Header for electronic or optoelectronic components and method for manufacturing such a header

Abstract

To provide a transistor outline (TO) header for mounting an electronic or opto-electronic component providing a low insertion loss, and a process for manufacturing the header.SOLUTION: A header (1) for an electronic component comprises a base (3) and at least one pedestal (7a, 7b). The base (3) has at least one electrical feedthrough (5). The electrical feedthrough (5) comprises a feedthrough pin (6) extending through the base (3) and electrically insulated from the base (3). The at least one pedestal (7a, 7b) is connected to the base, and comprises a submount (9) connected to the pedestal (7a, 7b). The pedestal (7a, 7b) is joined to the base (3) via a pedestal material bond part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention generally relates to the packaging of electronic components. More particularly, the present invention relates to the design of headers, preferably transistor outline (TO) headers for attaching electronic or optoelectronic devices. The present invention is particularly suitable for laser diodes as electronic or optoelectronic devices. However, the present invention relates to the electronic packaging of any electronic component in which a submount for electrically connecting to a feedthrough pin is disposed and attached to a pedestal.

Background Art

[0002] For example, in some optoelectronic applications, it is necessary to accurately control the wavelength of the beam emitted by the laser chip. This is because the wavelength of the laser depends on temperature. Therefore, the temperature of the laser should be stabilized within a narrow temperature range. For this purpose, it is known to use a thermoelectric cooler (TEC) that may be included within a housing for a laser diode, such as a transistor outline (TO) package. The TEC may be used in conjunction with a directly modulated laser (DML) for medium distances. The DML offers the advantage of lower cost compared to the EML. However, many laser driver ICs drive the DML using differential signals. In this case, the header requires two RF signal lines. These two signal lines preferably have a characteristic impedance Z 0 = 25 ohms to avoid signal degradation due to reflections from sources other than the DML.

[0003] Furthermore, the TEC has a high-temperature side and a low-temperature side. The high-temperature side is connected to the header for heat dissipation. The DML is attached to the low-temperature side. The low-temperature side should be thermally insulated from the high-temperature side to prevent thermal feedback and self-heating effects. On the other hand, two RF lines must be connected to the DML. One well-known concept is to use two separate RF lines. Each RF line includes a small printed circuit board (pedestal submount or submount) for sending signals to the DML within the header. Each pedestal submount may be attached to a separate pedestal. Typically, the pedestal and the header's eyelet or base are formed as one part in a single stamping process.

[0004] However, the present invention is not limited to headers for packaging DML laser chips, but generally relates to the packaging of electronic components.

[0005] The header's eyelet or base includes a plurality of openings for accommodating pins for electrically connecting, for example, the submounts connected to each pedestal. That is, each pedestal corresponds to its respective opening.

[0006] The drawback of the prior art header is that the position of the pedestal relative to each opening is fixed. However, the pin position within the opening can be changed between a maximum position and a minimum position and cannot be accurately controlled. When the pin is at the maximum position, the distance between the pin and the pedestal is large. This enables the submount to be placed on the pedestal. However, as a drawback, when the distance between the pin and the submount is this large, as a result, high insertion loss occurs. However, the distance between the opening and the pedestal should not be minimized. This is because, as a result, when the pin is at the minimum position, the distance between the two for placing the submount between the pedestal and the pin becomes excessively small.

[0007] Therefore, there is a need for a header for an electronic or optoelectronic device with low insertion loss and a method for manufacturing such a header.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] An object of the present invention is to provide a header for mounting an electronic component or an optoelectronic component, particularly a TO header, which provides low insertion loss. A further aspect of the present invention relates to a method for manufacturing such a header.

MEANS FOR SOLVING THE PROBLEMS

[0009] The object of the present invention is achieved by the means of the independent claims. Preferred embodiments and further improvements of the present invention are described in the subject matter of the dependent claims, the specification and the drawings.

[0010] The present invention further relates to a header for an electronic component, particularly an optoelectronic component such as a laser chip. The header comprises a base having at least one feed-through. The feed-through comprises a feed-through pin (or simply a pin) extending through the base. The pin is electrically insulated from the base. Further, the header comprises at least one pedestal connected to the base. The pedestal comprises a submount connected to the pedestal. The pedestal is joined to the base via a material bond, for example via a brazed joint or using a conductive adhesive.

[0011] Several advantages are obtained with such a header.

[0012] First, the base of the header and at least one pedestal are formed as separate parts. This reduces the complexity of the base forming process and enables rapid and inexpensive production of the base of the header.

[0013] Furthermore, if the header base and the pedestal or pedestals are formed as separate parts, the header base can be further processed without damaging the pedestal. For example, a header base that already has at least one feed-through can be processed to have more precise feed-through impedance control. For example, due to capillary action, the surface of the sealing glass is not flat, which affects the impedance. By grinding the sealing glass to obtain a flat surface, a more reliable performance of the feed-through can be achieved. Preferably, the surface of the header base and the surface of the sealing glass can also be ground in the same process, whereby a flat glass surface at the same level as the surface of the header base is obtained, that is, the glass surface and the header base surface are in the same plane, and as a result, almost 100% control of the impedance along the length of the feed-through is obtained.

[0014] Furthermore, at least one pedestal is formed in a separate manufacturing process, for example, by stamping, metal drawing, or extrusion. This allows for the formation of at least one pedestal with special and even complex geometries, such as chamfered edges (or beveled edges) or rounded edges (harmonious edges), and / or back-tapers, and / or a pedestal profile with a complex shape. For example, since the pedestal and the base of the header are formed as separate parts, the use of a pedestal with a complex shape may be considered, as will be explained in more detail below.

[0015] The separate manufacture of the header base and the pedestal provides the further advantage that the header base and the pedestal, or if two or more pedestals are provided, the plurality of pedestals, can be different. For example, the header base may be made of a material selected to facilitate a glass-to-metal seal, and the pedestal may be made of a material having, for example, high thermal conductivity.

[0016] Furthermore, in a separate manufacturing process, the pedestal or pedestals can be of various types of shapes that provide several advantages. If there are two or more pedestals, all the pedestals can have the same shape; however, one header can also be provided with a plurality of pedestals of different shapes.

