TW201946505A - Printed circuit board and optical device having same - Google Patents

Abstract

The present invention relates to a printed circuit board. The printed circuit board includes a main body and an electromagnetic shielding layer. The main body includes a conductive layer and an insulating layer formed on the conductive layer. The main body includes a top surface, a bottom surface and a side surface connecting the top surface and the bottom surface. The top surface defines at least one electronic connecting area. The at least one electronic connecting area is arranged with a plurality of connecting pads. The electromagnetic shielding layer is formed on the top surface, the bottom surface and the side surface and exposing the plurality of connecting pads, and the electromagnetic shielding layer is insulates with the conductive layer.

Description

Circuit board and optical device

The invention relates to a circuit board and an optical device including the circuit board.

With the development of multifunctionalization of electronic products, camera modules have been widely used in consumer electronic products such as mobile phones, notebook computers, and personal digital assistants. While pursuing multifunctionality, people also want electronic products to have excellent imaging effects, that is, they want camera modules to have high-quality imaging quality. The camera module is a micro-optoelectronic product, and it will be disturbed by external electromagnetic interference (EMI), which will affect the normal operation. Therefore, an EMI prevention design is needed.

The existing anti-EMI design is to place a metal sheet on the bottom of the circuit board included in the camera module and a metal iron frame on the top of the circuit board to achieve the anti-electromagnetic interference effect of the camera module. However, the metal sheet needs to be fixed by an adhesive layer. On the circuit board, in this way, the anti-interference metal iron frame, metal sheet and adhesive layer for the camera module will increase the thickness of the circuit board, which is not conducive to the camera module's lightness. A metal sheet is provided at the bottom, and the metal sheet is not flexible. Therefore, the circuit layer on the side surface of the circuit board is still exposed, resulting in the camera module still being affected by external electromagnetic interference and affecting the quality of the camera module.

An object of the present invention is to provide a circuit board and an optical device including the circuit board.

A circuit board includes a circuit board body and an electromagnetic shielding layer. The circuit board body includes a conductive circuit layer and an insulating layer covering the conductive circuit. The circuit board body includes an upper surface, a lower surface, and a vertical connection. Side surfaces of the upper surface and the lower surface, the upper surface includes at least one electrical connection region, at least one of the electrical connection regions is provided with a plurality of conductive pads, and the electromagnetic shielding layer is formed on the upper surface and The conductive pad is exposed on the surface and side surfaces, and the electromagnetic shielding layer is electrically insulated from the conductive circuit layer through the insulating layer.

In a preferred embodiment, the circuit board body includes a flexible substrate and a rigid substrate disposed on two surfaces opposite to the flexible substrate. The rigid substrate includes a window, and the window exposes a part of the flexible substrate. The electromagnetic shielding layer is further formed on the exposed surface of the flexible substrate and the side wall of the window.

In a preferred embodiment, the electromagnetic shielding layer is indium tin oxide, and the thickness of the electromagnetic shielding layer is 2 nm to 100 nm.

In a preferred embodiment, the flexible substrate includes a first insulating layer and an inner conductive circuit layer formed on two opposite surfaces of the first insulating layer, and an edge of the inner conductive circuit layer and the first conductive layer An edge of an insulating layer is spaced to expose a part of the first insulating layer, a second insulating layer is provided between the rigid substrate and the flexible substrate, and the second insulating layer is formed on the inner conductive circuit layer And the surface of the first insulation layer exposed by the inner conductive circuit layer to cover the inner conductive circuit layer.

In a preferred embodiment, the rigid substrate includes a third insulating layer and an outer conductive circuit formed on the third insulating layer, and an edge of the outer conductive circuit layer is spaced from an edge of the third insulating layer. To expose part of the third insulating layer, the circuit board further includes a fourth insulating layer formed on two surfaces opposite to the circuit board body, and the fourth insulating layer is formed on a surface of the outer conductive circuit layer. And a surface of the third insulating layer exposed by the outer conductive circuit layer to cover the outer conductive circuit layer, and the fourth insulating layer exposes the conductive pad.

In a preferred embodiment, the second insulating layer is a prepreg, and the fourth insulating layer is a solder resist green paint.

In a preferred embodiment, conductive holes are respectively provided between the inner conductive lines, between the inner conductive lines and the outer conductive lines, and between the outer conductive lines, and the inner conductive lines and the inner layers are conductive. Conduction is conducted between the circuit and the outer conductive circuit and between the outer conductive circuit through the conductive holes.

In a preferred embodiment, the lower surface of the circuit board includes a plurality of ground metal pads, and the fourth insulation layer and the electromagnetic shielding layer expose the ground metal pads.

