Kovar frame and sensor packaging structure

Abstract

The utility model discloses a Kovar frame and a sensor packaging structure, which are applied to the technical field of semiconductor device packaging and comprise a bottom frame, a solder area is arranged on the surface of one side of the bottom frame, a retaining wall is arranged on one side, facing the center of the Kovar frame, of the solder area, and a protruding part is arranged on one side, facing the solder area, of the retaining wall. A gap is formed between the protrusion and the bottom surface of the solder region. The blocking wall can prevent welding flux arranged in the welding flux area from splashing towards the center of the kovar frame, and therefore the situation that the welding flux splashes to the pixel area in the eutectic welding process is reduced. And the protruding part is used for increasing a solder climbing path when the solder climbs towards the top end of the retaining wall, preventing the solder from infiltrating towards a position close to the chip, further reducing the sputtering risk, and ensuring the yield of the device.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor device packaging, in particular to a kovar frame and a sensor packaging structure. Background Art

[0002] In recent years, with the rapid development of large-scale integrated circuit technology and micro-electro-mechanical system (MEMS) technology, the technology of uncooled infrared focal plane array (IRFPA) detectors has become increasingly mature, and related products have gradually been serialized. Driven by the academic and industrial communities, the technology of uncooled infrared focal plane detectors has developed rapidly, the sensitivity of the focal plane detectors has been significantly improved, the pixel pitch has become smaller and smaller, and the array scale has become larger and larger. Uncooled infrared imaging technology has been widely promoted and applied in military defense equipment and commercial fields due to its advantages of low cost, small size, low power consumption, and long service life.

[0003] At present, the packaging processes of uncooled infrared detectors mainly include three forms: metal packaging, ceramic packaging, and wafer-level packaging. Among them, as the second-generation packaging technology, ceramic packaging has mature technology, small volume and weight, high reliability, and can well meet the mass production requirements, and is widely used in military and civilian fields.

[0004] The ceramic packaging structure of an uncooled infrared detector consists of a window, solder, a kovar frame, a package shell, a chip, and a getter. At present, for most ceramic detectors, vacuum packaging is achieved through solder eutectic between the window and the kovar, and between the kovar and the package shell. The yield of the eutectic soldering step greatly affects the yield of the detector.

[0005] However, in actual situations, due to various factors such as the oxidation of the solder and the contamination of the surfaces of the window and the kovar, the solder is prone to splash during the eutectic soldering process, and the solder splashing onto the pixel area will affect imaging, and in severe cases, it will cause the detector to be directly scrapped. Therefore, how to reduce or even avoid the solder splashing onto the pixel area during the eutectic soldering process is an urgent problem to be solved by those skilled in the art. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a kovar frame, which can reduce the solder splashing onto the pixel area during the eutectic soldering process; another purpose of the utility model is to provide a sensor packaging structure, which can reduce the solder splashing onto the pixel area during the eutectic soldering process.

[0007] To solve the above technical problems, the present utility model provides a kovar frame, including a bottom frame, a solder area is arranged on one surface of the bottom frame, a retaining wall is arranged on the side of the solder area facing the center of the kovar frame, a protruding portion is arranged on the side of the retaining wall facing the solder area, and a gap is formed between the protruding portion and the bottom surface of the solder area.

[0008] Optionally, the retaining wall is perpendicular to the surface of the bottom frame, and the protruding portion extends out of the retaining wall in a direction perpendicular to the retaining wall.

[0009] Optionally, the retaining wall is arranged in a ring around the center of the kovar frame.

[0010] Optionally, the protruding portion is arranged in a ring along the circumferential direction of the retaining wall.

[0011] Optionally, the protruding portion includes a plurality of separated protruding sub-portions, and the plurality of protruding sub-portions are arranged in a ring along the circumferential direction of the retaining wall.

[0012] Optionally, a plurality of protruding portions are arranged on the side of the retaining wall facing the solder area, and the plurality of protruding portions are spaced along the height direction of the retaining wall.