[0017] Furthermore, the pedestal and the base are joined by a separate joining process, which enables optimization or at least control of the distance between the submount and the pins. As a result, the offset between the submount surface and the pins can be set within a narrow range, reducing the insertion loss of the packaged electronic component, particularly an optoelectronic component. Preferably, the joining is performed via a material bond (pedestal material bond), so that the pedestal is fixedly attached to the base. Within the scope of the present invention, material bonding is understood to refer to a joining process between different materials or different parts by forming an adhesive bond between adjacent materials or adjacent parts. Such an adhesive bond between materials or different parts may be formed by using an adhesive and / or by at least partially melting the parts or materials to be joined. In this case, since the present invention relates to a header used in electronic packaging, adhesives used for metal bonding are particularly suitable. For example, adhesives suitable for forming conductive joints of conductive adhesives, such as nano-sintered silver and conductive adhesives, may be particularly suitable. In particular, according to the present disclosure, without being limited to the pedestal material bond, the material bond may be formed as a brazed joint, i.e., by joining metal parts using a brazing material. In that sense, brazing materials and solder may be understood as adhesives in the meaning of the present disclosure. In contrast to solder, brazing is usually performed at a higher temperature. Furthermore, brazing usually requires closely fitting parts to be joined, so that the molten braze can be drawn into the gap between the metal parts to be joined by capillary action. As a result, only a very small amount of excess brazing material may occur, and as a result, only small brazing bulges are formed. This further enables a very tight and sealed connection with a minimum offset between adjacent parts, i.e., between the base (or rather the surface of the base) and the submount (or rather the side or edge of the submount).

[0018] According to one embodiment, in order to provide good signal transmission of the electronic components of the header, the offset (pin offset) between the pin and the surface of the submount is at most 0.2 mm. According to a further embodiment, in order to avoid damage to the component side of the submount during assembly, the pin offset is at least 0.05 mm.

[0019] According to one embodiment, the submount is joined to the pedestal via another material joint (submount material joint). As described above, such a material joint provides several advantages such as a tight connection between adjacent components, preferably a tight connection with minimal offset between adjacent components. For example, the formation of the material joint by soldering the submount to the pedestal can be carried out either before or after fixedly attaching the pedestal to the base by forming another material joint, for example by soldering the pedestal to the base. In either way, a very tight and sealed connection between adjacent parts of the header is possible.

[0020] According to one embodiment, the offset (submount offset) between the submount edge and the surface of the base is at most 0.1 mm.

[0021] Thus, in a particularly preferred embodiment, the offset between the surface of the base and the submount edge may be zero.

[0022] In other words, the header according to the embodiment of the present invention enables an optimal offset, as a result of which the insertion loss of the electronic component is reduced, and thus a larger signal bandwidth is obtained.

[0023] In the context of the present application, the following definitions apply.

[0024] The term "electronic component" encompasses optoelectronic components. Suitable electronic components for electronic or particularly optoelectronic applications can be, but are not limited to, laser diodes (LDs) such as electro-absorption modulated laser diodes (EMLs), distributed feedback lasers (DFBs), Fabry-Perot lasers (FPs), optical modulators, photodiodes (PDs), and other electronic components used for optical communication.

[0025] In the scope of the present invention, the submount, which may also be referred to as a "pedestal submount", typically includes an insulating material as a support. Suitable insulating materials include, but are not limited to, ceramics such as alumina Al 2 O 3 or aluminum nitride AlN, or glass. The thickness of the submount is preferably 0.1 mm to 0.5 mm. The length of the submount may be adjusted, for example, to match the focal length of the lens that couples light from the DML to the glass fiber when the electronic component included in the header is a DML. In this case, a typical submount length may be 1.0 mm to 2.5 mm. Further, the length of the submount is usually 0.77 mm wide and may generally range from 0.5 mm to 1 mm. The surface of the submount facing the side opposite the pedestal ("upper surface") has a metal pattern applied thereto and is also described in the scope of this application as the "component side" or "component surface". Further, the side of the submount facing the pedestal is also described as the "support side" (or "support surface") or "mounting side / mounting surface".

[0026] The present invention will be further described below with reference to the accompanying drawings. In the drawings, like reference numerals indicate like or corresponding members. Further, all drawings related to the header and parts of the header are not drawn to scale but are schematic.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0028] FIG. 1 is a perspective view of a header 1 according to one embodiment.

[0029] As shown in FIG. 1, header 1 includes a base 3 having two or more electrical feed-throughs 5. The feed-throughs 5 function to transmit electrical signals inside and outside the header 1. Each feed-through 5 includes a feed-through pin 6 extending through the base 3 and is electrically insulated from the base. For this purpose, the base 3 includes an insulator, preferably an eyelet 8 filled with glass, in which the feed-through pin 6 is fixed internally. Two pedestals 7a, 7b are connected to the base 3 and protrude from the base 3. Generally, without being limited to the embodiment shown in FIG. 1, the header 1 includes at least one pedestal 7. However, for example, for a header with a laser chip, especially a DML, it may be preferable to provide a header 1 with at least two pedestals 7a, 7b. This is because, in many cases, the laser driver IC drives the DML using differential signals, that is, such a header 1 requires two signal lines or a single-ended signal with one transmission line and one return line. Without being limited to the specific example shown, in a preferred embodiment, these pedestals 7, 7a, 7b are arranged at a distance with a gap 12 therebetween. The gap 12 serves to accommodate an assembly for supporting further elements, especially electronic devices such as laser chips. A submount 9 is attached to each pedestal 7a, 7b. Further, an example of the bonding region 70 of the base 3 is illustrated. Generally, the bonding region is understood to refer to a component or part of a component that is intended or at least suitable for being bonded to further components or parts, at least in its subportion. For example, the surface of the component, that is, the base 3 of the header 1 as shown in FIG. 1, may be processed to enable or facilitate the bonding process. For example, it is known to coat or plate at least partially the surface of the component to be bonded with a metal such as nickel and / or gold. Nickel is known to improve, for example, the solderability of copper, but a thin layer of gold may be used to avoid oxidation of the nickel layer.In the case of the header as shown in FIG. 1, for example, at least in the bonding region 70 that can be joined to the additional component and the header base 3, the front surface 58 of the base 3 may be understood to be at least partially Au-plated (or gold-plated). Of course, generally, the entire surface 58 of the base 3 or the entire base 3 can also be gold-plated. Further, the base may be at least partially nickelized. In this case, in order to avoid oxidation of the nickel layer, the nickel layer is at least partially, preferably entirely, covered by a layer of gold.

[0030] At least one of the pedestals 7a, 7b, preferably both, or in the case where the header 1 has more than the pedestals 7a, 7b illustratively depicted, all the pedestals 7 of the header 1 are joined to the base 3 via a material joint 24 (not shown in FIG. 1). The material joint 24 formed between the pedestals 7, 7a, 7b and the base 3 may be referred to as a pedestal material joint.

