Semiconductor module

Abstract

The semiconductor module includes: a substrate; the plurality of semiconductor elements are positioned on the substrate; and a control IC that is positioned on the substrate and that controls the plurality of semiconductor elements. Furthermore, each of the plurality of semiconductor elements has a light-emitting element, and in the control IC, an initial value of a different drive current value is set in advance for each light-emitting element.

Description

Technical Field

[0001] Embodiments of the present invention relate to a semiconductor module. Background Art

[0002] Conventionally, there is a known semiconductor module in which a semiconductor element (hereinafter also referred to as an optical element) that converts an electrical signal into an optical signal is mounted on a substrate. In this semiconductor module, an optical fiber cable that transmits the converted optical signal from the optical element to the outside is sometimes connected (see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent document 1: Japanese Patent Application Publication No. 2020-9824. Summary of the invention

[0006] The semiconductor module of the present invention comprises: a substrate; a plurality of semiconductor elements, the plurality of semiconductor elements being located on the substrate; and a control IC, the control IC being located on the substrate and controlling the plurality of semiconductor elements. In addition, the plurality of semiconductor elements each have a light emitting element, and in the control IC, a different initial value of a driving current value is pre-set for each of the light emitting elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a perspective view of the semiconductor module according to the embodiment as viewed obliquely from above.

[0008] Figure 2 This is a perspective view of the semiconductor module according to the embodiment as viewed diagonally from below.

[0009] Figure 3 It is a top view of the semiconductor module according to the embodiment.

[0010] Figure 4 This is a functional block diagram of a semiconductor module according to an embodiment.

[0011] Figure 5 It is a diagram for explaining the light-emitting operation of the semiconductor module in the reference example.

[0012] Figure 6 This is a diagram showing an example of the light emission amount of each optical element in the reference example.

[0013] Figure 7 It is a diagram for explaining the light emitting operation of the semiconductor module according to the embodiment.

[0014] Figure 8 This is a diagram showing an example of the light emission amount of each optical element according to the embodiment.

[0015] Fig. 9 It is a top view of the semiconductor module according to the embodiment.

[0016] Fig.10 It is a top view of the semiconductor module according to the embodiment. DETAILED DESCRIPTION

[0017] Hereinafter, the embodiments of the semiconductor module disclosed in the present application will be described with reference to the accompanying drawings. In addition, the present invention is not limited to the embodiments shown below. In addition, the various embodiments can be appropriately combined within the scope that does not cause inconsistency in the processing contents. In addition, in the following embodiments, the same reference numerals are marked on the same parts, and repeated descriptions are omitted.

[0018] In the embodiments described below, expressions such as "constant", "orthogonal", "perpendicular" or "parallel" are sometimes used, but these expressions do not need to be strictly "constant", "orthogonal", "perpendicular" or "parallel". That is, the above expressions allow for deviations such as manufacturing accuracy and setting accuracy.

[0019] In order to facilitate understanding of the description, in the drawings referred to below, an orthogonal coordinate system is sometimes shown which defines mutually orthogonal X-axis, Y-axis, and Z-axis directions and sets the positive Z-axis direction as the vertically upward direction.

[0020] Conventionally, there is known a semiconductor module in which a semiconductor element (hereinafter also referred to as an optical element) that converts an electrical signal into an optical signal is mounted on a substrate. The semiconductor module is sometimes connected to an optical fiber cable that transmits the converted optical signal from the optical element to the outside.

[0021] However, in the above-mentioned prior art, when a plurality of optical elements are mounted on a semiconductor module, the light emission of each optical element may vary, thereby causing the amplitude and median value of the optical signal output from the semiconductor module to vary, and thus the signal quality of the optical signal may be reduced.

[0022] Therefore, it is desired to realize a technology that can overcome the above-mentioned problems and improve the signal quality of an optical signal output from a semiconductor module.