[0013] Optionally, the lengths of the protruding portions are all equal.

[0014] Optionally, the wettability of the end surface of the retaining wall on the side away from the bottom of the solder area with respect to the solder is less than the wettability of the bottom of the solder area with respect to the solder.

[0015] Optionally, the end surface of the retaining wall on the side away from the bottom of the solder area is a non-gilded surface.

[0016] This embodiment also provides a sensor packaging structure, including a packaging shell, a window component and the kovar frame as described in any one of the above;

[0017] One side of the kovar frame is bonded to the packaging shell based on the solder arranged in the solder area, and the other side of the kovar frame is bonded to the window component.

[0018] A kovar frame provided by the present utility model includes a bottom frame, a solder area is arranged on one surface of the bottom frame, a retaining wall is arranged on the side of the solder area facing the center of the kovar frame, a protruding portion is arranged on the side of the retaining wall facing the solder area, and a gap is formed between the protruding portion and the bottom surface of the solder area.

[0019] The retaining wall can block the solder arranged in the solder area from splashing towards the center of the kovar frame, thereby reducing the risk of solder splashing into the pixel area during the eutectic soldering process. The function of the protruding portion is to increase the solder climbing path when the solder climbs towards the top of the retaining wall, prevent the solder from infiltrating towards the position close to the chip, further reduce the sputtering risk, and ensure the yield of the device.

[0020] The present utility model also provides a sensor packaging structure, which also has the above beneficial effects and will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 FIG. is a schematic structural diagram of a kovar frame provided by an embodiment of the present utility model;

[0023] Figure 2 For Figure 1 the side view structural diagram of;

[0024] Figure 3 FIG. is a solder climbing path diagram;

[0025] Figure 4 FIG. is a side view structural diagram of a specific kovar frame provided by an embodiment of the present utility model;

[0026] Figure 5 For Figure 4 the bottom view structural diagram of;

[0027] Figure 6 FIG. is a structural diagram of a sensor packaging structure provided by an embodiment of the present utility model.

[0028] In the figure: 1. Window component, 2. First solder sheet, 3. Kovar frame, 4. Second solder sheet, 5. Chip, 6. Getter, 7. Packaging tube shell, 8. Baffle wall, 9. Protrusion, 10. End, 11. Bottom frame, 12. Solder area. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The core of the present utility model is to provide a kovar frame. In the prior art, at present, most of the windows of ceramic detectors are vacuum packaged with kovar and the kovar and the tube shell through solder eutectic. The yield of the eutectic soldering step greatly affects the yield of the detectors. However, due to various factors such as the oxidation of the solder and the contamination of the surfaces of the window and the kovar, the solder is prone to splash during the eutectic soldering process, and the solder splashed into the pixel area will affect imaging, and in severe cases, it will cause the detector to be directly scrapped.

[0030] And a kovar frame provided by the utility model includes a bottom frame. A solder area is arranged on one side surface of the bottom frame. A retaining wall is arranged on the side of the solder area facing the center of the kovar frame. A protruding portion is arranged on the side of the retaining wall facing the solder area. A gap is formed between the protruding portion and the bottom surface of the solder area.

[0031] The retaining wall can block the solder arranged in the solder area from splashing towards the center of the kovar frame, thereby reducing the risk of solder splashing into the pixel area during the eutectic soldering process. The function of the protruding portion is to increase the solder climbing path when the solder climbs towards the top of the retaining wall, prevent the solder from infiltrating towards the position close to the chip 5, further reduce the sputtering risk, and ensure the yield of the device.

[0032] In order to enable those skilled in the art to better understand the solution of the present utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0033] Embodiment 1

[0034] Please refer to Figures 1 to 3 , Figure 1 which is a schematic structural diagram of a kovar frame provided by an embodiment of the present utility model; Figure 2 is Figure 1 a side view structural diagram of Figure 3 and is a solder climbing path diagram.