[0031] Here, the material joint preferably refers to the joint (or bonding) between adjacent parts (or components), such as between the pedestal 7 and the base 3 or between the submount 9 and the pin 6, in a tight and sealed joint that allows for precise control of the offset between the adjacent parts, especially metal parts. This is achieved by soldering in a particularly preferred embodiment. That is, according to this preferred embodiment, the material joint 24 may be formed as a soldered joint or a solder bond. However, such a joint may also be formed using a conductive adhesive. For the purpose of illustration, here reference is made to a partial cross-sectional view of the header 1 according to one embodiment having a pedestal 7 including the base 3, the feed-through 5 including the pin 6, and the submount 9 including the submount component surface 95 (or upper surface or upper side surface) and the submount support surface 94 (or back surface or bottom surface of the component surface). Here, the submount 9 is electrically connected to the pin 6 via the solder joint 23. In the exemplary header as shown in FIG. 2, the pin 6 is at the center of the opening 8 of the feed-through 5. However, without being limited to the exemplary header shown in FIG. 2, generally, the position of the pin 6 in the opening 8 varies due to manufacturing tolerances. Therefore, the offset (or distance) d between the surface of the submount 9 and the pin 6 1 usually varies. If the position of the pedestal 7 is fixed within the base, as is the case with a prior art header formed by a standard stamping process, the eccentricity of the pin 6 within the opening 8, which results in the distance between the pin 6 and the upper surface of the submount or the submount component surface 95 becoming extremely large or extremely small, cannot be compensated for. However, if the pedestal 7 is joined to the base 3 in a separate bonding process via a material joint 27 (not shown), the offset d 1 (pin offset) can be set within a narrow range. The same applies to the offset d between the side surface or edge 93 of the submount 9 (not shown in this figure) and the base 3 2This also applies to the (submount offset). A bonding process, preferably a bonding process using an adhesive material, and particularly preferably a soldering process, is used to join the pedestal 7 and the base 3, which are parts that fit together (or match) in a sealed manner. Since the adhesive material, such as molten solder, is drawn into the very small gaps between these parts by capillary action, only a very small amount of excess bonding material or adhesive material, such as soldering material, may result. As a result, only small material bulges 25 (such as soldering bulges), as shown in FIG. 5, occur. This further enables a very tight and sealed connection with a minimum or at least tightly controlled offset between adjacent parts.

[0032] The graphs in FIG. 3 (relating to insertion loss) and FIG. 4 (relating to reflection loss) as examples show the data and technical advantages obtained from simulations for a given header design of an exemplary header according to an embodiment. For the calculation of insertion loss and reflection loss, all header designs were maintained, and only the offset values of the pins and the submounts were changed. For the submount offset d 2 it was changed between 0 mm and 0.1 mm, and for the pin offset d 1 it was changed between 0.05 mm and 0.2 mm. In both figures, a) shows the values obtained when the submount offset (d 2 ) is 0 mm and the pin offset (d 1 ) is 0.05 mm, b) shows the values obtained when d 2 = 0 mm and d 1 = 0.2 mm, c) shows the values obtained when d 2 = 0.1 mm and d 1 = 0.05 mm, and d) shows the values obtained when d 2 = 0.1 mm and d 1 = 0.2 mm.

[0033] The bandwidth of the signal is defined as the frequency value at an insertion loss of 1 dB. As can be seen from FIG. 3, the bandwidth may vary between 27 GHz in the case of d) with a high offset, and may exceed 50 GHz when the offset is small (or the offset is zero) as in the case of a). That is, for offsets larger than the offset used for the calculations in FIGS. 3 and 4 when the offset is large, the bandwidth may be cut in half or even made lower.

[0034] FIG. 4 shows the reflection loss. The reflection loss bandwidth is usually defined by a reflection loss of -15 dB, and a high reflection loss is preferred. The reflection loss bandwidth may vary in the range of 15 GHz to 30 GHz depending on the offset value for the header as an example considered here, and is higher (and thus preferred) for low offsets (in the case of a).

[0035] In order to achieve high signal transmission, the offset value must be precisely controlled.

[0036] According to one embodiment, the offset (submount offset, d) between the submount 9 and the surface 58 of the base 3 2 ) can be up to 0.1 mm, and in a particularly preferred embodiment, can even be 0 mm.

[0037] According to a further embodiment, the offset (pin offset, d) between the pin 6 and the component surface 95 of the submount 9 1 ) is at most 0.2 mm. However, from the perspective of the signal bandwidth, the minimum pin offset d 1While it is preferable, considering the submount attachment process, the minimum value of the pin offset is, according to a further preferred embodiment, at least 0.05 mm. Thereby, the pedestal 7 can be first joined to the base 3 by a first bonding process, for example a soldering process, and subsequently the submount 9 can be joined to the pedestal 7 by a further second bonding process, for example a soldering process, without the risk of damaging the submount 9, i.e. the metal pattern, i.e. the metal pattern formed on the component side 95 of the submount 9.

[0038] FIG. 5 shows a further partial cross-sectional view of the header 1 as an example according to one embodiment. In the example shown in FIG. 5, the pedestal 7 is joined to the base 3 (or the surface 58 of the base 3) via a material bonding portion 24 (for example, a soldering joint or a soldering bond) located between the surface 58 of the base 3 and the mounting surface 40 of the pedestal 7. Further, the submount 9 is joined to the pedestal 7 via a material bonding portion 27 (for example, a soldering joint or a soldering bond) located between the upper surface 42 of the pedestal 7 and the support surface 94 of the submount 9. Further, the side surface 93 of the submount 9 is shown. In this case, the upper surface 42 is related to the side of the pedestal facing the pins 6 and may also be referred to as the pin surface 42 of the pedestal 7, and the bottom or back surface of the submount 9 is understood to be what is called the support side or support surface 94 of the submount 9 (in contrast to the component side or component surface 95 of the submount 9). The pins 6 are electrically connected to the submount 9 via solder joints 23.

[0039] According to one embodiment, to facilitate bonding, such as soldering, the surface 58 of the base 3 and / or the mounting surface 40 of the pedestal 7 and / or the upper surface 42 of the pedestal 7 and / or the back surface (or support side) 94 of the submount 9 are at least partially Au-plated (or gold-plated) in their bonding regions. In the case of the base, the bonding region 70 is shown in FIG. 1. For ease of viewing, the bonding regions are not shown for the mounting surface 40, the upper surface 42, and the submount back surface (or support side) 95. Further, since there is a very small gap between the pedestal mounting surface 40 and the surface 58 of the base 3, a bonding material such as an adhesive or a soldering material is drawn into this gap by capillary action. Thereby, a so-called submount offset (or d in FIG. 3) 2 ) formed between the submount 9, or rather the submount side surface 93 and the base 3, can be controlled within a very tight range.

