The invention relates to a component processing apparatus defining at least one component holding position for holding a component, such as comprising a semiconductor die, a substrate, a cooling plate, a package, an inverter casing, a spacer, etcetera, and comprising at least one displaceable member associated with each component holding position, each displaceable member being configured and arranged to allow exerting force on a component held in the associated component holding position. The component processing apparatus can be, for instance, a pressure sintering apparatus or a component encapsulation apparatus.
Pressure sintering of components is done while applying a pressure (exerting a force) on the component to achieve a good bond between the component and its underlying element. A semiconductor die and underlying carrier can, for instance, be bonded together by sintering. Other example are a power IC in a package and an inverter casing or cooling plate to be bonded together, a spacer and substrate to be bonded, etcetera. Multiple types of components and underlying elements can be bonded together by a pressure sintering process. Initially, the components to be sintered are placed onto their underlying element with a sintering paste, film, dispensed fluid or the like, such as a silver paste, film, dispensed fluid or the like, in between component and underlying element. Subsequently, a pressure is applied using, for instance, displaceable members that each exert a pressure on an associated component, while generally the components and underlying elements are heated. A processing apparatus employing displaceable inserts (displaceable members) is disclosed in WO 2014/123413 A1. The displaceable inserts/members allow for variation in heights and unevenness of the components to be sintered, but can also be employed in other manners in the apparatus for exerting a pressure on the components. The displaceable inserts can be arranged above the components to apply a downwards pressure, be arranged below the components to apply an upwards pressure, or both above and below the components to apply a pressure from both sides by the displaceable inserts. Generally, the component might be referred to as underlying element and the underlying element as component as well, since component and element are pressure bonded together. For the present description it has been chosen to refer to component as the part that is associated with a displaceable insert by corresponding size or location. In some embodiments both parts to be pressure bonded could be referred to as component or underlying element.
Another type of apparatus that may employ displaceable inserts concerns an encapsulation or packaging apparatus used for encapsulating or packaging components, such as semiconductor dies, a substrate, a cooling plate, a package, an inverter casing, a spacer, etcetera, and assemblies thereof. The component is held in a space of the apparatus and an encapsulation material is introduced into the space in a liquid state. The encapsulation material is allowed to solidify, while a pressure is being exerted onto the component using a displaceable member to prevent a surface area of the component to come into contact with the encapsulation material. This allows the component to be encapsulated by the encapsulation material while leaving part of the component uncovered.
The components to be encapsulated or sintered may additionally concern chips, sensors, power ICs, flip chips, MEMs, etcetera. For manufacturing, failure and reliability analysis and prediction it is very important that the pressure exerted on the component during the sintering process, encapsulation process, or any other process in which a pressure is exerted on a component while processing, is known or monitored. Especially, when using displaceable members for exerting a pressure, it is very important to verify in real time the pressure exerted. It might occur that a movable member experiences a malfunction due to a failure in force generation. The displaceable member may, for instance, get stuck during the process sequence. For the purpose of feedback control, it may be very important as well to have the real time pressure exerted available. Sensors applied for this purpose must be very compact, accurate and suitable for the conditions at hand, such high pressure and/or high temperature. Presently applied sensors have their disadvantages in this regard.
It is an objective of the invention to provide a component processing apparatus that provides for enhanced control and process optimization and/or for enhanced risk control.
It is another or alternative objective of the invention to provide a component processing apparatus providing good malfunction detection.
It is yet another or alternative objective of the invention to provide a component processing apparatus providing an accurate and/or reliable monitoring of pressure and optionally temperature process conditions, especially very close to the actual process region, i.e. sintering or encapsulation/molding region.
It is yet another or alternative objective of the invention to provide a component processing apparatus that allows real-time measuring pressure and optionally temperature process conditions, especially very close to the actual process region, i.e. sintering or encapsulation/molding region.
At least one of the above objectives is achieved by a component processing apparatus defining at least one component holding position for holding a component, such as comprising a semiconductor die, a substrate, a cooling plate, a package, an inverter casing, a spacer, etcetera, and comprising at least one displaceable member associated with each component holding position, each displaceable member being configured and arranged to allow exerting force on a component held in the associated component holding position, the component processing apparatus comprising at least one apparatus part that is susceptible to strain induced by force, in use, exerted by the at least one displaceable member on the respective component(s) held in the component holding position(s), and that has a Fiber Bragg Grating, FBG, strain sensor, wherein the FBG strain sensor is configured and arranged mechanically attached to the respective apparatus part to allow measuring strain of the respective apparatus part as induced by force, in use, exerted by the at least one displaceable member on the respective component(s).