[0023] <Structure of semiconductor module>

[0024] First, refer to Figure 1 to Figure 3 The structure of the semiconductor module 1 according to the embodiment will be described. Figure 1 This is a perspective view of the semiconductor module 1 according to the embodiment as viewed from obliquely above. Figure 2 This is a perspective view of the semiconductor module 1 according to the embodiment as viewed diagonally from below.

[0025] In each of the following embodiments, the semiconductor module 1 is described as an optical module in which the optical element 3 is mounted on a substrate. However, the semiconductor module of the present invention is not necessarily an optical module.

[0026] like Figure 1 and Figure 2 As shown, the semiconductor module 1 of the embodiment includes a substrate 2, a plurality of optical elements 3 (optical elements 3a to 3d), and a heat dissipation member 4. The optical element 3 is an example of a semiconductor element.

[0027] The substrate 2 has a rectangular plate shape when viewed from above. In addition to the plurality of optical elements 3a to 3d and the heat dissipation member 4, a power supply IC (Integrated Circuit) 5, a control IC 6, and a plurality of passive components 7 (see FIG. 1 ) are arranged on the first surface 21 (the upper surface in this case) of the substrate 2. Figure 3 ) etc. The passive component 7 is, for example, a resistor, a capacitor, a coil, etc.

[0028] A connector 25 is disposed on the second surface 22 (here, the lower surface) of the substrate 2. The substrate 2 is electrically connected to the main board via the connector 25.

[0029] The optical element 3 is a semiconductor element that converts an electrical signal into an optical signal. In addition, the optical element 3 can also convert an optical signal into an electrical signal. An interface 31 is arranged on the upper surface of each optical element 3. The interface 31 is connected to the optical fiber 32 via a cable group 32A (see Figure 3 ) is connected to the optical connector 33.

[0030] The heat dissipation member 4 is a so-called heat sink, and is located above the plurality of optical elements 3. In addition, the heat dissipation member 4 does not necessarily have to cover the entire upper portion of the plurality of optical elements 3. Figure 1 As shown, the upper surfaces of the plurality of optical elements 3 may be partially exposed from the heat dissipation member 4 .

[0031] The heat dissipation member 4 is close to the plurality of optical elements 3, and releases the heat generated by the optical elements 3 to the outside of the semiconductor module 1. In addition, the heat dissipation member 4 may be in direct contact with the optical elements 3. Alternatively, the heat dissipation member 4 may be in contact with the optical elements 3 via a thermal interface material (TIM). That is, the heat dissipation member 4 may be thermally connected to the plurality of optical elements 3.

[0032] The heat dissipation member 4 may be formed of a metal having a high thermal conductivity, such as aluminum, copper, or iron. TIM is a composite material containing a thermally conductive filler in a resin.

[0033] The heat dissipation member 4 includes a plate-like portion 41, a plurality of legs 42, and a plurality of heat dissipators 45. The plate-like portion 41 is a plate-like portion that is disposed opposite to the first surface 21 of the substrate 2 at a distance. The plurality of legs 42 are provided on the plate-like portion 41. Specifically, the plurality of legs 42 extend from the plate-like portion 41 toward the substrate 2 and contact the substrate 2 (are mounted on the substrate 2).

[0034] The leg portions 42 are formed in a shape where the thickness of the plate-like portion 41 is partially thickened. The leg portions 42 may be integrated with the plate-like portion 41. The plurality of leg portions 42 may be connected to the plate-like portion 41 and the substrate 2. The plurality of leg portions 42 extend in a constant direction (here, the X-axis direction).

[0035] The plurality of heat sinks 45 are disposed on the surface of the plate-shaped portion 41 opposite to the surface facing the substrate 2. Figure 1 and Figure 2 , an example is shown in which the heat sink 45 has a pin shape (ie, a heat sink pin), but the heat sink 45 may also have a plate shape (ie, a heat sink).

[0036] Figure 3 FIG. 1 is a top view of a semiconductor module 1 according to an embodiment. Figure 3 In the figure, for ease of understanding, the heat dissipation member 4 is shown with a dotted line.