[0040] Within the scope of the present invention, the upper surface 42 of the pedestal 7 is understood to refer to the surface of the pedestal facing the pins, and thus, without being limited to the special embodiment of the header shown in FIG. 5, it may generally be described as the "pin surface" or "pin side" 42 of the pedestal 7.

[0041] In the embodiment shown in FIG. 5, the pedestal 7 has an edge 50, such as a chamfered edge or a blending edge, between the mounting surface 40 and the pin surface 42. Preferably, the angles formed between the edge 50 and the pin surface 42 and / or between the edge 50 and the mounting surface 40 are 100° to 160°. Such an embodiment is preferable for minimizing the submount offset d 2 and a small cavity 26 is formed, as in the case of the chamfered edge or the blending edge 50. In this case, an excess bonding material, such as an adhesive, or solder, or a soldering material can be filled into the cavity 26, and this cavity functions as a "reservoir" for the excess bonding material. In this case, furthermore, only a very small, almost zero excess bulge 25 of the bonding material is formed, whereby the submount offset d 2can be controlled. Such an embodiment can be highly advantageous as it further facilitates obtaining a minimum submount offset that is zero. Generally, it should be noted that, in contrast to the embodiment shown in FIG. 5 where the cavity 26 is completely filled, it is not necessary to completely fill the cavity 26 with excess bonding material. Rather, the minimum offset d 2can also be achieved by only a partially filled reservoir. According to a further embodiment, the pedestal may be formed in a different shape, for example, having a pedestal step, whereby a gap may be formed between the surface of the base 3 of the header and / or the surface of the sealing material 60, which is preferable when larger electronic components are to be arranged within the header. Further, the pedestal may be formed and / or fixed so as to at least partially protrude from the opening 8. According to yet another embodiment, alternatively or additionally, the base may have a step (base step) 38 that protrudes at least partially beyond the sealing material 60. Such special shapes of the pedestal 7 and / or the base 3 are also shown in FIG. 8. According to one embodiment, at least one of the material joints 24 and 27 has gold (Au) and germanium (Ge) and / or tin (Sn). Gold-tin solder is usually used as a soldering material for TO headers because it requires only a low melting temperature. However, according to the embodiments of the present application, at least two material joints, namely at least one pedestal material joint 24 and at least one submount material joint 27, are required. Since these two material joints, i.e., the soldering joints as described in the embodiments herein, are formed at different stages of the manufacturing process, the temperature of the first soldering process must be higher than the temperature of the second soldering process in order to prevent the separation of the joints of the first joint during the second soldering. Generally, without being limited to the embodiments described herein having at least two different soldering joints formed in two different process steps, when the material joint is formed at a high temperature, the temperature of the first bonding process must be higher than the temperature of the second bonding process. Thus, preferably, at least one of the material joints 24 and 27, i.e., the pedestal soldering joint and the submount soldering joint as described herein, may have a gold-germanium solder (or, Au-Ge solder).

[0042] Referring to the state diagram shown in FIG. 6, the advantages of using such soldering for at least one of the material joints 24, 27 formed as soldered joints will be described. FIG. 6 shows the binary state diagram of gold-germanium, with the left side of the figure corresponding to a germanium content of 0, i.e., pure gold. The gold-germanium binary system is a nearly ideal eutectic system, containing only a small amount of gold-rich solid solution formed for germanium contents of less than about 4 at%. The eutectic composition is a germanium content of 28 at%, corresponding to 12 wt% germanium (so-called AuGe12 soldering material or AuGe12 brazing material), and the eutectic temperature is about 361 °C. Soldering with a gold-tin material is effective at a temperature of about 280 °C (AuSn20 soldering material or brazing material), so AuGe12 can be used for the first soldering step and AuSn20 can be used for the second soldering step. This is because the temperature difference between these soldering materials, i.e., between the soldering processes, is high enough that the first soldering joint does not remelt during the second soldering process. Note in this case that a soldering step, for example, the first soldering step, can include soldering several components simultaneously. That is, if the soldering step includes soldering the pedestal 7 to the base 3, all the pedestals 7, 7a, 7b included in the header 1 can be soldered in this step, thereby simultaneously forming a plurality of pedestal material joints 24 between the pedestals 7, 7a, 7b and the surface 58 (or front surface) of the base 3. The same applies to soldering a submount or a plurality of submounts 9 to a pedestal or a plurality of pedestals 7, 7a, 7b, forming a plurality of submount material joints 27. In general, not limited to the examples of the material joints 24 and 27 which are soldered joints, the bonding step includes bonding a plurality of components simultaneously.

[0043] Thus, according to one embodiment, the header has a pedestal 7a and another pedestal 7b, in which case the pedestal 7a is connected to the base 3 and includes a submount 9 connected to the pedestal 7a. The pedestal 7a is joined to the base 3 via a first pedestal material bonding portion 24. In this case, the pedestal 7b is connected to the base 3 and includes a submount 9 connected to the pedestal 7b. The other pedestal 7b is joined to the base 3 via another pedestal material bonding portion 24. In this case, the pedestal material bonding portion 24 between the base 3 and the pedestal 7a and the other pedestal material bonding portion 24 between the base 3 and the pedestal 7b have the same bonding material. For example, in a particularly preferred embodiment, the material bonding portions 24 and 27 may be brazed joints, and the pedestal material bonding portion 24 has the same brazing material or solder material.

[0044] However, apart from the fact that two different bonding materials, for example two different solders, can be used for the first and second bonding steps (e.g., brazing steps), as described above, since AuGe12 is a eutectic composition, AuGe12 can also be used in both brazing steps if at least one of the surfaces to be joined has at least partially a gold plating (or a gold layer) in its bonding region. This is because during the melting process, the gold of the gold plating (or the gold layer) moves into the melt, thereby increasing the gold content of the melt. The resulting melt composition is shifted towards the gold-rich side of the phase diagram, as indicated by the arrow 140 in FIG. 6, resulting in an increase in the melting temperature. The exemplary melting temperature T m,h of an exemplary brazed joint composition c m,h is shown in FIG. 6. As can be seen for a virtual concentration c m,h with a Ge content of 20 wt%, the resulting corresponding melting temperature T m,his approximately 600°C and is thus well above the eutectic temperature of 361°C. However, it should be understood here that this virtual composition is merely an example and may differ from the composition of the actually obtained brazed joint. For the reasons above, since the melting temperature of the first brazed joint is higher than the eutectic temperature, according to a particular embodiment, an AuGe12 brazing material can also be used in the second brazing step.

