JPH01143393A - Method for soldering flat package type element to wiring board - Google Patents

Abstract

PURPOSE:To optimize cream solder amount by removing the excess solder supplied and applied to the terminal pattern group of a wiring board by a cream solder sucking mechanism. CONSTITUTION:A copy material 4 movable in an axial direction Z is provided on a wiring board 3 held on an XY table 1 and provided with a flat package element (FP element) 2 on a predetermined surface region. The material 4 has a cylinder 6 for supplying solder cream 5. Further, a cream solder cutter 7 movable elevationally and an excess cream solder sucking mechanism of the excess cream solder cut by the cutter 7 are provided in front of the material 4 and the cylinder 6 with respect to the advancing direction for crossing the material 4 and the cylinder 6 over the terminal pattern 3a corresponding to the terminal leads 2 of the FP element 2. When the supplying amount of the solder is excessive, the excessive solder is removed, the solder is then melted by irradiating it with a laser beam to be soldered as required.

Description

[Detailed description of the invention] [Objective of the invention] (Industrial application field) The present invention is applicable to cases where a flat package type element (hereinafter abbreviated as FP element) is mounted on a wiring board to configure a high-density packaging circuit. Soldering of FP elements to a suitable wiring board relates to a method.

(Prior Art) With the miniaturization of electronic devices, high-density mounting circuit boards in which FP elements are mounted on, for example, ceramic wiring boards have been developed.

By the way, when soldering the terminal patterns of this type of wiring board and the FP element terminal pins, if too much cream solder adheres across the terminal pattern group, the soldering may cause damage between the terminal pins or between the terminal pins. This has the disadvantage of causing electrical short circuits and generating solder balls. To eliminate this inconvenience, for example, a partition wall may be installed between the terminal pins to prevent the solder from flowing in a direction perpendicular to the terminal pins, or to remove excess solder (flowing from the soldering part to the side area on the wiring board). Attempts are being made to absorb it.

(Problems with conventional technology) However, although these measures to deal with excess cream solder may achieve the purpose of preventing electrical short circuits, there is a practical problem in that cream solder is wasted. be. Therefore, the present invention provides a method for easily and reliably soldering an FP element onto a wiring board using an appropriate amount of cream solder without requiring complicated operations or equipment.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides for arranging an FP element in a predetermined area on the surface of a wiring board held on an XY table, and connecting lead terminals of the FP element to the corresponding wirings. When connecting to the terminal pattern on the circuit board via the cream solder layer, it is movable in the Z-axis direction with respect to the wiring board, is supported by a tracing material for the wiring board, and is positioned with respect to the wiring board by the tracing material. supplying and depositing cream solder from a cylinder onto a group of terminal patterns of a wiring board; removing an excess amount of the supplied and deposited cream solder by a cream solder suction mechanism; removing the excess amount of cream solder and applying the solder The main point of attachment is to align the parts and irradiate them with high energy, such as a laser beam, to melt the remaining cream solder and solder the parts.

(Function) According to the present invention, an FP is placed in a predetermined area of a wiring board held on an XY table movable in XYh directions for positioning.
When arranging the elements and soldering, for example, terminal pins of the FP element to terminal patterns on the wiring board provided corresponding to the terminal pins, cream solder is applied as follows.

In other words, the cream solder is applied to a predetermined area on the wiring board to be soldered (the soldering area is pattern or terminal pattern). In addition, when the cream solder is supplied in excess, the excess cream solder is removed by the tracing material itself supporting the cylinder or by, for example, a vacuum adsorption material structure attached to the tracing material, and is removed from the area to be soldered. This means that appropriate cream solder remains adhered. Therefore, even when the cream solder is melted by laser beam irradiation and the required soldering is performed, the required soldering can be performed without causing conduction or shorting or generation of solder balls due to solder between terminal pins or terminal patterns. attachment is achieved.

(Example) The present invention will be described in detail below with reference to the drawings.

