Method and system for pre-conditioning the temperature of the mold cavity of a mold for sealing electronic components.

Abstract

The present invention relates to a method for pre-conditioning the temperature of a mold cavity for sealing electronic components, comprising the steps of: A) preparing a mold for sealing electronic components, comprising a mold cavity having a mold cavity wall; and B) injecting a temperature pre-conditioning gas into the mold cavity. Prior to the step of injecting the temperature pre-conditioning gas into the mold cavity, the temperature of the temperature pre-conditioning gas is controlled to change the temperature of the mold cavity wall to a desired height through controlled temperature exchange with the temperature pre-conditioning gas. The present invention further relates to a system for pre-conditioning a mold cavity.

Description

Technical Field

[0001] The present invention relates to a method for temperature pre-conditioning a mould cavity of a mould for encapsulating electronic components. The present invention also relates to a system for temperature pre-conditioning such a mould cavity.

Background Art

[0002] Electronic components can be protected from their surroundings by at least partial encapsulation. In particular, semiconductors mounted on substrates such as lead frames. Examples of semiconductors include chips, light emitting diodes (LEDs), and other electronic components. Encapsulation prevents corrosion of these often delicate components and damage from mechanical shock. Encapsulation refers to creating a protective shell around an electronic component by molding a compound on and around the component. A variety of materials can be used for encapsulation, and the materials typically include thermosetting epoxies or resin with fillers.

[0003] There are various types of encapsulation processes such as transfer molding, compression molding, and injection molding. These encapsulation processes have in common that a substrate carrying electronic components is sandwiched between two mold parts, and at least one of the two mold parts has a mold cavity provided therein. Thereby, a mold cavity is formed around each electronic component to be encapsulated. Then, a liquid encapsulant is supplied into these cavities and cured. After the liquid encapsulant has at least partially cured or hardened, the mold parts are separated and the substrate with the encapsulated electronic components is removed from the mold.

[0004] Typically, in the encapsulation process, heat and pressure are applied to the encapsulant, causing it to liquefy. The liquid encapsulant fills the mold cavity and surrounds the electronic component. Subsequently, the liquid encapsulant cures at least partially within the mold cavity. Curing usually occurs as a result of crosslinking of the encapsulating polymer.

[0005] Precise sealing of electronic components is crucial. Some parts of the substrate must remain unsealed to allow other components to be connected to the substrate, and some electronic components may also remain unsealed. Because semiconductor components are so small, inaccurate, or low-precision, sealing can lead to unacceptably large errors in the sealed electronic component's size from its intended dimensions, or even to discarded components due to improper sealing, such as the presence of foreign matter. Therefore, on the one hand, the sealant must have sufficient fluidity to completely fill the mold cavity, while on the other hand, excess sealant must not be introduced into the mold cavity. Furthermore, molding burrs (sealant that enters between the mold halves, or between the electronic component carrier and the mold halves) must be prevented. Burr formation, also known as bleeding, can be mitigated by ensuring the sealant viscosity is not too low, while on the other hand, higher viscosity is necessary to ensure uniform flow of the sealant within the mold cavity. If the mold cavity is not completely filled with sealant, voids may remain in the sealant. Small air bubbles trapped in the sealing material can also create voids and must be avoided. To improve sealing quality, negative pressure may be applied to the mold cavity before and / or during the sealing process (negative pressure is a pressure lower than the ambient air pressure). Such negative pressure may be applied through suction channels called vents, which allow for the active or passive release of gases during sealing. Negative air pressure in the mold cavity may reduce void formation.

[0006] DE112012004392B4 discloses a method for low-pressure sealing of electronic components mounted on a carrier, in which the electronic components placed in a mold cavity are sealed by filling the mold cavity with a liquid sealant and then curing the sealant. This publication proposes introducing a volume-reducing material into the mold cavity before bringing the sealant into the mold cavity in order to create a lower pressure within the mold cavity. The volume-reducing material undergoes a phase change before or during the filling of the mold cavity with the sealant, minimizing the material content within the mold cavity, thereby improving filling quality and reducing the chance of foreign matter entering the cured sealant.

