JP2011222753A - Solder powder supplying device and printing apparatus, and solder powder supplying method and printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solder powder supplying device and a printing apparatus, which can supply solder precisely on a land which is used as an electrode and can print without generating a short-circuit between electrodes and blurring while a tolerance of height of both the land which forms a base plate and a resist is allowed, and provide a solder powder supplying method and a printing method.SOLUTION: A solder powder supplying device 10 which supplies solder powder P' on a land L of a base plate K comprises: at least a solder powder container sprayer 1 which contains a solder powder P and sprays the solder powder P, a negative charge atmosphere forming space 2 which makes the surfaces of the solder powder P to be sprayed a negative charge atmosphere, and a charging device 5 which charges the land L with positive charges.

Description

  The present invention relates to a solder powder providing apparatus and method for providing solder powder on a land of a substrate, and a solder powder printing apparatus and method for printing the provided solder powder.

  When solder is printed on the land that constitutes the electrode part on the board and various parts are mounted on the board via this solder, conventionally, cream solder, which is a mixed material of solder powder and flux, is applied onto the land. In general, a method for carrying out heat treatment after mounting a component to a reflow furnace or the like is generally used.

  In the conventional solder printing method described above, as shown in the method for manufacturing a component mounting board disclosed in Patent Document 1, a mask having an opening corresponding to a land is used, and cream solder is applied to the opening of the mask using a squeegee. A method of automatically applying cream solder on the land by embedding in the land is applied.

  By the way, when applying the cream solder on the land using the mask having the opening as described above, the cream solder needs to be applied in a state where the land and the mask are closely adhered. This will be described with reference to FIGS.

  FIG. 4 shows a case where there is no height tolerance between the land and the resist. On the surface of the substrate K on which various components are mounted, a plurality of lands L serving as electrodes and a space between the lands L and L are shown. An interstitial resist R is provided, and the cream solder H provided on the upper surface of the mask M is extended by the squeegee S (in the X1 direction), whereby the cream solder H is applied to each land L through each opening of the mask M. H is applied. As shown in the figure, when there is no height tolerance between the land L and the resist R, the cream solder is provided only on each land L.

  However, in reality, there are often steps, that is, height tolerances in the land L and the resist R due to product errors of the manufactured substrate. As shown in FIG. If there is a height tolerance, the mask M can be brought into close contact with the resist R, but it is difficult to make it close to the land L.

  Therefore, the cream solder H that has entered the land L side through the opening of the mask M protrudes through the gap G resulting from the height tolerance between the land L and the resist R, and spreads to the adjacent resist R. Or cause a short circuit between the electrodes. For example, the cream solder H that protrudes from the gap G of the land L described above (X2 direction) enters the resist R and accumulates to form ball solder, or the ball solder deposited on the resist R when printed. It can reach the adjacent land L (X3 direction) and cause a short circuit between the electrodes.

  In particular, in light of the recent miniaturization and high-density mounting of semiconductor devices and the like, the distance between the electrode land and the insulating resist is arranged at an extremely narrow pitch. It is inevitable that the issues will become more apparent.

Japanese Patent No. 3972883

  The present invention has been made in view of the above-described problems, and prints by providing solder precisely on the lands serving as electrodes while allowing the tolerance of the heights of both the lands and the diresist constituting the substrate. It is an object of the present invention to provide a solder powder providing device and a printing device, and a solder powder providing method and a printing method in which short-circuiting between electrodes and bleeding cannot occur.

  In order to achieve the above object, a solder powder providing apparatus according to the present invention is a solder powder providing apparatus for providing solder powder on a land of a substrate, and contains the solder powder and sprays the solder powder. And a negative charge atmosphere forming space in which the surface of the solder powder to be sprayed has a negative charge atmosphere, and a charger for charging the land to a positive charge.

  The solder powder providing apparatus of the present invention is literally an apparatus for providing solder powder without a flux instead of providing cream solder to the land of the substrate. Even when there is a height tolerance between the land and the resist and there is a gap, the surface of the solder powder is negatively charged as a configuration for precisely providing the solder powder on the land without protruding from the gap. It is characterized by having a negative charge atmosphere forming space as an atmosphere and a charger for charging the land to a positive charge.

  Since the conductive land is generally formed of copper or an alloy thereof, a positive charge is easily charged by a charger.

  The solder powder includes, for example, tin powder such as tin powder, alloy powder composed of tin and silver, alloy powder composed of tin and copper, alloy powder composed of tin, silver and copper, and the material of the solder powder is particularly limited. Although it is not a thing, it is preferable to use a metal powder of lead-free material in consideration of the recent trend of reducing environmental impact.

