and steps of which description is omitted are the same as those in the first embodiment. FIG. 6A is a plan view of the liquid ejection head 100 according to the second embodiment of the present invention, FIG. 6B is a sectional view taken along the line AA of FIG. 6A, and FIG. 6A is a sectional view taken along the line BB of FIG. 6A, and FIG. 6D is a sectional view taken along the line CC of FIG. 6A.
Similar to the first embodiment, the sealing material 110 is filled in the groove 109 between the support member 111 and the substrate 117, and the electrical connection portion 120 is covered with the sealing material 110. The filler 109 reduces the linear expansion coefficient of the encapsulant 110 as described above, but the contraction of the second portion 110b of the encapsulant 110 does not substantially affect the cracking of the substrate 117. Therefore, the high filler content in the second portion 110b of the sealing material 110 is unnecessary. On the other hand, the interface between the filler 109 and the resin of the sealing material 110 has a structure that easily absorbs moisture. When the liquid ejection head 100 is driven, the more moisture near the inner leads 102b and the electrode pads 107, the more easily metal deposits called dendrites grow on the inner leads 102b and the electrode pads 107. The dendrite may cause a short circuit between the anode and the cathode of the electrode pad 107 to cause an electrical failure. From the above, it is preferable that the filler content in the second portion 110b of the sealing material 110 is small.

In the present embodiment, the magnet M2 is continuously arranged along the first portion 110a at a position facing the first portion 110a on the back surface 111b of the support surface 111a. Therefore, the magnetic filler 109a contained in the uncured encapsulant 110 is easily moved from the second portion 110b to the first portion 110a. This suppresses the growth of metal deposits in the vicinity of the inner leads 102b and the electrode pads 107, so that the electrical reliability of the electrical connecting portion 120 is improved. In the present embodiment, the filler content in the second portion 110b is lower than the filler content in the first portion 110a. In addition, the filler content in the first portion 110a is generally high, and the high content region 123 is formed in a wider range than in the first embodiment. In the present embodiment as well, the region facing the end portion 105a of the supply port 105 is included in the high content region 123, so that the same effect as in the first embodiment can be obtained.

(Second embodiment)
After applying the encapsulant 110 having a filler content of 30%, the magnet M2 described above was placed, and the magnet M2 was held and heated at 100° C. for 1 hour to cure the encapsulant 110. After the encapsulant 110 was cured, the encapsulant 110 was cut along the line BB in FIG. 6A and the cross section was observed. As shown in FIG. 6C, the magnetic filler 109a was present at a high content in the region where the magnet M2 was arranged (high content region 123). In the high content region 123, the filler content was about 60%, the linear expansion coefficient of the encapsulating material 110 was 18 ppm, and the Young's modulus was 10 GPa. Further, the sealing material 110 was cut along the line C-C in FIG. 6A, and the cross section was observed. As shown in FIG. 6D, the filler content in the second portion 110b was about 10%. As a result, the probability that an electrical defect will occur due to the filler 109 is 1/3 that when the magnetic filler 109a is not moved by the magnet M2 (the filler content of the second portion 110b is 30%). It became a degree.

(Third Embodiment)
Next, a third embodiment will be described. Here, the difference from the first embodiment will be mainly described. The configuration and steps of which description is omitted are the same as those in the first embodiment. FIG. 7A is a plan view of the liquid ejection head 100 according to the third embodiment of the present invention, FIG. 7B is a sectional view taken along the line AA of FIG. 7A, and FIG. ) Is a cross-sectional view taken along the line BB of FIG. In the present embodiment, the filler 109 includes a magnetic filler 109a and a non-magnetic filler 109b. Since the magnetic filler 109a is moved by the magnet M1 as in the first embodiment, the filler content in a specific region (high content region 121) of the encapsulant 110 is made higher than the filler content in other regions. be able to. Since the non-magnetic filler 109b is not moved by the magnet M1, the filler content can be set to a certain value or more at any place of the sealing material 110. The ratio of the magnetic filler 109a and the non-magnetic filler 109b can be appropriately selected. The filler content in the high content region 121 (the sum of the volume content of the magnetic filler 109a and the volume content of the non-magnetic filler 109b) is preferably 40% or more and 80% or less.

