Packaging structure of photoelectric detection chip

Abstract

The utility model provides a packaging structure of a photoelectric detection chip. The packaging structure comprises a packaging substrate, a photoelectric detection chip mounted in a predetermined packaging area of the packaging substrate, a packaging insulator, a first conductive connector, a second conductive connector, a chip protection layer and a protection filling layer. One side, close to the second conductive pad, of the front surface of the photoelectric detection chip and a non-active region on the opposite side are respectively provided with a front surface electrode, and the front surface electrode close to one side of the second conductive pad is electrically connected with the second conductive pad through a second conductive connector; the packaging insulator is arranged on the front surface of the packaging substrate, and is at least packaged between the second conductive connector and the side wall of the photoelectric detection chip and between the second conductive connector and a non-active region on the front surface of the photoelectric detection chip; the protective filling layer at least covers the exposed second conductive connector so as to isolate air. The utility model can effectively prolong the service life of the device and reduce the failure rate of the product.

Description

TECHNICAL FIELD

[0001] The utility model relates to chip packaging technical field especially relates to a kind of packaging structure of photoelectric detection chip. BACKGROUND

[0002] The Chinese invention patent application with the publication number CN115732430A and the application name "Packaging structure and packaging method of photoelectric detection chip" proposes a packaging structure, which can improve the yield and reliability of the packaging structure. However, this packaging form still has the following defects, which cannot be used as a mature process to package photoelectric detection chips:

[0003] The chip protection layer in the current packaging structure is formed before cutting the packaging substrate, so after cutting the packaging substrate to obtain the packaging unit, the second conductive connector in the packaging unit for photoelectric detection is exposed, and it is in long-term contact with air during device use, which is easily affected by the external environment. For example, moisture, static electricity and dust in the environment can affect its conductive properties, which may cause the device to have a risk of open circuit, and contact with external conductors to cause leakage and short circuit problems, and also cause aging to affect the reliability of the device. Therefore, for the second conductive connector of the packaging unit, how to avoid affecting the characteristics of the photoelectric detection chip and improve the reliability of the photoelectric detection device for long-term use is a problem to be solved.

[0004] Further, three different materials with different thermal expansion coefficients are used to prepare the packaging insulator, the second conductive connector and the chip protection layer during the packaging process of the photoelectric detection chip. All of these three structures need high temperature to solidify during the packaging process, but due to the different thermal expansion coefficients, the temperature recovery process may cause gaps at the side connection, which may corrode the packaging structure during long-term use of the device, causing the electrical performance of the device to decrease, and even possibly causing the device to fail. How to overcome the above defects to enable the device to be used stably for a long time and thus reduce the product failure rate is a problem to be solved. UTILITY MODEL CONTENTS

[0005] Therefore, the utility model embodiment provides a packaging structure of photoelectric detection chip, which forms an insulating protective coating on the second conductive connector to improve the reliability of the photoelectric detection device for long-term use and reduce the product failure rate.

[0006] One aspect of the utility model provides a packaging structure of photoelectric detection chip, and the packaging structure comprises: a packaging substrate, a photoelectric detection chip, a packaging insulator, a first conductive connector, a second conductive connector, a chip protection layer and a protective filling layer.

[0007] The front surface of the packaging substrate is provided with a first conductive pad and a second conductive pad, and the back surface is provided with a first electrode and a second electrode, the first conductive pad and the first electrode are connected through a first conductive bonding structure, and the second conductive pad and the second electrode are connected through a second conductive bonding structure;

[0008] The back surface of the photoelectric detection chip is provided with a back surface electrode, the back surface electrode is electrically connected with the oppositely arranged first conductive pad through a first conductive connecting body, so that the photoelectric detection chip is mounted into a predetermined packaging area of the packaging substrate; the front surface of the photoelectric detection chip is provided with a front surface electrode on one side close to the second conductive pad and a non-active area on the opposite side, and the front surface electrode close to the second conductive pad is electrically connected with the exposed second conductive pad on the packaging substrate through a second conductive connecting body;

[0009] The packaging insulator is arranged on the front surface of the packaging substrate, and is at least packaged between the second conductive connecting body and the side wall of the photoelectric detection chip and between the second conductive connecting body and the non-active area of the front surface of the photoelectric detection chip, so as to insulate the photoelectric detection chip and the second conductive connecting body;

[0010] The chip protection layer is at least coated on the front surface of the photoelectric detection chip; and the protection filling layer at least covers the exposed second conductive connecting body to isolate air.