  In order to electrically attract the solder powder to the positively charged electrode land, the solder powder providing apparatus of the present invention is sprayed between the solder powder containing sprayer for containing and spraying the solder powder and the substrate. The solder powder has a negative charge atmosphere forming space in which the surface of the solder powder is negatively charged. The solder powder sprayed from the solder powder containing sprayer is negatively applied to the surface in the process of passing through the negative charge atmosphere forming space. The charged, negatively charged solder powder flies toward the positively charged electrode land and is adsorbed thereto.

  Here, the negative charge atmosphere forming space can be formed between the solder powder containing sprayer and the substrate using a sprayer that sprays negatively charged particles.

  For example, negatively charged particles such as hydroxide ions and chlorine ions can be generated through a charger and sprayed from the sprayer to form a negatively charged atmosphere.

  Further, the solder powder providing apparatus of the present invention is configured so that a solder powder containing sprayer is mounted above the container so that the solder powder can be sprayed downward from the container, and the substrate is placed below the container. The space between these in the container, or the entire space in the container may be a negative charge atmosphere forming space.

  The apparatus for providing solder powder according to the present invention is different from the conventional apparatus for providing cream solder, which is a mixture of solder powder and flux, and the object to be provided. This is based on a novel technical idea that only the target is provided and this is precisely provided to the electrode land. Even when there is a height tolerance between the land forming the substrate and the resist, for example, it is possible to provide the solder powder only to the land having a relatively low height.

  The solder powder printing apparatus according to the present invention includes the solder powder providing device, a mask having an opening at a position corresponding to the land, and a flux sprayer. The solder powder printing apparatus has the opening for the solder powder attached on the land. The flux is sprayed from the flux sprayer, and the solder powder is printed.

  The solder powder printing apparatus of the present invention comprises the solder powder providing apparatus of the present invention described above, and in addition, a mask having an opening and a flux (solvent) for improving the wettability of solder are sprayed. A flux sprayer is provided.

  Flux sprayed from the flux sprayer through the opening of the mask is provided to the solder powder that is provided in advance on the land and is electrically attracted to the land, and after the components to be mounted on the land are arranged Solder powder is heated and melted in a reflow furnace or the like, and solder printing is executed. Therefore, the solder powder printing apparatus of the present invention includes a wide range of apparatus configurations including a reflow furnace that finally mounts components in addition to the various essential configurations described above.

  According to the solder powder printing apparatus of the present invention, since the solder powder is provided only on the land surface and the flux is provided thereto, the resist is applied as in the conventional manufacturing method in which cream solder is extruded through a squeegee and provided from the mask opening. The solder paste extruded into the gap due to the height tolerance of the land and the gap between the resist and the mask hardly occurs. In addition, this solder powder printing apparatus may be provided with a heater, and the solder powder and the flux may be chemically adapted by this heater.

  Further, another embodiment of the solder powder printing apparatus according to the present invention includes the solder powder providing apparatus and a storage container for storing a flux in which a component mounted on a land is immersed, and the component to which the flux adheres is provided. The solder powder is printed on the solder powder on the land.

  In this embodiment, instead of injecting the flux onto the solder powder on the land through the mask opening, the part to be solder-printed on the electrode land and the lead extending from the part are immersed in the flux accommodated in the accommodating container. Then, this is taken out, the part of the part to which the flux is attached is positioned on the solder powder on the land, and the solder powder is heated and melted in a reflow furnace or the like to solder-print the part and the electrode land.

  The above-described solder powder printing apparatus of the present invention may be applied to all areas for a substrate having a relatively wide area and a very narrow area between the land and the resist. However, this apparatus may be applied only to an extremely narrow area, and a method of spreading the solder flux with a conventional squeegee may be applied to an area with a wide pitch.

  The present invention also extends to a method for providing solder powder, which is a method for providing solder powder on a land of a substrate, wherein the land is charged to a positive charge and negatively charged on the surface of the solder powder. Charge particles are attached and sprayed onto the land to provide solder powder on the land.

  The present invention also extends to a solder powder printing method, which is a solder powder printing method for printing solder powder on a land of a substrate, wherein the land is charged with a positive charge and negatively charged on the surface of the solder powder. Solder powder is attracted onto the land by adhering charged particles and sprayed onto the land, and a mask having an opening is arranged at a position corresponding to the land, and the solder powder sucked onto the land through the opening The solder powder is printed by spraying flux.