[0035] Referring to Figure 1 and Figure 2 , in the embodiment of the present utility model, the kovar frame includes a bottom frame 11. A solder area 12 is arranged on one side surface of the bottom frame 11. A retaining wall 8 is arranged on the side of the solder area 12 facing the center of the kovar frame. A protruding portion 9 is arranged on the side of the retaining wall 8 facing the solder area 12. A gap is formed between the protruding portion 9 and the bottom surface of the solder area 12.

[0036] The above-mentioned bottom frame 11 is the main structure of the kovar frame, and the bottom frame 11 generally has a rectangular frame structure. In this embodiment, solder is specifically arranged on the surface of the bottom frame 11 so that the bottom frame 11 can be eutectically bonded to other structures, such as the encapsulation shell 7, etc. In this embodiment, the central area of the kovar frame is usually a hollow structure for bonding with the window component 1, and a solder area 12 is usually arranged on the surface of the bottom frame 11. As the name implies, solder will be arranged in the solder area 12 during bonding for eutectic soldering, so as to fixedly connect the kovar frame with other components. Usually, the above-mentioned solder area 12 is annular and arranged along the circumferential direction of the bottom frame 11. In this embodiment, the specific structure of the bottom frame 11 is not specifically limited, and its outer edge can have a certain warpage to adapt to different encapsulation structures. In this embodiment, the specific structure of the bottom frame 11 is not specifically limited.

[0037] The above-mentioned solder area 12 is arranged on the surface of the bottom frame 11, and on the side of the solder area 12 facing the center of the kovar frame, that is, on the inner side of the solder area 12, a retaining wall 8 is arranged. Obviously, the retaining wall 8 will extend substantially upward with the surface of the bottom frame 11 as a reference, as Figure 3 shown, to prevent the solder arranged in the solder area 12 from splashing towards the center of the kovar frame during the eutectic soldering process. Specifically, in this embodiment, the retaining wall 8 is usually arranged perpendicular to the surface of the bottom frame 11, so that the retaining wall 8 can block a larger solder splash angle. Of course, the angle between the retaining wall 8 and the surface of the bottom frame 11 can also be a non-90° angle, and its specific content can be set according to the actual situation and is not specifically limited here. It should be noted that due to the existence of the retaining wall 8, during the eutectic soldering process, the solder can climb along the side surface of the retaining wall 8 towards the top of the retaining wall 8.

[0038] In this embodiment, the solder area 12 is usually arranged in a ring around the center of the kovar frame, and correspondingly, the retaining wall 8 is usually also arranged in a ring around the center of the kovar frame.

[0039] The above-mentioned protrusion 9 is arranged on the side of the retaining wall 8 facing the solder area 12, and a gap is formed between the retaining wall 8 and the bottom surface of the solder area 12, that is, the protrusion 9 is not arranged at the bottom of the solder area 12, but is arranged in the climbing path of the solder. Refer to Figure 3 , Figure 3 The arrow in shows part of the climbing path of the solder. The setting of the protrusion 9 enables the solder to climb along the lower surface, side surface, and upper surface of the protrusion 9 in sequence from the gap between the protrusion 9 and the bottom surface of the solder area 12 during climbing, thereby effectively increasing the solder climbing path and preventing the solder from climbing to the top of the retaining wall 8 and splashing towards the center of the kovar frame. In this embodiment, the protrusion 9 usually extends out of the retaining wall 8 in a direction perpendicular to the retaining wall 8. Of course, the angle between the protrusion 9 and the retaining wall 8 can also be a non-90° angle, and its specific content can be set according to the actual situation and is not specifically limited here.

[0040] Specifically, in this embodiment, the protrusion 9 may be arranged in a ring shape along the circumferential direction of the retaining wall 8. That is, in this embodiment, the protrusion 9 will also have a ring structure and is arranged on the side of the retaining wall 8 facing the solder area 12. In this structure, one protrusion 9 is usually a continuous whole and is arranged around the center of the kovar frame.