The FBG strain sensor allows integration into the respective apparatus part without compromising the basic functioning aspects of the processing apparatus, while providing a reliable and accurate strain measurement under actual process conditions. It is referred to as a strain sensor since a measuring signal from the FBG strain sensor is dependent on a strain in the respective apparatus part and the FBG strain sensor due to their mechanical connection. The strain measurement has shown to have a well-defined dependence on the force exerted by the displaceable member(s) on the respective component(s). An FBG sensor is very compact, accurate and suitable for process conditions at applicable pressures and temperatures for processes such as press sintering and component packaging or encapsulation.
In an embodiment at least one of the at least one apparatus part having the FBG strain sensor has a Fiber Bragg Grating, FBG, temperature sensor, and wherein the FBG temperature sensor is configured and arranged thermally in contact with the respective apparatus part to allow measuring temperature of the respective apparatus part while not being susceptible to strain in the respective apparatus part, especially the FBG temperature sensor being arranged mechanically isolated from the respective apparatus part.
The FBG temperature sensor is referred to as a temperature sensor since a measuring signal from the FBG temperature sensor is dependent on a temperature in the respective apparatus part and the FBG temperature sensor due to their thermal contact, but not dependent on strain in the respective apparatus part due to the mechanical isolation of the FBG temperature sensor from the respective apparatus part. Additionally measuring the temperature of the respective apparatus part allows monitoring a process temperature and correcting a measurement signal from the FBG strain sensor for any influence due to temperature change on the FBG strain sensor. The latter allows a strain measurement of the respective apparatus part by the FBG strain sensor, which is at least largely independent of temperature and at least predominantly dependent on strain.
In an embodiment the FBG strain sensor has been mechanically attached to said respective apparatus part by a pressureless sintering process, which provides an reliable mechanical bond between an FBG sensor and the respective apparatus part. The pressureless sintering process providing the sintering bond is shown to influence the measuring characteristics of the FBG sensor.
In an embodiment at least one of the FBG strain sensor and an applicable section of said respective apparatus part have been coated with a material comprising a precious metal, like silver or gold, optionally a silver or gold sintering paste, and subsequently heated for providing a pressureless sinter bond between the FBG strain sensor and said respective apparatus part.
In an embodiment the FGB strain sensor is arranged in a channel provided in said respective apparatus part.
In an embodiment the FGB temperature sensor is arranged in a channel provided in said respective apparatus part.
In an embodiment the channel is a groove provided at a side of said respective apparatus part.
In an embodiment said respective apparatus part comprises two sub apparatus parts having mutually abutting sides provided with matching grooves providing the channel.
In an embodiment the at least one apparatus part having the FBG strain sensor comprises one or more of the at least one displaceable member.
In an embodiment the at least one apparatus part having the FBG strain sensor comprises a support part of a support for the components.
In an embodiment the FBG strain sensor and the FBG temperature sensor that are provided in a single respective apparatus part are comprised in a single optical fiber.
In an embodiment the component processing apparatus comprises
The pressure tool part is referred to as a pressure tool part, since it allows exerting a force (equivalent to exerting/applying a pressure) onto the component(s) held on the component holding tool part.
In an embodiment the component holding tool part is configured for holding an underlying element, such as a carrier substrate, lead frame, cooling plate, inverter casing, etcetera, carrying the at least one component.
In an embodiment the component processing apparatus comprises a top pressure tool part and a bottom pressure tool part arranged on opposing sides of the component holding tool part to allow exerting force onto a respective one of the at least one components held in a respective component holding position on the component tool part onto opposing sides of said respective one component by opposing displaceable members of the top and bottom pressure tool parts, respectively.
In another aspect the invention provides for a pressure sintering apparatus, wherein the pressure sintering apparatus is the component processing apparatus as referred to above.
In another aspect the invention provides for a component encapsulation apparatus, wherein the component encapsulation apparatus is a component processing apparatus as referred to above. A component encapsulation apparatus is also referred to as a (component) packaging apparatus.
