JP4507359B2 - Optical / electrical wiring board, its connection structure and its connection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical / electrical wiring board capable of carrying an optical signal and an electric signal, and a connection method thereof.
[0002]
[Prior art]
In order to make a computer that can perform arithmetic processing faster, the clock frequency of the CPU tends to increase more and more, and now the one of the order of 1 GHz has appeared. As a result, there is a part where high-frequency current flows in the copper electrical wiring on the printed circuit board in the computer, so that malfunctions may occur due to the generation of noise, and electromagnetic waves may be generated, adversely affecting the surroundings. It will also be.
[0003]
In order to solve such problems, a part of the copper electrical wiring on the printed board is replaced with an optical wiring, and an optical signal is used instead of the electrical signal. This is because the generation of noise and electromagnetic waves can be suppressed in the case of optical signals.
[0004]
Initially, optical fibers were used as optical wiring. Since the technology of optical fibers is almost established as an optical communication system, it is relatively easy to divert. However, as the number of wirings increases, connection with optical fibers is not easy, and wiring with optical waveguides has been studied. As an optical waveguide, a quartz system was initially used as in the case of an optical fiber. However, a polymer system has been studied because it is easy to manufacture and can easily cope with an increase in area. .
[0005]
On the other hand, in an electrical wiring board, a connector capable of connecting multiple terminals by simply inserting the board is used. The electrode of the connector is devised so that the contact is reliably performed by a fixing mechanism using elasticity. A large circuit can be mounted very compactly by inserting a plurality of second electric wiring boards called daughter boards into connectors mounted on a first electric wiring board called a mother board.
[0006]
By the way, in the optical / electrical wiring substrate, an attempt as shown in FIG. In the drawing, the lower substrate is a first optical / electrical wiring substrate. On the first optical / electrical wiring board, an electric wiring board 1 and an optical wiring layer 2 are laminated, and an optical wiring (core) is embedded in the optical wiring layer. A mirror 41 is formed at the end of the optical wiring to convert the optical signal carrying direction by 90 °. A connector 5 having a fixing function 53 is provided on the surface of the first optical / electrical wiring board, and a second optical / electrical wiring board extending in the vertical direction is fitted therein. As a result, the optical wiring layer 4 (the mirror 41) of the first optical / electrical wiring board and the optical wiring layer 4 of the second optical / electrical wiring board are optically connected. The electrical connection between the electrical wiring 3 of the first optical / electrical wiring board and the electrical wiring 3 of the second optical / electrical wiring board is performed by an electrical cable 33.
[0007]
However, in the above example, the surface of the first optical / electrical wiring board and the optical wiring layer 2 at the end of the second optical / electrical wiring board have dents due to pressure or irregularities due to damage, and the optical axis is There is a problem that it is difficult to make a good optical connection due to a shift or a loss due to damage. In addition, it is necessary to perform electrical connection using a separate cable, and there is a problem that it takes time to assemble.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of the state of the related art, and when one or more second optical / electrical wiring boards (daughter boards) are connected to the first optical / electrical wiring board (motherboard), It is an object to improve connection reliability. Another object is to facilitate optical connection and electrical connection.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, first, the invention described in claim 1 is an optical / electrical wiring board having at least an optical wiring layer and an electric wiring, wherein the electric wiring of the first electric wiring board is formed. A first substrate having optical wiring laminated on the surface, a connector formed on a surface of the first substrate on the side where optical wiring is laminated, and a connector for fitting with the second optical / electrical wiring substrate; A first optical joint optically connected to a second optical / electrical wiring board provided on the inner first substrate surface, and formed on the first substrate surface inside the connector and / or the inner surface of the connector A first abutting portion made of a metal, and a fixing mechanism for fixing the second optical / electrical wiring substrate fitted on the optical / electrical wiring substrate by applying stress to the abutting portion. This is an optical / electrical wiring board.
The invention according to claim 2 is the optical / electrical wiring board according to claim 1, wherein the first abutting portion is electrically connected to the electric wiring.
