Metal fusion bonding – With means to remove – compact – or shape applied flux or filler
Patent
1997-11-10
1999-02-09
Heinrich, Samuel M.
Metal fusion bonding
With means to remove, compact, or shape applied flux or filler
228264, B23K 300
Patent
active
058682970
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a device for separating components connected to a substrate by a fusible or meltable material from said substrate and, in particular, for unsoldering components, in particular electronic components connected to a support, in particular a circuit board, by a solder. The device lifts the components from the support by means of a gripping element under a preloaded force acting in the direction in which the components are to be lifted from the support, wherein a lifting device connected to the gripping element causes the preloaded force to become effective when the fixing material reaches its melting temperature.
A device of this kind is described in DE-A-42 11 241. In this device, a gripping element or a bonding device is used as the lifting device being preloaded by a spring or another elastic means. The spring exerts a tensile force on the component to be unsoldered causing the respective component to be lifted when the soldering joints by means of which the component is connected to the circuit board have been caused to melt. Until that point of time the entire force of the spring acts on that component whose soldered terminals are subject to a respective load, thus possibly causing these soldering joints to rupture before their solder melts and leading to a destruction in the component and the circuit board.
It is an object of the invention to overcome this risk. According to the invention, this is achieved by providing the lifting device with a retaining member consisting of a meltable material, e.g. a fusion adhesive or a metal alloy similar to a solder, the melting temperature of which is equal to or higher than the melting temperature of the fusible material or the solder, and which triggers the action of lifting the component when the material or metal alloy melts.
Although in the following the invention is described in particular on the basis of a device for unsoldering components connected to a support by means of a metal alloy similar to a solder, the principle according to the invention can be used in all those cases in which the fixing material, such as an adhesive, has a specific melting temperature and a respective material having an essentially equal or higher melting temperature is used for the retaining member.
If a metal alloy similar to a solder is used as the retaining member, its melting temperature can easily be adapted to the melting temperature of the solder so that when the solder melts and releases the respective component immediately also the retaining member is caused to melt and thus triggers the lifting of the component. The preloaded force acting on the lifting device, which triggers a movement of the lifting device upon melting of the retaining element, thus becomes effective only after the solder melts so that the preloaded force can only have an effect on the component when it had already been released from the support due to the melting of the solder. Therefore, when the component is still connected to the support by the solid solder, the preloaded force does not act on the component. If a metal alloy similar to a solder which has a melting temperature equal to the melting temperature of the solder is used for the retaining element, e.g. when the same material composition is used, first also the solder melts and then the retaining element melts since the heating up necessary for the unsoldering process becomes first effective on the soldering joints of the components and, with a slight delay, in the same way on the retaining element since, due to its connection to the lifting device, it is surrounded by components which first cause a certain heat absorption. If the melting temperature of the metal alloy similar to a solder is higher than that of the solder, when heat is applied for unsoldering the components the solder melts automatically first and only then the retaining element melts if, of course, the application of heat for the unsoldering process takes place such that in the area of the components and the lifting device a temperature is reache
REFERENCES:
patent: 5553766 (1996-09-01), Jackson et al.
patent: 5556024 (1996-09-01), Olson et al.
patent: 5702051 (1997-12-01), Leicht
Leicht Helmut W.
Zabel Claus
Heinrich Samuel M.
IBL Lottechnik
Rauchfuss, Jr. George W.
LandOfFree
Device for separating components from a substrate, in particular does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for separating components from a substrate, in particular, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for separating components from a substrate, in particular will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1943711