(Third embodiment)
After applying the sealing material 110, as in the first embodiment, a magnet M1 having a width of 1 mm is arranged on the back surface 111b of the support surface 111a at a position facing the position where the high content region 121 is formed, With the magnet M1 held, the sealing material 110 was cured by heating at 100° C. for 1 hour. As the resin of the sealing material 110 and the magnetic filler 109a, the same materials as in the first embodiment were used. As the non-magnetic filler 109b, silica having a linear expansion coefficient of 0.5 ppm and a Young's modulus of 70 GPa was used. The filler content of both the magnetic filler 109a and the non-magnetic filler 109b was set to 15%. Therefore, the total filler content of the magnetic filler 109a and the non-magnetic filler 109b is 30%. After the encapsulant 110 was cured, the encapsulant 110 was cut along the line BB in FIG. 7A, and the cross section was observed. In FIG. 7C, the black circles indicate the magnetic filler 109a and the white circles indicate the non-magnetic filler 109b. In the region facing the magnet M1 (high content region 121), the sealing material 110 contained the magnetic filler 109a and the non-magnetic filler 109b, and exhibited a filler content of about 60%. In the region 122 where the magnet M1 is not arranged, the density of the magnetic filler 109a was lowered because the magnetic filler 109a moved, but the filler content was maintained to some extent by the non-magnetic filler 109b. In the region 122, the filler content was about 20%, the linear expansion coefficient of the encapsulating material 110 was 40 ppm, and the Young's modulus was 2.5 GPa.
Similar to the first example, evaluation was performed to cool the entire liquid ejection head 100 to -25°C. The generation of cracks in the substrate 117 was suppressed, and the maximum principal stress measured by Raman shift by Raman spectroscopy was 20 MPa.

(Fourth Embodiment)
Next, a fourth embodiment will be described. Here, the difference from the first embodiment will be mainly described. The configuration and steps of which description is omitted are the same as those in the first embodiment. 8A is a plan view of the liquid ejection head 100 according to the fourth embodiment of the present invention, FIG. 8B is a cross-sectional view taken along the line AA of FIG. 8A, and FIG. 8A is a cross-sectional view taken along the line BB of FIG. 8A, and FIG. 8D is an enlarged view of the filler. In the present embodiment, as in the third embodiment, the filler 109 includes a magnetic filler 109a and a non-magnetic filler 109b, and the average size of the magnetic filler 109a is the average size of the non-magnetic filler 109b. Has been made smaller. This facilitates the magnetic filler 109a to move due to the magnetic force. The average size can be calculated, for example, as the average radius of a sphere whose volume is equivalent to that of the magnetic filler 109a and the non-magnetic filler 109b.

As shown in FIG. 8D, when three spherical particles having a radius r are adjacent to each other, the maximum radius of the spherical particles that can pass through the gap is (2/√3-1)r or less (about 0). .154r or less). That is, if the ratio of the average size of the non-magnetic filler 109b to the average size of the magnetic filler 109a is 15% or less or (2/√3-1) or less, the movement of the magnetic filler 109a is at least the non-magnetic filler 109a. Not disturbed by 109b. Even if the radius of the magnetic filler 109a is larger than this, the magnetic filler 109a passes between the non-magnetic fillers 109b as compared with the case where the particle diameters of the magnetic filler 109a and the non-magnetic filler 109b are equal. Easier to do. As described above, in the present embodiment, the magnetic filler 109a can be moved more smoothly by the magnet M1, so that it is easy to increase the filler content in the high content region 121.

