Packaging structure of piezoelectric printing chip and packaging method thereof

Abstract

The invention discloses a packaging structure and a packaging method of a piezoelectric printing chip, the packaging structure comprises at least one piezoelectric printing chip, and each piezoelectric printing chip comprises a chip electrode; the anisotropic conductive adhesive is positioned on one side of the piezoelectric printing chip; the anisotropic conductive adhesive at least covers the chip electrode; the printed circuit board is positioned on one side, far away from the piezoelectric printing chip, of the anisotropic conductive adhesive; the printed circuit board comprises at least one circuit endpoint, and each chip electrode is electrically connected with the circuit endpoint through the anisotropic conductive adhesive; the anisotropic conductive adhesive is conducted along a first direction and is not conducted along a second direction; the first direction is the direction in which the printed circuit board points to the piezoelectric printing chip, and the second direction is perpendicular to the first direction. The structure is simple, the packaging requirement of the high-density pin of the piezoelectric printing chip can be met, and the packaging reliability is improved.

Description

Technical Field

[0001] The present invention relates to the field of printing technology, and in particular, to a packaging structure and a packaging method for a piezoelectric printing chip. Background Art

[0002] With the development of electronic devices towards thinner and lighter, chips manufactured by micro-electro-mechanical systems (MEMS) such as MEMS microphones, MEMS accelerometers, etc. are widely used. The traditional chip packaging process uses flip-chip technology to connect the chip and the substrate through solder. However, after the solder melts, it will form a hemispherical shape, increasing the height of the entire device and affecting the thin and light characteristics of the chip.

[0003] Inkjet printing technology is becoming increasingly important in the fields of industrial printing and consumer printing, posing new requirements for the packaging of printing chips. In the prior art, the packaging process of piezoelectric printing chips is relatively complex, with low manufacturing efficiency and high cost; or it relies on special equipment, resulting in limited production capacity. At the same time, with social progress and technological development, new challenges such as high resolution and fast printing are posed to printing chips.

[0004] To meet the requirements of thinness and high performance, thin-film piezoelectric printing chips have emerged. However, the characteristics of thin film chips such as thin thickness, large flexibility, and bendability have brought great challenges to the chip mounting and packaging processes. The traditional chip packaging process can no longer meet its packaging requirements. In the prior art, there are problems such as complex packaging processes for piezoelectric printing chips, low manufacturing efficiency, high costs, inability to meet the packaging requirements for high-density pins on thin-film piezoelectric printing chips, and the need to improve the electrical connection reliability and service life of printing chips and flexible printed circuits. Summary of the Invention

[0005] The present invention provides a packaging structure and a packaging method for a piezoelectric printing chip. The structure of the present invention is simple and can meet the packaging requirements for high-density pins of piezoelectric printing chips, improving packaging reliability.

[0006] According to one aspect of the present invention, a packaging structure for a piezoelectric printing chip is provided, including:

[0007] At least one piezoelectric printing chip, each piezoelectric printing chip includes a chip electrode;

[0008] Anisotropic conductive adhesive, the anisotropic conductive adhesive is located on one side of the piezoelectric printing chip; the anisotropic conductive adhesive covers at least the chip electrode;

[0009] A printed circuit board is located on the side of the anisotropic conductive adhesive away from the piezoelectric printing chip; the printed circuit board includes at least one circuit terminal, and each chip electrode is electrically connected to the circuit terminal through the anisotropic conductive adhesive; wherein, the anisotropic conductive adhesive conducts electricity along a first direction and does not conduct electricity along a second direction; the first direction is the direction from the printed circuit board to the piezoelectric printing chip, and the second direction is perpendicular to the first direction.

[0010] Optionally, the anisotropic conductive adhesive is conductive silver paste, and the solid content of the conductive silver paste is 65%-75%.

[0011] Optionally, the anisotropic conductive adhesive is conductive epoxy resin glue, and the solid content of the conductive epoxy resin glue is 77%-83%.

[0012] Optionally, the vertical projection of the anisotropic conductive adhesive on the printed circuit board coincides with the vertical projection of the piezoelectric printing chip on the printed circuit board.

