Chip packaging structure

Abstract

The utility model provides a chip packaging structure. The chip packaging structure comprises a substrate and an MEMS chip, wherein the substrate and the MEMS chip are oppositely arranged; wherein a first metal body is arranged on the surface, close to the substrate, of the MEMS chip; a bonding area used for bonding and a cutting channel area used for cutting are arranged on the surface, close to the MEMS chip, of the substrate, the cutting channel area is arranged around the bonding area, a second metal body is arranged on the bonding area, and the first metal body is bonded with the second metal body; a drainage structure is arranged on the substrate, the drainage structure is in bridge connection with the bonding area and the cutting channel area, and the drainage structure is made of a metal material so as to lead out redundant metal liquid in the bonding area. According to the chip packaging structure provided by the utility model, redundant metal liquid in the bonding area is drained to the cutting channel area through the drainage structure, so that the risk that molten metal overflows to the functional area in the chip in the metal bonding process is overcome, the bonding quality is improved, and the yield of the MEMS chip is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of chip packaging, in particular to a chip packaging structure. Background Art

[0002] Bonding technology is an important technology in MEMS processing, among which metal eutectic bonding is a commonly used method. Specifically, two specific metals melt at high temperature and then react to form an alloy. The alloy reacts in a liquid state and solidifies after cooling. In the high-temperature eutectic state, the liquid alloy is at risk of overflowing and may flow beyond the bonding area to the functional area inside the chip, damaging the MEMS device structure and reducing the product yield. Utility Model Content

[0003] The utility model aims to at least solve the problem in the prior art that liquid overflow is prone to occur during the metal bonding process, resulting in reduced yield of MEMS products, and provides a chip packaging structure.

[0004] The purpose of the utility model is achieved by the following technical solutions:

[0005] According to one aspect of the utility model, a chip packaging structure is provided, comprising a substrate and a MEMS chip arranged opposite to each other; wherein a first metal body is arranged on a surface of the MEMS chip close to the substrate;

[0006] The surface of the substrate close to the MEMS chip is provided with a bonding area for bonding and a cutting road area for cutting, wherein the cutting road area is arranged around the bonding area, a second metal body is arranged on the bonding area, and the first metal body is bonded to the second metal body;

[0007] A drainage structure is arranged on the substrate, the drainage structure is connected across the bonding area and the cutting path area, and the drainage structure is made of metal material to guide excess metal liquid in the bonding area.

[0008] Furthermore, one end of the drainage structure is connected to the second metal body, and the other end leads to the cutting path area.

[0009] Furthermore, the drainage structure is in a straight line shape.

[0010] Furthermore, the drainage structure is arc-shaped.

[0011] Furthermore, the drainage structure includes a first branch and a second branch, the first branch and the second branch are L-shaped, the first branch is connected to the second metal body, and the second branch leads to the cutting path area.

[0012] Furthermore, the drainage structure includes a drainage belt spanning the bonding area and the cutting road area, and the drainage belt is integrally formed with the second metal body and is arranged on the same layer as the second metal body.

[0013] Furthermore, the MEMS chip is an inertial sensor chip.

[0014] Furthermore, the number of the drainage structures is at least one.

[0015] The chip packaging structure provided in the embodiment of the present application is provided with a drainage structure on the substrate. The drainage structure is connected across the bonding area and the cutting path area, and the drainage structure is made of metal. The excess metal liquid in the bonding area is drained to the cutting path area through the drainage effect of the metal, thereby overcoming the risk of molten metal overflowing into the internal functional area of ​​the chip during the metal bonding process, improving the bonding quality, and increasing the yield of the MEMS chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other implementation methods can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 is a schematic diagram of a chip packaging structure provided according to an embodiment of the utility model;

[0018] Figure 2 It is one of the schematic diagrams of the drainage structure provided according to the embodiment of the utility model;

[0019] Figure 3 This is a second schematic diagram of a drainage structure provided according to an embodiment of the utility model;

[0020] Figure 4 This is the third schematic diagram of the drainage structure provided according to the embodiment of the utility model. DETAILED DESCRIPTION

[0021] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the utility model more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with the accompanying drawings.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "depth" will be used to indicate that each component element of the pressure sensor in the embodiment of the present invention extends along the direction of the first axis Z of the Cartesian reference system XYZ, and the terms "length" and "width" respectively indicate that each component element of the pressure sensor in the embodiment of the present invention extends along the direction of the second axis X and the third axis Y of the Cartesian coordinate system XYZ. The terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection or mutual communication; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. When it comes to method steps, the sequence of this article represents an exemplary scheme, but does not represent a limitation on the sequence of sequence. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0024] Figure 1 is a schematic diagram of a chip packaging structure provided according to an embodiment of the utility model; Figure 2 It is one of the schematic diagrams of the drainage structure provided according to the embodiment of the utility model; Figure 3 This is a second schematic diagram of a drainage structure provided according to an embodiment of the utility model; Figure 4 This is the third schematic diagram of the drainage structure provided according to the embodiment of the utility model.

[0025] like Figure 1-Figure 4 As shown, an embodiment of the utility model provides a chip packaging structure. The embodiment of the utility model provides a chip packaging structure, and the chip packaging structure includes a substrate 200 and a MEMS chip 100 that are arranged opposite to each other.

[0026] A first metal body 101 is disposed on the surface of the MEMS chip 100 close to the base substrate 200. Schematically, the MEMS chip may be an inertial sensor chip.

[0027] A bonding area (i.e. Figure 1 The area within B-B' and C-C' in the middle) and the cutting road area for cutting (i.e. Figure 1 The area outside AA' in the figure), wherein the cutting road area is arranged around the bonding area.

