KR100487972B1 - Optical connection rods for passive alignment - Google Patents

Abstract

The present invention provides an optical connection block installed on a multilayer printed circuit board in which optical waveguides are stacked, and configured to transmit light emitted or incident from an active photoelectric device through the optical waveguide, wherein the optical connection block is formed on the printed circuit board. Adjustment of the reflecting surface of the optical connection block is performed by manual alignment by forming a step on the side which can be fixed.

Description

OPTICAL CONNECTION RODS FOR PASSIVE ALIGNMENT}

The present invention provides an optical connection block necessary for making an optical connection between an active optical-optic component and an optical waveguide installed in a multilayer printed circuit board on which waveguides are stacked. It is about.

In general, two important technologies are required to achieve optical connection between semiconductor chips in a printed circuit board. The first is a technique of stacking an optical waveguide layer using a process of a conventional printed circuit board, and the second is a process between an active photoelectric device mounted on a surface of a substrate to transmit and detect an optical signal and an optical waveguide stacked in the substrate. It is a technology to make optical connection by loss. In particular, in the latter case, the structure and installation of an optical connection block that delivers light emitted from an active photoelectric device installed on a printed circuit board to an optical waveguide stacked on the printed circuit board is very important. I'm racing.

In the latter case, various methods may be used. A mirror of a structure in which the optical waveguide or the optical fiber is inclined at an angle of 45 degrees to be inclined at the end of the optical waveguide to inject light emitted from the active photoelectric device mounted on the printed circuit board into the optical waveguide. There is a method of forming a surface (US Pat. No. 6,257,771 B1, US Pat. No. 6,389,202 B1).

In addition, a reflective system having a reflective surface is inserted into a groove formed in a printed circuit board, and an active photoelectric device is integrated thereon to fold light at right angles (US Patent 6,285,808 B1, US Patent 6,370,292 B1).

In addition, there is a structure that omits the process of bending the light by installing an active optoelectronic device in the groove to face the optical waveguide cross section of the active window for sending or receiving an optical signal [US Patent 6,396,968].

However, the optical waveguide or optical fiber stacked in the printed circuit board has a structure in which the end of the optical fiber is inclined at an inclination of 45 degrees in order to inject light emitted from the active photoelectric device [US Patent 6,257,771 B1, US Patent 6,389,202 B1], After the end of the optical waveguide is made to have a 45 degree inclination, it should be laminated together with a copper plate and an insulating layer. / cm ² ) makes it difficult to maintain the reflector angle. In addition, the position of the mirror surface in the laminated printed circuit board must be precisely maintained, and it is difficult to prevent the mirror surface position before the lamination from being shifted during the lamination process. In addition, a structure in which a reflection system having a reflecting surface is inserted between an active photoelectric element and an optical waveguide to bend the light at a right angle (US Pat. No. 6,285,808 B1, US Pat. No. 6,370,292 B1) is used in the reflection system to maintain high optical connection efficiency. The reflected light must be accurately incident on the optical waveguide, and there is no discussion of a method and structure for precisely controlling the position of the reflection system in the printed circuit board, particularly in the thickness direction (vertical direction).

On the other hand, the structure that omits the process of bending the light by installing the active optoelectronic device in the board to face the end of the optical waveguide and the active window for sending or receiving optical signals [US Patent 6,396,968], inserted into the printed circuit board There is a difficulty in the electrical connection between the active photoelectric device and the IC mounted on the substrate.

The present invention to solve the above problems is to provide an optical connection block configured to be manually aligned to enable height adjustment in a direction perpendicular to the reflective surface.

Another object of the present invention is to provide an optical connecting block configured to be able to exactly match the height of the reflective surface to the core portion of the optical waveguide stacked on the printed circuit board by manual alignment.

