JPS6159273A - Probing method to double-sided element mount printed circuit board - Google Patents

Abstract

PURPOSE:To enable probing without generating the warpage of a printed circuit board, by probing two elements on both surfaces of the printed circuit board by confirming pressing force from both surfaces of the printed circuit board by a sensor. CONSTITUTION:The table 10 of an element selection and positional determination mechanism 8 is moved with respect to the element 3 on one surface of a printed circuit board 2 to perform the positional alignment of a probe 6 and the lead wire 4 of the element 3. Next, a press motor 9 is driven to temporarily contact the probe 6 with the lead wire 4 of the element 3 and this contact state is confirmed by a pressure sensor 13. The same operation is also performed in the other surface side of said board 2 to temporarily contact a probe 6' and the lead wire 4' of an element 3'. Subsequently, press motors 9, 9' are synchronously operated by the signal from a control unit 14 to simultaneously press probe heads 7, 7'. Pressing forces at this time are detected by pressure sensors 13, 13' and the signals thereof are fed back to set pressing forces necessary for probing, and the probes 6, 6' and the elements 3, 3' are certainly brought to an electrical continuity state. Therefore, the electric tests of the elements 3, 3' are enabled without warping the printed circuit board.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a probing method for electrical testing of a printed board with elements mounted on both sides, and more specifically, a probing method for simultaneously probing elements on both sides of the printed board. It is about the method.

When electrically testing a printed board, there is a method in which a needle-like probe is brought into contact with the lead wire of an element mounted on the printed board to establish electrical continuity, and the characteristics of the element are examined using various instruments. In this case, since the same number of probes are generally tested at the same time by simultaneously hitting many lead wires around the device, the number of probes is large (and it is difficult to properly hit each of these probes to the lead wires). It is important to probe so that the probe does not touch the lead wire and cause a connection failure.For this reason, when touching the probe to the lead wire,
A high pressurizing force is applied by air pressure from a pressurizing cylinder and feeding by a motor.

[Conventional technology]

Therefore, in conventional probing for each element of a printed circuit board with elements mounted on one side, in order to prevent the board from warping due to the high pressure applied during blow-by blowing, a support post (bank up plate) is installed on the opposite side of the board to prevent warping. is standing.

[Problem that the invention seeks to solve]

By the way, the above method can be carried out because the elements are mounted only on one side of the board, and since there are elements on the opposite side of the probing side for double-sided printed boards, it is difficult to prevent warpage. It is difficult to erect pillars effectively. Furthermore, even if support is provided, the above-mentioned probing method can only test one side at a time, requiring the printed board to be turned over and the probing to be reset, resulting in a problem of poor work efficiency.

[Means for solving problems]

In view of the above-mentioned problems, the present invention provides a method for probing a printed board with elements mounted on both sides, which performs probing for each element mounted on both sides without damaging the board, and shortens the test time. The purpose of this is to use two sets of probe heads equipped with an element selection and positioning mechanism, a driving source for probing, and a pressure sensor that directly detects the probing state when the probe is brought into contact with the element lead wire. A double-sided element-mounted printed board that has a probing unit and probes two opposing elements on both sides of a fixedly held printed board board by simultaneously facing each other using each set of probing units. The above probing method prevents warpage of the board by simultaneously probing two elements on both sides using two probing units provided on both sides of the board. In addition, it is possible to test two elements in this state, and the pressure sensor of each unit can accurately perform the contact between the lead wire and the probe during blow-by blowing and the necessary pressurizing operation.

〔Example〕

Embodiments suitable for carrying out the method of the present invention will be described below with reference to the drawings.

First, in FIGS. 2(a) and 2(b), a double-sided element-mounted printed board to which the present invention is applied will be explained. Reference numeral 1 denotes a printed board, and one surface 2a of a plate-shaped board 2
Element 3 is mounted and circuit-connected using lead wires 4, and element 3' is similarly mounted on the opposite side of element 3 on the other surface 2b using lead wires 4'.