[0045] The binary AuSn system is more complex than the AuGe system shown in FIG. 6, but this principle that the melting temperature increases by increasing the gold content of the melt also applies to AuSn brazing materials. Thus, when at least one of the surfaces of the components or parts to be joined is gold-plated, or when it has at least partially a gold plating or a gold layer in its bonding region, AuSn solder (or brazing alloy) can be used in both bonding steps.

[0046] Accordingly, according to one embodiment, the material joints 24 and 27 may both be brazed joints and may have Au and Ge and / or Sn. However, for the reasons described above, the compositions of the material joints 24 and 27 formed as brazed joints may be different, and the formed first brazed joint (or set of brazed joints) may have a higher gold content, probably, than the formed second brazed joint (or set of brazed joints). In this case, the term "first material joint (or first set of material joints)" is understood to refer to the material joint formed during the first bonding process, and "second material joint (or second set of material joints)" is understood to refer to the material joint or joint formed during the second bonding step performed after the first bonding. As will be described in detail later, in this regard, both the material joints 24 and 27 may be the "first" or "second" material joints. If the material joints 24 and / or 27 are brazed joints, this applies mutatis mutandis to the first brazed joint (or first set of brazed joints) and the second brazed joint (or second set of brazed joints).

[0047] Preferably, the surface to be joined that can be gold-plated, or the surface to be joined that at least partially includes gold plating or a gold layer in the bonding region thereof, is the surface 58 of the base 3 and the mounting surface 40 with respect to the material joint 24 (pedestal material joint 24), and the upper surface 42 and the support surface 94 of the submount 9 with respect to the material joint 27 (submount material joint 27). However, it may be sufficient if only one of the surfaces to be joined can be gold-plated. For example, with respect to the material joint 27, if the upper surface 42 is at least partially gold-plated at least in its bonding region, the support surface 94 of the submount 9 does not need to be gold-plated at all, and vice versa. The same, of course, also applies to the material joint 24 (pedestal material joint).

[0048] This application further relates to a method for manufacturing a header, in particular a header according to an embodiment of the present disclosure.

[0049] A method for manufacturing a header 1 for an electronic component, preferably a TO header 1, and particularly preferably a header 1 according to the disclosed embodiments, includes the following steps: - Forming a base 3 with an opening 8, where the base 3 does not have pedestals 7, 7a, 7b for accommodating a submount 9. That is, the base 3 may be understood as a "blank base". Such a blank base, i.e., a base having no pedestals integrally formed thereon, can be formed by a standard low-cost stamping process. Further, stamping such a blank base is not as complex as stamping a "standard base" including at least one integrally formed pedestal.

[0050] - Forming a feed-through 5 by introducing pins 6 into at least one opening 8, sealing the opening 8 with an insulating material 60, thereby fixing the pins 6 within the opening 8 and electrically insulating the pins 6 from the base 3. To fix the pins 6 within the opening 8 and electrically insulate them from the base 3, any suitable insulating material 60 can be used, but it may be advantageous to use glass as the insulating material 60, whereby the feed-through 5 is formed as a glass-metal seal. Such a glass-metal seal (GTMS) is a known product, and depending on the customer's needs, for example, by using particularly preferred materials for both the base 3 and the pins 6, the desired temperature stability of the feed-through, i.e., the header, can be adjusted and fabricated.

[0051] Optionally, at least partially applying a thin gold layer to at least the bonding area 70 of the base 3. The application of a thin gold layer, or gold plating, is a well-known process in electronic packaging to prevent oxidation of base metals, such as nickel. It may be particularly preferred to gold-plate at least partially the bonding area 70 of the base 3 if a gold-containing brazing material is used for the formation of the pedestal material bond 24 (or in this case the pedestal brazing joint). In this case, as explained in detail above with respect to the phase diagram shown in Fig. 6, the gold layer at least partially fuses with the gold migrating into the eutectic melt, resulting in an increase in the melting temperature, thereby thermally stabilizing the resulting material bond. However, instead of, as is commonly done, only one of the faces of the components to be joined with the AuGe 12 or AuSn 20 brazing material should be at least partially gold plated to produce a melting temperature increase, it may be considered to at least partially gold plate the mounting surface 40 of the pedestal 7, 7a, 7b. In this regard, the gold plating may be omitted if the pedestal material joint 24 is formed by another brazing material that does not contain gold.

[0052] - forming the pedestal 7, 7a, 7b, i.e. the pedestal is formed in a separate process. Thus, to form the pedestal, other manufacturing processes can be used, such as metal extrusion or metal drawing, rather than just stamping. Thus, the pedestal 7, 7a, 7b can be formed with a complex shape, for example with at least one edge 50 formed as a rounded or chamfered edge, as shown in FIG. 5 and described above. Furthermore, the pedestal 7, 7a, 7b can have further features that facilitate the process of mounting the submount or submounts 9.

[0053] These further features of the pedestal will be described with reference to the pedestal 7. However, it should be understood that when referring here to the shape of the pedestal 7, this also applies to the pedestals 7a, 7b and, generally, to any other pedestal provided on the header.

[0054] Without being limited to the embodiments shown in the drawings of the present application, generally, at least one pedestal 7 has a cubic or prismatic shape with at least one flat side 42 for accommodating a submount. This at least one flat side faces the pin 6 in the assembled state and is thus called the pin face 42. Further, the pedestal 7 has at least a partially flat base surface 40 for forming a joint with the base 3. This at least partially flat base surface 40 is called the mounting surface 40 of the pedestal 7. On the side opposite to the mounting surface 40 and preferably parallel to the mounting surface, the pedestal 7 has another surface, which may also be called the pedestal free surface. Generally, the pedestals 7, 7a, 7b of the header 1 may have equal shapes, or at least corresponding shapes, or may be formed mirror-symmetrically. According to a preferred embodiment, the pedestals 7, 7a, 7b may be arranged symmetrically on the base 3 with respect to a virtual plane parallel to the height direction and the width direction of the pedestal. That is, the pedestal has a first longitudinal direction, which is the first direction of a Cartesian coordinate system, extends parallel to the longest outer dimension of the pedestal, and is understood to be perpendicular to the surface 58 of the base 3. Further, the pedestal 7 has a second direction or width direction, which is the second direction of a Cartesian coordinate system perpendicular to the longitudinal direction and extends parallel to the pin face 42. Further, the height direction is perpendicular to both the longitudinal direction and the width direction. According to a further embodiment, the pedestal 7 may have at least one bar arranged on the pin face 42, and this bar preferably forms a side wall. This may be suitable when the bar can facilitate the alignment of the submount 9 on the pin face 42. Such a pedestal having at least one bar can be particularly said to have an L-shaped profile when this bar extends over the entire length of the pin face 42. Further, according to a further embodiment, the pedestal 7 may have another bar forming a U-shaped pedestal. When the bar or bars are shorter than the length of the pin face, they may each form a partially L-shaped profile or a partially U-shaped profile.The bar or plurality of bars and the pedestals 7 may preferably have the same material and are particularly preferably formed integrally as one part. As described above, the pedestals 7, 7a, 7b may have equal or corresponding shapes, but may also have different shapes.