[0007] Nevertheless, despite all efforts already made, the quality requirements for sealed electronic components remain high, thus further improving control over the electronic component sealing process is needed. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] DE112012004392B4 [Overview of the Initiative]

[0009] Therefore, an object of the present invention is to provide a method and system for sealing electronic components that further improves the sealing quality of electronic components.

[0010] In this regard, the present invention provides a method for temperature pre-conditioning the mold cavity of a mold for sealing electronic components, as described in claim 1. Heat is transferred from the temperature pre-conditioning gas to the mold cavity wall, or vice versa, by injecting a temperature pre-conditioning gas controlled to a temperature different from the temperature of the mold cavity wall. Heat is typically transferred from the temperature pre-conditioning gas to the mold cavity wall, i.e., the mold cavity wall is heated by the temperature pre-conditioning gas, but if the mold cavity is too hot for ideal sealing, the mold cavity wall can also be cooled. The mold cavity wall should be interpreted as part of the mold that defines the mold cavity or forms the boundary of the mold cavity. Therefore, after the temperature pre-conditioning gas is injected into the mold cavity, the mold cavity wall is in contact with the temperature pre-conditioning gas. The temperature pre-conditioning gas has a controlled temperature before injection. This makes it possible to control the temperature of the mold cavity walls with great precision immediately before the sealant flows into the mold cavity, and thus, by using a temperature-controlled conditioning gas, critical process conditions that greatly affect the sealing result are well controlled. Of course, the mold cavity temperature is for critical parts that are operated by an electric heating system incorporated into the mold. However, such a heating system does not respond quickly to rapid and fairly small changes in the surface temperature of one or more mold cavities. Changes in process conditions and / or environmental influences (e.g., temperature changes in the carrier containing the sealant and / or electronic components in the previous process cycle, changes in ambient temperature, rapid changes in weather conditions, opening the machine housing, ventilation, etc.) can cause rapid changes in the surface temperature within the mold cavity, for example. The present invention can also eliminate smaller and more rapid temperature deviations (deviations from the ideal mold cavity wall temperature). The temperature of the temperature pre-conditioning gas before it is injected into the mold cavity may be controlled based on temperature detection and subsequent pre-calculation of the required pre-conditioning gas temperature.

[0011] The total volume of the temperature-pre-conditioned gas to be used may also vary. In this specification, volume is defined under standard temperature and pressure (STP). STP is defined as a temperature of 273.15 K and an absolute pressure of 1.10 5 It is defined as Pa.

[0012] A further advantage of the present invention is that the heat transferred between the temperature pre-conditioning gas and the mold can also eliminate temperature inhomogeneities present across the mold cavity walls. This results in a more uniform temperature across the mold cavity walls, and consequently, a more uniform sealing result (i.e., uniform quality of the sealed product). The injection of the temperature pre-conditioning gas removes any remaining (undesirable) gas from the mold cavity, resulting in a more uniform and controlled filling of the mold cavity. In addition, particles or other contaminants can also be removed, at least partially, by the pre-conditioning gas.

[0013] This method may include the step of placing foil inside the mold cavity before injecting a temperature pre-conditioning gas into the mold cavity through the mold cavity inlet opening. The temperature pre-conditioning gas can ensure precise temperature control of the foil and reduce temperature non-uniformity of the foil. The pressure of the temperature pre-conditioning gas can also be advantageous in pressing the foil against the mold cavity walls.

[0014] Further optimization may involve controlling the total volume of temperature pre-conditioning gas injected into the mold cavity to change the temperature of the mold cavity walls to a desired temperature level. Controlling the volume of temperature pre-conditioning gas also brings the heat capacity (or cooling capacity) of the temperature pre-conditioning gas supplied into the mold cavity under control, making it easier to control the process conditions of the mold cavity at the time of filling with the sealant.