[0041] Specifically, in this embodiment, the protrusion 9 may include a plurality of separated protruding sub-parts, and the plurality of protruding sub-parts are arranged in a ring shape along the circumferential direction of the retaining wall 8. That is, in this embodiment, the protrusion 9 as a whole will also have a ring structure and is arranged on the side of the retaining wall 8 facing the solder area 12. However, the protrusion 9 is specifically composed of a plurality of separated protruding sub-parts, and the plurality of protruding sub-parts are arranged along the circumferential direction of the retaining wall 8 to form a discontinuous and overall ring-shaped structure around the center of the kovar frame. Of course, in addition to the above two structures, the protrusion 9 may have other structures, and its specific content can be set according to actual situations and will not be specifically limited here.

[0042] A kovar frame provided in this embodiment, the retaining wall 8 can block the solder in the solder area 12 from splashing towards the center of the kovar frame, thereby reducing the risk of solder splashing into the pixel area during the eutectic soldering process. The function of the protrusion 9 is to increase the solder climbing path when the solder climbs to the top of the retaining wall 8, prevent the solder from infiltrating towards the position close to the chip 5, further reduce the sputtering risk, and ensure the yield of the device.

[0043] The specific content of a kovar frame provided by the present utility model will be introduced in detail in the following embodiments of the utility model.

[0044] Embodiment Two

[0045] Please refer to Figure 4 and Figure 5 , Figure 4 which is a schematic side view structure diagram of a specific kovar frame provided by an embodiment of the present utility model; Figure 5 is Figure 4 the schematic bottom view structure diagram of

[0046] Different from the above embodiment of the utility model, this embodiment of the present utility model further limits the structure of the kovar frame on the basis of the above embodiment of the utility model. The remaining content has been introduced in detail in the above embodiment of the utility model and will not be repeated here.

[0047] See Figure 4 and Figure 5, in the embodiment of the present utility model, a plurality of protrusions 9 are provided on the side of the retaining wall 8 facing the solder area 12, and the plurality of protrusions 9 are arranged at intervals along the height direction of the retaining wall 8. That is, a plurality of the above-mentioned protrusions 9 can be arranged along the climbing direction of the solder on the retaining wall 8. At this time, the plurality of protrusions 9 are specifically arranged along the height direction of the retaining wall 8. During the climbing process of the solder, it will climb over each protrusion 9 in sequence from bottom to top, and there is a gap between adjacent protrusions 9 arranged along the height direction.

[0048] In this embodiment, the lengths of the plurality of protrusions 9 can be equal, and the extending directions of the plurality of protrusions 9 can be parallel, which is convenient for the preparation of the protrusions 9. Of course, in this embodiment, the specific morphology of the protrusions 9 and the positional relationship between the plurality of protrusions 9 are not specifically limited. The axes of the plurality of protrusions 9 can be parallel or intersect, and the length of the protrusions 9 is not specifically limited here. In other words, in this embodiment, more than one layer of protrusions 9 can be provided instead of only one layer of protrusions 9. This setting not limited to one layer of protrusions 9 can further extend the climbing path of the solder.

[0049] Furthermore, in this embodiment, the protrusion 9 can be provided with extending branches on its surface, that is, the surface of the protrusion 9 is provided with branches, and the branches will specifically extend outward from the surface of the protrusion 9 to further increase the climbing path of the solder and set obstacles to the climbing process of the solder to prevent the solder from climbing to the top end of the retaining wall 8. The morphology of the above-mentioned branches is not specifically limited here. It can be columnar or of any shape, and it can be provided at the end, middle, or bottom of the protrusion 9, which is not specifically limited here.