According to a third aspect of the present invention, in the optical / electrical wiring board connection structure in which the second optical / electrical wiring board is connected to the first optical / electrical wiring board, the first optical / electrical wiring board comprises: Item 2. The optical / electrical wiring board according to Item 1, wherein the second optical / electrical wiring board includes a second substrate obtained by stacking optical wirings on a surface of the second electric wiring board on which the electric wirings are formed , A second optical joint provided at a position optically connectable to the first optical joint when the second optical / electrical wiring board is fitted to the connector, and the surface of the second substrate. An optical / electrical wiring board connection structure comprising: a position to which stress is applied by a fixing mechanism; and / or a second abutting portion provided on a second optical joint forming surface.
According to a fourth aspect of the present invention, the first abutting part is electrically connected to the electrical wiring of the first optical / electrical wiring board, and the second optical / electrical wiring board includes the first abutting part and the first abutting part. 4. The optical / electrical wiring board connection structure according to claim 3, wherein a connection electrode for electrical connection is provided.
According to a fifth aspect of the present invention, the first optical / electrical wiring board and the second optical / electrical wiring board each have an optical wiring for alignment, respectively. -Connection structure of electrical wiring board.
According to a sixth aspect of the present invention, in the optical / electrical wiring board connection structure according to the fifth aspect, the first optical / electrical wiring board and the first optical / electrical wiring board are connected to each other on the basis of an optical signal passing through each of the alignment optical wirings. The optical / electrical wiring board connection method is characterized in that the connection position of the optical / electrical wiring board is corrected.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0011]
Claims 1 to 4 are optical / electrical wiring boards for increasing the positional accuracy of the connection and reducing the connection loss of the optical wiring. Further, claim 1 is a first optical / electrical wiring board (see FIGS. 1 and 2) which is a so-called mother board, and claim 2 is a second optical / electrical wiring board which is a so-called daughter board (see FIGS. 4 to 5). ) And claims 5 to 6 are connection methods using them (see FIG. 7).
[0012]
In the present specification, the optical coupling portion means an exposed portion of the optical wiring (core) 4 or the mirror 41 of the optical wiring layer. The connection end is a side where the optical wiring is exposed.
[0013]
The first optical / electrical wiring board (see FIGS. 1 and 2) has at least an optical wiring layer 2 on the electric wiring board 1. On the surface of the first optical / electrical wiring board, a connector 5 to be fitted to the second optical / electrical wiring board is mounted. A mirror 41 is formed on the optical wiring (core) 4 below the connector. The mirror 41 is configured so that the light traveling from the plane direction of the optical / electrical wiring board is in the vertical (thickness) direction, or the light traveling from the thickness direction of the optical / electrical wiring board is in the planar direction, that is, The optical path is converted by about 90 °. The connector 5 is attached so that its inner side defines the position of the second optical / electrical wiring board (hereinafter referred to as a connector reference surface 51) and the positional relationship with the mirror 41 is precisely matched.
[0014]
In the present invention, the abutting portion 6 made of a rigid body such as metal is formed on the side surface inside the connector and / or the surface of the first optical / electrical wiring board. When stress is applied from the outside, most of the stress is applied to the abutting portion 6 and is not applied to the optical wiring layer 2. Further, the deformation of the abutting portion 6 is smaller than the deformation of the optical wiring layer 2 when the abutting portion 6 is not provided. Therefore, the positional deviation of the second optical / electrical wiring board can be reduced.
[0015]
The second optical / electrical wiring board (see FIGS. 4 to 5) also has at least an optical wiring layer 2 on the electric wiring board 1. The optical wiring (core) 4 of the optical wiring layer 2 is exposed from the connection end 7.
[0016]
In the present invention, the abutting portion 6 made of a rigid body such as metal is formed on the surface near the optical wiring (optical coupling portion) 4 and / or the connection end 7 of the second optical / electrical wiring board. When stress is applied from the outside, most of the stress is applied to the abutting portion 6. Further, the deformation of the abutting portion 6 is smaller than the deformation of the optical wiring layer 2 when the abutting portion 6 is not provided. Therefore, the positional deviation with respect to the first optical / electrical wiring board can be reduced.
[0017]
Further, the abutting portion 6 of the first optical / electrical wiring substrate and / or the second optical / electrical wiring substrate is connected to the electrical wiring substrate 1 through the via hole 61, and the abutting portion 6 is in contact with the abutting portion 6. If metal electrodes are also formed on the second optical / electrical wiring board and / or the first optical / electrical wiring board, optical connection and electrical connection can be performed simultaneously (see FIG. 7).