[0055] - A step of providing a submount 9. The pedestals 7, 7a and 7b, preferably the pedestals 7, 7a, 7b according to the embodiments described in detail above, can be combined with any submount 9, but in the case of the pedestals according to the embodiments, it has been found that they can be preferably combined with a submount 9 which is equally formed but mounted in different orientations. In this case, the "equally formed submount" is understood to mean a submount having metal patterns corresponding to each other in order to facilitate assembly. However, these submounts are mounted in different orientations so as to enable an electronic device (for example, arranged in the gap 12 between the pedestals 7a, 7b) to be connected from the opposite direction. According to one embodiment, the submount 9 is mounted on at least one of the pedestals 7, 7a, 7b such that the ends of the conductor traces on the component surface 95 of the submount 9 connected to the feed-through pin 6 face each other. The conductor traces connected to the feed-through pin 6 are typically conductors for transmitting signals. Therefore, by using a configuration in which the ends on the distal side with respect to the feed-through pin 6 face each other, the distance for connection to the electronic device can be reduced.

[0056] In a preferred embodiment, the structured conductor plating pattern of the submount 9 is mirror-symmetrical. This enables the use of submounts 9 with different ends oriented and attached towards the base 3, thereby allowing the ends of conductor traces facing each other. Thus, according to a preferred embodiment, the submount 9 has two opposite ends, one end being attached facing the base 3, in which case the plane of symmetry of the mirror-symmetrical conductor plating is located between the ends. In particular, the submount 9 may have two opposite ends, especially ends distinguishable from each other, in which case one of the submounts 9 is attached to the pedestals 7, 7a, or 7b with one end facing the base, and the other submount 9 is attached to the pedestals 7, 7a, 7b with the opposite end facing the base 3. In this way, the "left" and "right" submounts 9 (with respect to the gap 12 or electronic components located between the submounts 9) are of the same type, but one of the submounts 9 is simply attached after being rotated by 180°.

[0057] - Optionally, the step of at least partially applying a thin gold layer to at least the bonding regions 70 of the pedestals 7, 7a, 7b and / or the support surface 94 of the submount 9. As described above with respect to the optional gold plating of at least the partial bonding regions 70, such a process may be suitable when AuGe solder joints and / or AuSn solder joints are formed between the pedestal or pedestals 7, 7a, 7b and the base 3 and / or the submount or submounts 9.

[0058] - A step of coupling a pedestal or a plurality of pedestals 7, 7a, 7b to the base 3, thereby forming a pedestal material joint 24, for example, by brazing. The coupling, for example, by brazing, can fixedly attach the pedestal 7 or, when the base 3 and / or the header 1 has a plurality of pedestals, the plurality of pedestals 7, 7a, 7b to the base 3. That is, the manufacturing of the blank base and the pedestal or the plurality of pedestals 7, 7a, 7b is separated, thereby enabling the formation and / or use of a pedestal having a complex shape that can be used to facilitate the assembly of the header or to improve the overall performance of the header, but a strong connection is still formed between the pedestal or the plurality of pedestals and the base.

[0059] - A step of coupling a submount 9 (or a plurality of submounts 9) to the pedestals 7, 7a, 7b (or some of the pedestals 7, 7a, 7b), thereby forming one submount material joint 27 (or some submount material joints 27), for example, by brazing, thereby forming one or more brazed joints.

[0060] - Optionally, polishing the surface of the base 3 and / or the seal material 60, thereby preferably leveling, i.e., making flat, the resulting surface 58a of the base 3 and the seal material 60.

[0061] According to a further embodiment, a plurality of pedestals 7, 7a, 7b are coupled, or joined, or connected to the base 3, thereby forming a plurality of pedestal material joints 24. It is preferred if all the pedestal material joints 24 have the same bonding material. For example, the material joints are formed by soldering, and all the pedestal soldered joints may have the same soldering material or solder. Such a process in which at least two pedestals are coupled, for example soldered, to the base may be suitable for the header 1 having a DML that requires two RF signal lines. Further, it may be advantageous to use the same bonding material, such as solder, to form the same or corresponding material joints, i.e., between the same or at least corresponding components, for example between some of the pedestals and the base. In this way, the material joints can be formed cost - effectively and simply, for example by soldering, in the same bonding step.

[0062] Similarly, according to a further embodiment, respective or corresponding sub - mounts 9 are coupled to each of the pedestals 7, 7a, 7b, thereby forming a plurality of sub - mount material joints 27. It is preferred if all the sub - mount material joints 27 have the same bonding material. Also in this case, all the material joints 27 may be formed simultaneously in a single step in this way. According to a preferred embodiment, the coupling may be achieved by soldering, in which case all the soldered joints (in this case, the sub - mount soldered joints) have the same soldering material or solder.

[0063] According to one embodiment, before the pedestal or pedestals 7, 7a, 7b are coupled, for example by a soldering process, to the base 3, the sub - mount or sub - mounts 9 are coupled to the pedestal or pedestals 7, 7a, 7b. Such a process results in a minimum pin offset (d in FIG. 2) 1When is to be achieved, in such a case, it may be suitable because the submount 9 (e.g., brazed to the pedestal 7) can be positioned very close to the pin 6. It is also conceivable to arrange the assembly including the submount 9 and the pedestal 7 (or rather 7a, 7b) on the base 3 such that the component surface 95 of the submount 9 contacts the pin 6.