[0011] In some embodiments of the utility model, the packaging insulator is a packaging member prepared from an insulating material with a first thermal expansion coefficient, the second conductive connecting body is a packaging member prepared from a conductive material with a second thermal expansion coefficient, and the chip protection layer is an insulating layer prepared from an insulating material with a third thermal expansion coefficient; and

[0012] The filling protection structure is also filled in the gap formed when the packaging insulator, the second conductive connecting body and the chip protection layer are cooled.

[0013] In some embodiments of the utility model, the protection filling layer is formed by using an insulating filling material with a viscosity of 0.75-0.85 mm 2 / s at 25 DEG C, and is used for protecting the packaging member of the second conductive connecting body.

[0014] The thickness of the protection filling layer for covering the exposed second conductive connecting body is 100 nm-1 mu m.

[0015] In some embodiments of the utility model, the protection filling layer is an insulating structure made of fluorine electronic protection nano coating agent X25.

[0016] In some embodiments of the utility model, the non-active area of the front surface of the photoelectric detection chip is located around the active area in the center of the photoelectric detection chip, and the width is less than 100 mu m.

[0017] The chip protection layer is an insulating organic silicon pouring sealant protection layer with a thickness of 200-400 mu m.

[0018] In some embodiments of the utility model, the front surface of the packaging substrate and the back surface of the photoelectric detection chip are both provided with alignment marks for positioning during chip mounting.

[0019] In some embodiments of the utility model, the packaging insulation body is a patterned epoxy insulation body structure formed by using a photoetching technology.

[0020] In some embodiments of the utility model, the first conductive bonding structure and the second conductive bonding structure are conductive through holes.

[0021] In some embodiments of the utility model, a conductive material layer for electrically connecting the second conductive bonding structure and the second conductive pad is arranged on the packaging substrate; and

[0022] An insulating medium layer is arranged on the conductive material layer for isolating the first conductive pad and the second conductive pad.

[0023] In some embodiments of the utility model, the insulating medium layer is a photoimaging solder resist ink layer.

[0024] The utility model provides a kind of packaging structure of photoelectric detection chip, on the basis of current chip packaging structure, new protective coating is covered to the exposed part of second conductive connecting body, to avoid the influence of device by air environment, to further improve the reliability of device long-term use on the basis of not affecting the original characteristics of current chip packaging structure.

[0025] The additional advantages, objects, and features of the present utility model will be in part apparent and in part pointed out hereinafter in the description, and will be appreciated by those of ordinary skill in the art upon reading the following detailed description of the present utility model and the appended claims, or can be learned from the practice of the present utility model. The objects and other advantages of the present utility model can be realized and attained by the structure particularly pointed out in the specification and the appended drawings.

[0026] Those skilled in the art will understand that the objects and advantages of the present utility model are not limited to the above specifically described, and the above and other objects that can be achieved by the present utility model will be more clearly understood according to the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and together with the description serve to explain the principles of the present application. The components in the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the present application. For purposes of clarity and understanding, some portions of the drawings can be exaggerated, and others can be dissembled. In the drawings:

[0028] Figure 1 FIG. 1 is a schematic diagram of a packaging structure of a photoelectric detection chip according to an embodiment of the present application.

[0029] Reference Signs:

[0030] 100, packaging substrate; 111, first conductive pad; 121, first electrode; 131, first conductive bonding structure; 112, second conductive pad; 122, second electrode; 132, second conductive bonding structure; 200, photoelectric detection chip; 210, back electrode; 220, front electrode; 300, packaging insulator; 410, first conductive connector; 420, second conductive connector; 500, chip protection layer; 600, insulating medium layer; 700, protective filling layer DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to embodiments and drawings. Here, the illustrative embodiments of the present application and the description thereof are used to explain the present application, but not as a limitation of the present application.

[0032] It should be further noted that, in order to avoid obscuring the present application due to unnecessary details, only structures and / or processing steps closely related to the scheme according to the present application are shown in the drawings, and other details not closely related to the present application are omitted.

[0033] It should be emphasized that the term "comprises / comprising" when used in this text indicates the presence of the stated features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0034] It should be further noted that, if not otherwise specified, the term "connected" in this text can not only mean direct connection, but also indirect connection with the presence of an intermediate.

[0035] In the following, embodiments of the present application will be described with reference to the drawings. In the drawings, the same reference signs represent the same or similar components, or the same or similar steps.