[0018]
Claims 5 to 6 are an optical / electrical wiring board and its connection method for further improving the positional accuracy of the connection and improving the reliability of the optical connection. That is, the optical connection line 42a, b (see FIGS. 8 to 11) is provided, and the optical connection of the optical connection is performed by performing precise alignment so that the amount of light passing through the alignment optical line 42a, b increases. Reliability can be greatly improved.
[0019]
The alignment optical wiring 42 is provided separately from the optical wiring 4 for signal transmission. The structure may be the same as or smaller than the optical wiring 4 for signal transmission (see FIGS. 8 to 9). The alignment optical wiring 42 may have a bend (see FIG. 10) or a mirror 41 (see FIG. 11).
[0020]
For precise alignment, a mechanical alignment mechanism 43 (see FIG. 12) using a micro screw or an electrical alignment mechanism 44 (see FIG. 13) using a piezo can be used while monitoring the amount of light. In particular, in the case of the electrical alignment mechanism 44, it can be performed not only when connecting, but also continuously during operation, and the reliability can be further improved. The optical path of the alignment optical wiring 42 only needs to pass through the connection portion one or more times, and various structures are possible, and the optical path is not limited to FIGS.
[0021]
The electrical wiring board may be a multilayer board or a single-layer board. The optical wiring layer 2 is provided with a metal pad 32 and a via hole 31, and the optical component 8, the electrical component 9, or a composite thereof can be mounted. The optical wiring 4 may have not only one-to-one wiring but also branching and multiplexing / demultiplexing functions.
[0022]
【Example】
[Simultaneous optical and electrical connection using a metal bumper]
As the mother board, an optical / electrical wiring board as shown in FIGS. The optical / electrical wiring board has a structure in which an optical wiring layer 2 is laminated on an electric wiring board 1.
[0023]
The optical wiring 4 in the surface optical wiring layer 2 is provided with a mirror 41 for optical path conversion. In the vicinity thereof, an abutting portion 6 made of metal is formed. The abutting portion 6 is connected to the electrical wiring substrate 1 through the via hole 61. The connector 5 is installed on the substrate. At this time, the positional relationship between the connector reference surface 51 and the mirror 41 is made constant by using an alignment mark or the like. The connector 5 is provided with a fixing mechanism 53 that presses the daughter board against the mother board and the connector reference surface 51. The connector reference surface 51 may be anything that is rigid as long as the purpose is optical connection only. However, since the electrical connection is performed at the same time, the connection electrode 52 is used.
[0024]
The manufacturing process will be described with reference to FIG. First, in order to produce an optical wiring layer, two layers of a clad 101 and a core 102 are formed on the temporary substrate 100 (a), a silicon-containing resist pattern is formed (b), and the core is processed by dry etching (c ), Removing the resist to form a clad (d). Next, a V-groove was formed with a dicing saw (e), metal was deposited to form a mirror 103 (f), and a layer made of the same material as the clad 104 was formed for protection (g).
[0025]
Subsequently, the optical wiring layer was peeled off (h) and attached to the separately prepared electric wiring substrate 105 (i). A hole is formed at a position to become a via hole with a laser (j), Cr and Cu are sputtered, a resist pattern is formed (k), a via hole and a pad are formed by plating 106 (l), the resist is peeled off, and soft etching is performed. The Cr / Cu thin film was removed (m). Finally, the connector 107 and optical parts and electrical parts were attached (n).
[0026]
As the daughter board, optical / electrical wiring boards as shown in FIGS. The optical / electrical wiring board has a structure in which an optical wiring layer 2 is laminated on an electric wiring board 1. The optical wiring 4 is formed substantially perpendicular to the connection end 7 of the daughter board. A metal abutting portion 6 is formed in the vicinity of the connection end 7. The metal abutting portion 6 is connected to the electric wiring board 1 through the via hole 61. In order to perform electrical connection simultaneously with optical connection, a connection electrode 71 was provided at the connection end 7 of the electrical wiring board.