[0013] Optionally, the printed circuit board is a flexible printed circuit board; the material of the printed circuit board includes polyimide.

[0014] Optionally, the thickness of the printed circuit board is 20μm - 30μm.

[0015] According to another aspect of the present invention, there is provided a packaging method for a packaging structure of a piezoelectric printing chip, for preparing the packaging structure described in any embodiment of the present invention, including:

[0016] Fix at least one piezoelectric printing chip on one side of the jig; each piezoelectric printing chip includes a chip electrode;

[0017] Form an anisotropic conductive adhesive on one side of the piezoelectric printing chip; the anisotropic conductive adhesive at least covers the chip electrode;

[0018] Form a printed circuit board on the side of the anisotropic conductive adhesive away from the piezoelectric printing chip; the printed circuit board includes at least one circuit terminal, and each chip electrode is electrically connected to the circuit terminal through the anisotropic conductive adhesive; wherein, the anisotropic conductive adhesive conducts electricity along a first direction and does not conduct electricity along a second direction; the first direction is the direction from the printed circuit board to the piezoelectric printing chip, and the second direction is perpendicular to the first direction;

[0019] Remove the jig.

[0020] Optionally, forming an anisotropic conductive adhesive on one side of the piezoelectric printing chip includes:

[0021] Form an anisotropic conductive adhesive on one side of the piezoelectric printing chip through a screen printing process.

[0022] Optionally, forming a printed circuit board on the side of the anisotropic conductive adhesive away from the piezoelectric printing chip includes:

[0023] Align the circuit terminals in the printed circuit board with the chip electrodes in each piezoelectric printing chip;

[0024] The circuit terminals are in contact with the aligned piezoelectric printing chips through anisotropic conductive adhesive;

[0025] Perform pressure and temperature treatment on the printed circuit board so that each chip electrode is electrically connected to the circuit terminal through anisotropic conductive adhesive.

[0026] Optionally, perform pressure and heating treatment on the printed circuit board so that each chip electrode is electrically connected to the circuit terminal through anisotropic conductive adhesive, including:

[0027] Perform pressure treatment of 0.4 MPa - 0.6 MPa and temperature treatment of 140 °C - 160 °C on the printed circuit board so that each chip electrode is electrically connected to the circuit terminal through anisotropic conductive adhesive.

[0028] In the technical solution provided by the embodiment of the present invention, each piezoelectric printing chip includes a chip electrode; the anisotropic conductive adhesive covers at least the chip electrode; the printed circuit board includes at least one circuit terminal, and each chip electrode is electrically connected to the circuit terminal through anisotropic conductive adhesive; anisotropic conductive adhesive can be used as the electrical connection material between the piezoelectric printing chip and the printed circuit board, which can ensure that the chip electrodes in the piezoelectric printing chip are all in full contact with the circuit terminals in the printed circuit board, meet the packaging requirements of high-density pins on the piezoelectric printing chip, and have the advantages of reliable conductivity and long service life; at the same time, the packaging structure is simple, the manufacturing efficiency is high and the cost is low, without relying on special equipment, the production capacity is not limited, and it can be applied to the packaging of thin and light and high-performance printing chips.

[0029] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0031] Figure 1 It is a schematic diagram of a packaging structure of a piezoelectric printing chip provided by an embodiment of the present invention.

[0032] Figure 2 It is a schematic diagram of another packaging structure of a piezoelectric printing chip provided by an embodiment of the present invention.

[0033] Figure 3 It is a flowchart of a packaging method for a packaging structure of a piezoelectric printing chip provided by an embodiment of the present invention.

[0034] Figure 4 is Figure 3 A refined flowchart included in S130 in

[0035] Figure 5 It is a schematic diagram of left-side packaging alignment for a packaging structure of a piezoelectric printing chip provided by an embodiment of the present invention.

[0036] Figure 6 It is a schematic diagram of right-side packaging alignment for a packaging structure of a piezoelectric printing chip provided by an embodiment of the present invention. Detailed implementation manners

[0037] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0038] It should be noted that the terms "first", "second", etc. in the present invention are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0039] Just as the piezoelectric printing chip packaging process in the background technology is relatively complex, with low manufacturing efficiency and high cost; it relies on special equipment for packaging, resulting in limited production capacity; it cannot meet the packaging requirements for high-density pins on thin-film piezoelectric printing chips; in terms of the electrical connection between the piezoelectric printing chip and the printed circuit board, it is necessary to explore a simpler and more efficient wire bonding technology and consider using more stable connection materials to improve the reliability and service life of the print head.