[0015] The supply rate of the temperature pre-conditioning gas injected into the mold cavity may be controlled to change the temperature of the mold cavity to a desired temperature level within a controlled time frame. Controlling the supply rate includes a time component in the process control, making it even easier to improve process control (and consequently, improve the control of the sealed electronic components). A relatively large volumetric flow rate allows for a larger temperature difference to be maintained between the temperature pre-conditioning gas and the mold cavity wall, resulting in a higher heat transfer coefficient than at low flow rates.

[0016] The mold cavity may be filled with a temperature pre-conditioning gas through at least one mold cavity opening, which may later be used as an inlet opening for a liquid sealant. Such a supply opening, or runner, may be embodied as an opening that penetrates a portion of the mold half surrounding the mold cavity. The temperature pre-conditioning gas may be supplied to a closed mold cavity (where the mold half is in a closed position and the electronic components to be sealed are already inside the mold cavity), or it may be supplied in an open position where the mold cavity is still open because the mold half is not (yet) in contact with each other. Alternatively, the temperature pre-conditioning gas may also be introduced into the mold cavity through an existing discharge opening connected to the mold cavity, also called a "venting." Preferably, the temperature pre-conditioning gas flows into the mold cavity through an inlet opening and is discharged from the mold cavity through a discharge opening. By controlling the supply and discharge of the pre-conditioning gas, the pressure within the mold cavity can also be controlled, which allows for even greater control over heat transfer between the temperature pre-conditioning gas and the mold cavity walls. Increasing the amount of temperature pre-conditioning gas within the mold cavity can increase the pressure inside the mold cavity, potentially leading to a higher heat transfer rate between the temperature pre-conditioning gas and the mold.

[0017] The temperature pre-conditioning gas may have a temperature of at least 50°C, preferably at least 100°C, more preferably at least 125°C, even more preferably at least 150°C, and most preferably 150°C to 200°C. The temperature of the temperature pre-conditioning gas may be set to a specific desired temperature depending on the desired final temperature of the mold cavity wall.

[0018] The temperature pre-conditioning gas may also be a condensable gas. Condensable gases can undergo a phase change from gas to liquid. If the temperature pre-conditioning gas has a temperature higher than the temperature of the mold cavity wall, it may condense upon contact with the mold cavity wall. The temperature pre-conditioning gas may also undergo a phase change from gas directly to solid (i.e., sublimation (deposition)) or from gas to liquid and then to solid (solidification). This exothermic process efficiently transfers heat from the temperature pre-conditioning gas to the mold cavity wall, but residuals may hinder the sealing process. When utilizing phase changes, it is advantageous for the temperature pre-conditioning gas to have a relatively low molecular weight, such as less than 25 g / mol, for example, 46 g / mol (ethanol), more preferably less than 18 g / mol (water), or even lower, less than 50 g / mol, such as less than 15 g / mol or less than 10 g / mol. The relatively low molecular weight is advantageous because it significantly reduces the volume when the phase change from the gas phase to the liquid phase of the temperature pre-conditioning gas occurs. The temperature pre-conditioning gas is preferably water vapor, ethanol gas, or a combination thereof, such that the gas is condensable and has a relatively low molecular weight. The change of the temperature pre-conditioning gas to a higher density phase is an exothermic reaction, and therefore energy is released. When this exothermic reaction occurs at the mold cavity wall, this energy is transferred to the mold very efficiently in the form of heat.

[0019] In embodiments where foil is used within a mold, a liquid encapsulant is typically supplied between the substrate and the foil material, and a temperature pre-conditioning gas may be delivered between the foil and the mold within the mold cavity. Thus, in such embodiments, the encapsulant is on the opposite side of the foil from the temperature pre-conditioning gas, and the two do not come into contact with each other. Therefore, the temperature pre-conditioning gas, the electronic components, and the encapsulant are separated and do not affect each other. Yet another option is to supply the temperature pre-conditioning gas into the mold cavity while the foil is already in contact with the mold cavity wall. The temperature pre-conditioning gas contacts the foil on the side of the foil facing away from the mold cavity. In this embodiment, the pressure applied by the temperature pre-conditioning gas can press the foil against the mold cavity wall. Heat exchange between the temperature pre-conditioning gas and the mold cavity wall then must therefore pass through the foil, which is less efficient than when the temperature pre-conditioning gas is in direct contact with the mold cavity wall.