  Furthermore, as another embodiment of the method for printing solder powder according to the present invention, the land is charged to a positive charge, and negatively charged particles are adhered to the surface of the solder powder and sprayed onto the land, thereby soldering onto the land. A method may be used in which the powder is sucked and the component is immersed in the flux and then placed on the solder powder to print the solder powder.

  As can be understood from the above description, according to the solder powder providing device and the printing device of the present invention, and the solder powder providing method and the printing method, negatively charged particles are attached to the positively charged electrode land and the surface thereof. By forming a solder powder that is electrically attracted to both, even if there is a height tolerance between the land and the resist, the solder powder can be provided precisely on the land. Solder printing can be performed without causing bleeding or short-circuiting between electrodes.

It is the schematic diagram explaining the solder powder provision apparatus of this invention. It is the schematic diagram explaining one Embodiment of the solder powder printing apparatus of this invention. It is the schematic diagram explaining other embodiment of the solder powder printing apparatus of this invention. It is the schematic diagram explaining the conventional solder printing method, Comprising: It is the figure which showed the case where there is no height tolerance in a land and a resist. It is the schematic diagram explaining the conventional solder printing method, Comprising: It is the figure which showed the case where a height tolerance exists in a land and a resist.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, although the solder powder providing apparatus of the illustrated example shows a form in which the substrate, the solder powder containing sprayer, and the negative charge atmosphere forming space are open to the outside, these are the forms accommodated in one container. Of course, it is also good. In order to clarify the effects of the solder powder providing device and the solder powder printing device of the present invention, the land and resist of the substrate in the illustrated example have a height tolerance. Further, the reflow furnace is not shown.

  FIG. 1 is a schematic diagram illustrating a solder powder providing apparatus according to the present invention. The illustrated solder powder providing apparatus 10 includes a charger 5 communicating with a high-voltage power source, a solder powder containing sprayer 1 that contains the solder powder P and sprays the solder powder P onto the substrate K, and the surface of the sprayed solder powder P is negative. A negative charge atmosphere forming space 2 serving as a charge atmosphere is generally constituted.

  The negative charge atmosphere forming space 2 is electrically connected to the high voltage power source 4 and the charger 5 to generate negative charge particles (or negative ions), and this negative charge is formed between the solder powder containing sprayer 1 and the substrate K. It is formed from a negatively charged particle sprayer 3 for spraying charged particles.

  Here, the solder powder used is preferably a lead-free metal powder such as Sn, Sn-Ag, Sn-Cu, Sn-Ag-Cu, and the negatively charged particles to be sprayed include hydroxide ions, A chlorine ion etc. can be mentioned.

  On the substrate K, lands L serving as electrodes and resists R for insulating between adjacent lands are alternately arranged, and the positive and negative electrodes from the charger 5 are connected to the conductive pattern L1 leading to the lands L. By energizing, each land L can be charged with a positive charge via the pattern L1.

  The solder powder P sprayed from the solder powder containing sprayer 1 (in the Y1 direction) has negatively charged particles attached to the surface in the process of passing through the negative charge atmosphere forming space 2 (in the Y1 direction), and has a negative charge on the surface. The solder powder P ′ is electrically attracted to the land L charged to a positive charge and adheres to this surface (Y2 direction). By performing this operation for a predetermined time or intermittently a plurality of times, the solder powder P ′ laminated to a desired thickness can be formed on the land L surface.

  In providing the solder powder P ′ to the surface of the land L, the resist R is non-conductive because it is non-conductive. Therefore, almost all of the sprayed solder powder P ′ is deposited on the surface of the land L. It will be sucked and deposited.

  2 and 3 simulate two embodiments of a solder powder printing apparatus including the solder powder providing apparatus 10 shown in FIG.

  The solder powder printing device 20 shown in FIG. 2 surrounds the mask 6 having an opening 61 at a position corresponding to the land L, a flux sprayer 72 movable along the guide rail 71 (in the Z1 direction), and the entire substrate K. The heater 8 for promoting a chemical reaction between the solder powder P ′ provided on the land and the flux is roughly constituted. In addition, the flux sprayer 72 is not self-propelled in a posture suspended on the rail, but an actuator such as an operator or a robot hand operates the flux sprayer 72 through the mask opening to execute the flux spraying. May be.

  The flux sprayer 72 stops on an arbitrary land, a desired amount of flux F is provided from the flux sprayer 72 to the solder powder P ′ through the mask opening 61 (Y3 direction), and the flux sprayer 72 moves to the next land. And provide the desired amount of flux F as well. This is performed for all the lands L, and lead or the like of components (not shown) is arranged on the solder powder P ′ and the flux F on each land L, and the heater 8 is operated to supply the solder powder P ′ and the flux. By being familiarized (heat flow: Y4), the component mounting preparation is completed. Here, the heating temperature by the heater 8 is preferably adjusted to a temperature of 100 ° C. or lower.