[0027]
The manufacturing process will be described with reference to FIG. First, in order to produce an optical wiring layer, two layers of a clad 101 and a core 102 are formed on a temporary substrate 100 (a), a silicon-containing resist pattern is formed (b), and the core is processed by dry etching ( c) The resist was removed to form a clad (d). Next, a V-groove was formed with a dicing saw (e), metal was deposited to form a mirror 103 (f), and a layer made of the same material as the clad 104 was formed for protection (g).
[0028]
Subsequently, the optical wiring layer was peeled off (h) and attached to the separately prepared electric wiring substrate 105 (i). A laser is drilled at a position to be a via hole (j), Cr and Cu are sputtered to form a resist pattern (k), a via hole and a pad are formed by plating 106 (l), the resist is stripped and soft etched to form Cr / Cu thin film was removed (m). Finally, the back surface of the electric substrate was processed, the connection end was formed by cutting, and the optical component 108 and the electric component were attached (n).
[0029]
FIG. 7 shows a state in which these are connected. When the daughter board is inserted into the connector and the fixing function 53 is used, the daughter board is pressed against the connector reference surface 51 and the motherboard. This automatically aligns and completes the optical connection. In addition, at that time, the force is applied to the metal abutting portion 6 and the via hole 61, and is not applied to the optical wiring layer 2. Therefore, the optical wiring layer 2 is not deformed, and the change in optical connection with time is small. The abutting portion 6 comes into contact with the connection electrodes 52 and 71 formed on the connector reference surface 51 and the connection end 7 of the daughter board electrical wiring board, so that the electrical connection is completed at the same time.
[0030]
[Comparative example (conventional optical connection)]
FIG. 14 shows a connection state when there is no abutting portion. Since the pressed force is applied to the optical wiring layer 2, the deformation occurs, and the optical axis shift and the contact damage of the waveguide 4 occur. Therefore, it is impossible to maintain a good connection state. Further, since the electrical connection is performed by the electric cable 33, the wiring length is long.
[0031]
[Precise alignment using alignment optical wiring]
An optical / electrical wiring board having the alignment optical wiring 42 was produced (see FIGS. 8 to 11). The alignment optical wiring 42 has the same size as the normal optical wiring 4 for signal transmission. The production is also performed simultaneously with the normal optical wiring 4. The state where these are connected is shown in FIGS.
[0032]
In FIG. 12, the light emitted from the light emitting component 81 (laser diode, light emitting diode, etc.) on the mother board is once put into the optical wiring 42 of the daughter board through the alignment optical wiring 42a (including the mirror 41a), and then returned to the mother board. Light passing through the alignment optical wiring 42b (including the mirror 41b) is detected by the light receiving component 82 (photodiode or the like). Then, precise alignment is performed so that the amount of light increases.
[0033]
Alternatively, as shown in FIG. 13, the light emitting component 81 is placed on the daughter board, and the light emitted from the light emitting component 81 enters the motherboard through the alignment optical wirings 42 and 42a (including the mirror 41a) and is detected by the light receiving component 82. To do. Precise alignment was performed so that the amount of light increased.
[0034]
【The invention's effect】
As can be understood from the above description, the present invention has the following effects.
[0035]
First, by providing the abutting portion inside the connector or in the vicinity of the connection end, deformation of the optical / electrical wiring board can be prevented, optical axis deviation can be suppressed, and highly reliable optical wiring can be performed.
[0036]
Second, the assembly can be simplified by performing optical connection and electrical connection simultaneously.
[0037]
Third, by performing alignment with the amount of light passing through the alignment optical wiring, highly accurate alignment and alignment during use can be performed.
[0038]
Fourthly, it is possible to connect at a shorter distance than in the case where the electrical connection is made with another cable, and it is easy to obtain impedance matching.
[0039]
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an example of an optical / electrical wiring board (motherboard) according to the present invention.
2 is a cross-sectional view of the optical / electrical wiring board (motherboard) of FIG. 1;
FIG. 3 is an explanatory view showing an example of a manufacturing process of the optical / electrical wiring board (motherboard) of FIGS.
FIG. 4 is an explanatory view showing an example of an optical / electrical wiring board (daughter board) according to the present invention.