[0037] like Figure 3 As shown, when viewed along the extension direction (X-axis direction) of the optical fiber cable 32, the plurality of optical elements 3a to 3d are arranged in a direction (Y-axis direction) orthogonal to the extension direction. Specifically, the plurality of optical elements 3a to 3d are arranged in the order of optical element 3d, optical element 3c, optical element 3b, and optical element 3a in the positive direction of the Y-axis.

[0038] In addition, the plurality of optical elements 3a to 3d are arranged to be separated from each other. By adopting this structure, when the plurality of optical elements 3a to 3d are arranged on the substrate 2, thermal interference between the optical elements 3a to 3d can be reduced.

[0039] Specifically, if Figure 3 As shown, the positions of the optical element 3a among the plurality of optical elements 3a to 3d and the optical element 3b located at the position closest to the optical element 3a are offset from each other in the extension direction (X-axis direction) and the direction orthogonal to the extension direction (Y-axis direction) of the optical fiber cable 32. Similarly, the positions of the optical element 3d among the plurality of optical elements 3a to 3d and the optical element 3c located at the position closest to the optical element 3d are offset from each other in the X-axis direction and the Y-axis direction.

[0040] Thus, the plurality of optical elements 3 are arranged to be staggered. Thus, in the embodiment, the distance between adjacent optical elements 3 can be ensured, in other words, the thermal interference between adjacent optical elements 3 can be reduced, and the size of the substrate 2 can be reduced.

[0041] Here, an example is described in which two adjacent optical elements (for example, optical element 3a and optical element 3b) among the plurality of optical elements 3a to 3d are separated in the X-axis direction and the Y-axis direction. However, the present invention is not limited to this, and the positions of two adjacent semiconductor elements among all the plurality of optical elements 3a to 3d may be staggered in the extension direction (X-axis direction) of the optical fiber cable 32 and in the direction orthogonal to the extension direction (Y-axis direction).

[0042] For example, the plurality of optical elements 3a to 3d may be arranged in a staggered manner. This can also reduce thermal interference between the optical elements 3 and reduce the size of the substrate 2.

[0043] A blower (not shown) such as a cooling fan that blows air toward the semiconductor module 1 may be disposed on the negative side of the semiconductor module 1 in the X-axis direction. The blower generates wind W in the positive direction of the X-axis.

[0044] The wind W blown out from the blower hits the plurality of heat sinks 45 (see Figure 1 ), and flows along the first surface 21 of the substrate 2 by passing through the ventilation path 100 formed between the substrate 2 and the plate-like portion 41 of the heat dissipation member 4.

[0045] Then, in the embodiment, the wind W contacts the plurality of optical elements 3 located at the outlet side of the ventilation path 100 , so that the heat dissipation efficiency of the plurality of optical elements 3 can be further improved.

[0046] Furthermore, in the embodiment, since the plurality of optical elements 3 are arranged in a direction intersecting the flow direction of the wind W (here, the Y-axis direction), the wind W contacts all the optical elements 3 approximately equally. Therefore, according to the embodiment, the heat dissipation efficiency of the plurality of optical elements 3 can be further improved.

[0047] like Figure 3 As shown, the control IC 6 may be disposed below the heat dissipation member 4. In addition, the control IC 6 may be thermally connected to the heat dissipation member 4. Thus, the heat generated by the control IC 6 can be efficiently dissipated by the heat dissipation member 4.

[0048] For example, a plurality of power ICs 5 may be disposed on the substrate 2. Thus, it is possible to supply power to the optical element 3 at a plurality of reference voltages.

[0049] In addition, when looking down at the first surface 21, the power IC 5 may be located on the opposite side of the control IC 6 relative to the optical element 3. For example, the control IC 6 may be located on the negative side of the optical element 3 in the X-axis direction, and the power IC 5 may be located on the positive side of the optical element 3 in the X-axis direction.

