A circuit board and a print head

Abstract

The utility model relates to a kind of circuit board, including PCB board, and chip and encapsulation ring being set on PCB board, pad is equipped on chip, encapsulation ring is set at the outer periphery of chip, pad is fused with bonding wire based on fusion tool, the first insulating layer of basicity is covered and set on encapsulation ring, the second insulating layer of being located the top of first insulating layer is also equipped in the top of encapsulation ring.The circuit board, by setting the second insulating layer in the top of encapsulation ring, even in the case where the size tolerance and position accuracy tolerance fluctuation of fusion tool exist, bonding wire and encapsulation ring can be effectively isolated from contact, realize the insulation between bonding piece and encapsulation ring, avoid short circuit problem caused by bonding wire and encapsulation ring contact, corresponding avoid chip damage.The utility model is also related to a kind of print head, including body, and the inside of body is equipped with the aforementioned circuit board.The print head is reliable in operation.

Description

Technical Field

[0001] This utility model relates to a circuit board, and also to a printhead using the circuit board. Background Technology

[0002] Existing circuit boards typically require encapsulation, a crucial step in the circuit board manufacturing process. Its main purposes include protecting the chip, facilitating the connection between the chip and external circuits, ensuring power supply, and providing heat dissipation. Encapsulation technology not only protects the chip from physical damage and electromagnetic interference but also ensures a precise connection between the chip and external circuits, enhancing the chip's performance and functionality.

[0003] A circuit board typically consists of a PCB and chips mounted on it. The chips have internal pads for connecting to external circuits, usually distributed around the chip's periphery or in an array. To protect the internal circuitry from external environmental damage, an environmental metal structure is placed around the chip during the chip packaging process to form a packaging ring. This packaging ring prevents mechanical stress from damaging the internal circuitry during chip dicing, ensuring the dicing blade does not directly damage the chip's interior. The packaging ring also acts as electrical shielding, effectively isolating external noise or interference to prevent it from affecting the signal integrity within the chip. Furthermore, the packaging ring prevents moisture, dust, and other external substances from entering from the sides of the chip, protecting the stability and reliability of the internal circuitry and extending the chip's lifespan.

[0004] During thermoforming soldering, a thermoforming fixture is used to fuse bonding wires to the pads. Bonding wires are very thin conductors used to connect pads within a chip to package pins or the package substrate, enabling electrical connections and signal transmission during chip packaging. Due to the operating characteristics of the package ring, it typically has an insulating layer. However, during thermoforming the bonding wires and pads, fluctuations in the dimensional and positional tolerances of the thermoforming fixture, coupled with the close proximity of the pads to the package ring, can damage the insulating layer. This can lead to short circuits caused by contact between the package ring and the bonding wires, affecting the normal operation of the circuit board. Utility Model Content

[0005] The first technical problem to be solved by this utility model is to provide a circuit board that can avoid short circuits between the packaging ring and the bonding wire, in contrast to the above-mentioned prior art.

[0006] The second technical problem to be solved by this utility model is to provide a printhead that uses the aforementioned circuit board, in contrast to the prior art.

[0007] The technical solution adopted by this utility model to solve the first technical problem mentioned above is as follows: a circuit board, including a PCB board, and a chip and a packaging ring disposed on the PCB board. The chip is provided with pads, the packaging ring is disposed on the outer periphery of the chip, the pads are fused with bonding wires based on a welding fixture, the packaging ring is covered with a basic first insulating layer, and a second insulating layer is provided above the first insulating layer on the packaging ring.

[0008] Preferably, the second insulating layer is a resin layer.

[0009] To further prevent short circuits between the packaging ring and the bonding wires, the distance between the inner edge of the packaging ring and the outer edge of the chip is A;

[0010] In the direction from the chip to the packaging ring, the maximum horizontal distance of the tolerance fluctuation of the welding fixture used for welding bonding wires is B;

[0011] Set B > A.

[0012] The technical solution adopted by this utility model to solve the second technical problem mentioned above is: a printhead, including a body, wherein the aforementioned circuit board is disposed inside the body.