In FIG. 1, the overall configuration will be described. Two sets of probing units 5.5' are arranged on both sides of a substrate 2 of a printed board 1 which is fixed and held vertically. This unit 5 includes a probe head 7 having a plurality of needle probes 6, an element selection and positioning mechanism 8, and a pressurizing motor 9 as a driving source for probing. The mechanism 8 has a table 10 that moves in the vertical Y direction and the front and back Z direction, and a slider 11 equipped with a probe head 7 is placed on the table 10 so as to be movable in the left and right X directions. The pressurizing motor 9 is attached to the table 10, and a ball screw 12 from the pressurizing motor 9 is screwed onto the slider 11 so that pressurizing force is applied by feeding the slider 11. Also, slider 11
A pressure sensor 13 is provided between the probe 6 and the opposite side of the probe head 7, and the probe 6 is connected to the element lead %'.
The probing state that hits i4 is directly detected.

Since the other units 5' are constructed in exactly the same way, their explanations will be omitted, but portions corresponding to those of the unit 5 are denoted by the same reference numerals with dashes in the drawings.

Each pressure sensor 13, 13' is connected to the control unit node 1.
The circuit is connected to a pressurizing motor 9.9' via 4.

Next, to explain the operation of the above configuration, the table 10 of the element selection and positioning mechanism 8 in the unit 5 is moved to a desired element 3 on one surface 2a of the substrate 2 that is fixedly held, and the probe of the probe head 7 is moved. 6 and the lead cotton 4 of the element 3 are aligned. Next, the pressure motor 9 is driven to move the slider 11 along with the probe head 7.
is moved, and the tip of the probe 6 is lightly butted against the element lead wire 4 to make temporary contact, and this is confirmed by the pressure sensor 13. On the other hand, in other units 5', similar operations are performed simultaneously or separately for the elements 3' on the other side 2b of the substrate 2 on the side opposite to the element 3.

In this way, after each probe 6.6' of the two sets of probing units 5, 5' temporarily contacts the element lead wire 4°4', the left and right pressurizing morphs 9.9 are activated by a signal from the control unit 14. ′ in synchronized operation and probe head 7.
7' are simultaneously pressed against each other. Then, by detecting the pressurizing force at this time with the pressure sensors 9 and 9' and feeding back the signal, the pressurizing force necessary for probing is set to ensure electrical continuity, and in this state, the two elements Electrical tests 3 and 3' are conducted together.

The above has described the action on one set of elements on both sides of the substrate, but by repeating the same action on other sets of elements, a probing test can be performed on all the elements.

The substrate 2 during probing does not need to be fixed and held only vertically as in the above embodiment, but if it is held horizontally, it is required to equalize the pressing force by taking into account its own weight and the like.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, when probing a double-sided element-mounted printed board, two elements placed opposite each other on both sides are selected and probed there simultaneously, without warping the board. Accurate probing can be performed. It is easy to implement as there is no need to prevent warpage of the support columns or the like. Since the test can be performed between two elements, the test time is shortened. Further, since the pressure sensor directly detects the contact between the probe and the element lead wire during blowing, and also detects the pressing force during the pressurizing operation and performs feedback control, pressurizing can be performed optimally.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment suitable for the method of the present invention;
FIGS. 2(a) and 2(b) are a side view and a perspective view showing an example of a double-sided element-mounted printed board to which the present invention is applied. In the figure, 1 is a printed board, 2 is a substrate, 3°3' is an element, 4 and 4' are lead wires, 5 and 5' are probing units, 6.6' is a probe, and 7.7' is a probe. Head, 8.8' is element selection positioning mechanism,
9.9' is a pressurizing motor, and 13.13' is a pressure sensor.

Claims (1)

[Claims] The probe head has two probing units equipped with an element selection and positioning mechanism, a driving source for probing, and a pressure sensor that directly detects the probing state when the probe is pressed against the element lead wire, and is held fixed. A method for probing a double-sided element-mounted printed board, characterized in that two opposing elements on both sides of a printed board are simultaneously probed by each set of probing units.