In order to solve the above object, the present invention is provided on a multilayer printed circuit board in which the optical waveguide is stacked in the optical connection block for transmitting the light emitted from or incident from the active photoelectric device through the optical waveguide, The optical connecting block is characterized in that adjustment of the reflective surface of the optical connecting block is performed by manual alignment by forming a step with a step that can be fixed on the printed circuit board on the side surface.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an optical photonic integrated circuit board 1 in which an optical waveguide layer 6 is stacked and an active photoelectric device 7 is integrated on a substrate, and an optical connection block is installed therebetween. It shows a structure in which an arc is transferred from an active photoelectric device to an optical waveguide. Referring to FIG. 1, the multilayer printed circuit board 1 having the optical waveguide layer 6 stacked thereon includes an electrical circuit board layers 4 and 5 including an insulating substrate 2 and a copper foil 3 having a conductor pattern formed thereon; It consists of the optical waveguide layer 6. An active photoelectric element 7 for transmitting or receiving an optical signal is mounted on a metal pad 11 on a substrate to transmit an optical signal in the direction of the substrate or to receive an optical signal from the direction of the substrate. The optical signal emitted from the transmitting optoelectronic device is transferred into the optical connection block 9 inserted into the via groove 8 formed on the printed circuit board and reflected by the mirror surface 10 formed on the inclined surface of the end of the optical connection block. It enters and guides the optical waveguide layer, and enters the receiving optoelectronic device through the via groove and the optical connection block formed on the other side. The mirror surface 10 is a film made of gold (Au) for the reflection of the optical signal. The via grooves 8 are filled with fillers having the same or similar refractive index as the optical waveguide layer 6 stacked with the optical connection block 9, which is intended to fix the optical connection block and increase the optical connection efficiency.

2 is a side of the optical connection block according to an embodiment of the present invention is a structure having a step (22) for adjusting the height of the reflective surface 24 on the inclined end surface of the optical fiber 21 made of silica or polymer . The optical fiber 21 is fixed to a substrate 23 made of a semiconductor material such as Si, GaAs, glass or polymer, and the step 22 serves to fix the height adjusting function and the optical fiber. Or glass or polymer material.

FIG. 3 is an AA cross-section of FIG. 2 depicting a side of an optical connection block in accordance with an embodiment of the present invention, wherein four silica or polymer optical fibers 31a, 31b, 31c, 31d are commonly used. The filler 32 is fixed at regular intervals. For convenience, four optical waveguides are shown, and the number of optical waveguides is not limited. The height adjustment step of 34 also functions to fix the optical fiber.

4 shows another structure of the A-A cross section of FIG. 2 in accordance with an example of the present invention. Cores 42a, 42b, 42c, 42d of silica or polymer optical fiber are surrounded by cladding 43a, 43b, 43c, 43d, and several strands of optical fiber are fixed by a filler 41 made of polymer material. The surface is contacted between the cladding and the structure of the core is kept constant. Step 44 for adjusting the height of the reflective surface may be made of the same material or different materials.

5 shows a structure of an optical connection block having a height adjustment staircase in a planar optical waveguide having a rectangular core shape according to an embodiment of the present invention. It is shown as four channels for convenience, and there is no limit to the number of channels, and the optical connection block having a rectangular cross section of the cores 51a, 51b, 51c, and 51d surrounded by the cladding 52 is shown, and the surface of the core may be circular. have. Reflecting surface 53 is formed on the inclined surface at one end to inject (57) or outgoing light from the upper end surface to the optical waveguide (56) or to emit light. The side has a structure of stepped shape 54 for the purpose of adjusting. The height of the optical connection block reflecting surface 53 is adjusted as the height 55 of the stairs, and the protruding steps may be in the same direction as the reflecting surfaces (54), may be opposite to each other (58), or the stairs It is a 59 structure on both sides. The optical connection block is made to have a desired step height, and then installed in a manual alignment method that is inserted and fixed in the groove of the substrate.

6 shows a triangular prism-shaped optical connection block structure according to an embodiment of the present invention. The cores 61a, 61b, 61c, 61d of the optical waveguide are surrounded by the cladding 62, and the cores are connected from the upper surface 61 to the side surface 63, with an inclined surface having a reflective surface 64 in the middle. . In this structure, the height of the mirror surface is controlled by the distance 65 between the top surface and the center of the lateral waveguide.

FIG. 7 shows a structure in which the stepless optical connecting block 72 is attached to the transparent film 71 substrate so that the height of the reflective surface 73 can be easily adjusted and installed according to an embodiment of the present invention.

FIG. 8 illustrates a printed circuit board structure 80 in which optical waveguides in which alignment marks are formed around via grooves for horizontal alignment of optical connection blocks according to an exemplary embodiment of the present invention are stacked. The optical waveguides 82a, 82b, 82c, and 82d are stacked on the printed circuit board 80, and the via grooves 83a and 83b are positioned at the positions where the active photoelectric elements are to be integrated. As before, only 4 channels are shown for convenience and the number of channels is not limited. Alignment in the horizontal direction requires alignment in both the x-axis direction and the z-axis direction. Alignment marks 85a, 85b, 85c, 85d are located next to the via holes on the substrate surface 81 to align and install the optical connection blocks in the x-axis direction, and alignment marks 84a, 84b for alignment in the z-axis direction. , 84c, 84d). For convenience, there is a height adjustment staircase described in FIG. 5 and the structure 90 is provided with an optical connection block 88 in which square cores 86a, 86b, 86c, and 86d are surrounded by the cladding 87.