(Fourth embodiment)
After applying the sealing material 110, as in the first embodiment, a magnet M1 having a width of 1 mm is arranged on the back surface 111b of the support surface 111a at a position facing the position where the high content region 121 is formed, With the magnet M1 held, the sealing material 110 was cured by heating at 100° C. for 1 hour. Similar to the third embodiment, the sealing material 110 containing the magnetic filler 109a and the non-magnetic filler 109b was used. Ferrite was used for the magnetic filler 109a, and silica was used for the non-magnetic filler 109b. The size of the magnetic filler 109a was set to about 1/10 of the size of the non-magnetic filler 109b. The volume content of the magnetic filler 109a was 15%, the volume content of the non-magnetic filler 109b was 25%, and the total filler content was 40%. After the encapsulating material 110 was cured, the encapsulating material 110 was cut along the line BB in FIG. 8A and the cross section was observed. In FIG. 8C, a small black circle indicates the magnetic filler 109a and a white circle indicates the non-magnetic filler 109b. In the region facing the magnet M1 (high content region 121), the sealing material 110 contained the magnetic filler 109a and the non-magnetic filler 109b, and exhibited a filler content of about 70%. In the region 122 where the magnet M1 is not arranged, the magnetic filler 109a moved, so that the density of the magnetic filler 109a decreased, but the non-magnetic filler 109b maintained a certain filler content. In the region 122, the filler content was about 15%, the linear expansion coefficient of the encapsulating material 110 was 47 ppm, and the Young's modulus was 2.2 GPa.
Similar to the first example, evaluation was performed to cool the entire liquid ejection head 100 to -25°C. The generation of cracks in the substrate 117 was suppressed, and the maximum principal stress measured by Raman shift by Raman spectroscopy was 10 MPa.

(Fifth Embodiment)
Next, a fifth embodiment will be described. Here, the difference from the first embodiment will be mainly described. The configuration and steps of which description is omitted are the same as those in the first embodiment. 9A is a plan view of the liquid ejection head 100 according to the fifth embodiment of the present invention, FIG. 9B is a sectional view taken along the line AA of FIG. 9A, and FIG. ) And 9(d) are sectional views taken along the line BB of FIG. 9(a). In each of the above-described embodiments, the magnet M1 is fixed to the high content region 121, but in the present embodiment, the magnetic field strength received by the sealing material 110 is changed temporally and placeally by moving the magnet M1. I am making it. That is, in the present embodiment, a pair of magnets M1 are arranged on both sides of the back surface 111b of the support surface 111a opposite to the position where the high content region 121 is formed, and each magnet M1 is moved toward that position. There is. The magnetic force is applied so that the application position of the maximum magnetic field strength moves with time toward a position facing the end portion 105a of the supply port 105 on the back surface 111b of the support surface 111a. FIG. 9C shows the position of the magnet M1 before the movement and the moving direction of the magnet M1, and FIG. 9D shows the position of the magnet M1 after the movement. When the magnet M1 is fixed, it is necessary to retain the magnetic force while the magnetic filler 109a moves, but moving the magnet M1 may reduce the holding time.

An electromagnet M3 may be used instead of the permanent magnet M1 as a magnetic force generating means. 10A is a plan view of a liquid ejection head 100 according to a modified example of the fifth embodiment of the present invention, FIG. 10B is a cross-sectional view taken along line AA of FIG. 10A, and FIG. 10C is a sectional view taken along the line BB of FIG. In this modification, a plurality of electromagnets M3 are arranged on both sides of the back surface 111b of the support surface 111a opposite to the position where the high content region 121 is formed. Then, the plurality of electromagnets M3 are energized in the order of the electromagnet M3 which is far from the electromagnet M3 which is far from the position where the high content region 121 is formed. Therefore, also in this modification, the magnetic force is applied so that the application position of the maximum magnetic field strength moves with time toward the position where the high content region 121 of the sealing material 110 is formed. Since the electromagnet M3 functions as a magnet only when a current is flowing, it is possible to generate a magnetic force at a necessary timing by switching the current ON and OFF. First, the electromagnet M3 arranged in the region 142 farthest from the high content region 121 is turned on, and the magnetic filler 109a is collected and then turned off. Subsequently, the electromagnet M3 in the region 141 closer to the high content region 121 than the region 142 is similarly turned on, and the magnetic filler 109a is collected and then turned off. Finally, the magnet M1 in the area 140 is turned on to collect the magnetic filler 109a in the high content area 121.

The electromagnet M3 may be incorporated in the liquid ejection head 100. Specifically, the electromagnet M3 is formed on the back surface 111b of the support member 111 at a position facing the position where the high content region 121 is formed. By previously incorporating the electromagnet M3 into the liquid ejection head 100, it is not necessary to prepare a magnet during manufacturing. The electromagnet M3 may be energized only during manufacturing and not energized after manufacturing.