[0064] Preferably, in this case, the submount material joint or joints 27 are formed as brazed joints or a plurality of brazed joints, including gold and germanium, and the pedestal material joint or joints 24 are formed as brazed joints or a plurality of brazed joints, including gold and germanium and / or tin. In this way, according to the embodiments described herein, it can be ensured that the submount brazed joint formed prior to the pedestal brazed joint does not remelt during the second brazing process.

[0065] However, according to a further embodiment, the pedestal or pedestals 7, 7a, 7b can be coupled to the base 3 before the submount or submounts 9 are coupled to the pedestal or pedestals 7, 7a, 7b. Similarly in this case, the coupling can be achieved quickly and easily by brazing. Such a process is similar to the prior art processes in electronic packaging using a base with a pedestal formed as one integral part, and thus known submount joining processes and equipment can be used, which may be suitable. However, in this case, known problems regarding pin offset may thus occur, resulting in a degraded RF signal performance of the electronic component.

[0066] Preferably, if the pedestal brazed joint, i.e., the pedestal material joint or joint 24 formed by a brazing process, is formed prior to the formation of the submount brazed joint, i.e., the submount material joint or joint 27 formed as the submount brazed joint, the pedestal brazed joint has gold and germanium, and the submount brazed joint has gold and germanium and / or tin. As described in detail above, generally, the material joint (or set of material joints) to be formed first should include a bonding material with a higher melting point to avoid remelting of the material joint (or set of material joints) during subsequent brazing procedures. As a result, in the embodiments described herein, since the material joint or joint 24 is formed prior to the material joint or joint 27, the pedestal material joint or joint 24 preferably includes gold and germanium and may be formed, for example, by AuGe12 as the brazing material, and the submount material joint or joint 27 may include gold and germanium and / or gold. However, AuSn20 or AuGe12 can also be used in both brazing steps. However, when using different brazing materials (such as AuGe12 in the first brazing step and AuSn20 in the second brazing step) or when using AuGe12, due to the very prominent eutectic in the AuGe binary phase diagram, the difference in melting temperature is large, so it may not be preferable to use AuSn20 in both brazing steps.

[0067] Furthermore, without being limited to the embodiments of the manufacturing process described in the previous paragraph, generally, when both the material joint or joints 24 and the material joint or joints 27 are formed as brazed joints by AuGe12 as a brazing material, it may be considered to electroplate at least one of the surfaces to be joined, at least in its bonding region, with gold. As a result, the material joint (or joints) to be formed first will have a melting temperature higher than the eutectic temperature of the AuGe12 eutectic composition due to at least partial melting of the electroplated gold, and the melting temperature of the resulting metal melt will increase.

[0068] According to an embodiment of the manufacturing process, generally, the pin offset can be adjusted by executing process steps in a carefully selected order. According to this embodiment, the pin or pins 6 are sealed within the opening 8 by the insulating material 60 before the pedestal or pedestals 7, 7a, 7b including the submount or submounts 9 are coupled to the base 3. By doing so, the pin offset can be adjusted to a predefined value. In particular in this case, the pin offset d 1 can also be set to "0". Thus, in one embodiment, the pins may be adjacent to the submount or may each directly contact the submount. The pin offset d 1 is desirably as small as possible, so this is particularly advantageous. However, it has been demonstrated that it is extremely difficult to set the pin offset d 1 to zero without the risk of damaging the submount. In a very simple and rapid method, a zero pin offset d 1 can be adjusted by first sealing the pin or pins 6 within the opening 8 and subsequently coupling the pedestal or pedestals 7, 7a, 7b already provided with the submount or submounts 9 to the base 3.

[0069] According to this embodiment, all deviations in the position of the pin or pins 6 within the opening 8 can be compensated for by adjusting the position of the pedestal or pedestals 7, 7a, 7b, so that the pin offset d 1 can be adjusted extremely simply. Thus, without being limited to a specific example, a pedestal with a submount can be attached to the base 3, whereby the predefined distance of the submount relative to the pins 6 can be adjusted. Alternatively, by attaching a pedestal with a submount to the base, direct contact between the submount 9 and the pins 6 can be formed.

[0070] Thus, according to one embodiment, the pin or pins 6 are sealed within the opening 8 by an insulating material 60, so that the pin or pins 6 are position-fixed within the opening or openings 8 and are electrically insulated from the base 3 before the pedestal or pedestals 7, 7a, 7b are coupled to the base 3.

[0071] FIG. 7 shows a further partial cross-sectional view of two headers 1 according to an embodiment. In this case, the lower part of FIG. 7 shows the partial cross-sectional view of the header 1 shown in the partial cross-sectional view of FIG. 2. Further, the surface 58 of the base 3 and the ground level or ground level 150 are shown. In order to achieve extremely good optimal control of the header impedance, according to one embodiment, in a further process, it is conceivable to grind the surface of the seal material, for example a glass seal material. This is possible according to the present disclosure because the base 3 of the header is provided as a blank base, i.e., without any pedestals 7 at all. When grinding is performed, both the base material and the seal material 60 are preferably removed in the same process, whereby the surface of the seal material and the resulting base surface 58a (i.e., the surface of the base 3 after material removal) are flush. The resulting surface 58a is shown in the upper part of FIG. 7, and a partial cross-sectional view of the header 1 obtained by grinding the header shown in the lower part of FIG. 7 having a ground level 150 is shown. In this case, the resulting surface 58a corresponds to the ground level 150, and it should be noted that the seal material surface and the surface 58a are flush. The fact that the seal material surface and the surface 58a are flush is preferred because this allows for extremely good control of the resulting header impedance and thus a more reliable performance can be achieved.

[0072] FIG. 8 shows a further partial cross-sectional view of the header 1 according to a further embodiment, showing the technical advantage of forming the pedestal 7 or the plurality of pedestals 7, 7a, 7b and the base 3 of the header in separate manufacturing processes. That is, if the base 3 and the pedestal or the plurality of pedestals 7, 7a, 7b are obtained in separate manufacturing processes, the pedestal or the plurality of pedestals 7, 7a, 7b can be of various types of shapes that provide several advantages. In the case of one or more pedestals, all the pedestals provided in the header 1 can have the same shape; however, the header 1 can also have pedestals 7, 7a, 7b of different shapes. With respect to the header 1 shown in FIG. 8a), the pedestal 7 is formed to project over the opening 8 filled with the sealing material 60. This can be suitable when a thin submount or a plurality of thin submounts 9 are used. Further, the pedestal 7 projecting at least partially over the opening 8 can preferably be combined with the grinding of the sealing material 60 and the base 3. Thus, in the upper part of FIG. 8, the surface of the base 3 is shown to be the resulting surface 58a, that is, the surface obtained after a material wear process such as grinding and / or polishing. However, without being limited to the header 1 as partially shown in the upper part of FIG. 8, generally, a special shape of the pedestal 7, such as the pedestal 7 projecting over the opening 8, can be combined with the header 1 having the original base surface 58 of the header.