[0013] Compared with the prior art, the advantages of this utility model are as follows: The circuit board of this utility model, by setting a second insulating layer above the packaging ring, can effectively isolate the contact between the bonding wire and the packaging ring even if the dimensional tolerance and positional accuracy tolerance of the welding fixture are fluctuating and damage the first insulating layer, thereby achieving insulation between the bonding component and the packaging ring, avoiding short circuit problems caused by the contact between the bonding wire and the packaging ring, and correspondingly avoiding chip damage.

[0014] The printhead using this circuit board has high operational reliability. Attached Figure Description

[0015] Figure 1 This is a longitudinal cross-sectional view of the circuit board in an embodiment of this utility model.

[0016] Figure 2 This is a longitudinal cross-sectional view of the encapsulation ring and solder pads in an embodiment of this utility model. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0018] like Figure 1 and Figure 2 As shown, the circuit board in this embodiment includes a PCB board, a chip 1 and a packaging ring 5 disposed on the PCB board. The chip 1 is provided with a pad 4, and the packaging ring 5 is disposed on the outer periphery of the chip 1. The pad 4 is welded with bonding wires 3 based on the welding fixture 2.

[0019] A basic first insulating layer 7, typically made of SiO2, is provided on the encapsulation ring 5. A second insulating layer 6 is also provided above the first insulating layer 7. The area of ​​the second insulating layer 6 is larger than the area of ​​the encapsulation ring 5, thus completely covering it. The material of the second insulating layer 6 can be selected from various materials that can perform insulating functions, and in this embodiment, the second insulating layer 6 is a resin layer.

[0020] To further prevent short circuits between the encapsulation ring 5 and the bonding wire 3, the distance between the inner edge of the encapsulation ring 5 and the outer edge of the chip 1 is A; the maximum horizontal distance for tolerance fluctuations of the welding fixture 2 used for welding the bonding wire 3 in the direction from the chip 1 to the encapsulation ring 5 is B; B is set to be greater than A. Based on this specific facility, it is also possible to minimize contact between the encapsulation ring 5 and the bonding wire 3 due to tolerance fluctuations of the welding fixture 2, thus constraining contact between the encapsulation ring 5 and the bonding wire 3 by setting a distance.

[0021] By setting a second insulating layer 6 above the packaging ring 5, the circuit board can effectively isolate the contact between the bonding wire 3 and the packaging ring 5 even when there are fluctuations in dimensional tolerances and positional accuracy tolerances in the welding fixture 2. This achieves insulation between the bonding component and the packaging ring 5, avoids short circuit problems caused by contact between the bonding wire 3 and the packaging ring 5, and correspondingly avoids damage to the chip 1.

[0022] The aforementioned circuit board can be used in various products that require chip 1 encapsulation. This embodiment relates to a printhead including the aforementioned circuit board. Specifically, the printhead includes a body, within which the aforementioned circuit board is disposed. The printhead using this circuit board exhibits high operational reliability.

[0023] In the specification and claims of this utility model, terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of this utility model. However, the use of these terms is merely for the purpose of explanation and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this utility model can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

Claims

1. A circuit board, comprising a PCB board, and a chip (1) and a packaging ring (5) disposed on the PCB board, wherein the chip (1) has pads (4), the packaging ring (5) is disposed on the outer periphery of the chip (1), and the pads (4) are welded with bonding wires (3) based on a welding fixture (2), characterized in that: The encapsulation ring (5) is covered with a basic first insulating layer (7), and a second insulating layer (6) is also provided above the first insulating layer (7).

2. The circuit board according to claim 1, characterized in that: The second insulating layer (6) is a resin layer.

3. The circuit board according to claim 1 or 2, characterized in that: The distance between the inner edge of the encapsulation ring (5) and the outer edge of the chip (1) is A; In the direction from the chip (1) to the packaging ring (5), the maximum horizontal distance of the tolerance fluctuation of the welding fixture (2) used for welding the bonding wire (3) is B; Set B > A.

4. A printhead, comprising a body, characterized in that: The body is provided with a circuit board as described in any one of claims 1 to 3.

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