110 Encapsulating Material 111 Supporting Member 117 Substrate 120 Electrical Connection Part 110a First Part 121 High Content Area

Claims (18)

A discharge port forming member having a discharge port for discharging liquid,
A substrate having an energy generating element for generating energy for the liquid to be ejected from the ejection port, and a liquid supply port having a long axis arranged on a surface facing the ejection port forming member,
A support member that supports the substrate and forms a groove extending along the peripheral edge of the substrate between the substrate and the substrate,
An electric connecting portion that crosses the groove and transmits an electric signal and electric power to the energy generating element,
A sealing material including a filler, which fills the groove and covers the electrical connection portion,
The encapsulant has a first portion extending parallel to the long axis, the first portion faces the end of the supply port in a direction orthogonal to the long axis, and has a filler content other than that. A liquid ejection head having a high content area higher than the area. The encapsulant has a second portion that intersects with the first portion, and the high content region straddles a straight line that extends through the end portion and in parallel with the second portion. 1. The liquid ejection head according to item 1. The portion having the highest filler content is between a position 2.0 mm away from the straight line toward the center of the substrate and a position 0.5 mm away from the straight line at the opposite side. The liquid ejection head described. The encapsulant has a second portion that intersects with the first portion, and the filler content in the second portion is lower than the filler content in the first portion. 4. The liquid ejection head according to any one of 3 above. The electrical connection portion is connected to the electrode pad of an electrode pad provided on the substrate and electrically connected to the energy generating element, and an electric wiring member for transmitting the electric signal and the electric power to the energy generating element. The liquid ejection head according to claim 1, wherein the liquid ejection head is formed by the inner lead. The liquid ejection head according to claim 1, wherein the filler is a magnetic filler, and the filler content in the high content region is 40% or more and 80% or less. 6. The filler according to claim 1, wherein the filler contains a magnetic filler and a non-magnetic filler, and the filler content in the high content region is higher than the filler content in other regions. 7. Liquid ejection head. The liquid ejection head according to claim 7, wherein the filler content in the high content region is 40% or more and 80% or less. The liquid ejection head according to claim 7, wherein the average size of the magnetic filler is smaller than the average size of the non-magnetic filler. The liquid ejection head according to claim 9, wherein the ratio of the average size of the non-magnetic filler to the average size of the magnetic filler is (2/√3−1) or less. The liquid ejection head according to claim 6, wherein the support member has an electromagnet at a position facing the high content region on the back surface of the support surface of the substrate. A discharge port forming member having a discharge port for discharging liquid,
A substrate having an energy generating element for generating energy for the liquid to be ejected from the ejection port, and a liquid supply port having a long axis arranged on a surface facing the ejection port forming member,
A support member that supports the substrate and forms a groove extending along the peripheral edge of the substrate between the substrate and the substrate,
A method for manufacturing a liquid ejection head, comprising: an electric connection portion that crosses the groove and transmits an electric signal and electric power to the energy generating element,
With an uncured encapsulant containing a magnetic filler, filling the groove and covering the electrical connection,
In the region of the first portion of the uncured encapsulant that extends parallel to the major axis, facing the end of the supply port in the direction orthogonal to the major axis, the filler content is higher than other regions. Moving the magnetic filler by magnetic force so that a high high content region is formed;
A method of manufacturing a liquid ejection head, comprising: curing the sealing material in which the high content region is formed. The method for manufacturing a liquid ejection head according to claim 12, wherein the magnetic force is applied by a magnet provided on a back surface of the supporting surface of the substrate at least at a position facing a position where the high content region is formed. .. The method of manufacturing a liquid ejection head according to claim 13, wherein the magnet is arranged only at a position facing a position where the high content region is formed on the back surface. 14. The method of manufacturing a liquid ejection head according to claim 13, wherein the magnet is continuously arranged along the first portion at a position facing the first portion of the back surface. 13. The liquid ejection head according to claim 12, wherein the magnetic force is applied so that the application position of the maximum magnetic field strength moves with time toward the position where the high content region of the sealing material is formed. Production method. The pair of magnets is arranged on both sides of a position opposite to a position where the high content region is formed on the back surface of the supporting surface of the substrate, and each magnet is moved toward the position. Liquid ejection head manufacturing method. A plurality of electromagnets are arranged on both sides of a position opposite to the position where the high content region is formed on the back surface of the support surface of the substrate, and the plurality of electromagnets are energized in order from an electromagnet far from the position to a near electromagnet. The method for manufacturing a liquid ejection head according to claim 16, wherein the method is performed.

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