[0050] This can reduce interference between various wirings (not shown) between the control IC 6 and the optical element 3 on the first surface 21 of the substrate 2 and the power IC 5. Therefore, according to the embodiment, the degree of freedom in wiring design can be ensured.

[0051] <Implementation Method>

[0052] Then, refer to Figures 4 to 10 The operation of the semiconductor module 1 according to the embodiment will be described in detail. Figure 4 1 is a functional block diagram of the semiconductor module 1 according to the embodiment.

[0053] like Figure 4 As shown, the semiconductor module 1 of the embodiment includes an optical element 3, a control IC 6, a connector 25, and an optical fiber cable 32. The optical element 3 also includes an LD (laser diode) 34, a driver 35, and a modulated optical circuit 36. The LD 34 is an example of a light emitting element.

[0054] The control IC 6 sets the driving current value of the LD 34 of the optical element 3 based on the preset initial value of the driving current value. The LD 34 emits light by the driving current of the set driving current value. The continuous light generated by the LD 34 is transmitted to the modulated light circuit 36.

[0055] Furthermore, a pulsed electric signal is inputted from an external FPGA (Field-Programmable Gate Array) 200 to the driver 35 of the optical element 3 via the connector 25. The pulsed electric signal has a characteristic that serves as a reference for the optical signal outputted from the optical element 3.

[0056] The driver 35 generates a drive signal for driving the modulated light circuit 36 ​​based on the electrical signal supplied from the FPGA 200, and supplies the drive signal to the modulated light circuit 36. In addition, the driver 35 controls the ON / OFF of the action, the modulation degree of the pulse, etc. according to the control signal supplied from the control IC 6.

[0057] The light modulating circuit 36 ​​modulates the continuous light supplied from the LD 34 based on the driving signal supplied from the driver 35 , and generates pulse light. The pulse light generated by the light modulating circuit 36 ​​is transmitted to the outside via the optical fiber cable 32 .

[0058] Figure 5 1 is a diagram for explaining the light emitting operation of the semiconductor module 1 in the reference example. Figure 5 As shown, in the semiconductor module 1, one control IC 6 controls all of the plurality of optical elements 3a to 3d.

[0059] In this reference example, the LD 34 (see Figure 4 ) are all equal in initial value (driving current value=A). That is, in the reference example, the initial values ​​of the driving current values ​​in the plurality of LDs 34 that are preset in the control IC 6 are all equal in initial value.

[0060] On the other hand, even if the initial values ​​of the driving current values ​​are all equal, the light emission of each optical element 3a~3d is not necessarily the same. This is because even if the driving current value of LD34 is consistent, other elements in each optical element 3a~3d are not completely consistent, so the light emission is not necessarily the same.

[0061] That is, Figure 6 As shown, the light emission amount B1 of the optical element 3a, the light emission amount B2 of the optical element 3b, the light emission amount B3 of the optical element 3c, and the light emission amount B4 of the optical element 3d may vary. Figure 6 This is a diagram showing an example of the light emission amount of each of the optical elements 3 a to 3 d in the reference example.

[0062] Therefore, in the reference example, since the plurality of optical connectors 33 (refer to Figure 1 ) will produce deviations in the amplitude and central value of the optical signals outputted from the semiconductor module 1, and therefore, the signal quality of the optical signal outputted from the semiconductor module 1 may be reduced.

[0063] Therefore, in an embodiment, if Figure 7 As shown, the control IC6 can be used for each LD34 (refer to Figure 4 ) Different initial values ​​of the driving current values ​​are set (driving current values=A1 to A4). That is, in the embodiment, in the control IC 6, different initial values ​​of the driving current values ​​can be set in advance for each LD 34.

[0064] For example, in the control IC 6, a driving current value A (refer to Figure 5 ) as the initial value. Figure 8 As shown, the optical element 3 a emits light at a light emission amount B1 ′ which is larger than the light emission amount B1 of the optical element 3 a in the reference example.