[0036] A packaging unit structure is disclosed in CN115732430A, entitled "Packaging structure and packaging method of photoelectric detection chip", in which the second conductive connecting body is partially exposed, thereby being in long-term contact with air during use of the device, affecting the reliability of the device during long-term use. To solve the above problems, the present application uses a novel nanoscale electronic protection coating agent to coat the surface of the second conductive connecting body that is not covered, further improving the reliability of the device during long-term use without affecting the original characteristics of the packaging structure, and reducing the product failure rate.

[0037] The nanoscale electronic protection coating agent is a colorless and transparent liquid with high impedance value. Due to its ultra-low viscosity, it can uniformly wrap the four side walls of the packaging unit and penetrate into the gaps of the device, thereby rapidly evaporating at room temperature to form a nanoscale ultra-thin coating that can block ions and water vapor.

[0038] The present application proposes a packaging structure of a photoelectric detection chip, as shown in Figure 1 The packaging structure includes a packaging substrate 100, a photoelectric detection chip 200, a packaging insulator 300, a first conductive connecting body 410, a second conductive connecting body 420, a chip protection layer 500, and a protective filling layer 700.

[0039] More specifically, the front surface of the packaging substrate 100 is provided with a first conductive pad 111 and a second conductive pad 112, and the back surface is provided with a first electrode 121 and a second electrode 122. The first conductive pad 111 and the first electrode 121 are connected by a first conductive bonding structure 131, and the second conductive pad 112 and the second electrode 122 are connected by a second conductive bonding structure 132.

[0040] In some embodiments of the present application, the first conductive bonding structure 131 and the second conductive bonding structure 132 can be conductive through holes. For example, the conductive through holes can be conductive vias (the hole walls are attached with conductive material connecting the top and bottom of the via) or conductive filled holes (such as through silicon vias) that penetrate through the packaging substrate 100, to realize vertical connection between the conductive pads on the packaging substrate 100 and the corresponding electrodes. The aforementioned conductive bonding structure is only an example of a conductive through hole, and other bonding structures can also be used, such as using a lead to connect the first conductive pad 111 and the first electrode 121, and the present application is not limited thereto. Furthermore, the present application does not specifically limit the shape and position of the first conductive pad 111, the second conductive pad 112, the first electrode 121, and the second electrode 122.

[0041] In some embodiments of the utility model, the packaging substrate 100 is paved with a conductive material layer for electrically connecting the second conductive bonding structure 132 and the second conductive pad 112, and an insulating medium layer 600 is covered on the conductive material layer for electrically isolating the first conductive pad 111 and the second conductive pad 112. The insulating medium layer 600 can be a photoimaging solder resist ink layer, or an insulating layer prepared from other insulating materials. The application does not specifically limit the preparation materials of the conductive material layer and the insulating medium layer 600, as long as they can play the roles of conduction and insulation.

[0042] Moreover, the back surface of the photoelectric detection chip 200 is provided with a back electrode 210, the back electrode 210 is electrically connected with the oppositely arranged first conductive pad 111 through the first conductive connecting body 410, so that the photoelectric detection chip 200 is attached to the predetermined packaging area of the packaging substrate 100; the front surface of the photoelectric detection chip 200 is respectively provided with a front electrode 220 on the side close to the second conductive pad 112 and the non-active area of the opposite side, and the front electrode 220 close to the second conductive pad 112 is electrically connected with the exposed second conductive pad 112 on the packaging substrate 100 through the second conductive connecting body 420. It should be noted that when the photoelectric detection chip 200 is attached to the packaging substrate 100 by the first conductive connecting body 410, only the first conductive pad 111 can be covered so that the second conductive pad 112 is exposed, so as to facilitate the subsequent connection of the packaging substrate 100 and the photoelectric detection chip 200 by the second conductive connecting body 420.

[0043] In some embodiments of the utility model, in order to minimize the invalid area of the photoelectric device after packaging, the non-active area of the front surface of the photoelectric detection chip 200 can be located around the active area in the center of the photoelectric detection chip 200, and the width of the non-active area of the chip suitable for the application can be less than 100 μm, so as to realize narrow edge packaging. In addition, in order to facilitate chip attachment, the front surface of the packaging substrate 100 and the back surface of the photoelectric detection chip 200 are both provided with alignment marks for positioning the positions of the packaging substrate 100 and the photoelectric detection chip 200 during the chip attachment process.