[0040] To solve the above problems, an embodiment of the present invention provides a packaging structure for a piezoelectric printing chip, Figure 1 It is a schematic diagram of a packaging structure of a piezoelectric printing chip provided by an embodiment of the present invention,Figure 2 This is a schematic diagram of another packaging structure of a piezoelectric printing chip provided by an embodiment of the present invention. Refer to Figure 1 and Figure 2 , the packaging structure of the piezoelectric printing chip includes:

[0041] At least one piezoelectric printing chip 10, and each piezoelectric printing chip 10 includes chip electrodes;

[0042] Anisotropic conductive adhesive 20, and the anisotropic conductive adhesive 20 is located on one side of the piezoelectric printing chip 10; the anisotropic conductive adhesive 20 covers at least the chip electrodes;

[0043] A printed circuit board 30, and the printed circuit board 30 is located on the side of the anisotropic conductive adhesive 20 away from the piezoelectric printing chip 10; the printed circuit board 30 includes at least one circuit terminal, and each chip electrode is electrically connected to the circuit terminal through the anisotropic conductive adhesive 20; wherein, the anisotropic conductive adhesive 20 conducts electricity along the first direction X and does not conduct electricity along the second direction Y; the first direction X is the direction from the printed circuit board 30 to the piezoelectric printing chip 10, and the second direction Y is perpendicular to the first direction X.

[0044] Among them, the chip electrodes in the piezoelectric printing chip 10 are high-density pins; the piezoelectric printing chip 10 is fixed through a jig, and then the anisotropic conductive adhesive 20 is coated on the piezoelectric printing chip 10; the anisotropic conductive adhesive 20 is a conductive glue used for the packaging of electronic components, and has the functions of single-direction conduction and gluing and fixing. In the embodiment of the present invention, the anisotropic conductive adhesive 20 conducts electricity along the direction from the printed circuit board 30 to the piezoelectric printing chip 10, and does not conduct electricity along the second direction Y, that is, the anisotropic conductive adhesive 20 electrically connects the printed circuit board 30 and the piezoelectric printing chip 10, and the anisotropic conductive adhesive 20 does not conduct electricity horizontally. Before the printed circuit board 30 and the piezoelectric printing chip 10 are electrically connected through the anisotropic conductive adhesive 20, it is necessary to align the circuit terminals on the printed circuit board 30 with the chip electrodes on the piezoelectric printing chip 10 so that the circuit terminals on the printed circuit board 30 correspond to the chip electrodes on the piezoelectric printing chip 10; apply pressure and heat to the printed circuit board 30 to make the anisotropic conductive adhesive 20 conduct electricity under the action of pressure, so as to realize the electrical connection between the chip electrodes and the circuit terminals; after the anisotropic conductive adhesive 20 is cured by heating, the packaging of the piezoelectric printing chip 10 and the printed circuit board 30 is completed.

[0045] Specifically, when applying the anisotropic conductive adhesive 20, the chip electrodes are pre-coated so that the edge of the anisotropic conductive adhesive 20 extends outward from the position of the chip electrodes, and the size of the anisotropic conductive adhesive 20 at least covers the chip electrodes, or the anisotropic conductive adhesive 20 completely covers the piezoelectric printing chip 10, so that the piezoelectric printing chip 10 and the anisotropic conductive adhesive 20 have dimensions corresponding to the printed circuit board 30; the printed circuit board 30 and the piezoelectric printing chip 10 are bonded and electrically connected together through the anisotropic conductive adhesive 20, so that in the coating process, an anisotropic conductive glue with a suitable size can be selected according to actual needs to cover all the chip electrodes on each piezoelectric printing chip 10 and the area where each piezoelectric printing chip 10 contacts the printed circuit board 30. Through one coating, the electrical connection and fixation of each piezoelectric printing chip 10 to the printed circuit board 30 can be achieved, thereby realizing the encapsulation of the piezoelectric printing chip 10 and improving production efficiency.