5 is a cross-sectional view of the optical / electrical wiring board (daughter board) of FIG. 4;
6 is an explanatory view showing an example of a manufacturing process of the optical / electrical wiring board (daughter board) of FIGS. 4 to 5; FIG.
FIG. 7 is a cross-sectional view showing an example of a method for connecting an optical / electrical wiring board according to the present invention.
FIG. 8 is an explanatory view showing another example of the optical / electrical wiring board (motherboard) of the present invention.
FIG. 9 is an explanatory view showing another example of the optical / electrical wiring board (motherboard) of the present invention.
FIG. 10 is an explanatory view showing another example of the optical / electrical wiring board (daughter board) of the present invention.
FIG. 11 is an explanatory view showing another example of the optical / electrical wiring board (daughter board) of the present invention.
FIG. 12 is an explanatory view showing another example of a method for connecting an optical / electrical wiring board according to the present invention.
FIG. 13 is an explanatory view showing another example of a method for connecting an optical / electrical wiring board according to the present invention.
FIG. 14 is a sectional view showing an example of a conventional method for connecting an optical / electrical wiring board.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electric wiring board 2 ... Optical wiring layer 3 ... Electric wiring 4 ... Optical wiring 5 ... Connector 6 ... Abutting part 7 ... Connection end 8 ... Optical component 9 ... Electrical component 31 ... Via hole 32 ... Pad 33 ... Electric cable 41 ... Mirror 41a ... Mirror 41b ... Mirror 42 ... Alignment optical wiring 42a ... Alignment optical wiring 42b ... Alignment optical wiring 43 ... Mechanical alignment mechanism 44 ... Electrical alignment mechanism 51 ... Connector reference plane 52 ... Connection Electrode 53 ... Fixing mechanism 61 ... Via hole 71 ... Connection electrode 81 ... Light emitting part 82 ... Light receiving part 100 ... Temporary substrate 101 ... Cladding 102 ... Core 103 ... Mirror 104 ... Cladding 105 ... Electric wiring board 106 ... Plating 107 ... Connector 108 ... Light parts

Claims (6)

An optical / electrical wiring board having at least an optical wiring layer and electrical wiring,
A first substrate in which optical wiring is stacked on a surface of the first electrical wiring substrate on which the electrical wiring is formed;
A connector for mating with the second optical / electrical wiring board formed on the surface of the first board on which the optical wiring is laminated;
A first optical joint that is optically connected to a second optical / electrical wiring board provided on the surface of the first board inside the connector;
A first abutting portion made of metal formed on the first substrate surface inside the connector and / or the inner surface of the connector;
A fixing mechanism for fixing the second optical / electrical wiring board fitted on the optical / electrical wiring board by applying stress to the abutting portion;
An optical / electrical wiring board comprising:   The optical / electrical wiring board according to claim 1, wherein the first abutting portion is electrically connected to the electric wiring. In the optical / electrical wiring board connection structure for connecting the second optical / electrical wiring to the first optical / electrical wiring board,
The first optical / electrical wiring board is the optical / electrical wiring board according to claim 1,
The second optical / electrical wiring board
A second substrate in which optical wiring is laminated on the surface of the second electrical wiring substrate on which the electrical wiring is formed ;
A second optical joint provided at a position optically connectable to the first optical joint when the second optical / electrical wiring board is fitted to the connector;
A position where stress is applied by the fixing mechanism on the surface of the second substrate, and / or a second abutting portion provided on the second optical joint forming surface,
An optical / electrical wiring board connection structure characterized by comprising:   The first abutting portion is electrically connected to the electrical wiring of the first optical / electrical wiring substrate, and the second optical / electrical wiring substrate is provided with a connection electrode that is electrically connected to the first abutting portion. The connection structure for an optical / electrical wiring board according to claim 3.   5. The optical / electrical wiring board connection structure according to claim 3, wherein the first optical / electrical wiring board and the second optical / electrical wiring board each have an alignment optical wiring. 6.   6. The optical / electrical wiring board connection structure according to claim 5, wherein the first optical / electrical wiring board and the second optical / electrical wiring board are connected based on an optical signal passing through each of the alignment optical wirings. A method of connecting an optical / electrical wiring board, wherein the position is corrected.

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