1 and 2 show embodiments of the present invention, and in these figures, Z
A device is provided with an axially movable profiler 4. Therefore, the tracing material 4 is placed at a predetermined position with respect to the wiring board 3, that is, the soldering material corresponding to the terminal lead 2a of the FP element 2 arranged on the wiring board 3 is placed in the XY direction so that the soldering material is located in the pattern or the terminal pattern 3a. It is positioned by driving a table 1, and this profiling material 4 is attached with a cylinder 6 for supplying solder cream 5.

Further, the profiling material 4 and the cream solder cylinder 6 form a terminal pattern 3 corresponding to the terminal lead 2a of the FP element 2.
A cream solder cutter 7 that can move up and down as appropriate and a cream solder suction mechanism (not shown) for the excess cream solder cut by the cream solder cutter 7 are installed in front of the tracing material 4 in the direction of movement across the upper surface of a. placed inside the body.

Next, the method or means for soldering using the above device will be described. The XY table 1 is driven so that the solder spout 6 of the cream solder cylinder 6 attached to the profile material 4 is positioned on a predetermined terminal lead 2a of the atfiFP element 2. to align.

In conjunction with the drive of the XY table 1, the cream solder 5 is sequentially ejected from the cream solder cylinder 6 onto the soldering pattern or terminal pattern 3a, and the cream solder is applied across the group of terminal patterns. On the other hand, if the cream solder 5 deposited here is excessive, that is, the solder cream 5
If the bulge height or coating width exceeds a predetermined range (for example, part A in Fig. 2), the solder cream cutter 7 is used to cut it out and the cream solder crosspiece structure is used to remove it to reduce the coating amount of cream solder 5. always be regulated within a predetermined range. The above FP element 2
When the cream solder 5 has been applied to the terminal pattern 3a corresponding to the terminal lead 2a on one side, the XY table 1 is driven to apply cream solder to the terminal pattern group corresponding to the terminal lead 2a group on the other side of the FP element 2. Supply cylinder 6
The process of depositing a predetermined amount of cream solder 5 in the same way as in the solder spout is repeated. After applying a predetermined amount of cream solder across the terminal pattern 2a on the wiring board corresponding to the terminal lead of the FP element 2, the FP element 2 is bonded to the terminal pattern 3a corresponding to the terminal lead 2a of the FP element 2. Position and place them so that they are facing each other. Then, for example, a laser beam is irradiated (scanned) onto the cream solder area.
By doing so, the terminal leads 2 can be easily and reliably soldered to the corresponding terminal patterns on the wiring board 2.

In the above case, if the amount of cream solder 5 supplied from the cream solder supply cylinder 6 is excessive, it is cut by the cream solder cutter 7 and removed by suction by the suction mechanism. It may also be carried out using a suction tank or the like.

[Effects of the Invention] As described above, according to the method of the present invention, the amount of cream solder deposited on the portion to which the terminal lead of the FP element is soldered is always controlled to a predetermined amount.

In other words, the amount of cream solder involved in soldering between the FP element terminal lead and the second terminal pattern of the wiring board corresponding to this terminal lead can be easily optimized.

Therefore, a reliable electrical connection is always achieved without the occurrence of air shorts between soldered terminal leads or solder balls caused by excessive amounts of solder.

[Brief explanation of the drawing]

1-2 are side and perspective views showing an embodiment of the method of the present invention. 1...XY table 2...FP element 3...Wiring board 4...Profiling material 5...Cream solder 6... ...Cream solder supply cylinder 7...
・Catta applicant Toshiba Corporation Patent attorney Sa Suyama - Figure 1, Figure 21

Claims (1)

[Claims] When placing a flat package type element on a wiring board held on an XY table and connecting the lead terminals of this flat package type element to the corresponding terminal patterns on the wiring board via a cream solder layer, A cylinder movable in the Z-axis direction with respect to the board, supported by a tracing material for the wiring board, and whose position relative to the wiring board is determined by the tracing material, is moved onto the terminal pattern group of the wiring board so as to cross the terminal pattern group. Means for sequentially supplying cream solder to the substrate, removing the excess cream solder with a cutter or a suction mechanism, and then aligning and soldering the lead terminals of the flat package type element and the corresponding terminal pattern of the wiring board. A method of soldering a flat package type element to a wiring board containing.