[0044] Further, the packaging insulator 300 is arranged on the front surface of the packaging substrate 100, and is at least packaged between the second conductive connecting body 420 and the side wall of the photoelectric detection chip 200 and between the second conductive connecting body 420 and the non-active area of the front surface of the photoelectric detection chip 200, so as to insulate the photoelectric detection chip 200 and the second conductive connecting body 420. In addition, the packaging insulator 300 can be arranged around the chip 200 to form an insulating structure coated on the side wall of the chip and the non-active area of the chip.

[0045] In some embodiments of the present application, the encapsulation insulator 300 can be a patterned epoxy insulator structure formed by using photolithography technology, for example, the encapsulation insulator 300 can be prepared by using SU-8 epoxy near-ultraviolet curing negative photoresist.

[0046] In addition, the chip protection layer 500 in the encapsulation structure is coated at least on the front surface of the photoelectric detection chip 200, for insulating protection of the chip. For example, the chip protection layer can be arranged on the front surface of the photoelectric detection chip, the reserved encapsulation insulator, and the second conductive connecting body. In addition, the chip protection layer 500 can be an insulating organic silicon potting adhesive protection layer, and the thickness thereof can be 200-400 μm.

[0047] The present application innovatively uses a new type of nano coating material to insulate and protect the exposed part of the second conductive connecting body, and the nano coating material can also be used to solve the gap problem caused by the different material thermal expansion coefficients, thereby improving the reliability of the device. The protection filling layer 700 in the encapsulation structure proposed by the present application covers at least the exposed second conductive connecting body 420, so that the exposed part of the second conductive connecting body can be isolated from air, for example, the protection filling layer 700 can cover four side surfaces of the encapsulation unit, so as to achieve insulating protection while solving the gap problem.

[0048] As an example, the protection filling layer 700 is in the form of a nano coating, and the thickness of the protection filling layer 700 for covering the exposed second conductive connecting body 420 can be 100 nm-1 μm, but the present application is not limited thereto.

[0049] In some embodiments of the present application, the encapsulation insulator 300 can be an encapsulation member prepared from an insulating material having a first thermal expansion coefficient, the second conductive connecting body 420 can be an encapsulation member prepared from a conductive material having a second thermal expansion coefficient, and the chip protection layer 500 can be an insulating layer prepared from an insulating material having a third thermal expansion coefficient, i.e., the encapsulation insulator 300, the second conductive connecting body 420, and the chip protection layer 500 are prepared from materials having different thermal expansion coefficients. At this time, the filling protection structure can also be filled in the gap formed when the encapsulation insulator 300, the second conductive connecting body 420, and the chip protection layer 500 are cooled.

[0050] As an example, the protection filling layer 700 can be formed by using an insulating potting material having a viscosity of 0.75-0.85 mm 2 / s at 25℃, for protecting the encapsulation member of the second conductive connecting body 420, for example, the protection filling layer 700 is an insulating structure made of fluorine electronic protection nano coating agent X25 having a viscosity of 0.8 mm 2 / s. The present application does not specifically limit the specific preparation material of the protection filling layer 700, and any insulating material capable of isolating air and having a low viscosity can be used.

[0051] In some embodiments of the present application, the method for preparing the protective filling layer 700 on the packaging unit by using the nanoscale electronic protection coating agent comprises the following steps:

[0052] Step S01: Obtain a single packaging unit by segmenting the packaging substrate, clean and dry the packaging unit, and cover the back of the packaging substrate 100 and the side of the chip protection layer 500 away from the photodetector chip with the protective adhesive film to ensure that the nanoscale electronic protection coating agent is only coated on the four side walls of the packaging unit (at this time, the exposed part of the second conductive connecting body is not covered by the protective adhesive film).

[0053] Step S02: Soak the device wrapped with the protective adhesive film in the solution of the corresponding nanoscale electronic protection coating agent, and use the ultrasonic device to perform ultrasonic according to the set parameters, so that the nanoscale electronic protection coating agent is coated on the surface of the packaging unit not covered by the protective adhesive film, and is filled in the gap generated by the device during the reheat process.

[0054] Step S03: Dry the device after ultrasonic treatment, and obtain the chip packaging unit including the protective filling layer 700 after removing the protective adhesive film.