[0028] A second metal body 202 is provided on the bonding area, and the first metal body 101 is bonded to the second metal body 202. The first metal body 101 on the MEMS chip 100 is the main metal in the metal-to-metal bonding, and optionally, it can be copper, aluminum, iron, titanium, nickel, germanium and other metals. The second metal body 202 on the substrate 200 is the filling material (or solder, brazing material) in the metal-to-metal bonding, and can be tin, lead, silver, copper, gold, aluminum and other metals. Preferably, the first metal body 101 is germanium, and the second metal body 202 is aluminum.

[0029] A drainage structure 201 is disposed on the surface of the substrate close to the MEMS chip. The drainage structure 201 is connected across the bonding area and the cutting path area to drain excess metal liquid in the bonding area.

[0030] Since the cutting path area is arranged around the bonding area, usually, there is a certain gap between the cutting path area and the bonding area to facilitate the blade to cut the cutting path area. Based on this, the drainage structure 201 is connected across the bonding area and the cutting path area. The drainage structure 201 may be partially in the cutting path area and partially in the bonding area. It is also possible that one end of the drainage structure 201 abuts the bonding area and the other end abuts the cutting path area. The drainage structure 201 is used to guide the excess metal liquid in the bonding area to the cutting path area to prevent the excess metal liquid from flowing into the MEMS chip 100, thereby achieving overflow prevention and improving the bonding quality and chip yield.

[0031] More specifically, one end of the drainage structure 201 is connected to the second metal body 202, and the other end leads to the cutting path area.

[0032] In addition, the drainage structure 201 is generally made of metal. Preferably, the drainage structure 201 and the second metal body 202 are made of the same material, which can be tin, lead, silver, copper, gold, aluminum, etc.

[0033] Indicatively, Figure 2 As shown, the drainage structure 201 is in a straight line shape, that is, it extends directly from the second metal body 202 to the cutting area. When the second metal body 202 is bonding with the first metal body 101, the excess metal liquid flows to the cutting area through the straight line drainage structure 201.

[0034] In other embodiments of the present invention, Figure 3 As shown, the utility model also provides a drainage structure 201, which is arc-shaped. Compared with the straight drainage structure 201, the arc-shaped drainage structure 201 extends the flow path, and the arc-shaped drainage structure 201 can accommodate more excess metal liquid, further improving the anti-overflow effect and bonding quality.

[0035] In other embodiments of the present invention, Figure 4 As shown, the utility model also provides a drainage structure 201, which includes a first branch and a second branch, the first branch and the second branch are L-shaped, the first branch is connected to the second metal body 202, the second branch leads to the cutting path area, and the first branch and the second branch are integrally formed. The first branch drains the excess metal liquid generated by the second metal body 202 in the bonding reaction to the second branch, and the second branch then discharges the metal liquid to the cutting path area. Compared with the straight-line and arc-shaped drainage structures 201, the drainage structure 201 in this embodiment has a longer flow path, thereby further improving the anti-overflow effect and bonding quality.

[0036] The drainage structure 201 of the utility model adopts the form of a drainage belt. Compared with the prior art that sets an overflow groove and / or a baffle, which requires additional etching or addition between the bonding area and the cutting path area, the drainage belt of the utility model is integrally formed with the second metal body 202 and is arranged on the same layer as the second metal body. Its essence is a section extended from the second metal body 202. The drainage effect of the metal is used to guide the excess metal liquid in the bonding process to the cutting path area. The manufacturing process is more convenient and efficient, and can effectively simplify the chip manufacturing process.

[0037] It should be noted that the number of the drainage structures 201 is at least one, which can be determined according to the reaction amount of the first metal body 101 and the second metal body 202. When the reaction amount is large, multiple drainage structures 201 can be arranged around the bonding area to drain out the excess metal liquid in the entire bonding area. When the reaction amount is small, a small number of drainage structures 201 are arranged to ensure the simplicity of the chip packaging structure.

[0038] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A chip packaging structure, characterized in that: It comprises a substrate and a MEMS chip which are arranged opposite to each other; wherein a first metal body is arranged on a surface of the MEMS chip close to the substrate; The surface of the substrate close to the MEMS chip is provided with a bonding area for bonding and a cutting road area for cutting, wherein the cutting road area is arranged around the bonding area, a second metal body is arranged on the bonding area, and the first metal body is bonded to the second metal body; A drainage structure is arranged on the substrate, the drainage structure is connected across the bonding area and the cutting path area, and the drainage structure is made of metal material to guide excess metal liquid in the bonding area.

2. The chip packaging structure according to claim 1, characterized in that: One end of the drainage structure is connected to the second metal body, and the other end leads to the cutting path area.

3. The chip packaging structure according to claim 1, characterized in that: The drainage structure is in a straight line shape.

4. The chip packaging structure according to claim 1, characterized in that: The drainage structure is arc-shaped.

5. The chip packaging structure according to claim 1, characterized in that: The drainage structure includes a first branch and a second branch, the first branch and the second branch are L-shaped, the first branch is connected to the second metal body, and the second branch leads to the cutting path area.

6. The chip packaging structure according to claim 1, characterized in that: The drainage structure includes a drainage belt spanning the bonding area and the cutting road area. The drainage belt is integrally formed with the second metal body and is arranged in the same layer as the second metal body.

7. The chip packaging structure according to claim 1, characterized in that: The MEMS chip is an inertial sensor chip.

8. The chip packaging structure according to any one of claims 1 to 7, characterized in that: The number of the drainage structures is at least one.

Images