[0065] In addition, in the control IC6, if Figure 7 As shown, for the LD34 of the optical element 3b, a driving current value A2 smaller than the driving current value A shown in the reference example is preset as an initial value. Figure 8As shown, the optical element 3b emits light at a light emission amount B2' which is smaller than the light emission amount B2 of the optical element 3b in the reference example.

[0066] In addition, in the control IC6, if Figure 7 As shown, for the LD34 of the optical element 3c, a driving current value A3 larger than the driving current value A shown in the reference example is preset as an initial value. Figure 8 As shown, the optical element 3 c emits light at a light emission amount B3 ′ which is larger than the light emission amount B3 of the optical element 3 c in the reference example.

[0067] In addition, in the control IC6, if Figure 7 As shown in FIG. 1 , for LD34 of the optical element 3d, a driving current value A4 smaller than the driving current value A shown in the reference example is set in advance as an initial value. Figure 8 As shown, the optical element 3d emits light at a light emission amount B4' which is smaller than the light emission amount B4 of the optical element 3d in the reference example.

[0068] Therefore, if Figure 8 As shown, the light emission amounts B1' to B4' of all the optical elements 3a to 3d mounted on the semiconductor module 1 can be made uniform. Therefore, according to the embodiment, the signal quality of the optical signal output from the semiconductor module 1 can be improved.

[0069] In addition, in the embodiment, the initial value of the driving current value in the plurality of LDs 34 can be set according to the light emission of each optical element 3a to 3d. For example, in the embodiment, the initial value of the driving current value in the plurality of LDs 34 can be set so that the light emission of the plurality of optical elements 3a to 3d is equal.

[0070] This can improve the signal quality of the optical signal output from the semiconductor module 1 .

[0071] In the embodiment, for example, after assembling the semiconductor module 1, the light emission of each optical element 3 when emitting light at the same drive current value is measured. Then, the initial value of the drive current value of the plurality of LDs 34 can be set based on the measured light emission of each optical element 3 so that the light emission of all optical elements 3 is equal. Thus, the initial value of the drive current value in the plurality of LDs 34 can be set so that the light emission of the plurality of optical elements 3a to 3d is equal.

[0072] In addition, in the embodiment, the initial values ​​of the drive current values ​​in the plurality of LDs 34 may be set by a method different from the above method. Fig. 9 and Fig.10 It is a plan view of the semiconductor module 1 according to the embodiment.

[0073] like Fig. 9As shown, in the embodiment, the wiring lengths of the wirings C1 to C4 disposed on the substrate 2 and connecting the connector 25 to the optical elements 3a to 3d, respectively, may be different from each other. Fig. 9 In the example, the wiring lengths of the wirings C2 and C3 connecting the connector 25 to the optical elements 3b and 3c, respectively, are longer than the wirings C1 and C4 connecting the connector 25 to the optical elements 3a and 3d, respectively.

[0074] Therefore, for the slave FPGA 200 (refer to Figure 4 ) The electrical signal input via the connector 25 may be attenuated more before reaching the optical elements 3b and 3c than before reaching the optical elements 3a and 3d. In this case, the light emission of the optical elements 3b and 3c may be smaller than that of the optical elements 3a and 3d.

[0075] Therefore, in the embodiment, the initial value of the driving current value in the LD34 of each optical element 3a to 3d can also be set according to the wiring length between the connector 25 and the optical element 3a to 3d. For example, in the embodiment, the initial value of the driving current value in the LD34 of each optical element 3a to 3d can be set to increase as the wiring length between the connector 25 and the optical element 3a to 3d becomes longer.

[0076] For example, in Fig. 9 In the example of FIG. 1 , the initial value of the driving current value in the LD34 of the optical elements 3 b and 3 c may be set to be larger than the initial value of the driving current value in the LD34 of the optical elements 3 a and 3 d .