  When the component mounting preparation is completed, the mounted component is placed on the surface of the solder powder P ′ and the flux F whose reaction is chemically promoted on the land L, and heated in a reflow furnace (not shown) to mount the component. It is carried out.

  On the other hand, the solder powder printing apparatus 20A shown in FIG. 3 includes a storage container 9 for storing the flux F in place of the guide rail 71 and the flux sprayer 72 that runs along the guide rail 71 in the solder powder printing apparatus 20 shown in FIG. Device.

  An actuator such as an operator or a robot hand immerses the lead of the component B in the storage container 9 and, for example, takes out the component B with the flux F attached to the lead (in the Z2 direction) and places it on the solder powder P ′ on the land L. The component mounting preparation is completed by operating the heater 8 so that the solder powder P ′ and the flux become familiar. Then, the substrate K on which the mounted component is placed on the land L is accommodated in a reflow furnace (not shown) and heated to perform component mounting.

  According to the illustrated solder powder printing apparatuses 20 and 20A, a solder powder P ′ having a desired amount (desired thickness) is provided only on the surface of the land L by the solder powder providing apparatus that is a component thereof. Thus, even when there is a height tolerance between the land L and the resist R, the solder leaks to the surface of the resist R to form solder balls, or the solder can be smeared, or between adjacent electrode lands. The problem of short-circuiting is effectively eliminated.

  In addition, since the solder powder P ′ can be provided precisely only on the land surface, the solder powder printing apparatus of the present invention is suitable for solder printing between electrodes and components in a semiconductor device that requires miniaturization and high-density mounting. It is.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

DESCRIPTION OF SYMBOLS 1 ... Solder powder accommodation sprayer, 2 ... Negative charge atmosphere formation space, 3 ... Negative charge particle sprayer, 4, 5 ... Charger, 6 ... Mask, 72 ... Flux sprayer, 8 ... Heater, 9 ... Accommodation which accommodates flux Container, 10 ... Solder powder providing device, 20, 20A ... Solder powder printing device, K ... Substrate, L ... Land (electrode land), L1 ... Pattern, R ... Resist, B ... Parts (and leads), F ... Flux ( solvent)

Claims (8)

A solder powder providing apparatus for providing solder powder on a land of a substrate,
A solder powder containing sprayer for containing the solder powder and spraying the solder powder;
A negative charge atmosphere forming space in which the surface of the solder powder to be sprayed has a negative charge atmosphere; and
A solder powder providing apparatus comprising at least a charger for charging the land to a positive charge.   The solder powder providing apparatus according to claim 1, wherein the negative charge atmosphere forming space is formed by a sprayer that sprays negative charge particles.   The negative charge atmosphere forming space comprises an internal space of a container in which negative charge particles float, the solder powder containing sprayer is disposed at one of the positions sandwiching the internal space, and the substrate is disposed at the other. The solder powder providing apparatus according to 1 or 2.   The solder powder providing device according to any one of claims 1 to 3, a mask having an opening at a position corresponding to a land, and a flux sprayer, and the solder powder adhering to the land through the opening. A solder powder printing device that prints solder powder by spraying flux from a flux sprayer.   The solder powder providing device according to any one of claims 1 to 3 and a container for containing a flux into which a component mounted on a land is immersed, and the component to which the flux is attached is placed on the solder powder on the land. Solder powder printing device that is arranged and printed with solder powder. A solder powder providing method for providing solder powder on a land of a substrate,
Charging the land to a positive charge,
A method for providing solder powder, wherein negatively charged particles are adhered to the surface of the solder powder and sprayed onto the land to provide the solder powder on the land. A solder powder printing method for printing solder powder on a land of a substrate,
Charging the land to a positive charge,
By adhering negatively charged particles to the surface of the solder powder and spraying on the land, the solder powder is sucked onto the land,
A solder powder printing method in which a mask having an opening is disposed at a position corresponding to a land, and solder powder is printed by spraying a flux onto solder powder sucked onto the land through the opening. A solder powder printing method for printing solder powder on a land of a substrate,
Charging the land to a positive charge,
By adhering negatively charged particles to the surface of the solder powder and spraying on the land, the solder powder is sucked onto the land,
A solder powder printing method in which a part is immersed in a flux and then placed on the solder powder to print the solder powder.

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