[0046] In the technical solution provided by the embodiment of the present invention, each piezoelectric printing chip 10 includes chip electrodes; the anisotropic conductive adhesive 20 at least covers the chip electrodes; the printed circuit board 30 includes at least one circuit end point, and each chip electrode is electrically connected to the circuit end point through the anisotropic conductive adhesive 20; the anisotropic conductive adhesive 20 can be used as the electrical connection material between the piezoelectric printing chip and the printed circuit board, which can ensure that the chip electrodes in the piezoelectric printing chip are in full contact with the circuit end points in the printed circuit board, meet the packaging requirements of high-density pins on the piezoelectric printing chip 10, and have the advantages of reliable conductivity and long service life; at the same time, the packaging structure is simple, the manufacturing efficiency is high, the cost is low, it does not rely on special equipment, the production capacity is not limited, and it can be applied to the packaging of thin and light and high-performance printing chips.

[0047] Optionally, referring to Figure 1 and Figure 2 , the anisotropic conductive adhesive 20 is a conductive silver paste, and the solid content of the conductive silver paste is 65%-75%.

[0048] Among them, the solid content of the conductive silver paste is 70% ± 5%, and the solid content of the conductive silver paste can be 70%, 75% or 80%, etc.; the solid content of the conductive silver paste refers to the percentage of the mass of the remaining solid substances after the silver paste is dried under specified conditions in the total mass of the original conductive silver paste. Setting the solid content of the conductive silver paste to 65%-75% can form a thicker and denser silver film after curing, which is beneficial to improving the conductivity, adhesion and wear resistance of the silver film.

[0049] Optionally, referring to Figure 1 and Figure 2 , the anisotropic conductive adhesive 20 is a conductive epoxy resin adhesive, and the solid content of the conductive epoxy resin adhesive is 77%-83%.

[0050] Among them, the solid content of the conductive epoxy resin adhesive is 80% ± 3%, and the solid content of the conductive silver paste can be 77%, 80%, 83%, etc.; the size of the anisotropic conductive adhesive can be 10 mm × 5 mm; the solid content of the conductive epoxy resin adhesive refers to the percentage of the mass of the remaining solid components in the total mass of the original adhesive after removing volatile components such as solvents. Setting the solid content of the conductive epoxy resin adhesive to 77%-83% is beneficial to forming a good conductive path, thereby improving the conductivity of the conductive epoxy resin adhesive. Sufficient solid components can ensure that the adhesive forms a firm bonding structure after curing; and for the adhesive with a higher solid content during the curing process, due to fewer volatile components, the shrinkage rate is relatively small, and the dimensional stability after curing is better, which helps to improve the reliability of the packaging structure.

[0051] Optionally, referring to Figure 1 and Figure 2 , the vertical projection of the anisotropic conductive adhesive 20 on the printed circuit board 30 coincides with the vertical projection of the piezoelectric printing chip 10 on the printed circuit board 30.

[0052] Among them, the vertical projection of the anisotropic conductive adhesive 20 on the printed circuit board 30 coincides with the vertical projection of the piezoelectric printing chip 10 on the printed circuit board 30, and the anisotropic conductive adhesive 20 completely covers the piezoelectric printing chip 10, so that the chip electrodes in the piezoelectric printing chip 10 can be electrically connected to the circuit endpoints on the printed circuit board 30. At the same time, other areas of the piezoelectric printing chip 10 except the chip electrodes can be in contact with the printed circuit board. By fixing the piezoelectric printing chip 10 through the anisotropic conductive adhesive 20, while meeting the packaging of high-density pins on the thin-film piezoelectric printing chip, the packaging of the piezoelectric printing chip 10 is realized, and the reliability of the connection is improved.

[0053] Optionally, referring to Figure 1 and Figure 2 , the printed circuit board 30 is a flexible printed circuit board; the material of the printed circuit board 30 includes polyimide.