[0020] The ratio of the total volume of the pre-temperature-preparing gas after injection to the total volume of the mold cavity is preferably at least 5:1, preferably at least 10:1, more preferably at least 20:1, and most preferably at least 30:1. The larger the ratio of the volume of the pre-temperature-preparing gas to the volume of the mold cavity, the more heat can be transferred, and the pre-temperature-preparing gas may have a spraying effect, allowing it to better clean the mold cavity.

[0021] Before injecting the pre-conditioning gas, it is advantageous that the temperature difference between the pre-conditioning gas and the mold cavity wall is less than 100°C, preferably less than 50°C, more preferably less than 20°C, and most preferably less than 5°C. This prevents temperature shock and / or prevents the temperature pre-conditioning gas from condensing within the mold cavity.

[0022] In beneficial embodiments, the temperature change of the mold cavity wall is such that the resulting temperature is substantially uniformly distributed across the wall surface. This is a significant further advantage of the present invention, as temperature differences across the mold cavity wall, which are absolutely undesirable from a process control standpoint, can be reduced or even more uniformly achieved through temperature exchange with the pre-conditioning gas of the mold cavity wall. A further effect of using a temperature pre-conditioning gas is that this further maintains a state where there is less or no temperature difference across the surface of the mold cavity wall.

[0023] The method step A) preparing a mold comprising a mold cavity and at least one mold cavity opening preferably includes moving a first mold section and a second mold section toward each other, bringing at least a portion of the first mold section into contact with the second mold section, and / or sandwiching a carrier with electronic components between the mold halves to obtain a substantially sealed mold cavity. In certain embodiments, the mold cavity may be substantially closed, and at least one electronic component supported on a substrate may be placed inside the mold cavity before the temperature pre-conditioning gas comes into contact with the cavity walls. This method is particularly effective when the temperature pre-conditioning gas comes into contact with the mold cavity walls when the mold cavity is substantially closed, because in such circumstances, contact of the pre-conditioning gas with the mold cavity walls is very effective. In such circumstances, the pre-conditioning gas may be supplied into the mold cavity through a mold cavity inlet opening and at least partially discharged from the mold cavity through a mold cavity outlet opening. The supply and discharge openings in the mold cavity, provided for supplying the sealant and venting the mold cavity, may also be used for supplying and discharging a temperature pre-conditioning gas. When a temperature pre-conditioning gas is injected into the mold cavity, if part of the substrate and at least one electronic component are located within the mold cavity, the temperature of not only the mold cavity walls but also part of the substrate and the electronic component(s) within the mold cavity are controlled. As a result, the behavior of the sealant during the molding process is more predictable because the temperature of all surfaces (mold cavity, substrate, and electronic component(s)) can be uniformly controlled. Consequently, the quality of the sealant will be better due to the (almost) complete control of the viscosity of the sealant during the molding process.

[0024] Alternatively, the temperature of the mold cavity may be corrected using a temperature-controlled pre-conditioning gas while the mold cavity is open (this is before the mold cavity is closed around at least one electronic component supported on the substrate). In such a situation, it is easier to bring the temperature-controlled pre-conditioning gas (in a larger volume) into contact with the mold cavity walls in a shorter time frame.

[0025] The contact time of the pre-adjustment gas with the mold cavity wall may be at least 0.1 seconds, at least 0.5 seconds, at least 1 second, at least 2 seconds, or at least 5 seconds. A longer contact time will facilitate the equalization of the temperature of the mold cavity wall.

[0026] In one embodiment, the temperature of at least a part of the mold cavity wall is measured at at least two different locations to provide at least two temperature measurement values, and the contact time between the temperature pre-adjustment gas and the mold cavity wall is controlled based on these temperature measurement values. By measuring the temperature at two different locations, not only temperature information but also information on the (non-)uniformity of the temperature distribution across the mold cavity wall can be obtained. This information may be used, for example, to control the temperature, volume, and duration of the mold cavity wall treatment by the temperature pre-adjustment gas.

