Tool for inserting dual in-line packaged circuits into printed circuit board sockets

A tool adapted to assist in the placement of dual in-line packaged circuits (DIPs) into printed circuit board sockets. The tool includes a channel-shaped body having parallel sides of a springlike material each side having a gripper jaw attached to the lower edge thereof to grasp and support a dual in-line packaged circuit. A manually operated piston operates to force a DIP circuit which is properly oriented to the socket, into the appropriate location with the leads from the circuit placed in proper engagement with a printed circuit board socket. Operation of the piston also in addition to properly placing the circuit, also automatically disengages the tool from the circuit after placement has been effected.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to tools utilized in the assembly of 
electronic printed circuit boards and more particularly to a tool useful 
in the manual assembly of dual in-line packaged (DIP) circuits or 
components into printed circuit board sockets, ensuring control of the 
integrity of that assembly process. 
2. Description of Background Art 
The assembly of socket mounted devices can and has frequently been 
accomplished in two ways. First, some socketed devices such as dual 
in-line packages (DIPs) can be mounted automatically using high speed 
automatic insertion machines currently available from a number of 
commercial sources. Another method commonly available in the use of a hand 
held insertion tool which is also generally available from commercial 
sources. 
A number of recent developments have rendered these past methods either 
obsolete or difficult to implement. These developments include but are not 
limited to the following: 
The state-of-the-art in electronic assembly has identified component lead 
to socket contact corrosion as a major fault affecting long term 
reliability of such connections. The use of "lubricants" is now mandated 
for most socketed devices. Such lubricants, however, are attacked by post 
soldering cleaning solvents, therefore, they must now be assembled after 
this process. This requirement eliminates the use of automatic placement 
equipment, or, in the alternative, makes this process problematic in terms 
of the quality of placement depending on the configuration of the 
assembled printed circuit board. 
The increased use of DIP packaged microprocessors, application specific 
integrated circuits (ASICs) and electrically alterable memory devices 
preempts the use of automatic insertion machines since these devices 
typically exceed the capability of existing machines. 
The high lead count on such DIP devices, coupled with their physical size 
and relative fragility of the leads, makes the placement and insertion of 
these devices very difficult to accomplish and virtually impossible to 
inspect for correct lead-to-socket seating after assembly, whether done 
manually or automatically. Because of the high density of electronic 
component packaging, no tool currently available is capable of lead 
constraint during assembly, coupled with tool extraction as a simultaneous 
feature. 
The only two present methods available to verify the quality of the device 
to socket connection is to electrically check the assembly or to partially 
remove the electronic component to manually verify correct lead to socket 
alignment. The first method, an electrical check, is a questionable 
technique, inasmuch as devices that have been improperly assembled might 
still pass the electrical test. Such condition may cause a failure in the 
"field" due to minute movements which could open the faulty connection. 
The second method, that of partially removing the devices, is unreliable 
and may cause component damage since it subjects the devices to additional 
stresses and reseating may cause subsequent defects. 
SUMMARY OF THE INVENTION 
The present invention consists of a hand held assembly tool which preempts 
the possibility of unseated leads by constraining them in the parts 
positioning phase of assembly. The circuit or component to be assembled to 
a socket is positioned in the placement head of the insertion tool after 
which the tool and component are then placed on the target socket. The 
restraining feature of the tool allows sufficient component lead 
protrusion for the leads to partially enter the socket. At this point, the 
proper component to socket positioning is easily verified visually. Once 
accomplished, actuating the insertion tool simultaneously releases the 
component and forces it to completely seat in the receiving socket. 
A particularly unique feature of the present tool is that is preempts the 
creation of defective assemblies by positively constraining the component 
leads so they cannot deform to cause the typical unseated component 
condition. The device will either locate properly in the socket or it 
cannot be assembled. Since very high insertion forces are required to seat 
the component, it is extremely difficult to determine whether a single 
unseated component lead could be detected by an operator using those 
manual insertion tools presently available. This, in fact, has been found 
to be the case and is the basis for the tool design. Its purpose is 
prevention, not detection. 
As an added feature, the placement of the component into the tool provides 
a defacto inspection function of the quality of the component to be 
assembled. In other words, if the device cannot be properly "loaded" into 
the tool, then the tolerances of body and lead locations are not 
acceptable and assembly should not be attempted. No other tool presently 
available commercially provides these features.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIG. 1, a hand assembly tool in accordance with the 
present invention is shown. The tool, consisting of a channel shaped body 
portion 10, has two sides 12 and 13 both made of a compliant material such 
as spring steel, certain flexible plastics, etc. Embossed into each 
sidewall is a teardrop-shaped embossed or raised area which may also be 
seen by reference to FIGS. 2 and 3 as embosses 18 and 18'. The units, when 
engaged by a downward motion of a portion of the plunger mechanism 31, 
which shall be described in detail later, are used to force the two sides 
12 and 13 in an outward direction. 