[0054] Among them, the printed circuit board 30 is a flexible printed circuit board (FPC); the flexible circuit board has good flexibility and insulation performance; the copper foil is the key part to realize the circuit conduction function; the cover film is used to protect the circuit and enhance the flexibility; the binder is used for bonding between layers. The material of the printed circuit board 30 includes polyimide, the material is mature, and the process preparation is simple.

[0055] Optionally, referring to Figure 1 and Figure 2 , the thickness of the printed circuit board 30 is 20 μm - 30 μm.

[0056] Among them, the thickness of the printed circuit board 30 is 20μm - 30μm. Exemplarily, the thickness of the printed circuit board 30 can be 20μm, 21μm, 22μm, 25μm, 26μm, 27μm, 28μm, 30μm, etc. When the thickness of the printed circuit board is 20μm - 30μm, it has better electrical conductivity and flexibility, and the process is simple.

[0057] Based on the above embodiments, an encapsulation method for a piezoelectric printing chip encapsulation structure according to an embodiment of the present invention is used to prepare the encapsulation structure described in any embodiment of the present invention. Figure 3 It is a flowchart of an encapsulation method for a piezoelectric printing chip encapsulation structure provided by an embodiment of the present invention. Refer to Figure 3 , and the encapsulation method includes:

[0058] S110. Fix at least one piezoelectric printing chip on one side of the jig; each piezoelectric printing chip includes a chip electrode.

[0059] Among them, on one side of the jig where at least one piezoelectric printing chip is fixed, the exposed surface of the piezoelectric printing chip includes a chip electrode, and the chip electrode is a high-density pin.

[0060] S120. Form an anisotropic conductive adhesive on one side of the piezoelectric printing chip; the anisotropic conductive adhesive covers at least the chip electrode.

[0061] Among them, the anisotropic conductive glue 30 is coated on the piezoelectric printing chip by screen printing process. The anisotropic conductive adhesive is a conductive silver paste of model XYZ, and the solid content of the conductive silver paste is 65% - 75%; or, the anisotropic conductive adhesive is a conductive epoxy resin glue of model ABC, and the solid content of the conductive epoxy resin glue is 77% - 83%. The size of the anisotropic conductive adhesive can be 10mm × 5mm. The anisotropic conductive adhesive covering at least the chip electrode includes that the anisotropic conductive adhesive only covers the chip electrode or the vertical projection of the anisotropic conductive adhesive on the printed circuit board coincides with the vertical projection of the piezoelectric printing chip on the printed circuit board; the vertical projection of the anisotropic conductive adhesive on the printed circuit board coincides with the vertical projection of the piezoelectric printing chip on the printed circuit board, that is, the anisotropic conductive adhesive completely covers the piezoelectric printing chip, so that the chip electrode in the piezoelectric printing chip can be electrically connected to the circuit end point on the printed circuit board, and at the same time, other areas of the piezoelectric printing chip except the chip electrode can be in contact with the printed circuit board. By fixing the piezoelectric printing chip through the anisotropic conductive adhesive, while meeting the encapsulation of the high-density pins on the thin-film piezoelectric printing chip, the encapsulation of the piezoelectric printing chip is realized, and the reliability of the connection is improved.

[0062] S130. Form a printed circuit board on the side of the anisotropic conductive adhesive away from the piezoelectric printing chip; the printed circuit board includes at least one circuit terminal, and each chip electrode is electrically connected to the circuit terminal through the anisotropic conductive adhesive; wherein, the anisotropic conductive adhesive conducts electricity along the first direction and does not conduct electricity along the second direction; the first direction is the direction from the printed circuit board to the piezoelectric printing chip, and the second direction is perpendicular to the first direction.

[0063] Among them, forming a printed circuit board on the side of the anisotropic conductive adhesive away from the piezoelectric printing chip means bonding the piezoelectric printing chip and the printed circuit board through the anisotropic conductive adhesive; the printed circuit board is a flexible printed circuit board; the material of the printed circuit board includes polyimide; the thickness of the printed circuit board is 20μm - 30μm.

[0064] S140. Remove the fixture.