[0027] The present invention also provides a system for pre-adjusting the temperature of a mold cavity as described in claim 12. For the advantages of the system according to the present invention, reference may be made to the advantages of the method according to the present invention listed above.

[0028] Preferably, the system comprises at least one, preferably at least two, temperature sensors located on the mold cavity wall. Although a single sensor can provide temperature information for automatic process control, temperature measurement values at at least two different locations can also provide information on the temperature uniformity of the mold cavity wall. Such measurement values, and in some cases the differences between multiple temperature measurement values, can also (automatically) control the required temperature pre-adjustment process.

[0029] The system may comprise a heater for heating the temperature pre-adjustment gas supplied from the injector. The temperature pre-adjustment gas may be injected into the mold cavity as a gas, but alternative forms such as superheated liquid or vapor are also possible.

[0030] The system includes a controller that controls the volumetric flow rate and / or temperature of the pre-conditioned gas injector in accordance with the above. The controller may control the volumetric flow rate and / or temperature of the temperature pre-conditioned gas based on one or more temperature measurements.

[0031] The present invention will be further illustrated hereafter based on the following non-limiting exemplary embodiments. [Brief explanation of the drawing]

[0032] [Figure 1A] This is a cross-sectional view of an unadjusted mold cavity. [Figure 1B] This is a cross-sectional view of a pre-adjusted mold cavity. [Figure 1C] This is a cross-sectional view of a mold cavity in which electronic components are sealed. [Figure 1D] This is a pre-adjusted cross-sectional view of a mold cavity containing electronic components. [Figure 2A] This is a cross-sectional view of an unadjusted mold cavity with a foil layer. [Figure 2B] This is a cross-sectional view of a pre-adjusted mold cavity with a foil layer. [Figure 3] This is a diagram of a system for pre-adjusting the mold cavity. [Modes for carrying out the invention]

[0033] Figure 1A shows a cross-sectional view of a mold cavity 1, which includes a mold cavity wall 30 formed between an upper mold section 2 and a lower mold section 3. The mold cavity 1 has a mold cavity inlet opening 4 and a mold cavity outlet opening 5. The mold cavity wall 30 has not been pre-conditioned and has several small debris particles 6 adhering to it. The temperature of the mold cavity wall 30 is non-uniform because the temperature of the mold cavity wall 30 at the first location 7 is lower than the temperature of the mold cavity wall 30 at the second location 8.

[0034] Figure 1B shows the same mold cavity 1 as in Figure 1A, where the temperature pre-conditioning gas 9, indicated by the arrows, flows into the mold cavity 1 through the mold cavity inlet opening 4 and out of the mold cavity 1 through the mold cavity outlet opening 5. The flow of temperature pre-conditioning gas 9 through the mold cavity 1 ensures the removal of debris particles 6 while cleaning the mold cavity wall 30, which are then removed from the mold cavity 1 by the temperature pre-conditioning gas 9. The temperature pre-conditioning gas 9 has a different temperature than the temperature at the first location 7 and second location 8 of the mold cavity wall 30. Due to the temperature difference between the temperature pre-conditioning gas 9 and the temperature at the first location 7 and second location 8 of the mold cavity wall 30, heat is transferred from the temperature pre-conditioning gas 9 to the first location 7 and second location 8 of the mold cavity wall 30 (arrows 10 and 11) (or, when cooling, from the first location 7 and second location 8 of the mold cavity wall 30 to the opposite side). Because the temperature difference between the temperature pre-conditioning gas 9 and the second location 8, and consequently the driving force, is larger than the temperature difference between the temperature pre-conditioning gas 9 and the first location 7, the heat transfer 10 from the temperature pre-conditioning gas 9 to the first location 7 (or to the temperature pre-conditioning gas 9) may be less than, for example, the heat transfer 11 from the temperature pre-conditioning gas 9 to the second location 8 (or to the temperature pre-conditioning gas 9). As a result, if the flow rate of the temperature pre-conditioning gas 9 through the mold cavity 1 is relatively high, it can be inferred that the temperature of the temperature pre-conditioning gas 9 is constant throughout the mold cavity 1.