[0077] Thus, since the light emission amounts of the plurality of optical elements 3a to 3d are equal, it is possible to improve the signal quality of the optical signal output from the semiconductor module 1. In addition, according to the embodiment, even if the lengths of the wirings C1 to C4 are not set to the same length, the light emission amounts of the plurality of optical elements 3a to 3d are equal, so the degree of freedom of wiring design can be ensured.

[0078] In addition, if Fig.10 As shown in FIG. 1 , in the embodiment, the lengths of the optical fiber cables 32 connected to the optical elements 3a to 3d may be different. Fig.10 In the example of FIG. 1 , the length L1 of the optical fiber cable 32 connected to the optical elements 3a and 3d is longer than the length L2 of the optical fiber cable 32 connected to the optical elements 3b and 3c.

[0079] Therefore, the optical signals transmitted from the optical elements 3a and 3d to the optical connector 33 via the optical fiber cable 32 may be attenuated more than the optical signals transmitted from the optical elements 3b and 3c to the optical connector 33 via the optical fiber cable 32 .

[0080] In this case, the amplitude and median value of the optical signal transmitted from the optical elements 3a and 3d to the optical connector 33 may be smaller than the amplitude and median value of the optical signal transmitted from the optical elements 3b and 3c to the optical connector 33.

[0081] Therefore, in the embodiment, the initial value of the driving current value in the LD34 of each optical element 3a to 3d can also be set according to the length of the optical fiber cable 32 connected to each optical element 3a to 3d. For example, in the embodiment, the initial value of the driving current value of the LD34 can be set to increase as the length of the optical fiber cable 32 connected to the optical element 3a to 3d becomes longer.

[0082] For example, in Fig.10 In the example of FIG. 1 , the initial value of the driving current value in the LD34 of the optical elements 3 a and 3 d may be set to be larger than the initial value of the driving current value in the LD34 of the optical elements 3 b and 3 c.

[0083] As a result, the amplitude and median value of the optical signals transmitted to all the optical connectors 33 are equalized, and therefore the signal quality of the optical signal output from the semiconductor module 1 can be improved.

[0084] In the embodiment, the control IC 6 may have a correction function for correcting the driving current value of the LD 34 in each of the light elements 3a to 3d based on the light emission amount of the light elements 3a to 3d. Furthermore, the control IC 6 may use a preset initial value of the driving current value (for example, the driving current values ​​A1 to A4 (see Figure 7 ) etc.) as the initial value of the correction function.

[0085] This is in accordance with the above, and the same driving current value A is used in all the optical elements 3a to 3d (see Figure 5 ) as the initial value of the correction function, the correction amount of the driving current value caused by the correction function can be reduced.

[0086] Therefore, according to the embodiment, since the structure of the correction circuit for realizing the correction function can be simplified, the manufacturing cost of the semiconductor module 1 can be reduced.

[0087] Furthermore, according to the embodiment, the configuration of the correction circuit for realizing the correction function can be simplified, and the correction function can be realized without causing the LD 34 to emit excessive light, so that the power consumption of the semiconductor module 1 can be reduced.

[0088] The above is a description of the embodiments of the present invention, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the main purpose of the present invention. For example, in the above embodiments, an example of using a laser diode as a light-emitting element mounted on the optical element 3 is shown, but the present invention is not limited to this example, and a light-emitting diode (LED: Light Emitting Diode) or the like can also be mounted as a light-emitting element.

[0089] Those skilled in the art can easily derive further effects, other modes. Therefore, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Therefore, various changes can be made without departing from the spirit or scope of the concept of the overall invention defined by the appended claims and their equivalents.

[0090] In addition, the present technology may also adopt the following structure.

[0091] (1) A semiconductor module, wherein:

[0092] The semiconductor module comprises:

[0093] substrate;

[0094] a plurality of semiconductor elements, wherein the plurality of semiconductor elements are located on the substrate; and

[0095] a control IC, which is located on the substrate and controls the plurality of semiconductor elements;

[0096] The plurality of semiconductor elements each have a light emitting element,

[0097] In the control IC, different initial values ​​of the driving current are preset for each of the light emitting elements.