[0065] The packaging method provided by the technical solution of the embodiment of the present invention bonds the piezoelectric printing chip and the printed circuit board through the anisotropic conductive adhesive. The packaging process is simple, with high manufacturing efficiency and low cost. It does not rely on special equipment, and the production capacity is not restricted, which can improve production efficiency; it can meet the packaging requirements of high-density pins on the thin-film piezoelectric printing chip and is suitable for the packaging of thin and high-performance piezoelectric printing chips; using the anisotropic conductive adhesive as the electrical connection material between the piezoelectric printing chip and the printed circuit board, the connection reliability is high, and the service life of the print head is improved; the packaged structure is compact, thin and light, meeting the development trend of the thin and light of electronic devices.

[0066] Optionally, forming the anisotropic conductive adhesive on one side of the piezoelectric printing chip includes: forming the anisotropic conductive adhesive on one side of the piezoelectric printing chip through a screen printing process.

[0067] Among them, the screen printing process is simple, with high manufacturing efficiency and low cost. It does not rely on special equipment, and the production capacity is not restricted, which can improve production efficiency.

[0068] Specifically, when coating the anisotropic conductive adhesive, the chip electrode is pre-coated first, so that the edge of the anisotropic conductive adhesive extends outward from the position of the chip electrode, making the size of the anisotropic conductive adhesive at least cover the chip electrode, or making the anisotropic conductive adhesive completely cover the piezoelectric printing chip, so that the piezoelectric printing chip and the anisotropic conductive adhesive have corresponding sizes to the printed circuit board; the printed circuit board and the piezoelectric printing chip are bonded and conducted together through the anisotropic conductive adhesive, so that in the coating process, an anisotropic conductive adhesive with a suitable size can be selected according to actual needs to cover all the chip electrodes on each piezoelectric printing chip and the area where each piezoelectric printing chip contacts the printed circuit board. Through one coating, the electrical connection and fixation between each piezoelectric printing chip and the printed circuit board can be achieved, thus realizing the packaging of the piezoelectric printing chip and improving production efficiency.

[0069] Optionally, Figure 4 YesFigure 3 A refined flowchart included in S130. S130 is to form a printed circuit board on the side of the anisotropic conductive adhesive away from the piezoelectric printing chip, specifically including:

[0070] S131: Align the circuit endpoints in the printed circuit board with the chip electrodes in each piezoelectric printing chip.

[0071] Among them, Figure 5 is a schematic diagram of the left-side encapsulation alignment of a packaging structure of a piezoelectric printing chip provided by an embodiment of the present invention. Figure 6 is a schematic diagram of the right-side encapsulation alignment of a packaging structure of a piezoelectric printing chip provided by an embodiment of the present invention. The packaging structure includes a left side and a right side arranged oppositely. Refer to Figure 5 and Figure 6 . During the encapsulation process, the left alignment mark 11 of the piezoelectric printing chip 10 is aligned with the left alignment mark 31 on the printed circuit board 30, and the right alignment mark 12 of the piezoelectric printing chip 10 is aligned with the right alignment mark 32 on the printed circuit board 30; this enables the alignment of the circuit endpoints in the printed circuit board with the chip electrodes in each piezoelectric printing chip, avoiding subsequent misalignment between the circuit endpoints and the chip electrodes and affecting the reliability of the device.

[0072] S132: The circuit endpoints contact the aligned piezoelectric printing chips through the anisotropic conductive adhesive.

[0073] Among them, after alignment, the circuit endpoints contact the aligned piezoelectric printing chips through the anisotropic conductive adhesive to ensure the reliability of subsequent connections.

[0074] S133: Apply pressure and temperature treatment to the printed circuit board so that each chip electrode is electrically connected to the circuit endpoints through the anisotropic conductive adhesive.

[0075] Among them, apply a pressure treatment of 0.4 MPa - 0.6 MPa and a temperature treatment of 140°C - 160°C to the printed circuit board so that each chip electrode is electrically connected to the circuit endpoints through the anisotropic conductive adhesive; for example, apply a pressure of 0.5 MPa ± 0.1 MPa to the printed circuit board and heat it to 150°C ± 10°C to make the anisotropic conductive adhesive conduct under pressure, thereby realizing the electrical connection between the chip electrode and the circuit endpoints; after the anisotropic conductive adhesive is cured, the encapsulation of the piezoelectric printing chip and the printed circuit board is completed; using the method of applying pressure and heating to the printed circuit board to complete the encapsulation, the process is simple and efficient, which is conducive to realizing automated production.