[0055] As an example, the protective adhesive film can be made of T-80 blue film protective adhesive tape and other materials that are easy to tear and not easy to leave glue. Moreover, the type of nanoscale electronic protection coating agent is not specifically limited in the present application, and the above preparation method can solve the problem of the exposed second conductive connecting body and the device failure caused by the gap generated on the side wall of the packaging unit under the existing packaging technology.

[0056] The nanoscale electronic protection coating agent used in the present application can not only insulate and protect the second conductive connecting body 420 exposed to the air, but also can be used to fill the gap generated during the reheat process of the packaging insulator 300, the second conductive connecting body 420 and the chip protection layer 500. On the basis of retaining the advantages of the existing packaging technology, no additional labor and equipment costs are increased, and the invalid area (i.e. non-active area) of the device is not increased, and the long-term reliability of the finished device is greatly improved.

[0057] It should be clear that the present application is not limited to the specific configurations and processes described above and shown in the drawings. For the sake of brevity, detailed descriptions of known methods are omitted herein. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between steps, after understanding the spirit of the present application.

[0058] Features described and / or illustrated with respect to one implementation can be used in the same manner or in a similar manner in one or more other implementations and / or in combination with or in place of features of other implementations.

[0059] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the embodiments of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A packaging structure of a photodetection chip, characterized in that, The packaging structure comprises a packaging substrate, a photoelectric detection chip, a packaging insulator, a first conductive connector, a second conductive connector, a chip protection layer, and a protective filling layer. The front surface of the packaging substrate is provided with a first conductive pad and a second conductive pad, and the back surface is provided with a first electrode and a second electrode, the first conductive pad and the first electrode are connected through a first conductive bonding structure, and the second conductive pad and the second electrode are connected through a second conductive bonding structure. The back surface of the photoelectric detection chip is provided with a back surface electrode, the back surface electrode is electrically connected with the oppositely arranged first conductive pad through the first conductive connector, so that the photoelectric detection chip is attached to the predetermined packaging area of the packaging substrate; the front surface of the photoelectric detection chip is provided with a front surface electrode on the non-active area of the side close to the second conductive pad and the opposite side, and the front surface electrode close to the second conductive pad is electrically connected with the exposed second conductive pad on the packaging substrate through the second conductive connector. The packaging insulator is arranged on the front surface of the packaging substrate, and is at least packaged between the second conductive connector and the side wall of the photoelectric detection chip and between the second conductive connector and the non-active area of the front surface of the photoelectric detection chip, so as to insulate the photoelectric detection chip from the second conductive connector. The chip protection layer is at least coated on the front surface of the photoelectric detection chip; and the protective filling layer at least covers the exposed second conductive connector to isolate air.

2. The package structure of claim 1, wherein, The packaging insulator is a packaging member prepared from an insulating material with a first thermal expansion coefficient, the second conductive connector is a packaging member prepared from a conductive material with a second thermal expansion coefficient, and the chip protection layer is an insulating layer prepared from an insulating material with a third thermal expansion coefficient. The protective filling layer also fills the gap formed when the packaging insulator, the second conductive connector, and the chip protection layer are cooled. The thickness of the protective filling layer for covering the exposed second conductive connector is 100 nm to 1 μm.

3. The package structure of claim 1, wherein, The protective filling layer is formed by an insulating potting material with a viscosity of 0.75-0.85 mm 2 / s at 25°C, and is used to protect the second conductive connecting body. The protective filling layer is an insulating structure made of fluorine electron protection nano coating agent X25.

4. The package structure of claim 3, wherein, The non-active area of the front surface of the photoelectric detection chip is located around the active area at the center of the photoelectric detection chip, and the width is less than 100 μm.

5. The package structure of claim 1, wherein, The chip protection layer is an insulating organic silicon potting adhesive protection layer with a thickness of 200 to 400 μm. The front surface of the packaging substrate and the back surface of the photoelectric detection chip are both provided with alignment marks for positioning during chip attachment.

6. The package structure of claim 1, wherein, The packaging insulator is a patterned epoxy type insulator structure formed by using a photoetching technology.

7. The package structure of claim 1, wherein, The first conductive bonding structure and the second conductive bonding structure are conductive through holes.

8. The package structure of claim 1, wherein, The packaging substrate is provided with a conductive material layer for electrically connecting the second conductive bonding structure and the second conductive pad.

9. The package structure of claim 1, wherein, An insulating medium layer is arranged on the conductive material layer to isolate the first conductive pad and the second conductive pad. The insulating medium layer is a photoimaging solder resist ink layer. ​ 10. The package structure of claim 9, wherein, ​

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