An optical device includes a circuit board, an integrated circuit element electrically connected to the circuit board, a lens mount provided on the circuit board, and a lens module housed in the lens mount. The circuit The board is the circuit board described above, and the integrated circuit element is disposed in the electrical connection area and is electrically connected to the conductive pad.

In a preferred embodiment, the integrated circuit element is an image sensor or a vertical cavity surface laser emitter wafer.

Compared with the prior art, the present invention provides a circuit board and an optical device including the circuit board. The circuit board includes a circuit board body and an electromagnetic shielding layer. The circuit board body includes a conductive circuit layer and a cover. The insulating layer of the conductive circuit, the circuit board body includes an upper surface, a lower surface, and a side surface vertically connecting the upper surface and the lower surface, the upper surface includes at least one electrical connection area, and at least one of the electrical connections A plurality of conductive pads are provided in the area, the electromagnetic shielding layer is formed on the upper surface, the lower surface, and the side surface but the conductive pad is exposed, and the electromagnetic shielding layer communicates with the conductive line through the insulating layer Layered electrical insulation. In this way, the electromagnetic shielding layer on the entire outer surface of the circuit board can better achieve the function of resisting electromagnetic interference, and the electromagnetic shielding layer provided on the entire outer surface of the circuit board can also achieve the effect of heat conduction, so that The heat generated by the electronic components on the circuit board is dissipated to the outside in a timely manner.

The present invention will be further described in detail below with reference to the accompanying drawings.

Please refer to Figs. 1-3, a circuit board 100 provided by the present invention. The circuit board 100 includes a circuit board body 1 and an electromagnetic shielding layer 4.

Specifically, the circuit board body 1 includes a flexible substrate 2 and a rigid substrate 3 disposed on opposite surfaces of the flexible substrate 2. The flexible substrate 2 includes a first insulating layer 21 and an inner conductive circuit layer 23 formed on two opposite surfaces of the first insulating layer 21. An edge of the inner conductive circuit layer 23 is spaced from an edge of the first insulating layer 21 to expose a part of the first insulating layer 21. A second insulating layer 25 is formed on the surface of the inner conductive circuit layer 23.

Specifically, the second insulating layer 25 is formed on a surface of the inner conductive circuit layer 23 and a surface of the first insulating layer 21 exposed by the inner conductive circuit layer 23 to cover the inner layer. Conductive line layer 23. The second insulating layer 25 has fluidity before curing, so that it can be formed on the side surface of the inner conductive circuit layer 23 by way of side overflow vertical flow during lamination. The second insulating layer 25 may be a prepreg. The prepreg may be, for example, a film formed of a thermosetting polymer such as epoxy resin, and may optionally contain glass fibers.

The rigid substrate 3 is formed on a surface of the second insulating layer 25. The rigid substrate 3 includes a cover film 31 made of polyimide, a core 33, a third insulating layer 35, and an outer conductive circuit layer in this order from a direction close to the flexible substrate 2 to a direction away from the flexible substrate 2. 37 and plating layer 39. Of course, it can be understood that, in other embodiments, the rigid substrate 3 may not be provided as such, but the required number of layers may be set as required.

One of the two outer conductive circuit layers 37 includes at least one electrical connection region 370, and at least one of the electrical connection regions 370 and a plurality of conductive pads 371 are disposed around the electrical connection region 370. The conductive pads 371 of the electrical connection area 370 are used to set integrated circuit elements, and the conductive pads 371 around the conductive pads 371 are used to set passive components, so that the integrated circuit element components, passive components and the conductive pads 371 are electrically Sexual connection.

The other outer conductive circuit layer 37 of the two outer conductive circuit layers 37 includes a plurality of ground metal pads 372.

A fourth insulating layer 45 is formed on the surface of the outer conductive circuit layer 37, and the fourth insulating layer 45 also has fluidity before being cured. Therefore, the outer conductive circuit layer 37 can be formed on the outer conductive circuit layer 37 by way of lateral overflow. The exposed surface of the third insulating layer 35 is the side of the outer conductive circuit layer 37. In this embodiment, the fourth insulating layer 45 is a green solder resist.

The rigid substrate 3 includes a window 301, and the window 301 exposes a part of the flexible substrate 2.

Conductive holes 110 are provided between the inner conductive lines 23, between the inner conductive lines 23 and the outer conductive lines 37, and between the outer conductive lines 37 and the outer conductive lines 37, respectively. The conductive hole 110 may be a blind hole, a buried hole, or a through hole. In this embodiment, the inner conductive lines 23 are connected through buried holes; the inner conductive line layers 23 and the outer conductive line layer 37 are connected through blind holes; the upper outer conductive line layer 37 and the lower outer layer are connected. The conductive circuit layers 37 are electrically connected to each other through through holes.