[0050] Furthermore, in this embodiment, the wettability of the surface of the end 10 of the retaining wall 8 on the side far from the bottom of the solder area 12 with respect to the solder can be less than the wettability of the bottom of the solder area 12 with respect to the solder. That is, in this embodiment, the end 10 of the retaining wall 8 far from the bottom of the solder area 12 can be specially treated, so that the wettability of the surface of the end 10 with respect to the solder is less than the wettability of the bottom of the solder area 12 with respect to the solder. This setting makes it possible that even if the solder climbs to the end 10 of the retaining wall 8 through the blockage of the protrusions 9, due to the poor wettability of the end 10 with respect to the solder, the solder is prevented from climbing to the end 10 of the retaining wall 8 and splashing towards the pixel area. In actual situations, in order to ensure the firm bonding of the solder to the kovar frame, the surface of the kovar frame is usually treated, such as gold plating, to increase the wettability of the solder with the kovar frame. In this application, the end 10 of the retaining wall 8 is further specially treated, so that the wettability of the surface of the end 10 with respect to the solder is less than the wettability of the bottom of the solder area 12 with respect to the solder, thereby reducing the risk of the solder splashing towards the pixel area.

[0051] Specifically, in this embodiment, the surface of the end portion 10 of the barrier wall 8 on the side away from the bottom of the solder region 12 can be a non-gilded surface. That is, during the process of gilding the surface of the kovar frame, the above-mentioned end portion 10 of the barrier wall 8 is isolated from other positions of the kovar frame, such as the position of the bottom surface of the solder region 12. Specifically, only other positions of the kovar frame are gilded, for example, only the bottom surface of the solder region 12, the bottom surface of the barrier wall 8, and the surface of the protrusion 9, which are areas that may be in contact with the solder, are gilded, and a gold layer is provided on their surfaces to increase the wettability of the above positions with the solder. For the end portion 10 of the barrier wall 8, no gilding is performed, that is, no coating is provided or a film layer with low wettability with the solder is provided to prevent the solder from climbing to the end portion 10 of the barrier wall 8.

[0052] In this embodiment, the processing technology of the above-mentioned kovar frame includes but is not limited to machining, powder metallurgy, cold extrusion, etc. A kovar frame provided in this embodiment can further extend the climbing path length by arranging multiple protrusions 9, and reduce the amount of solder climbing to the end portion 10 of the barrier wall 8. And setting the top of the barrier wall 8 to be not easily wetted by the solder can ensure that a small amount of solder climbing to the end portion 10 of the barrier wall 8 wets the end portion 10 of the barrier wall 8, thereby further reducing the sputtering risk and ensuring the yield of the device.

[0053] Embodiment III

[0054] Next, a sensor packaging structure provided by an embodiment of the present invention will be introduced. The sensor packaging structure described below can be correspondingly referred to the kovar frame described above.

[0055] Please refer to Figure 6 , Figure 6 which is a schematic structural diagram of a sensor packaging structure provided by an embodiment of the present invention.

[0056] See Figure 6 , in this embodiment, the sensor packaging structure includes a packaging case 7, a window component 1, and a kovar frame 3 as described in any of the above embodiments; one side of the kovar frame 3 is bonded to the packaging case 7 based on the solder provided in the solder region 12, and the other side of the kovar frame 3 is bonded to the window component 1.

[0057] The Kovar frame 3 located in the central area of the baffle wall 8 facing away from the solder area 12 will be bonded to the window component 1, and the bonding process can use solder for eutectic bonding. The Kovar frame 3 and the package housing 7 will be eutectically bonded through the solder provided in the above-mentioned solder area 12 to encapsulate the chip 5 fixed to the package housing 7. An getter 6 is usually provided inside the package housing to ensure that the package is internally vacuum. The specific structure of the Kovar frame 3 has been introduced in detail in the above-mentioned utility model embodiment and will not be elaborated here. The above-mentioned package housing 7 is usually fixed with a chip 5, and the window component 1, as the window of the chip 5, is usually fixed in the central area of the Kovar frame 3. The specific structures of the package housing 7, the window component 1, and the chip 5 can refer to the prior art and will not be elaborated here.