[0098] (2) The semiconductor module according to (1), wherein:

[0099] An initial value of the driving current value of the light emitting element is set according to the light emission amount of the semiconductor element.

[0100] (3) The semiconductor module according to (2), wherein:

[0101] The initial value of the driving current value of the light emitting element is set so that the light emission amounts of the plurality of semiconductor elements are equal.

[0102] (4) The semiconductor module according to any one of (1) to (3), wherein:

[0103] The semiconductor module further includes a connector that receives an electrical signal from the outside that is a reference for the optical signal output from the light emitting element.

[0104] An initial value of the driving current value of the light emitting element is set according to a wiring length between the connector and the semiconductor element.

[0105] (5) The semiconductor module according to (4), wherein:

[0106] The initial value of the driving current of the light emitting element is set to increase as the wiring length increases.

[0107] (6) The semiconductor module according to any one of (1) to (5), wherein:

[0108] The semiconductor module further comprises a plurality of optical fiber cables, wherein the plurality of optical fiber cables are respectively connected to the plurality of semiconductor elements.

[0109] An initial value of the driving current value of the light emitting element is set according to the length of the optical fiber cable.

[0110] (7) The semiconductor module according to (6), wherein:

[0111] The initial value of the driving current value of the light emitting element is set to increase as the optical fiber cable becomes longer.

[0112] (8) The semiconductor module according to any one of (1) to (7), wherein:

[0113] The control IC has a correction function for correcting a driving current value of the light emitting element based on the light emission amount of the semiconductor element.

[0114] The control IC uses a preset initial value of the driving current value as an initial value of the correction function.

[0115] Description of reference numerals:

[0116] 1 Semiconductor module

[0117] 2 substrate

[0118] 25 Connectors

[0119] 3.3a~3d Optical element (an example of a semiconductor element)

[0120] 32 Fiber Optic Cable

[0121] 33 Optical connector

[0122] 34 LD (an example of a light emitting element)

[0123] 35 Driver

[0124] 36 Modulation optical circuit

[0125] 6. Control IC

Claims

1. A semiconductor module, wherein: The semiconductor module comprises: substrate; A plurality of semiconductor elements, wherein the plurality of semiconductor elements are located on the substrate; as well as a control IC, which is located on the substrate and controls the plurality of semiconductor elements; The plurality of semiconductor elements each have a light emitting element, In the control IC, different initial values ​​of the driving current are preset for each of the light emitting elements.

2. The semiconductor module according to claim 1, wherein: An initial value of the driving current value of the light emitting element is set according to the light emission amount of the semiconductor element.

3. The semiconductor module according to claim 2, wherein: The initial value of the driving current value of the light emitting element is set so that the light emission amounts of the plurality of semiconductor elements are equal.

4. The semiconductor module according to any one of claims 1 to 3, wherein: The semiconductor module further includes a connector that receives an electrical signal from the outside that is a reference for the optical signal output from the light emitting element. An initial value of a driving current value of the light emitting element is set according to a wiring length between the connector and the semiconductor element.

5. The semiconductor module according to claim 4, wherein: The initial value of the driving current of the light emitting element is set to increase as the wiring length increases.

6. The semiconductor module according to any one of claims 1 to 5, wherein: The semiconductor module further comprises a plurality of optical fiber cables, wherein the plurality of optical fiber cables are respectively connected to the plurality of semiconductor elements. An initial value of the driving current value of the light emitting element is set according to the length of the optical fiber cable.

7. The semiconductor module according to claim 6, wherein: The initial value of the driving current value of the light emitting element is set to increase as the optical fiber cable becomes longer.

8. The semiconductor module according to any one of claims 1 to 7, wherein: The control IC has a correction function for correcting a driving current value of the light emitting element based on the light emission amount of the semiconductor element. The control IC uses a preset initial value of the driving current value as an initial value of the correction function.

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