The circuit board body 1 includes an upper surface 101, a lower surface 103, and a side surface 105 vertically connecting the upper surface 101 and the lower surface 103. The electromagnetic shielding layer 4 is formed on the upper surface 101, the lower surface 103, and The side surface 105, that is, the electromagnetic shielding layer 4 is formed on the surface of the fourth insulating layer 45, the side surface 105, the surface of the flexible substrate 2 and the side wall 303 of the opening window 301. The electromagnetic shielding layer 4 and the inner conductive circuit layer 23 are electrically insulated from each other through the second insulating layer 25 on the side of the inner conductive circuit layer 23, and the electromagnetic shielding layer 4 and the inner conductive circuit layer 23 are electrically insulated from each other. The outer conductive circuit layers 37 are electrically insulated from each other by the fourth insulating layer 35 on the side of the outer conductive circuit layer 23. The electromagnetic shielding layer 4 and the fourth insulating layer 45 expose the conductive pad 371 and the ground metal pad 372, and connect the conductive pad 371 with the integrated circuit element 5 (50) and the passive component 52 to make the ground metal The pad 372 can be grounded to achieve grounding of the optical device.

The electromagnetic shielding layer 4 can be formed on the surface and side surfaces of the circuit board body 1 in the following two ways. The first method is: Chemical Vapor Deposition (CVD) or sputtering in the semiconductor process; the second method is electro-deposition. That is, any material that can be formed on the circuit board body 1 by the above-mentioned two methods and can realize a signal mask can be used for this. In a preferred embodiment, the material of the electromagnetic shielding layer 4 may be indium tin oxide, and the thickness may be 2 nm to 100 nm. Preferably, the thickness of the electromagnetic shielding layer 4 is 100 um. This is because when the thickness is 100um, the conductivity is 1.6 × 10-4 s / m, which has a good conductive effect.

Please refer to FIG. 4 and FIG. 5. FIG. 4 and FIG. 5 are cross-sectional views of the optical device 200 assembled by using the circuit board 100 provided in FIG. 1. The optical device 200 is a camera module. The optical device 200 includes the circuit board 1, an integrated circuit element 5 electrically connected to the circuit board 1, a support frame 19 provided on the circuit board 1, and a voice coil motor (lens) Base) 6, a lens module 7 housed in the voice coil motor 6. A filter glass 73 is provided in the support frame 19. The lens module 7 includes at least one lens 71. The integrated circuit element 5 is an image sensor. The integrated circuit element 5 is disposed in the electrical connection area 370 on the circuit board 1 and is electrically connected to the conductive pad 371 on the circuit board 100 through a surface mount technology (SMT). The image sensor 5 may be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS), and is used to convert an optical signal into an electrical signal. A passive element 107 is further provided on the circuit board 100 and around the integrated circuit element 5.

Since the circuit board 100 includes the circuit board body 1 and the electromagnetic shielding layer 4 formed on the upper surface, the lower surface, and the side surface of the circuit board body 1, the area of the electromagnetic shielding layer 4 is increased compared to the prior art. In this way, it is possible to prevent external signals from generating signal interference to the optical device 100 from the side of the circuit board 100, and since the electromagnetic shielding layer 4 is formed on the surface of the circuit board body 1 by a semiconductor process or electrodeposition, so The thickness of the electromagnetic shielding layer 4 can be controlled; and the electromagnetic shielding layer 4 can also be used for heat dissipation, so that the heat generated by the electronic components on the circuit board can be timely radiated to the outside.

Please refer to FIG. 6 and FIG. 7. FIG. 6 and FIG. 7 are cross-sectional views of still another optical device 300 formed by using the circuit board 100 provided in FIG. 1. The optical device 300 is an optical projection module. The optical device 300 includes the circuit board 100, an integrated circuit element 50 electrically connected to the circuit board 100, a lens mount 60 provided on the circuit board 100, and a lens mount 60 housed therein. The lens module 7 and the diffractive optical element 8 are arranged in the light emitting direction of the lens module 7. In this embodiment, the integrated circuit element 50 is a vertical cavity surface emitting laser (VCSEL). The integrated circuit element 50 is used to emit a light beam; the lens module 7 is used to receive and collimate the light beam; the diffractive optical element 8 is used to expand the beam to form a fixed beam pattern and Fire outward.

It can be understood that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. For those skilled in the art, various other corresponding changes and modifications made according to the technical concept of the present invention fall within the protection scope of the claims of the present invention.