[0073] In Fig. 8b), the pedestal 7 is shaped such that a stepped portion 48 (pedestal stepped portion 48) is formed, resulting in a pedestal 7 that is L-shaped in cross-section as shown in this figure. The pedestal 7 is formed to protrude from the opening 8 of the base 3. However, due to the stepped portion 48, a gap 49 is formed between the base surface 58 of the header (or 58a if the surface of the header is obtained by a material removal process such as grinding or polishing) and the surface of the sealing material. The gap 49 may be used to accommodate additional components or to provide a larger space for larger components, such as a monitor photodiode (MPD).

[0074] In Fig. 8c), yet another embodiment of the header 1 is shown in partial cross-section. In this case, the opening 8 of the base 3 is shaped such that a stepped portion 38 (or base stepped portion) is formed, and in this case, the base material at least partially overlaps the sealing material 60. Such a shape of the base 3 of the header can be used for circuit compensation. In particular, this compensation may be a C-L-C sequence, i.e., a sequence of a capacitive element, an inductive element, and another capacitive element. In this case, the stepped portion 38 is formed as a circumferential stepped portion with respect to the opening 8. The present application further relates to a header 1 manufactured or manufacturable by a method according to any of the embodiments of the present disclosure, preferably a header 1 according to any of the embodiments of the present disclosure.

Description of the reference numerals

[0075] 1 Header 3 Base 5 Electrical feed-through 6 Feed-through pin 7 Pedestal 7a First pedestal 7b Second pedestal 8 Opening 9 Submount 12 Gap 23 Solder joint 24 Material joint, pedestal joint (or bonding part) 25 Bonding bulge 26 Cavity, bonding reservoir 27 Another material joint, submount joint (or bonding part) 38 Step, base step 40 Mounting surface 42 Top surface, pin surface 48 Step, pedestal step 49 Gap 50 Edge 58 Front surface of base 3, surface of base 3 60 Insulating material 93 Side edge of submount 9 94 Support surface of submount 9 95 Component surface of submount 9 140 Arrow 150 Ground level, grinding level d 1 Pin offset d 2 Submount offset T m,h Melting temperature of virtual melt c m,h Concentration of virtual melt

Claims

1. A header (1) for an electronic component, comprising a base (3) and at least one pedestal (7, 7a), wherein the base (3) has at least one feed-through (5), and the feed-through (5) comprises a feed-through pin (6) that extends through the base (3) and is electrically insulated from the base (3), wherein the at least one pedestal (7, 7a) is connected to the base (3) and comprises a submount (9) connected to the pedestal (7), wherein the pedestals (7, 7a, 7b) are joined to the base (3) via a pedestal material joint (24), wherein the submount (9) is joined to the pedestals (7, 7a) via a submount material joint (27), wherein the melting temperature of the pedestal material joint (24) is lower than the melting temperature of the submount material joint (27), wherein the feed-through pin (6) is in direct contact with the submount (9) such that there is a zero pin offset (d1), header (1).

2. The header (1) has a submount offset (d) of up to 0.1 mm formed between the submount (9) and the surface of the base (3). ２ ), and / or a pin offset (d) formed between the feed-through pin (6) and the surface of the submount (9). １ ​ The header (1) according to claim 1.

3. The surface of the base (3) and / or the mounting surface (40) of the pedestal (7) and / or the pin surface (42) of the pedestals (7, 7a) and / or the support surface (94) of the submount (9) is at least partially Au-plated in its bonding region (70), The header (1) according to claim 1 or 2.

4. At least one material joint (24, 27) contains Au and Ge and / or Sn, The header (1) according to any one of claims 1 to 3.

5. The pedestals (7, 7a, 7b) have an edge (50), thereby forming a cavity (26), and / or, The pedestals (7, 7a, 7b) have a pedestal step (48), thereby forming a gap (49), and / or, The pedestals (7, 7a, 7b) at least partially protrude above the opening (8), and / or, The base (3) has a base step (38). The header (1) according to any one of claims 1 to 4.

6. The header (1) has a further pedestal (7b) connected to the base (3), and a submount (9) connected to the further pedestal (7b), the further pedestal (7b) being joined to the base via a further pedestal material joint (24), the further pedestal material joint (24) having the same bonding material between the pedestal (7, 7a) and the further pedestal (7b). The header (1) according to any one of claims 1 to 5. **Claim 7** A method for manufacturing a header (1) for an electronic component according to any one of claims 1 to 6, comprising the following steps, namely - forming a base (3) with an opening (8), the base (3) not having pedestals (7, 7a, 7b) for accommodating a submount (9); - forming a feedthrough (5) by introducing pins (6) into at least one opening (8), sealing the opening (8) with an insulating material (60), thereby fixing the pins (6) in the opening (8) and electrically insulating them from the base (3); - forming pedestals (7, 7a, 7b); - providing a submount (9); - bonding the pedestals (7, 7a, 7b) to the base (3), thereby forming a pedestal material joint (24); - bonding the submount (9) to the pedestals (7, 7a, 7b), thereby forming a submount material joint (27); comprising the submount (9) being joined to the pedestals (7, 7a) via the submount material joint (27), the melting temperature of the pedestal material joint (24) being lower than the melting temperature of the submount material joint (27), by bonding the submount (9) to the pedestals (7, 7a, 7b) before bonding the pedestals (7, 7a, 7b) to the base (3), a zero pin offset (d1) is obtained, the method further comprises - before bonding the pedestals (7, 7a, 7b) to the base (3), sealing the pins (6) in the opening (8) with the insulating material (60). - Place the pedestal (7, 7a, 7b) already provided with the submount (9) such that the pin (6) directly contacts the submount (9), and then couple the pedestal (7, 7a, 7b) already provided with the submount (9) to the base (3); comprising a method. **Claim 8** Brazing a plurality of pedestals (7, 7a, 7b) to the base (3), thereby forming a plurality of pedestal material joints (24); The method according to claim 7. **Claim 9** Coupling one submount (9) to each pedestal (7, 7a, 7b), thereby forming a plurality of submount material joints (27); The method according to claim 8. **Claim 10** The submount material joint or joints (27) comprise gold and germanium, The pedestal material joint or joints (24) comprise gold and germanium and / or tin; The method according to claim 7.

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