[0076] It should be understood that various forms of the flow shown above can be used, reordering, adding or deleting steps. For example, the steps described in the present invention can be executed in parallel, sequentially, or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and no limitations are imposed herein.

[0077] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A packaging structure of a piezoelectric printing chip, characterized in that: include: At least one piezoelectric printing chip, each of the piezoelectric printing chips comprising a chip electrode; Anisotropic conductive glue, the anisotropic conductive glue is located on one side of the piezoelectric printed chip; the anisotropic conductive glue at least covers the chip electrodes; A printed circuit board, wherein the printed circuit board is located on a side of the anisotropic conductive adhesive away from the piezoelectric printed chip; the printed circuit board comprises at least one circuit terminal, and each chip electrode is electrically connected to the circuit terminal through the anisotropic conductive adhesive; wherein the anisotropic conductive adhesive is conductive along a first direction and non-conductive along a second direction; the first direction is the direction in which the printed circuit board points to the piezoelectric printed chip, and the second direction is perpendicular to the first direction.

2. The packaging structure according to claim 1, characterized in that: The anisotropic conductive adhesive is conductive silver paste, and the solid content of the conductive silver paste is 65%-75%.

3. The packaging structure according to claim 1, characterized in that: The anisotropic conductive adhesive is conductive epoxy resin adhesive, and the solid content of the conductive epoxy resin adhesive is 77%-83%.

4. The packaging structure according to claim 1, characterized in that: The vertical projection of the anisotropic conductive adhesive on the printed circuit board coincides with the vertical projection of the piezoelectric printed chip on the printed circuit board.

5. The packaging structure according to claim 1, characterized in that: The printed circuit board is a flexible printed circuit board; the material of the printed circuit board includes polyimide.

6. The packaging structure according to claim 5, characterized in that: The thickness of the printed circuit board is 20 μm-30 μm.

7. A packaging method for a packaging structure of a piezoelectric printing chip, characterized in that: Used to prepare the packaging structure according to any one of claims 1 to 6, comprising: Fixing at least one piezoelectric printing chip on one side of the fixture; each of the piezoelectric printing chips includes a chip electrode; Anisotropic conductive glue is formed on one side of the piezoelectric printed chip; the anisotropic conductive glue at least covers the chip electrode; A printed circuit board is formed on a side of the anisotropic conductive adhesive away from the piezoelectric printed chip; the printed circuit board includes at least one circuit terminal, and each chip electrode is electrically connected to the circuit terminal through the anisotropic conductive adhesive; wherein the anisotropic conductive adhesive is conductive along a first direction and non-conductive along a second direction; the first direction is the direction in which the printed circuit board points to the piezoelectric printed chip, and the second direction is perpendicular to the first direction; The jig is removed.

8. The packaging method of the packaging structure according to claim 7, characterized in that: Anisotropic conductive glue is formed on one side of the piezoelectric printed chip, comprising: Anisotropic conductive glue is formed on one side of the piezoelectric printed chip through a screen printing process.

9. The packaging method of the packaging structure according to claim 7, characterized in that: A printed circuit board is formed on a side of the anisotropic conductive adhesive away from the piezoelectric printed chip, comprising: Aligning the circuit terminals in the printed circuit board with the chip electrodes in each of the piezoelectric printed chips; The circuit endpoints are in contact with the aligned piezoelectric printed chip through the anisotropic conductive adhesive; The printed circuit board is subjected to pressure and temperature treatment so that each chip electrode is electrically connected to the circuit terminal through the anisotropic conductive adhesive.

10. The packaging method of the packaging structure according to claim 9, characterized in that: The printed circuit board is subjected to pressure and heating treatment so that each chip electrode is electrically connected to the circuit terminal through the anisotropic conductive adhesive, comprising: The printed circuit board is subjected to a pressure treatment of 0.4MPa-0.6MPa and a temperature treatment of 140°C-160°C, so that each chip electrode is electrically connected to the circuit terminal through the anisotropic conductive adhesive.

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