100‧‧‧Circuit Board

1‧‧‧Circuit board body

2‧‧‧ flexible substrate

3‧‧‧ rigid substrate

4‧‧‧ electromagnetic shielding layer

5, 50‧‧‧ Integrated circuit components

19‧‧‧ bearing frame

21‧‧‧The first insulation layer

23‧‧‧Inner conductive circuit layer

25‧‧‧Second insulation layer

31‧‧‧ cover film

33‧‧‧ core board

35‧‧‧Third insulation layer

37‧‧‧ Outer conductive circuit layer

39‧‧‧Plating

101‧‧‧ top surface

103‧‧‧ lower surface

105‧‧‧ side surface

200, 300‧‧‧ optical devices

6‧‧‧Voice coil motor

60‧‧‧ lens mount

7‧‧‧ lens module

71‧‧‧Lens

73‧‧‧ Filter Glass

8‧‧‧ Diffractive Optical Element

107‧‧‧Passive components

370‧‧‧ Electrical connection area

371‧‧‧Conductive pad

372‧‧‧ ground metal pad

110‧‧‧ conductive hole

301‧‧‧open window

303‧‧‧ sidewall

FIG. 1 is a structural diagram of a circuit board provided by the present invention.

FIG. 2 is a cross-sectional view of a circuit board provided by the present invention.

FIG. 3 is a bottom view of the circuit board shown in FIG. 1.

4 is a cross-sectional view of an optical device including the circuit board shown in FIG. 1.

FIG. 5 is an exploded view of the optical device provided in FIG. 4.

FIG. 6 is a cross-sectional view of still another optical device including the circuit board shown in FIG. 1.

FIG. 7 is an exploded view of the optical device provided in FIG. 6.

Claims (10)

A circuit board includes a circuit board body and an electromagnetic shielding layer. The circuit board body includes a conductive circuit layer and an insulating layer covering the conductive circuit. The circuit board body includes an upper surface, a lower surface, and a vertical connection. Side surfaces of the upper surface and the lower surface, the upper surface includes at least one electrical connection region, at least one of the electrical connection regions is provided with a plurality of conductive pads, and the electromagnetic shielding layer is formed on the upper surface and the lower surface The conductive pad is exposed on the surface and side surfaces, and the electromagnetic shielding layer is electrically insulated from the conductive circuit layer through the insulating layer. The circuit board according to claim 1, wherein the circuit board body includes a flexible substrate and a rigid substrate disposed on two surfaces opposite to the flexible substrate. The rigid substrate includes a window, and the window is exposed. In part of the flexible substrate, the electromagnetic shielding layer is further formed on the exposed surface of the flexible substrate and a side wall of the window. The circuit board according to claim 1, wherein the electromagnetic shielding layer is indium tin oxide, and the thickness of the electromagnetic shielding layer is 2 nm to 100 nm. The circuit board according to claim 2, wherein the flexible substrate includes a first insulating layer and an inner conductive circuit layer formed on two surfaces opposite to the first insulating layer. An edge is spaced from an edge of the first insulating layer to expose a part of the first insulating layer, a second insulating layer is provided between the rigid substrate and the flexible substrate, and the second insulating layer is formed on the A surface of the inner-layer conductive circuit layer and a surface of the first insulation layer exposed by the inner-layer conductive circuit layer cover the inner-layer conductive circuit layer. The circuit board according to claim 4, wherein the rigid substrate includes a third insulating layer and an outer conductive circuit formed on the third insulating layer, and an edge of the outer conductive circuit layer is insulated from the third insulation. The edges of the layers are spaced apart to expose a portion of the third insulating layer, and the circuit board further includes a fourth insulating layer formed on two opposite surfaces of the circuit board body, and the fourth insulating layer is formed on the outer layer A surface of the conductive circuit layer and a surface of the third insulating layer exposed by the outer conductive circuit layer are used to cover the outer conductive circuit layer, and the fourth insulating layer exposes the conductive pad. The circuit board according to claim 5, wherein the second insulating layer is a prepreg, and the fourth insulating layer is a solder resist green paint. The circuit board according to claim 5, wherein conductive holes are provided between the inner conductive lines, between the inner conductive lines and the outer conductive lines, and between the outer conductive lines, respectively. Intermediate, inner conductive lines and outer conductive lines and between outer conductive lines are conducted through the conductive holes. The circuit board according to claim 7, wherein the lower surface of the circuit board includes a plurality of ground metal pads, and the fourth insulating layer and the electromagnetic shielding layer expose the ground metal pads. An optical device includes a circuit board, an integrated circuit element electrically connected to the circuit board, a lens mount provided on the circuit board, and a lens module housed in the lens mount. The circuit board is the circuit board according to any one of claims 1 to 8, and the integrated circuit element is disposed in the electrical connection area and is electrically connected to the conductive pad. The optical device according to claim 9, wherein the integrated circuit element is an image sensor or a vertical cavity surface laser emitter chip.