[0035] Figure 1C shows the mold cavity 1 after pre-conditioning as in Figures 1A and 1B. A substrate 12 with electronic components 13 is placed in the mold cavity 1 and rests on the lower mold section 3. Liquid sealant 14 is supplied through the mold cavity inlet opening 4, and the remaining temperature pre-conditioning gas 9 is pushed out of the mold cavity 1 through the mold cavity outlet opening 5. Ideally, the mold cavity wall 30 can be pre-conditioned to the same temperature as the sealant 14 so that there is little to no heat exchange between the sealant 14 and the mold cavity wall 30.

[0036] Figure 1D shows the mold cavity 1 of Figures 1A to 1C, where the substrate 12 with the electronic component 13 is placed between mold sections 2 and 3 before the pre-conditioning of the mold cavity 1 so that the electronic component 13 is positioned inside the mold cavity 1. The temperature pre-conditioning gas 9, which flows into the mold cavity 1 through the mold cavity inlet opening 4 and exits the mold cavity 1 through the mold cavity outlet opening 5, transfers heat to (or from) the mold cavity wall 30, but may also transfer heat to (or from) a portion of the substrate 12 and the electronic component 13. The temperature at a first location 7 of the mold cavity wall 30 may be higher than the temperature at a second location 8 of the mold cavity wall 30, so more heat is transferred from (or to) the temperature pre-conditioning gas 9 at the second location 8 compared to the first location 7. In addition, heat is transferred 15 to (or from) parts of the electronic components 13 and substrate 12, which may have a similarly uneven temperature distribution before temperature pre-conditioning. Thus, not only is the mold cavity 1 temperature pre-conditioned, but the substrate 12 and electronic components 13 are also temperature pre-conditioned. In the case of compression molding, it is also conceivable to similarly temperature pre-condition the sealant 14 by placing the sealant in the mold cavity 1 and similarly heating or cooling the sealant 14 using a temperature pre-conditioning gas 9.

[0037] Figure 2A shows the mold cavity 1 of Figures 1A to 1D, with the upper foil layer 16 and the lower foil layer 17 placed in the upper mold section 2 and lower mold section 3, respectively, within the mold cavity 1. Both foil layers 16 and 17 are not optimally aligned with their respective mold sections 2 and 3. The foil layers 16 and 17 contain small wrinkles 18 that negatively affect the sealing process. As can be seen in Figure 2B, by forcibly pushing the temperature pre-conditioning gas 9 through the mold cavity inlet opening 4, pressure 19 is applied from the temperature pre-conditioning gas 9 to the foil layers 16 and 17 toward the upper mold section 2 and lower mold section 3. This smooths the foil layers 16 and 17 and reduces the wrinkles 18. By limiting the flow rate of the temperature pre-conditioning gas 9 through the mold cavity outlet opening 5, the pressure applied by the temperature pre-conditioning gas 9 can be adjusted so that the foil layers 16 and 17 are optimally smooth.

[0038] Figure 3 shows a system 20 for pre-conditioning the mold cavity 1. The system 20 comprises an upper mold section 2 and a lower mold section 3 configured to form a mold comprising the mold cavity 1. For example, an injector 21 having a reservoir 22 filled with water is heated by a heater 23. Steam 24 flowing out of the injector 21 is regulated by a valve 25 and flows into the mold cavity 1 through the mold cavity inlet opening 4. In the mold cavity 1, the steam 24 releases particles 6 and gases from the mold cavity 1 through the mold cavity outlet opening 5. A first temperature sensor 26 and a second temperature sensor 27 are in contact with the mold cavity wall 30. The temperature difference recorded by the temperature sensors 26 and 27 is supplied to a controller 28, which then adjusts the operation of the heater 23 and / or valve 25 to equalize the temperature of the mold cavity wall 30 to a desired level, thereby achieving the optimal flow rate and temperature of the pre-conditioning gas 24.