Optical connection block structure capable of adjusting the height of the reflective surface in the vertical direction according to the present invention has the effect of matching the height of the reflective surface with the core of the optical waveguide by manual alignment.

1 is a partial cross-sectional perspective view showing a state in which an optical connection block is installed on a multilayer printed circuit board according to an embodiment of the present invention;

2 is a side view of an optical connection block according to an embodiment of the present invention;

3 shows a cross section A-A of FIG. 2 in accordance with an embodiment of the invention;

4 illustrates another structure of section A-A of FIG. 2 in accordance with an embodiment of the present invention;

5 is a diagram showing the structure of an optical connection block according to a second embodiment of the present invention;

6 is a diagram showing the structure of an optical connection block according to a third embodiment of the present invention;

7 illustrates the structure of an optical connection block according to a fourth embodiment of the present invention; And

8 illustrates alignment marks for alignment of optical connection blocks on a printed circuit board according to an embodiment of the present invention.

<Description of Major Symbols in Drawing>

1: printed circuit board with optical waveguides laminated 2: insulated substrate

3: copper foil 4, 5: electrical circuit board layer

6: optical waveguide layer 7: active photoelectric device

8: Via groove 9: Optical connection block

10: mirror surface 11: metal pad

21: optical fiber 22: step for height adjustment

23: substrate 24: reflective surface

31a, 31b, 31c, 31d: optical fiber 32: filler

33: substrate with v-groove 34: step

41: filling material

42a, 42b, 42c, 42d: fiber optic core

43a, 43b, 43c, 43d: fiber optic cladding 44: step

51a, 51b, 51c, 51d: polymer or silica optical fiber in optical connection block

52: filler for fixing the optical fiber 53: reflecting surface

54: step 55: height of step

56, 57: optical signal entering or exiting the optical connection block

58: step in the same direction as the reflecting surface 59: step on both sides

61a, 61b, 61c, 61d: square shaped core

62: Filler acting as cladding 63: Core in horizontal direction

64: reflective surface

65: height of the core in the optical connection block should coincide with the center of the optical waveguide layer laminated on the substrate

71: transparent film 72: stepless optical connection block

73: reflective surface

80: printed circuit board in which an optical waveguide with alignment marks is stacked

81: substrate surface

82a, 82b, 82c, 82d: optical waveguide array

83a, 83b: Via Home

84a, 84b, 84c, 84d: Alignment mark for aligning the z axis

85a, 85b, 85c, 85d: Alignment mark for aligning x axis

86a, 86b, 86c, 86d: cores in the optical connection block

87: cladding of optical connection block 88: optical connection block with stairs

90: printed circuit board with optical connection block

Claims (7)

In the optical connection block is installed on a multi-layer printed circuit board laminated with optical waveguides for transmitting the light emitted or incident from the active photoelectric device through the optical waveguide, The optical connecting block is formed on the side by step with a step (step) that can be fixed on the printed circuit board, the optical connection block characterized in that the adjustment of the reflective surface of the optical connecting block is performed by manual alignment . The method of claim 1, The optical connection block, A substrate composed of any one of a semiconductor material, glass, and a polymer; A plurality of V-grooves formed on the substrate surface at regular intervals; An optical fiber fixed by a predetermined filler on the V-groove of the substrate; And Optical connection block comprising a stepped step (step) formed of the same material as the substrate. The method of claim 2, And the inter-core spacing in the optical connection block is kept constant by the contact of the surfaces of the neighboring cladding interlayers. The method of claim 1, The optical connection block is a plurality of rectangular cores are inserted into the cladding having a predetermined block shape at equal intervals, the optical connection block, characterized in that forming a stepped step (step) on one or both sides. The method of claim 1, The optical connection block is formed in a triangular pillar shape, the optical connection block, characterized in that the core is vertically bent in the triangular pole, the reflection surface is formed in the bent portion. The method of claim 1, And the optical connecting block is fixed on a printed circuit board by attaching a transparent film having a larger area than at least the block to the upper part of the block including the core. The method of claim 1, And a predetermined alignment mark is formed around a mounting portion on the printed circuit board in order to horizontally align the optical connection block.