[0058] In this embodiment, to achieve the bonding between the Kovar frame 3 and the window component 1, and to achieve the bonding between the Kovar frame 3 and the package housing 7, solder sheets can be specifically used for encapsulation. The solder sheet used for bonding between the Kovar frame 3 and the window component 1 is the first solder sheet 2, and the solder sheet used for bonding between the Kovar frame 3 and the package housing 7 is the second solder sheet 4. When encapsulating the chip 5 in this embodiment, first, the window component 1, the package housing 7, and the Kovar frame 3 need to be wet-cleaned and dried; then the chip 5 is fixed to the package housing 7 by die bonding or eutectic bonding, and the electrical function output of the chip 5 can be realized through wire bonding. Then, the window component 1, the Kovar frame 3, and the first solder sheet 2 can be plasma-cleaned. After cleaning, these three materials are assembled and the first eutectic soldering is completed to obtain a pre-welded part. After the first eutectic soldering, the pre-welded part and the second solder sheet 4 are plasma-cleaned again. After cleaning, the pre-welded part, the second solder sheet 4, and the package housing 7 with the chip 5 are assembled again and the second eutectic soldering is completed to complete the encapsulation of the chip 5.

[0059] During the above process, it is necessary to ensure that the melting point of the first solder sheet 2 is higher than that of the second solder sheet 4 to ensure that the first solder sheet 2 will not melt again during the second eutectic soldering, so as to ensure that the solder at the first solder sheet 2 will not splash onto the chip 5, and the splash at the second solder sheet 4 can be blocked by the structure of the above-mentioned Kovar frame 3.

[0060] Since the sensor encapsulation structure provided in this embodiment specifically uses the Kovar frame 3 provided in the above-mentioned embodiment, this sensor encapsulation structure can have a high yield.

[0061] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0062] Finally, it should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the said element.

[0063] The above has introduced in detail a kovar frame and a sensor packaging structure provided by the present utility model. Specific examples are used in this text to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and modifications can be made to the present utility model, and these improvements and modifications also fall within the protection scope of the claims of the present utility model.

Claims

1. A cuttable frame, characterized in that: The invention comprises a bottom frame (11), a soldering area (12) being arranged on one side surface of the bottom frame (11), a retaining wall (8) being arranged on the side of the soldering area (12) facing the center of the cavable frame, a protrusion (9) being arranged on the side of the retaining wall (8) facing the soldering area (12), and a gap being formed between the protrusion (9) and the bottom surface of the soldering area (12).

2. The cuttable frame according to claim 1, characterized in that: The retaining wall (8) is perpendicular to the surface of the bottom frame (11), and the protruding portion (9) extends out of the retaining wall (8) in a direction perpendicular to the retaining wall (8).

3. The cuttable frame according to claim 1, characterized in that: The retaining wall (8) is arranged in a ring shape around the center of the cuttable frame.

4. The cuttable frame according to claim 3, characterized in that: The protrusion (9) is arranged in a ring shape along the circumferential direction of the retaining wall (8).

5. The cuttable frame according to claim 3, characterized in that: The protruding portion (9) comprises a plurality of protruding sub-portions separated from each other, and the plurality of protruding sub-portions are arranged in a ring shape along the circumferential direction of the retaining wall (8).

6. The cuttable frame according to claim 1, characterized in that: A plurality of protrusions (9) are arranged on the side of the retaining wall (8) facing the soldering area (12), and the plurality of protrusions (9) are arranged at intervals along the height direction of the retaining wall (8).

7. The cuttable frame according to claim 6, characterized in that: The protrusions (9) are all of equal length.

8. The cuttable frame according to claim 1, characterized in that: The wettability of the surface of the end portion (10) of the retaining wall (8) away from the bottom of the solder area (12) with the solder is lower than the wettability of the bottom of the solder area (12) with the solder.

9. The cuttable frame according to claim 8, characterized in that: The surface of the end portion (10) of the retaining wall (8) away from the bottom of the solder area (12) is a non-gold-plated surface.

10. A sensor packaging structure, characterized in that: It comprises a packaging tube shell (7), a window component (1) and a detachable frame (3) as claimed in any one of claims 1 to 9; One side of the avable frame (3) is bonded to the package tube shell (7) based on the solder arranged in the solder area (12), and the other side of the avable frame (3) is bonded to the window component (1).

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