Further features and advantages of the invention will become apparent from the description of the invention by way of non-limiting and non-exclusive embodiments. These embodiments are not to be construed as limiting the scope of protection. The person skilled in the art will realize that other alternatives and equivalent embodiments of the invention can be conceived and reduced to practice without departing from the scope of the present invention. Embodiments of the invention will be described with reference to the accompanying drawings, in which like or same reference symbols denote like, same or corresponding parts, and in which
The component holding tool part 110 and the pressure tool part 120 have generally been moved apart from one another while the component carrier 110 with components 10 is provided onto the component holding tool part 110. The component holding part 110 and the pressure tool part 120 are then moved towards one another. They may be move towards one another until the displaceable members 125 of the pressure tool part 120 touch their respective associated components 10, or both tool parts 110, 120 may be moved towards each other to leave a gap between the displaceable members 125 and their respective associated components 10. Alternatively, the component carrier 11 carrying components 10 may be moved in between stationary component holding tool part 110 and pressure tool part 120 while having a gap between displaceable members 125 and components 10.
Subsequently, the displaceable members 125 are activated for applying a pressure (applying a pressure and exerting a force are to be understood as being equivalent) on their respective associated components 10. The embodiment depicted in
An optical fiber 200 is provided in each displaceable member 125. Each optical fiber 200 comprises an FBG strain sensor 210 and an FBG temperature sensor 220. The FBG strain sensor 210 is configured and arranged for measuring the strain induced in the respective displaceable member 125 while exerting a force onto the associated component 10. The FBG temperature sensor is configured and arranged for measuring the temperature of the respective displaceable member 125. Both the FBG strain sensor 210 and the FBG temperature sensor 220 can be a same type of FBG sensor, but they differ in the way that they are provided on the displaceable member 125. The FBG strain sensor 210 is mechanically attached to the displaceable member 125, which implies that any mechanical strain in the displaceable member is induced in the FBG strain sensor 210 as well. The FBG strain sensor is provided such on the displaceable member that the strain induced by applying a force on the respective component 10 is measurable with the FBG strain sensor. This means that the grating provided in the FBG strain sensor is oriented to allow measuring a signal with the FBG strain sensor that is dependent on the strain induced in the displaceable member. The grating of the FBG strain sensor 210 in the fiber 200 has its grating period along the optical fiber. The grating period therefore varies as function of the strain induced in the displaceable member 125 while exerting a force on a respective component 10, which as a result provides a related variation in signal measured using the FBG strain sensor 210.
The part of the optical fiber 200 having the FBG strain sensor 210 has been mechanically attached to the displaceable member 125 by a pressureless sintering process.
The FBG temperature sensor 220 is provided such on the displaceable member that it is not susceptible to strain in but in thermal contact with the displaceable member 125. The FBG temperature sensor 220 is arranged mechanically isolated from the displaceable member 125.
The FBG temperature sensor 220 is provided such on respective displaceable members 125 that it does not experience any strain. The Bragg wavelength of the FBG temperature sensor 220 will therefore provide a measure of the temperature of the displaceable member 125 and the respective component 10. The FBG strain sensor 210 is provided such on the displaceable member 125 that it will experience the strain in the displaceable member 125, which will affect the Bragg wavelength of the FBG strain sensor 210. Additionally, the FBG strain sensor 210 will be at the temperature of the displaceable member 125. Therefore, the Bragg wavelength of the FBG strain sensor 220 will be dependent on both the strain and the temperature of the FBG strain sensor. Since the temperature of the displaceable member is known from the Bragg wavelength shift of the FBG temperature sensor 220, the Bragg wavelength shift of the FBG strain sensor 210 can be corrected for the wavelength shift due to temperature change, so that the strain of the FBG strain sensor can be determined from the signal reading of the FBG strain sensor. In case the temperature would be kept constant in a component processing process and apparatus, only an FBG strain sensor is required to determine the strain of the FBG strain sensor and the displaceable member, or any other machine part in which the FBG strain sensor would be employed.
Number | Date | Country | Kind |
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2024038 | Oct 2019 | NL | national |
Filing Document | Filing Date | Country | Kind |
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PCT/NL2020/050638 | 10/16/2020 | WO |