Also included in each side is a pair of vertical slots 19 and 19'. These 
slots, however, are not straight in that the angle included therein helps 
facilitate a forward motion of the housing 10 which will be described in 
detail later on. Attached to the bottom of each of the sides 12 and 13 is 
an inward facing gripper jaw, such as 14 and 15 respectively. Each gripper 
jaw in turn has a plurality of L-shaped openings such as 16 and 17 of 
which a further detail might be seen by reference to FIG. 4. The gripper 
jaws and the openings included therein suffice to position dual in-line 
packaged components or circuits in such a manner that they provide a 
protective and orientating location for leads 41 and 42 extending from the 
DIP component and which appear in FIGS. 2, 3, 4 and 5. 
Attached to the top of the housing 10 is a separate housing 20 which has a 
piston 22 supported by housing 20 with piston 22 having a finger operating 
button 21 on its end. Also attached to housing 20 are a pair of finger 
grasping brackets 24 and 25. Located within the housing is a lower part of 
the plunger assembly consisting of section 31 which is engaged by plunger 
22. Section 31 finds support and proper positioning by means of a 
plurality of dual cam actuators 33 and 33' as well as 34 and 34' (not 
shown). These actuators extend through the slots 19 and 19' on side 12 and 
similar slots (not shown) on side 13. 
Fastened to the lower portion of section 31 of the plunger is the component 
engaging section or actuating section 32 which when the plunger is in the 
operated condition applies pressure to the component to be inserted in a 
printed circuit board socket, forcing it into the socket in its proper 
destination. 
Referring now to FIG. 2 which is a cross-section of the tool of the present 
invention taken along lines A--A of FIG. 1, the components previously 
described are shown in cross-section with the addition of jam screw 26 
which along with jam screw 26' (not shown) are used to secure the upper 
plunger base 23 to the top of the main base 11 to maintain a secured 
position. However, it should be noted that the opening in top 11 is 
elongated in the same direction as the side panels are oriented so that 
when the upper plunger portion is operated (as will be described later 
herein), the lower housing portion is free to move forward and still be 
supported by the head of jam screw 26 and jam screw 26'. 
Referring now to FIG. 3, another sectional view taken through the tool of 
the present invention along lines B--B of FIG. 1 is shown. The principal 
distinction between this sectional view and that of FIG. 2 is that it is 
taken right through the center of piston 22 and shows the addition to 
piston 22 a surrounding and supporting spring 27 which acts to maintain 
the plunger in the upper position. The lower end of piston 22 is shown as 
engaging the upper section 31 of the lower portion of the piston 22. 
Referring now to FIG. 4, a portion of the bottom of the tool of the instant 
invention is shown, particularly the gripper jaws 14 and 15 which each 
have a plurality of openings such as 16 and 17, respectively. These 
openings are L-shaped and as can be seen from FIG. 4 the component to be 
mounted is placed within the lower portion of the tool but above the 
gripper jaws and with the leads such as 41 and 42 first moved into the 
lateral portions of openings 16 and 17 and then down in the retention 
position as shown in FIG. 4. As can be seen by reference to FIG. 4, the 
gripper jaws 14 and 15 retain the component leads such as 41 and 42 in 
their proper position so that they cannot be deformed during the insertion 
operation. 
Reference is now made to FIG. 5 which is a partial end view of the tool of 
the present invention showing the component 40 in its preinsertion 
position where the pins 41 and 42 are retained in openings 16 and 17 of 
gripper jaws 14 and 15, respectively. It may be seen by reference to this 
figure that the component is supported on the gripper jaws 14 and 15 with 
the pins properly aligned for positioning into the socket of the printed 
circuit board. 
FIG. 6 is similar to FIG. 5 but in addition shows the printed circuit 
socket 50 mounted on printed circuit board 60 where its leads 53 and 54 
are inserted in openings 61 and 62 of the printed circuit board. The tool 
is now positioned over socket 50 in such a manner that pins 41 and 42, 
respectively, are oriented to properly find location in socket openings 
and 51 and 52, respectively. At this time the operator of the tool, 
referring back to FIG. 1, will grasp the upper portion of the tool with 
fingers placed beneath finger grips 25 and 24 and the thumb on button 21 
which will in turn operate piston 22 with the the lower portion 32 of 
piston 22 pressing down on component 40 to properly insert it into the 
openings in socket 50. At the same time the tool lower portion gripper 
jaws will slide forward and downward inserting the component and at the 
same time dislodging the tool from the engagement with the DIP component. 
Thus, from the foregoing it would be apparent that components may be 
seated while maintaining the integrity of the leads associated therewith 
without danger of deformation or misalignment. 
While but a single embodiment of the present invention has been shown, it 
will be obvious to those skilled in the art that numerous modifications 
may be made without departing from the spirit of the present invention 
which shall be limited only by the scope of the claims appended hereto.