Claims

1. A method for pre-conditioning the temperature of the mold cavity of a mold for sealing electronic components, A) A step of preparing a mold for sealing electronic components, which comprises a mold cavity having a mold cavity wall, B) A step of injecting a temperature-pre-adjusted gas into the type cavity. Includes, The ratio of the total volume of the temperature-pre-treated gas injected to the total volume of the mold cavity is at least 1:

1. A method in which the temperature of the temperature pre-conditioning gas prior to the step of injecting the temperature pre-conditioning gas into the mold cavity is controlled to change the temperature of the mold cavity wall to a desired temperature level through controlled temperature exchange with the temperature pre-conditioning gas.

2. The method according to claim 1, wherein the total volume of temperature pre-conditioning gas injected into the mold cavity is controlled by the temperature pre-conditioning gas to change the temperature of the mold cavity wall to a desired temperature level.

3. The method according to claim 1 or 2, wherein the supply rate of a temperature pre-conditioning gas injected into the mold cavity is controlled by the temperature pre-conditioning gas to change the temperature of the mold cavity to a desired temperature level within a controlled time frame.

4. The method according to any one of claims 1 to 3, wherein the temperature pre-adjusted gas has a temperature of at least 50°C, preferably at least 100°C, more preferably at least 125°C, even more preferably at least 150°C, and most preferably 150°C to 200°C.

5. The method according to any one of claims 1 to 4, wherein the pre-conditioning gas is a condensable gas.

6. The method according to any one of claims 1 to 5, wherein the ratio of the total volume of temperature-pre-treated gas injected to the total volume of the mold cavity is at least 5:1, preferably at least 10:1, more preferably at least 20:1, and most preferably at least 30:

1.

7. The method according to any one of claims 1 to 6, wherein the temperature difference between the temperature pre-conditioning gas and the mold cavity wall before injecting the pre-conditioning gas is less than 100°C, preferably less than 50°C, more preferably less than 20°C, and most preferably less than 5°C.

8. The method according to any one of claims 1 to 7, wherein the temperature change of the mold cavity wall is such that the resulting temperature is distributed substantially uniformly across the wall surface.

9. The method according to any one of claims 1 to 8, wherein the mold cavity is substantially closed and at least one electronic component supported on a substrate is placed in the mold cavity before the temperature pre-conditioning gas comes into contact with the cavity wall.

10. The method according to claim 9, wherein a temperature pre-conditioning gas is supplied into the mold cavity through a mold cavity inlet opening and discharged at least partially from the mold cavity through a mold cavity outlet opening.

11. The method according to any one of claims 1 to 10, wherein the contact time between the temperature pre-conditioning gas and at least a portion of the wall of the mold cavity is at least 0.1 seconds, preferably at least 0.5 seconds, more preferably at least 1 second, even more preferably at least 2 seconds, and most preferably at least 5 seconds.

12. The temperature of at least a portion of the mold cavity wall is measured at at least two different locations to provide at least two temperature measurements. The method according to any one of claims 1 to 11, wherein the contact time between the temperature-pre-conditioned gas and the mold cavity wall is controlled based on a temperature measurement.

13. A molding system for pre-temperature-adjusting and sealing electronic components mounted on a carrier, - At least one mold comprising at least two mold portions that are displaceable relative to each other, wherein at least one of the mold portions has a recessed mold cavity in its contact surface, and these mold portions are configured to engage with the mold cavity around the electronic component to be sealed, - A temperature pre-conditioning gas injector connected to a type cavity and Equipped with, A system suitable for carrying out the method according to any one of claims 1 to 12.

14. The system according to claim 13, comprising at least two temperature sensors located on the wall of the mold cavity.

15. The system according to claim 13 or claim 14, further comprising a heater for heating the pre-adjusted gas supplied from the injector.

16. The system according to any one of claims 13 to 15, comprising a controller for controlling the volumetric flow rate and / or temperature of a temperature pre-adjusted gas injector.

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